Sample records for hydraulic brakes

  1. Combined hydraulic and regenerative braking system

    Microsoft Academic Search

    R. R. Venkataperumal; G. E. Mericle

    1979-01-01

    A combined hydraulic and regenerative braking system and method for an electric vehicle is disclosed. The braking system is responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially

  2. Combined hydraulic and regenerative braking system

    Microsoft Academic Search

    G. E. Mericle; R. R. Venkataperumal

    1981-01-01

    A combined hydraulic and regenerative braking system and method is disclosed for an electric vehicle. The braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially

  3. Combined hydraulic and regenerative braking system

    Microsoft Academic Search

    Rama R. Venkataperumal; Gerald E. Mericle

    1981-01-01

    A combined hydraulic and regenerative braking system and method for an electric vehicle, with the braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative

  4. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Air brake system and air-over-hydraulic brake subsystem. 570...570.57 Air brake system and air-over-hydraulic brake subsystem. ...brake and air-over-hydraulic brake systems. Trailer(s)...

  5. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Air brake system and air-over-hydraulic brake subsystem. 570...570.57 Air brake system and air-over-hydraulic brake subsystem. ...brake and air-over-hydraulic brake systems. Trailer(s)...

  6. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Air brake system and air-over-hydraulic brake subsystem. 570...570.57 Air brake system and air-over-hydraulic brake subsystem. ...brake and air-over-hydraulic brake systems. Trailer(s)...

  7. Combined hydraulic and regenerative braking system

    DOEpatents

    Venkataperumal, Rama R. (Troy, MI); Mericle, Gerald E. (Mount Clemens, MI)

    1981-06-02

    A combined hydraulic and regenerative braking system and method for an electric vehicle, with the braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  8. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Hydraulic brake system. 570.55 Section...Than 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake...

  9. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 2012-10-01 false Hydraulic brake system. 570.55 Section 570...000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system...

  10. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 2013-10-01 false Hydraulic brake system. 570.55 Section 570...000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system...

  11. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 2011-10-01 false Hydraulic brake system. 570.55 Section 570...000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system...

  12. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...false Air brake system and air-over-hydraulic brake subsystem. 570.57 Section...57 Air brake system and air-over-hydraulic brake subsystem. The following requirements...vehicles with air brake and air-over-hydraulic brake systems. Trailer(s)...

  13. Disturbance Control of the Hydraulic Brake in a Wind Turbine

    E-print Network

    Yang, Zhenyu

    Disturbance Control of the Hydraulic Brake in a Wind Turbine Frank Jepsen, Anders Søborg brake in a wind turbine. Brake torque is determined by friction coefficient and clamp force; the latter brake is one1 of the two independent brake systems in a wind turbine. As a consequence of the gearing

  14. Modified hydraulic braking system limits angular deceleration to safe values

    NASA Technical Reports Server (NTRS)

    Briggs, R. S.; Council, M.; Green, P. M.

    1966-01-01

    Conventional spring actuated, hydraulically released, fail-safe disk braking system is modified to control the angular deceleration of a massive antenna. The hydraulic system provides an immediate preset pressure to the spring-loaded brake shoes and holds it at this value to decelerate the antenna at the desired rate.

  15. COUNTERWEIGHT, CONNECTED TO HYDRAULIC BRAKE SYSTEM, IN REAR OF VAULT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    COUNTERWEIGHT, CONNECTED TO HYDRAULIC BRAKE SYSTEM, IN REAR OF VAULT MOTOR ROOM, LOOKING SOUTHWEST. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

  16. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...supplies energy, in the event of a primary brake power source failure. Brake power assist unit means a device installed in a hydraulic...muscular force on the service brake control. Brake power unit means a device installed in a brake...

  17. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...supplies energy, in the event of a primary brake power source failure. Brake power assist unit means a device installed in a hydraulic...muscular force on the service brake control. Brake power unit means a device installed in a brake...

  18. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...supplies energy, in the event of a primary brake power source failure. Brake power assist unit means a device installed in a hydraulic...muscular force on the service brake control. Brake power unit means a device installed in a brake...

  19. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...supplies energy, in the event of a primary brake power source failure. Brake power assist unit means a device installed in a hydraulic...muscular force on the service brake control. Brake power unit means a device installed in a brake...

  20. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...supplies energy, in the event of a primary brake power source failure. Brake power assist unit means a device installed in a hydraulic...muscular force on the service brake control. Brake power unit means a device installed in a brake...

  1. Operation Pattern Recognition and Control for Hydraulic Accumulator Type Braking Energy Regeneration System of Bus

    Microsoft Academic Search

    Jinyu Qu; Xiaodong Zhang

    2009-01-01

    To improve the fuel economic character of bus, a hydraulic accumulator-type braking energy regeneration system is designed. Hydraulic accumulator was designed for braking energy storage. Hydraulic pump\\/motor was aimed at braking energy recovery and regeneration conversion. Electromagnetic clutch is a device used to mechanical connection and control. The composing scheme of electronic control system is proposed, sensors are equipped with

  2. Semi-similarity design of motorcycle-hydraulic-disk brake: strategy and application

    Microsoft Academic Search

    Fei Gao; Gang Xiao; Yuanming Zhang

    2009-01-01

    Semi-similarity design is a reasonable and effective approach for motorcycle-hydraulic-disk brake design, which is an indeterminate problem because of incomplete required parameters. First, equation of semi-similar level scale is set up through analyzing the design model of motorcycle-hydraulic-disk brake. Second, algorithm of semi-similarity design and a fuzzy evaluation model for design scheme are proposed. Third, work flowchart of semi-similarity design

  3. Model based fault detection of vehicle suspension and hydraulic brake systems

    Microsoft Academic Search

    Marcus Börner; Harald Straky; Thomas Weispfenning; Rolf Isermann

    2002-01-01

    In modern vehicles, mechatronic systems are increasingly used. To improve reliability, safety and economy, an early recognition of small or drifting faults is becoming increasingly important. After a short introduction to methods of model based fault detection and diagnosis, application examples for fault detection of automotive vehicle suspension and hydraulic brake systems are given.

  4. Fault diagnosis of automobile hydraulic brake system using statistical features and support vector machines

    NASA Astrophysics Data System (ADS)

    Jegadeeshwaran, R.; Sugumaran, V.

    2015-02-01

    Hydraulic brakes in automobiles are important components for the safety of passengers; therefore, the brakes are a good subject for condition monitoring. The condition of the brake components can be monitored by using the vibration characteristics. On-line condition monitoring by using machine learning approach is proposed in this paper as a possible solution to such problems. The vibration signals for both good as well as faulty conditions of brakes were acquired from a hydraulic brake test setup with the help of a piezoelectric transducer and a data acquisition system. Descriptive statistical features were extracted from the acquired vibration signals and the feature selection was carried out using the C4.5 decision tree algorithm. There is no specific method to find the right number of features required for classification for a given problem. Hence an extensive study is needed to find the optimum number of features. The effect of the number of features was also studied, by using the decision tree as well as Support Vector Machines (SVM). The selected features were classified using the C-SVM and Nu-SVM with different kernel functions. The results are discussed and the conclusion of the study is presented.

  5. Integrative control strategy of regenerative and hydraulic braking for hybrid electric car

    Microsoft Academic Search

    Liang Chu; Wanfeng Sun; Liang Yao; Yongsheng Zhang; Yang Ou; Wenruo Wei; Minghui Liu; Jun Li

    2009-01-01

    Since electric braking involvement, the braking system of an EV, HEV and FCV becomes much more complex than conventional mechanical alone braking system. The target in this hybrid braking system is to recover the braking energy as much as possible and meanwhile maintain a good braking performance for vehicle safety. For this purpose, the control of this braking system is

  6. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (b) Service brakes —(1) Hydraulic brake systems. Motor vehicles equipped with hydraulic brake systems and manufactured on or after September...failure of service brakes —(1) Hydraulic brake systems. Motor vehicles...

  7. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (b) Service brakes —(1) Hydraulic brake systems. Motor vehicles equipped with hydraulic brake systems and manufactured on or after September...failure of service brakes —(1) Hydraulic brake systems. Motor vehicles...

  8. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... (b) Service brakes —(1) Hydraulic brake systems. Motor vehicles equipped with hydraulic brake systems and manufactured on or after September...failure of service brakes —(1) Hydraulic brake systems. Motor vehicles...

  9. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (b) Service brakes —(1) Hydraulic brake systems. Motor vehicles equipped with hydraulic brake systems and manufactured on or after September...failure of service brakes —(1) Hydraulic brake systems. Motor vehicles...

  10. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... (b) Service brakes —(1) Hydraulic brake systems. Motor vehicles equipped with hydraulic brake systems and manufactured on or after September...failure of service brakes —(1) Hydraulic brake systems. Motor vehicles...

  11. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...false Parking brake system. 393.41 Section...41 Parking brake system. (a) Hydraulic-braked vehicles manufactured...of ice and snow). Hydraulic-braked vehicles...with a parking brake system that meets the...

  12. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...false Parking brake system. 393.41 Section...41 Parking brake system. (a) Hydraulic-braked vehicles manufactured...of ice and snow). Hydraulic-braked vehicles...with a parking brake system that meets the...

  13. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...false Parking brake system. 393.41 Section...41 Parking brake system. (a) Hydraulic-braked vehicles manufactured...of ice and snow). Hydraulic-braked vehicles...with a parking brake system that meets the...

  14. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...false Parking brake system. 393.41 Section...41 Parking brake system. (a) Hydraulic-braked vehicles manufactured...of ice and snow). Hydraulic-braked vehicles...with a parking brake system that meets the...

  15. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...false Parking brake system. 393.41 Section...41 Parking brake system. (a) Hydraulic-braked vehicles manufactured...of ice and snow). Hydraulic-braked vehicles...with a parking brake system that meets the...

  16. Automotive Brake Systems.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, orginally developed for the Marine Corps, is designed to provide mechanics with an understanding of the basic operations of automotive brake systems on military vehicles. The course contains four study units covering hydraulic brakes, air brakes, power brakes, and auxiliary brake systems. A troubleshooting guide for…

  17. 49 CFR 393.53 - Automatic brake adjusters and brake adjustment indicators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...indicators. (a) Automatic brake adjusters (hydraulic brake systems). Each commercial motor vehicle manufactured on or after October 20, 1993, and equipped with a hydraulic brake system, shall meet the automatic brake...

  18. Hydraulic Drivetrain and Regenerative Braking Team 13: Andrew Brown, Karan Desai, Andrew McGrath, Hurst Nuckols, Grant Wilson Adviser: Dr. Andrew Jackson

    E-print Network

    Carpick, Robert W.

    Hydraulic Drivetrain and Regenerative Braking Team 13: Andrew Brown, Karan Desai, Andrew Mc Pressure Reservior Filter Variable Vane Pump Motor/Pump Hydraulic Accumulators Solenoid Valve Relief Valve Suction Line Since their development in 2006, hydraulic drivetrain systems have gained considerable

  19. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...OPERATION Brakes § 393.55 Antilock brake systems. (a) Hydraulic brake systems. Each truck and bus manufactured on...driveaway-towaway operations), and equipped with a hydraulic brake system, shall be equipped with an antilock...

  20. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...OPERATION Brakes § 393.55 Antilock brake systems. (a) Hydraulic brake systems. Each truck and bus manufactured on...driveaway-towaway operations), and equipped with a hydraulic brake system, shall be equipped with an antilock...

  1. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...OPERATION Brakes § 393.55 Antilock brake systems. (a) Hydraulic brake systems. Each truck and bus manufactured on...driveaway-towaway operations), and equipped with a hydraulic brake system, shall be equipped with an antilock...

  2. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...OPERATION Brakes § 393.55 Antilock brake systems. (a) Hydraulic brake systems. Each truck and bus manufactured on...driveaway-towaway operations), and equipped with a hydraulic brake system, shall be equipped with an antilock...

  3. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...system capability. The brake system, associated systems and components must be designed...any electrical, pneumatic, hydraulic, or mechanical connecting...2) Fluid lost from a brake hydraulic system following a failure...

  4. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...system capability. The brake system, associated systems and components must be designed...any electrical, pneumatic, hydraulic, or mechanical connecting...2) Fluid lost from a brake hydraulic system following a failure...

  5. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...system capability. The brake system, associated systems and components must be designed...any electrical, pneumatic, hydraulic, or mechanical connecting...2) Fluid lost from a brake hydraulic system following a failure...

  6. 76 FR 7623 - Parts and Accessories Necessary for Safe Operation; Brakes; Application for Exemption From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-10

    ...self-contained, permanently closed hydraulic brake system'' [Emphasis added...FMCSRs to allow the use of automatic hydraulic inertia brake systems (surge brakes...self-contained, permanently closed hydraulic brake system for trailers that...

  7. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...failure indicator lamp. The brake system shall withstand the application...vehicles equipped with power brake systems, and the ignition turned to...equipped with full power (central hydraulic) brake systems, or to vehicles with brake...

  8. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...failure indicator lamp. The brake system shall withstand the application...vehicles equipped with power brake systems, and the ignition turned to...equipped with full power (central hydraulic) brake systems, or to vehicles with brake...

  9. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...failure indicator lamp. The brake system shall withstand the application...vehicles equipped with power brake systems, and the ignition turned to...equipped with full power (central hydraulic) brake systems, or to vehicles with brake...

  10. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...failure indicator lamp. The brake system shall withstand the application...vehicles equipped with power brake systems, and the ignition turned to...equipped with full power (central hydraulic) brake systems, or to vehicles with brake...

  11. Modeling and Simulation about an Electric Car's Regenerative Braking System

    Microsoft Academic Search

    Zuowu Ding; Dongbiao Zhao; Jianmin Zuo

    2007-01-01

    A kind of regenerative braking system of an electric car is studied in the paper. The car's speed, acceleration, the hydraulic accumulator's pressure and volume are simulated with Matlab while the electric car is braking or accelerating from stop. The hydraulic accumulator can absorb all of the braking energy when braking and the energy stored in the hydraulic accumulator can

  12. Brakes Specialist. Teacher Edition. Automotive Service Series.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains teacher's materials for a course on becoming an automotive brakes specialist, based on the National Institute of Automotive Service Excellence task lists. The course consists of three instructional units: service brake hydraulic system and wheel bearings, service drum brakes, and service disc brakes. Depending on the…

  13. 49 CFR 571.122a - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... A leakage failure in a hydraulic service brake system shall not result in a loss...motorcycle equipped with a hydraulic brake system shall have the equipment...III Effectiveness partial hydraulic systems (S5.7.2)—IV...

  14. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... A leakage failure in a hydraulic service brake system shall not result in a loss...motorcycle equipped with a hydraulic brake system shall have the equipment...III Effectiveness partial hydraulic systems (S5.7.2)—IV...

  15. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... A leakage failure in a hydraulic service brake system shall not result in a loss...motorcycle equipped with a hydraulic brake system shall have the equipment...III Effectiveness partial hydraulic systems (S5.7.2)—IV...

  16. Diesel Technology: Brakes. Teacher Edition [and] Student Edition.

    ERIC Educational Resources Information Center

    Hilley, Robert; Scarberry, Terry; Kellum, Mary

    This document contains teacher and student materials for a course on brakes in the diesel technology curriculum. The course consists of 12 units organized in three sections. The three units of the introductory section cover: (1) brakes; (2) wheel bearings and seals; and (3) antilock brake systems. The second section, Hydraulic Brakes, contains the…

  17. An Instructor's Guide for a Program in Brake Services.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    The instructor's guide is designed to present an understanding of the automotive hydraulic brake system and to help individuals develop new skills for employment in this specialized field of automotive service. Applicable for secondary or adult education, this guide describes: the brake system, types of brakes, diagnosis and correction of brake

  18. Automobile Brake-by-Wire Control System Design and Analysis

    Microsoft Academic Search

    Weidong Xiang; Paul C. Richardson; Chenming Zhao; Syed Mohammad

    2008-01-01

    The automobile brake-by-wire (BBW) system, which is also called the electromechanical brake system, has become a promising vehicle braking control scheme that enables many new driver interfaces and enhanced performances without a mechanical or hydraulic backup. In this paper, we survey BBW control systems with focuses on fault tolerance design and vehicle braking control schemes. At first, the system architecture

  19. Hydraulics.

    ERIC Educational Resources Information Center

    Decker, Robert L.; Kirby, Klane

    This curriculum guide contains a course in hydraulics to train entry-level workers for automotive mechanics and other fields that utilize hydraulics. The module contains 14 instructional units that cover the following topics: (1) introduction to hydraulics; (2) fundamentals of hydraulics; (3) reservoirs; (4) lines, fittings, and couplers; (5)…

  20. Hydraulics.

    ERIC Educational Resources Information Center

    Engelbrecht, Nancy; And Others

    These instructional materials provide an orientation to hydraulics for use at the postsecondary level. The first of 12 sections presents an introduction to hydraulics, including discussion of principles of liquids, definitions, liquid flow, the two types of hydraulic fluids, pressure gauges, and strainers and filters. The second section identifies…

  1. Control of ElectroMechanical Brake with Electronic Control Unit

    Microsoft Academic Search

    Venkata Ramesh Mamilla; M. V. Mallikarjun

    This paper deals with a study of electro-mechanical braking (EMB) system and the design basics of its control based Electronic Control Module (ECM). Electro-mechanical braking systems also referred to as brake by-wire, replace conventional hydraulic braking systems with a completely dry electrical component system. This occurs by replacing conventional actuators with electric motor-driven units. The braking force is generated directly

  2. Gravity brake

    DOEpatents

    Lujan, Richard E. (Santa Fe, NM)

    2001-01-01

    A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

  3. Better Brakes

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Through continuing studies on high-temperature space materials useful for better brake linings, Bendix Corporation worked with Ames Research Center to develop a novel composite. This team worked to fabricate several combinations of composite materials and evaluated results. The one selected increases wear rates and lowers costs. It exhibits constant coefficient of friction at temperatures as high as 650 degrees Fahrenheit, a region where conventional brake linings fade markedly. Other suitable markets include brakes for trucks and industrial equipment such as overhead cranes and hoists. Afterwards brake linings could find successful application in passenger cars.

  4. 78 FR 21189 - Agency Requests for Approval of a New Information Collection: Motor Vehicle Brake Fluids

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ...brake fluids as well as packagers of hydraulic system mineral oils. The information...requirements for motor vehicle brake fluids and hydraulic system mineral oils. Section 5.2...brake fluids as well as packagers of hydraulic system mineral oils. The...

  5. Electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, S.R.

    1995-09-12

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydraulic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control. 10 figs.

  6. Braking system

    DOEpatents

    Norgren, D.U.

    1982-09-23

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling means causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  7. Hydraulics.

    ERIC Educational Resources Information Center

    Decker, Robert L.

    Designed for use in courses where students are expected to become proficient in the area of hydraulics, including diesel engine mechanic programs, this curriculum guide is comprised of fourteen units of instruction. Unit titles include (1) Introduction, (2) Fundamentals of Hydraulics, (3) Reservoirs, (4) Lines, Fittings, and Couplers, (5) Seals,…

  8. A compromise solution for energy recovery in vehicle braking

    Microsoft Academic Search

    Ricardo Chicurel

    1999-01-01

    A combined regenerative-dissipative brake system for a city bus is considered. The regenerative component consists of a fixed displacement hydraulic pump\\/motor discharging into or receiving high pressure fluid from a hydropneumatic accumulator. The braking force provided by the pump is determined by the pressure in the accumulator. It is brought into action only when a greater total braking force is

  9. Electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, Susan R. (Wixom, MI)

    1995-01-01

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

  10. Hydraulics

    NSDL National Science Digital Library

    These interactive learning objects, created by instructors from Fox Valley Technical College and other colleges in the Wisconsin Technical College program, focus on concepts that cover a broad-based electromechanical program. Here visitors will find learning objects in Hydraulics with over 25 lessons in Actuators, Relief Valves, Basic Concepts, and Directional Control Valves.

  11. Engine brake control in automatic transmission

    SciTech Connect

    Hayasaki, K.; Sugano, K.

    1988-09-13

    This patent describes an engine braking control for a transmission for an automotive vehicle having an engine, the transmission including an input member drivingly coupled to the engine and an output member subject to load from driving wheels of the automotive vehicle, the transmission also including a first rotary member, a second rotary member, a hydraulically operated clutch selectively establishing a drive connection between the first rotary member and the second rotary member, and a one-way clutch arranged in parallel to the hydraulically operated clutch such that when the hydraulically operated clutch is released, the one-way clutch transmits forward torque from the first rotary member to the second rotary member, but interrupts transmission of revers torque to the first rotary member from the second rotary member, the engine braking control comprising: means for providing an engine braking command fluid pressure signal when demanded by a vehicle operator; a valve means for normally discharging hydraulic fluid from the hydraulically operated clutch to deactivate the hydraulically operated clutch, the valve means being fluidly connected to the hydraulically operated clutch, the engine braking command fluid pressure signal providing means and a drain port. The valve means including a valve spool having a first position where the hydraulically operated clutch is allowed to communicate with the drain port to permit discharge of hydraulic fluid therefrom and thus the hydraulically operated clutch is caused to be deactivated and a second position where the hydraulically operated clutch is disconnected from the drain port and allowed to communicate with the engine braking command fluid pressure signal.

  12. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...contacting the vehicle's exhaust system or any other source of high temperatures...connections for air, vacuum, or hydraulic braking systems shall be installed so as to...affect the performance of the brake system. [70 FR 48050, Aug....

  13. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...contacting the vehicle's exhaust system or any other source of high temperatures...connections for air, vacuum, or hydraulic braking systems shall be installed so as to...affect the performance of the brake system. [70 FR 48050, Aug....

  14. Hydraulic control device for automatic transmissions

    Microsoft Academic Search

    Y. Sakaguchi; Y. Taga; Y. Kashihara

    1989-01-01

    This patent describes a hydraulic control device for an automatic transmission including a control unit, a shift gear mechanism, clutches and brakes for controlling the shift gear mechanism, hydraulic servos for actuating the clutches and brakes to control the shift gear mechanism and having hydraulic servo for a forward clutch, and an electronically operated regulating value for regulating pressure according

  15. On optimal motorcycle braking

    Microsoft Academic Search

    Matteo Corno; Sergio Matteo Savaresi; Mara Tanelli; Luca Fabbri

    2008-01-01

    The optimal braking strategy in a high-performance motorbike is discussed. First, the control strategy using the front brake only is analyzed, highlighting the role of aerodynamics and studying how to select and modify the control objective during braking. The importance of the brake modulation in the very first part of the braking maneuver is also discussed. The role played by

  16. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, S.R.

    1994-10-25

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control. 123 figs.

  17. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, Susan R. (Wixom, MI)

    1994-01-01

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control.

  18. Contact analysis for drum brakes and disk brakes using ADINA

    Microsoft Academic Search

    C Hohmann; K Schiffner; K Oerter; H Reese

    1999-01-01

    Brakes in cars and trucks are safety parts. Requirements not only in performance but also in comfort, serviceability and working lifetime are high and rising. Optimal design of today’s brake systems is found using additional calculations based on finite element methods. For both types of brake systems, drum brakes and disk brakes, the different parts of brakes, i.e. the brake

  19. Give Me a Brake

    NSDL National Science Digital Library

    IEEE

    2013-08-30

    In this activity, learners explore the concept of how brakes can stop or slow mechanical motion. Learners examine the operation of a bicycle brake and use low cost materials to devise a simple braking system, then work as a team to suggest improvements to current bicycle brake designs.

  20. A performance evaluation of an automotive magnetorheological brake design with a sliding mode controller

    Microsoft Academic Search

    Edward J. Park; Dilian Stoikov; Luis Falcao da Luz; Afzal Suleman

    2006-01-01

    The aim of this work is to develop a magnetorheological brake (MRB) system that has performance advantages over the conventional hydraulic brake system. The proposed brake system consists of rotating disks immersed in a MR fluid and enclosed in an electromagnet, which the yield stress of the fluid varies as a function of the magnetic field applied by the electromagnet.

  1. A unique concept for automatically controlling the braking action of wheeled vehicles during minimum distance stops

    NASA Technical Reports Server (NTRS)

    Barthlome, D. E.

    1975-01-01

    Test results of a unique automatic brake control system are outlined and a comparison is made of its mode of operation to that of an existing skid control system. The purpose of the test system is to provide automatic control of braking action such that hydraulic brake pressure is maintained at a near constant, optimum value during minimum distance stops.

  2. Engine brake control in automatic transmission

    Microsoft Academic Search

    K. Hayasaki; K. Sugano

    1988-01-01

    This patent describes an engine braking control for a transmission for an automotive vehicle having an engine, the transmission including an input member drivingly coupled to the engine and an output member subject to load from driving wheels of the automotive vehicle, the transmission also including a first rotary member, a second rotary member, a hydraulically operated clutch selectively establishing

  3. Research on brake disk modal characteristic of disk brake

    Microsoft Academic Search

    Liya Yao

    2011-01-01

    The brake disk modal characteristic of disk brake is an important factor for braking stability of the whole system. In order to reduce the judder and noise in braking process, the ANSYS software was applied to conduct the modal simulation analysis of brake disk, and a multi-purpose experimental bench was built for modal test of brake disk. The results including

  4. Hydraulic drive system prevents backlash

    NASA Technical Reports Server (NTRS)

    Acord, J. D.

    1965-01-01

    Hydraulic drive system uses a second drive motor operating at reduced torque. This exerts a relative braking action which eliminates the normal gear train backlash that is intolerable when driving certain heavy loads.

  5. TGV disc brake squeal

    NASA Astrophysics Data System (ADS)

    Lorang, X.; Foy-Margiocchi, F.; Nguyen, Q. S.; Gautier, P. E.

    2006-06-01

    The discomfort generated by the noise emission of braking systems in trains has aroused recently many studies on the mechanical modelling of brake noise in France. A theoretical and numerical discussion on the phenomenon of brake squeal is given in this paper in relation with some experimental data. This study is based upon a flutter instability analysis giving unstable modes of the brake system under the contact and Coulomb friction.

  6. TGV disc brake squeal

    Microsoft Academic Search

    X. Lorang; F. Foy-Margiocchi; Q. S. Nguyen; P. E. Gautier

    2006-01-01

    The discomfort generated by the noise emission of braking systems in trains has aroused recently many studies on the mechanical modelling of brake noise in France. A theoretical and numerical discussion on the phenomenon of brake squeal is given in this paper in relation with some experimental data. This study is based upon a flutter instability analysis giving unstable modes

  7. Automotive disc brake squeal

    Microsoft Academic Search

    N. M. Kinkaid; O. M. O'Reilly; P. Papadopoulos

    2003-01-01

    Disc brake squeal remains an elusive problem in the automotive industry. Since the early 20th century, many investigators have examined the problem with experimental, analytical, and computational techniques, but there is as yet no method to completely suppress disc brake squeal. This paper provides a comprehensive review and bibliography of works on disc brake squeal. In an effort to make

  8. Roller Locking Brake

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1993-01-01

    Roller locking brake is normally braking rotary mechanism allowing free rotation when electromagnet in mechanism energized. Well suited to robots and other machinery which automatic braking upon removal of electrical power required. More compact and reliable. Requires little electrical power to maintain free rotation and exhibits minimal buildup of heat.

  9. Automotive Drum Brakes

    NSDL National Science Digital Library

    Mr. Hjorten

    2006-02-03

    Do you know when the first car was built? Do you know who built the first automobile? Would you guess, Henry Ford? Try again. Do you know by what means they used to stop that car? We know the brakes on the vehicles we drive today are quite different from those back in the 1800s. While knowing the history of the automobile is interesting, knowing how they work is also interesting. The automotive brake or to be more specific, the drum brake is what this instruction is designed to review. In this instruction, we will begin by briefly looking at the history of automobile brakes and then learn how drum brakes work. While disk brakes can be easier to understand, are becoming more and more popular, especially on the rear tires, drum brakes, to some can be a challenge. The purpose of this lesson is to provide you with resources and encourage you to search more additional resources that will help you gain a mental moving picture of how the drum brake works. OBJECTIVES: In this instructional module, you will: Know a brief history of automobile brakes. Have a minimum of 8 web resources that provide instructions of drum brakes. Develop a mental moving picture of how drum brakes work. MATERIALS: To complete this learning activity, each student will need: Access to a computer with internet connection capabilities. A strong desire ...

  10. Brake Lining Decomposition Products

    Microsoft Academic Search

    Jeremiah R. Lynch

    1968-01-01

    A number of investigators have found asbestos bodies in the lungs of urban residents who were not occupationally exposed to asbestos. A relationship between the carinogenic properties of asbestos and the urban excess of lung cancer has been suggested. The decomposition products of brake linings have been described as a possible source of these fibers. Brake testing laboratory methods were

  11. Pulsar braking indices revisited

    NASA Astrophysics Data System (ADS)

    Johnston, Simon; Galloway, David

    1999-07-01

    Using the standard equation for the slowdown of a neutron star, we derive a formula for the braking index via integration rather than the conventional differentiation. The new formula negates the need to measure the second time derivative of the rotation frequency, nu ? . We show that the method gives similar braking indices for PSR B1509-58 and the Crab pulsar to those already in the literature. We point out that our method is useful for obtaining the braking indices of moderate-aged pulsars without the need for long, phase-connected timing solutions. We applied the method to 20 pulsars and discuss the implications of the results. We find that virtually all the derived braking indices are dominated by the effects of (unseen) glitches, the recovery from which corrupts the value of nu solar. However, any real, large, positive braking index has implications for magnetic field decay and offers support to recent models of pulsar evolution.

  12. WIND BRAKING OF MAGNETARS

    SciTech Connect

    Tong, H. [Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, Xinjiang 830011 (China); Xu, R. X.; Qiao, G. J. [KIAA and School of Physics, Peking University, Beijing 100871 (China); Song, L. M., E-mail: tonghao@xao.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2013-05-10

    We explore the wind braking of magnetars considering recent observations challenging the traditional magnetar model. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin-down measurements may be strongly biased by particle wind. Recent observations challenging the traditional model of magnetars may be explained naturally by the wind braking scenario: (1) the supernova energies of magnetars are of normal value; (2) the non-detection in Fermi observations of magnetars; (3) the problem posed by low magnetic field soft gamma-ray repeaters; (4) the relation between magnetars and high magnetic field pulsars; and (5) a decreasing period derivative during magnetar outbursts. Transient magnetars with L{sub x}<- E-dot{sub rot} may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. A strong reduction of the dipole magnetic field is possible only when the particle wind is very collimated at the star surface. A small reduction of the dipole magnetic field may result from detailed considerations of magnetar wind luminosity. In the wind braking scenario, magnetars are neutron stars with a strong multipole field. For some sources, a strong dipole field may no longer be needed. A magnetism-powered pulsar wind nebula will be one of the consequences of wind braking. For a magnetism-powered pulsar wind nebula, we should see a correlation between the nebula luminosity and the magnetar luminosity. Under the wind braking scenario, a braking index smaller than three is expected. Future braking index measurement of a magnetar may tell us whether magnetars are wind braking or magnetic dipole braking.

  13. Improved Electromagnetic Brake

    NASA Technical Reports Server (NTRS)

    Martin, Toby B.

    2004-01-01

    A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may still be possible to set the brake by applying an electromagnet current to aid the permanent magnetic field instead of canceling it, this action can mask an out-of-tolerance condition in the brake and it does not restore the fail-safe function of setting the brake when current is lost.

  14. Evaluation of Aircraft Brake Materials

    Microsoft Academic Search

    T. L. Ho; F. E. Kennedy; M. B. Peterson

    1979-01-01

    A test program was carried out to evaluate several new high-temperature friction materials for use in aircraft disk brakes. A specially built test apparatus utilizing a disk brake and wheel half from a small jet aircraft was used. The apparatus enabled control of brake pressure, velocity and braking time. Tests were run under both constant and variables velocity conditions and

  15. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...KEEP HYDRAULIC SYSTEM MINERAL OIL CLEAN. Contamination with dust or other materials may result in brake failure or costly repair...water-vapor-proof seals; (b) Desiccator and cover. Two bowl-form glass desiccators, 250-mm. inside diameter,...

  16. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...KEEP HYDRAULIC SYSTEM MINERAL OIL CLEAN. Contamination with dust or other materials may result in brake failure or costly repair...water-vapor-proof seals; (b) Desiccator and cover. Two bowl-form glass desiccators, 250-mm. inside diameter,...

  17. Vehicle brake testing system

    DOEpatents

    Stevens, Samuel S. (Harriman, TN); Hodgson, Jeffrey W. (Lenoir City, TN)

    2002-11-19

    This invention relates to a force measuring system capable of measuring forces associated with vehicle braking and of evaluating braking performance. The disclosure concerns an invention which comprises a first row of linearly aligned plates, a force bearing surface extending beneath and beside the plates, vertically oriented links and horizontally oriented links connecting each plate to a force bearing surface, a force measuring device in each link, a transducer coupled to each force measuring device, and a computing device coupled to receive an output signal from the transducer indicative of measured force in each force measuring device. The present invention may be used for testing vehicle brake systems.

  18. Braking System for Wind Turbines

    NASA Technical Reports Server (NTRS)

    Krysiak, J. E.; Webb, F. E.

    1987-01-01

    Operating turbine stopped smoothly by fail-safe mechanism. Windturbine braking systems improved by system consisting of two large steel-alloy disks mounted on high-speed shaft of gear box, and brakepad assembly mounted on bracket fastened to top of gear box. Lever arms (with brake pads) actuated by spring-powered, pneumatic cylinders connected to these arms. Springs give specific spring-loading constant and exert predetermined load onto brake pads through lever arms. Pneumatic cylinders actuated positively to compress springs and disengage brake pads from disks. During power failure, brakes automatically lock onto disks, producing highly reliable, fail-safe stops. System doubles as stopping brake and "parking" brake.

  19. Apply the Brakes

    NSDL National Science Digital Library

    The representation depicts a dot moving across the screen together with two graphs of the dot's motion. An arrow shows the dot's velocity and marks appear at regular time intervals show the dot's position at different clock readings. The dot moves at a constant velocity until the user presses a button marked "Brake," at which point the dot slows to a stop. Sliders allow the user to change the dot's initial velocity and the braking acceleration.

  20. Unidirectional high gain brake stop

    NASA Technical Reports Server (NTRS)

    Lang, David J. (Inventor)

    1987-01-01

    This invention relates to a unidirectional high gain brake arrangement that includes in combination a shaft mounted for rotation within a housing. The shaft is rotatable in either direction. A brake is selectively releasably coupled to the housing and to the shaft. The brake has a first member. An intermittent motion device is respectively coupled through the first member to the housing and through a one-way clutch to the shaft. The brake also has a second member that is mechanically coupled to the first brake member and to the housing. The intermittent motion device causes the brake to be activated by movement imparted to the first brake member after a preset number of revolutions of the shaft in one direction. The brake is released by rotation of the shaft in an opposite direction whereby torque transmitted through the one-way clutch to the first brake member is removed.

  1. Safety brake for tape reels

    NASA Technical Reports Server (NTRS)

    Carle, C. E.

    1977-01-01

    All-mechanical device senses end of tape and stops reel, even in event of electronic system failure. Assembly includes stop to prevent brake from overriding tape. Recentering mechanism returns brake to neutral position after torque is removed from reels.

  2. Chaos in brake squeal noise

    Microsoft Academic Search

    S. Oberst; J. C. S. Lai

    2011-01-01

    Brake squeal has become an increasing concern to the automotive industry because of warranty costs and the requirement for continued interior vehicle noise reduction. Most research has been directed to either analytical and experimental studies of brake squeal mechanisms or the prediction of brake squeal propensity using finite element methods. By comparison, there is a lack of systematic analysis of

  3. Evaluation of aircraft brake materials

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Kennedy, F. E.; Peterson, M. B.

    1977-01-01

    A test program was carried out to evaluate several new high-temperature friction materials for use in aircraft disk brakes. A specially built test apparatus utilizing a disk brake and wheel half from a small jet aircraft was used. The apparatus enabled control of brake pressure, velocity and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The materials evaluation showed that two newly developed friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary, however, since both materials show a significant negative slope of the friction-velocity curve at low velocities.

  4. Experiments with airplane brakes

    NASA Technical Reports Server (NTRS)

    Michael, Franz

    1931-01-01

    This report begins by examining the forces on the brake shoes. For the determination of the load distribution over the shoes it was assumed that the brake linings follow Hooke's law, are neatly fitted and bedded in by wear. The assumption of Hooke's law, that is, the proportionality between compression of the lining and the absorption of force, is fulfilled to a certain extent for the loading, as becomes apparent from the load tests described further on. But there is a material discrepancy at unloading. From the load distribution we merely defined the position of the normal force resultant, while for the rest, the effect of the distribution was disregarded in the comparison of the different shoe dispositions.

  5. Tether Deployer And Brake

    NASA Technical Reports Server (NTRS)

    Carroll, Joseph A.; Alexander, Charles M.

    1993-01-01

    Design concept promises speed, control, and reliability. Scheme for deploying tether provides for fast, free, and snagless payout and fast, dependable braking. Developed for small, expendable tethers in outer space, scheme also useful in laying transoceanic cables, deploying guidance wires to torpedoes and missiles, paying out rescue lines from ship to ship via rockets, deploying antenna wires, releasing communication and power cables to sonobuoys and expendable bathythermographs, and in reeling out lines from fishing rods.

  6. Deployable Engine Air Brake

    NASA Technical Reports Server (NTRS)

    2014-01-01

    On approach, next-generation aircraft are likely to have airframe noise levels that are comparable to or in excess of engine noise. ATA Engineering, Inc. (ATA) is developing a novel quiet engine air brake (EAB), a device that generates "equivalent drag" within the engine through stream thrust reduction by creating a swirling outflow in the turbofan exhaust nozzle. Two Phase II projects were conducted to mature this technology: (1) a concept development program (CDP) and (2) a system development program (SDP).

  7. Design of a squeeze film magnetorheological brake considering compression enhanced shear yield stress of magnetorheological fluid

    NASA Astrophysics Data System (ADS)

    Sarkar, C.; Hirani, H.

    2013-02-01

    A magnetorheological brake, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnet, is proposed to replace the conventional heavy weight low response hydraulic disk brake. The frictional characteristics of the proposed brake can be controlled by regulating the yield stress of the MR fluid as function of magnetic field and normal compressive force. The controllable yield stress retards the surfaces of rotating disks, thus MR fluid can be used as a brake lining material. The present research work attempts designing a squeeze film MR brake by accounting compression enhanced shear yield stress of magnetorheological fluid. Theoretical calculations indicate that the estimated braking torque of the six plate squeeze film MR brake, under compression, is in the order of 600Nm. To validate the theoretical design and its findings, a prototype of single-plate squeeze film MR disk brake has been developed. Experimental test setup helps to illustrate braking torque under different control currents (0.0 to 1.25 A).

  8. Design of hydraulic output Stirling engine

    NASA Technical Reports Server (NTRS)

    Toscano, W. M.; Harvey, A. C.; Lee, K.

    1983-01-01

    A hydraulic output system for the RE-1000 free piston stirling engine (FPSE) was designed. The hydraulic output system can be readily integrated with the existing hot section of RE-1000 FPSE. The system has two simply supported diaphragms which separate the engine gas from the hydraulic fluid, a dynamic balance mechanism, and a novel, null center band hydraulic pump. The diaphragms are designed to endure more than 10 billion cycles, and to withstand the differential pressure load as high as 14 MPa. The projected thermodynamic performance of the hydraulic output version of RE-1000 FPSE is 1.87 kW at 29/7 percent brake efficiency.

  9. Thermal cracking in disc brakes

    Microsoft Academic Search

    Thomas J. Mackin; Steven C. Noe; K. J. Ball; B. C. Bedell; D. P. Bim-Merle; M. C. Bingaman; D. M. Bomleny; G. J. Chemlir; D. B. Clayton; H. A. Evans; R. Gau; J. L. Hart; J. S. Karney; B. P. Kiple; R. C. Kaluga; P. Kung; A. K. Law; D. Lim; R. C. Merema; B. M. Miller; T. R. Miller; T. J. Nielson; T. M. O'Shea; M. T. Olson; H. A. Padilla; B. W. Penner; C. Penny; R. P. Peterson; V. C. Polidoro; A. Raghu; B. R. Resor; B. J. Robinson; D. Schambach; B. D. Snyder; E. Tom; R. R. Tschantz; B. M. Walker; K. E. Wasielewski; T. R. Webb; S. A. Wise; R. S. Yang; R. S. Zimmerman

    2002-01-01

    Disc brakes are exposed to large thermal stresses during routine braking and extraordinary thermal stresses during hard braking. High-g decelerations typical of passenger vehicles are known to generate temperatures as high as 900°C in a fraction of a second. These large temperature excursions have two possible outcomes: thermal shock that generates surface cracks; and\\/or large amounts of plastic deformation in

  10. Influence of initial braking velocity and braking frequency on tribological performance of non-asbestos brake shoe

    Microsoft Academic Search

    Bao Jiusheng; Zhu Zhencai; Yin Yan; Chen Guoan

    2009-01-01

    Purpose – The purpose of this paper is to find the influence of the initial braking velocity and braking frequency on the tribological performance of the non-asbestos brake shoe used in mine hoisters during some continuous emergency brakings. Design\\/methodology\\/approach – The tribological performance experiments of the WSM-3 non-asbestos brake shoe braking on the 16 Mn steel are investigated on the

  11. 49 CFR 236.712 - Brake pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... A pipe running from the engineman's brake valve through the train, used for the transmission of air under pressure to charge and actuate the automatic brake equipment and charge the reservoirs of the electro-pneumatic brake equipment...

  12. Chaos in brake squeal noise

    NASA Astrophysics Data System (ADS)

    Oberst, S.; Lai, J. C. S.

    2011-02-01

    Brake squeal has become an increasing concern to the automotive industry because of warranty costs and the requirement for continued interior vehicle noise reduction. Most research has been directed to either analytical and experimental studies of brake squeal mechanisms or the prediction of brake squeal propensity using finite element methods. By comparison, there is a lack of systematic analysis of brake squeal data obtained from a noise dynamometer. It is well known that brake squeal is a nonlinear transient phenomenon and a number of studies using analytical and experimental models of brake systems (e.g., pin-on-disc) indicate that it could be treated as a chaotic phenomenon. Data obtained from a full brake system on a noise dynamometer were examined with nonlinear analysis techniques. The application of recurrence plots reveals chaotic structures even in noisy data from the squealing events. By separating the time series into different regimes, lower dimensional attractors are isolated and quantified by dynamic invariants such as correlation dimension estimates or Lyapunov exponents. Further analysis of the recurrence plot of squealing events by means of recurrence quantification analysis measures reveals different regimes of laminar and random behaviour, periodicity and chaos-forming recurrent transitions. These results help to classify brake squeal mechanisms and to enhance understanding of friction-related noise phenomena.

  13. Emergency Brake for Tracked Vehicles

    NASA Technical Reports Server (NTRS)

    Green, G. L.; Hooper, S. L.

    1986-01-01

    Caliper brake automatically stops tracked vehicle as vehicle nears end of travel. Bar on vehicle, traveling to right, dislodges block between brake pads. Pads then press against bar, slowing vehicle by friction. Emergencybraking system suitable for elevators, amusement rides and machine tools.

  14. Position control optimization of aerodynamic brake device for high-speed trains

    NASA Astrophysics Data System (ADS)

    Zuo, Jianyong; Luo, Zhuojun; Chen, Zhongkai

    2014-03-01

    The aerodynamic braking is a clean and non-adhesion braking, and can be used to provide extra braking force during high-speed emergency braking. The research of aerodynamic braking has attracted more and more attentions in recent years. However, most researchers in this field focus on aerodynamic effects and seldom on issues of position control of the aerodynamic braking board. The purpose of this paper is to explore position control optimization of the braking board in an aerodynamic braking prototype. The mathematical models of the hydraulic drive unit in the aerodynamic braking system are analyzed in detail, and the simulation models are established. Three control functions—constant, linear, and quadratic—are explored. Two kinds of criteria, including the position steady-state error and the acceleration of the piston rod, are used to evaluate system performance. Simulation results show that the position steady state-error is reduced from around 12-2 mm by applying a linear instead of a constant function, while the acceleration is reduced from 25.71-3.70 m/s2 with a quadratic control function. Use of the quadratic control function is shown to improve system performance. Experimental results obtained by measuring the position response of the piston rod on a test-bench also suggest a reduced position error and smooth movement of the piston rod. This implies that the acceleration is smaller when using the quadratic function, thus verifying the effectiveness of control schemes to improve to system performance. This paper proposes an effective and easily implemented control scheme that improves the position response of hydraulic cylinders during position control.

  15. Regenerative braking device

    DOEpatents

    Hoppie, Lyle O. (Birmingham, MI)

    1982-01-12

    Disclosed are several embodiments of a regenerative braking device for an automotive vehicle. The device includes a plurality of rubber rollers (24, 26) mounted for rotation between an input shaft (14) connectable to the vehicle drivetrain and an output shaft (16) which is drivingly connected to the input shaft by a variable ratio transmission (20). When the transmission ratio is such that the input shaft rotates faster than the output shaft, the rubber rollers are torsionally stressed to accumulate energy, thereby slowing the vehicle. When the transmission ratio is such that the output shaft rotates faster than the input shaft, the rubber rollers are torsionally relaxed to deliver accumulated energy, thereby accelerating or driving the vehicle.

  16. EXPERIMENTAL MODAL ANALYSIS OF BRAKE SQUEAL NOISE

    Microsoft Academic Search

    MUHAMMAD ZAHIR HASSAN

    Disc brake squeal noise continues to be the major problem concern for the automotive industry. In this paper, the brake squeal phenomenon of brake rotor disc had been investigated using experimental modal analysis (EMA). The modal analysis excitation technique known as impact hammer test has been carried out to obtain modal parameter of brake disc structure namely the natural frequencies

  17. Wheel brakes and their application to aircraft

    NASA Technical Reports Server (NTRS)

    Dowty, G H

    1928-01-01

    The advantages to be gained from braking have not been ignored, and in the search for a suitable method many schemes have been suggested and tried. Some of the methods discussed in this paper include: 1) increasing the height of the landing gear; 2) air brakes of various forms; 3) sprags on tail skid and axle; and 4) wheel brakes. This report focuses on the design of wheel brakes and wheel brake controls.

  18. Brake Stops Both Rotation And Translation

    NASA Technical Reports Server (NTRS)

    Allred, Johnny W.; Fleck, Vincent J., Jr.

    1995-01-01

    Combination of braking and positioning mechanisms allows both rotation and translation before brake engaged. Designed for use in positioning model airplane in wind tunnel. Modified version used to position camera on tripod. Brake fast and convenient to use; contains single actuator energizing braking actions against both rotation and translation. Braking actuator electric, but pneumatic actuator could be used instead. Compact and lightweight, applies locking forces close to load, and presents minimal cross section to airflow.

  19. Well servicing methods using a hydraulic actuated workover mast

    Microsoft Academic Search

    P. F. Maroney; F. C. Blalock

    1988-01-01

    A method is described of removing a stuck object from a well by operating a hydraulically operated workover rig which has a mast with a crown and a traveling block, a first winch with a brake, a first hydraulic motor, a line connected to the winch, and tubing in a well, which comprises: (a) connecting the end of the line

  20. Variable ratio regenerative braking device

    DOEpatents

    Hoppie, Lyle O. (Birmingham, MI)

    1981-12-15

    Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

  1. Development of aircraft brake materials

    NASA Technical Reports Server (NTRS)

    Ho, T.-L.; Peterson, M. B.

    1976-01-01

    A program has been carried out to study and develop high temperature aircraft brake materials. A survey of the requirements of brake materials was made to select materials to meet these requirements. Based upon their physical and thermal properties, a number of materials were selected and evaluated in sliding tests which simulated aircraft braking. The mating material is 17-22 AS steel. Additives were incorporated into these materials to optimize their wear or strength behavior with particular emphasis on nickel and molybdenum base materials. Optimum materials were developed which had improved wear behavior over conventional brake materials in the simulated test. The best materials were a nickel, aluminum oxide, lead tungstate composition containing graphite and a molybdenum base material containing LPA 100 (an intermetallic compound of cobalt, molybdenum and silicon).

  2. Hydraulic control system for automatic transmission

    SciTech Connect

    Sakaguchi, Y

    1989-05-16

    A hydraulic control system is described for an automatic transmission including hydraulic servos for clutches and brakes to engage and disengage components in the transmission gear mechanism and having a forward clutch hydraulic servo and a brake hydraulic servo, and a manual valve, comprising:a modulator valve for adjusting line pressure to a predetermined modulator pressure; a control valve adapted to be shifted in response to signals based on positions of the manual valve and the vehicle running condition; a first oil path connected between the control valve and the manual valve as a line pressure oil path; the control valve including a first port connecting to the forward clutch hydraulic servo; a second oil path connected between the control valve and the brake hydraulic servo; and a shift valve situated in the second oil path, the shift valve not operating during a low speed vehicle condition, the shift valve being adapted to connect the second oil path when the shift valve shifts to a low speed position and to disconnect the oil path when the shift valve shifts to a high speed position.

  3. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT IX, AUTOMATIC TRANSMISSIONS--HYDRAULIC SYSTEM (PART I).

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OIL FLOW WITHIN HYDRAULIC TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE GENERAL DESCRIPTION, HYDRAULIC CIRCUITS, AND BRAKE HYDRAULIC CIRCUIT AND OPERATION. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL PROGRAMED TRAINING FILM "LEARNING ABOUT THE ALLISON…

  4. A Switched Control Strategy for Antilock Braking System With On\\/Off Valves

    Microsoft Academic Search

    Houhua Jing; Zhiyuan Liu; Hong Chen

    2011-01-01

    In this paper, a switched control strategy for an antilock braking system (ABS), which has conventional hydraulic actuators equipped with on\\/off valves, is presented. The investi- gated system contains the continuous dynamics of the vehicle and the inherent discontinuous characteristics of the on\\/off valves. Accordingly, a novel approach based on nonlinear state feedback and a switching strategy renders a controller

  5. 49 CFR 236.701 - Application, brake; full service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...reduction in brake pipe pressure at a service rate until maximum brake cylinder pressure is developed. As applied to an automatic or electro-pneumatic brake with speed governor control, an application other than emergency which develops the maximum brake...

  6. 49 CFR 236.701 - Application, brake; full service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...reduction in brake pipe pressure at a service rate until maximum brake cylinder pressure is developed. As applied to an automatic or electro-pneumatic brake with speed governor control, an application other than emergency which develops the maximum brake...

  7. 49 CFR 236.712 - Brake pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...valve through the train, used for the transmission of air under pressure to charge and actuate the automatic brake equipment and charge the reservoirs of the electro-pneumatic brake equipment on each vehicle of the...

  8. 49 CFR 236.712 - Brake pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...valve through the train, used for the transmission of air under pressure to charge and actuate the automatic brake equipment and charge the reservoirs of the electro-pneumatic brake equipment on each vehicle of the...

  9. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...testing devices utilize this factor. (b) The decelerations...application and brake-force buildup. Also, other factors may cause the deceleration...application and brake-force buildup varies with vehicle...

  10. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...testing devices utilize this factor. (b) The decelerations...application and brake-force buildup. Also, other factors may cause the deceleration...application and brake-force buildup varies with vehicle...

  11. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...testing devices utilize this factor. (b) The decelerations...application and brake-force buildup. Also, other factors may cause the deceleration...application and brake-force buildup varies with vehicle...

  12. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...testing devices utilize this factor. (b) The decelerations...application and brake-force buildup. Also, other factors may cause the deceleration...application and brake-force buildup varies with vehicle...

  13. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed...b) Usable during power-off landings; and (c) Adequate...

  14. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed...b) Usable during power-off landings; and (c) Adequate...

  15. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed...b) Usable during power-off landings; and (c) Adequate...

  16. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed...b) Usable during power-off landings; and (c) Adequate...

  17. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed...b) Usable during power-off landings; and (c) Adequate...

  18. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed...b) Usable during power-off landings; and (c) Adequate...

  19. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed...b) Usable during power-off landings; and (c) Adequate...

  20. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed...b) Usable during power-off landings; and (c) Adequate...

  1. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed...b) Usable during power-off landings; and (c) Adequate...

  2. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed...b) Usable during power-off landings; and (c) Adequate...

  3. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...a) A passenger train's primary brake system shall be capable...consistent with prevailing adhesion, passenger safety, and...shall develop and implement a process or procedure to verify that...braking systems, the design process shall include computer...

  4. 49 CFR 229.46 - Brakes: General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...carrier shall know before each trip that the locomotive brakes and devices for regulating all pressures, including but not limited to the automatic and independent brake valves, operate as intended and that the water and oil have been drained from...

  5. 49 CFR 229.46 - Brakes: General.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...carrier shall know before each trip that the locomotive brakes and devices for regulating all pressures, including but not limited to the automatic and independent brake valves, operate as intended and that the water and oil have been drained from...

  6. Four-wheel dual braking for automobiles

    NASA Technical Reports Server (NTRS)

    Edwards, H. B.

    1981-01-01

    Each master cylinder applies braking power to all four wheels unlike conventional systems where cylinder operates only two wheels. If one master system fails because of fluid loss, other stops car by braking all four wheels although at half force.

  7. Piecewise polynomial chaos expansion with an application to brake squeal of a linear brake system

    E-print Network

    Paris-Sud XI, Université de

    are also inferred from these calculations. Keywords: brake squeal noise, stochastic, friction, eigenvalue problem 1. Introduction Brake squeal noise is a real problem for the automotive [1, 2] and railway [3Piecewise polynomial chaos expansion with an application to brake squeal of a linear brake system E

  8. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 6 2013-10-01 2013-10-01 false Vacuum brake assist unit and vacuum brake system. 570.56 Section 570.56 ...GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system....

  9. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 6 2014-10-01 2014-10-01 false Vacuum brake assist unit and vacuum brake system. 570.56 Section 570.56 ...GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system....

  10. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 6 2012-10-01 2012-10-01 false Vacuum brake assist unit and vacuum brake system. 570.56 Section 570.56 ...GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system....

  11. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 6 2011-10-01 2011-10-01 false Vacuum brake assist unit and vacuum brake system. 570.56 Section 570.56 ...GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system....

  12. Production of ceramic additive automotive brake lining and investigation of its braking characterisation

    Microsoft Academic Search

    I. Mutlu; O. Eldogan; F. Findik

    2005-01-01

    Purpose – The aim of the research is to investigate the ceramic brake lining on the brake performance.Design\\/methodology\\/approach – The brake lining which has new formulation has been produced by using various additive materials. Various techniques have been used in the production of brake lining. These ceramic linings were subjected to friction and wear tests under different loads, and changes

  13. Measuring Braking Indices for Young, Energetic Pulsars

    Microsoft Academic Search

    M. A. Livingstone; V. M. Kaspi; F. P. Gavriil; R. N. Manchester

    2004-01-01

    Pulsar braking indices are only measurable for the very youngest of objects. In all cases, values less than 3 (for magnetic dipole radiation) have been reported. Due in large part to contamination from timing noise, values of the braking index or the second braking index for several of these objects have been called into question. We present an updated timing

  14. Statistical analysis of brake squeal noise

    Microsoft Academic Search

    S. Oberst; J. C. S. Lai

    2011-01-01

    Despite substantial research efforts applied to the prediction of brake squeal noise since the early 20th century, the mechanisms behind its generation are still not fully understood. Squealing brakes are of significant concern to the automobile industry, mainly because of the costs associated with warranty claims. In order to remedy the problems inherent in designing quieter brakes and, therefore, to

  15. Compact, Lightweight Servo-Controllable Brakes

    NASA Technical Reports Server (NTRS)

    Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky

    2010-01-01

    Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.

  16. Active control of brake squeal via \\

    Microsoft Academic Search

    Utz von Wagner; Daniel Hochlenert; Thira Jearsiripongkul; Peter Hagedorn

    2004-01-01

    Considerable effort is spent in the design and testing of disk brakes of modern passenger cars. This effort can be reduced if refined mathematical-mechanical models and new experimental techniques are used for studying the dynamics of these brakes. The present paper is devoted to the modeling and experimental investigation of a floating caliper disk brake, special regard being given to

  17. Minimal models for disk brake squeal

    Microsoft Academic Search

    Utz von Wagner; Daniel Hochlenert; Peter Hagedorn

    2007-01-01

    Numerous publications on the modeling of disk brake squeal can be found in the literature. Recent publications describe the onset of disk brake squeal as an instability of the trivial solution resulting from the non-conservative friction forces even for a constant friction coefficient. Therefore, a minimal model of disk brake squeal must contain at least two degrees of freedom. A

  18. Disk Brake Squeal: Modeling and Active Control

    Microsoft Academic Search

    Thira Jearsiripongkul; Daniel Hochlenert

    2006-01-01

    Considerable effort is spent in the design and testing of disk brakes of modern passenger cars. This effort can be reduced if refined mathematical-mechanical models are used for studying the dynamics of these brakes before prototypes are available. The present paper is devoted to the modeling of a floating caliper disk brake, special regard being given to the suppression of

  19. Contactless magnetic brake for automotive applications

    E-print Network

    Gay, Sebastien Emmanuel

    2009-05-15

    magnets. This brake is wear-free, less-sensitive to temperature than friction brakes, has fast and simple actuation, and has a reduced sensitivity to wheel-lock. The present dissertation includes an introduction to friction braking, a theory of eddy...

  20. Brake wear warning device: A concept

    NASA Technical Reports Server (NTRS)

    Hawkins, S. F.

    1973-01-01

    Heat-insulated wire is introduced through brake shoe and partially into brake lining. Wire is connected to positive terminal and light bulb. When brakes wear to critical point, contact between wire and wheel drum grounds circuit and turns on warning light.

  1. Design and Engineering of Carbon Brakes

    Microsoft Academic Search

    I. L. Stimson; R. Fisher

    1980-01-01

    The need for weight saving on Concorde stimulated the development of lightweight aircraft brakes. Carbon has long been recognized as a major constituent of brake friction materials and a carbon carbon composite has been engineered to provide adequate structural, thermal and friction characteristics for these disks. The use of carbon brake disks offered a 60% weight saving compared with steel.

  2. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...in exceeding the allowable stopping distance; (2) The friction brake alone is adequate to safely stop the train under all...operating speed for safe operation of the train using only the friction brake portion of the blended brake with no thermal damage...

  3. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...in exceeding the allowable stopping distance; (2) The friction brake alone is adequate to safely stop the train under all...operating speed for safe operation of the train using only the friction brake portion of the blended brake with no thermal damage...

  4. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...in exceeding the allowable stopping distance; (2) The friction brake alone is adequate to safely stop the train under all...operating speed for safe operation of the train using only the friction brake portion of the blended brake with no thermal damage...

  5. Hydraulic control device for automatic transmissions

    SciTech Connect

    Sakaguchi, Y.; Taga, Y.; Kashihara, Y.

    1989-06-20

    This patent describes a hydraulic control device for an automatic transmission including a control unit, a shift gear mechanism, clutches and brakes for controlling the shift gear mechanism, hydraulic servos for actuating the clutches and brakes to control the shift gear mechanism and having hydraulic servo for a forward clutch, and an electronically operated regulating value for regulating pressure according to signals from the control unit. The control device consists of: a selecting value switched by signals indicating stopping and running condition of a vehicle, the selecting valve being connected to the hydraulic servo for the forward clutch for engaging and transmitting torque during the forward running conditon, the selecting valve selectively receiving a line pressure and a control pressure from the regulating valve so that hydraulic pressure just below engaging pressure regulated by the regulating valve is applied to the hydraulic servo for the forward clutch during stopping, and a line pressure is applied to the hydraulic servo for the forward clutch during running.

  6. Bidirectional drive and brake mechanism

    NASA Technical Reports Server (NTRS)

    Swan, Scott A. (inventor)

    1991-01-01

    A space transport vehicle is disclosed as including a body which is arranged to be movably mounted on an elongated guide member disposed in outer space and driven therealong. A drive wheel is mounted on a drive shaft and arranged to be positioned in rolling engagement with the elongated guide carrying the vehicle. A brake member is arranged on the drive shaft for movement into and out of engagement with an adjacent surface of the drive wheel. An actuator is mounted on the body to be manually moved back and forth between spaced positions in an arc of movement. A ratchet-and-pawl mechanism is arranged to operate upon movements of the actuator in one direction between first and second positions for coupling the actuator to the drive wheel to incrementally rotate the wheel in one rotational direction and to operate upon movements of the actuator in the opposite direction for uncoupling the actuator from the wheel. The brake member is threadedly coupled to the drive shaft in order that the brake member will be operated only when the actuator is moved on beyond its first and second positions for shifting the brake member along the drive shaft and into frictional engagement with the adjacent surface on the drive wheel.

  7. Minimal models for squealing of railway block brakes

    Microsoft Academic Search

    Utz von Wagner; Gottfried Spelsberg-Korspeter

    2011-01-01

    Block brakes have been used to brake railway vehicles for approximately 200 years. During the last 40 years, disk brakes have\\u000a replaced the block brakes at passenger cars but block brakes are still used for all freight wagons. One problem of block brakes\\u000a is that they show an enormous tendency to squeal. Although the block brake is a very common and old

  8. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...running at the manufacturer's maximum recommended number of revolutions per minute with the compressor governor in the cut-off...engine running at the manufacturer's recommended number of revolutions per minute and the compressor governor in the...

  9. ENVIRONMENTAL HYDRAULICS

    EPA Science Inventory

    The thermal, chemical, and biological quality of water in rivers, lakes, reservoirs, and near coastal areas is inseparable from a consideration of hydraulic engineering principles: therefore, the term environmental hydraulics. In this chapter we discuss the basic principles of w...

  10. Space shuttle wheels and brakes

    NASA Technical Reports Server (NTRS)

    Carsley, R. B.

    1985-01-01

    The Space Shuttle Orbiter wheels were subjected to a combination of tests which are different than any previously conducted in the aerospace industry. The major testing difference is the computer generated dynamic landing profiles used during the certification process which subjected the wheels and tires to simulated landing loading conditions. The orbiter brakes use a unique combination of carbon composite linings and beryllium heat sink to minimize weight. The development of a new lining retention method was necessary in order to withstand the high temperature generated during the braking roll. As with many programs, the volume into which this hardware had to fit was established early in the program, with no provisions made for growth to offset the continuously increasing predicted orbiter landing weight.

  11. Falling Magnets and Electromagnetic Braking

    NASA Astrophysics Data System (ADS)

    Culbreath, Christopher; Palffy-Muhoray, Peter

    2009-03-01

    The slow fall of a rare earth magnet through a copper pipe is a striking example of electromagnetic braking; this remarkable phenomenon has been the subject of a number of scientific paper s [1, 2]. In a pipe having radius R and wall thickness D, the terminal velocity of the falling magnet is proportional to (R?4)/D. It is interesting to ask what happens in the limit as D becomes very large. We report our experimental observations and theoretical predictions of the dependence of the terminal velocity on pipe radius R for large D. [1] Y. Levin, F.L. da Silveira, and F.B. Rizzato, ``Electromagnetic braking: A simple quantitative model''. American Journal of Physics, 74(9): p. 815-817 (2006). [2] J.A. Pelesko, M. Cesky, and S. Huertas, Lenz's law and dimensional analysis. American Journal of Physics, 3(1): p. 37-39. 2005.

  12. Frictional performance of semimetal brake lining for automobiles

    Microsoft Academic Search

    Yan Yin; Jiusheng Bao; Lei Yang

    2012-01-01

    Purpose – The purpose of this paper is to find the variations of brake lining's frictional performance with braking conditions, and their influence on the braking safety and reliability of automobiles. Design\\/methodology\\/approach – As the semimetal brake lining is widely used currently in automobiles, it was selected as the experimental material. By simulating the braking conditions and environment of automobiles,

  13. Hydraulics Lectures

    NSDL National Science Digital Library

    Pytel, Jim

    This page from the WindTech TV project provides a link to lectures created by Jim Pytel for his hydraulics course at Columbia Gorge Community College. The lectures consist of live videos and screen capture style presentations and may be viewed free of charge. Clicking on the video link in the center of the page will lead users to a YouTube page with 31 lectures. Topics include hydraulics math, hydraulic safety, basic hydraulic schematics, viscosity, piston pumps, actuators, troubleshooting and more. These lectures would be extremely useful for technical and community college students taking a fundamental hydraulics course. Flash is required to view the videos.

  14. Two-stage actuation system using DC motors and piezoelectric actuators for controllable industrial and automotive brakes and clutches

    Microsoft Academic Search

    Vijay A. Neelakantan; Gregory N. Washington; Norman K. Bucknor

    2005-01-01

    High bandwidth actuation systems that are capable of simultaneously producing relatively large forces and displacements are required for use in automobiles and other industrial applications. Conventional hydraulic actuation mechanisms used in automotive brakes and clutches are complex, inefficient and have poor control robustness. These lead to reduced fuel economy, controllability issues and other disadvantages. This paper involves the design, development,

  15. Asbestos dust exposure during brake repair

    Microsoft Academic Search

    K. J. Roedelsperger; H. Jahn; B. M. Brueckel; J. Manke; R. Paur; H. J. Woitowitz

    1986-01-01

    About 10,000 tons of chrysotile per year are used in the Federal Republic of Germany for the production of friction materials. During brake repair an unknown number of approximately 300,000 mechanics in automobile service stations are exposed to asbestos dust. In a field study, asbestos fiber concentrations during brake repair were measured. Occupational histories and chest X-rays of brake service

  16. Bidirectional Drive-And-Brake Mechanism

    NASA Technical Reports Server (NTRS)

    Swan, Scott A.

    1991-01-01

    Vehicle that crawls along monorail combines features of both bicycle and railroad handcar. Bidirectional drive-and-brake mechanism includes selectable-pawl-and-ratchet overrunning clutch (drive mechanism) and mating stationary and rotating conical surfaces pressing against each other (brake mechanism). Operates similarly to bicycle drive-and-brake mechanism except limits rotation of sprocket in both directions and brakes at both limits. Conceived for use by astronaut traveling along structure in outer space, concept also applied on Earth to make very small railraod handcars or crawling vehicles for use on large structures, in pipelines under construction, or underwater.

  17. A control system for maintaining constant braking torque on a disk brake dynamometer

    Microsoft Academic Search

    G. P. Hancke; R. E. Zietsman

    1989-01-01

    Most manufacturers of composite friction materials do not possess adequate facilities to test their products dynamically. A practical solution is to simulate the braking process in the laboratory mechanically by means of a disc brake dynamometer. The authors describe a control-system design for the dynamometer. The function of the control system is to maintain a constant braking torque for the

  18. Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems

    ERIC Educational Resources Information Center

    Tavares, J. M.

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and…

  19. Multidisciplinary design optimization of an automotive magnetorheological brake design

    E-print Network

    Park, Edward

    Multidisciplinary design optimization of an automotive magnetorheological brake design Edward J This paper presents the development of a new electromechanical brake system using magnetorheological (MR: Magnetorheological fluid; Automotive brake; Finite element analysis; Computational fluid dynamics; Multidisciplinary

  20. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Periodic brake equipment maintenance. 238...I Passenger Equipment § 238.309 Periodic brake equipment maintenance. (a...car brake valves. (f) Records of periodic maintenance. (1) The date...

  1. 30 CFR 57.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Resources 1 2011-07-01 2011-07-01 false Brakes for rail equipment. 57.14102 Section 57.14102 Mineral...Devices and Maintenance Requirements § 57.14102 Brakes for rail equipment. Braking systems on railroad cars...

  2. 30 CFR 56.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Resources 1 2011-07-01 2011-07-01 false Brakes for rail equipment. 56.14102 Section 56.14102 Mineral...Devices and Maintenance Requirements § 56.14102 Brakes for rail equipment. Braking systems on railroad cars...

  3. 30 CFR 56.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Resources 1 2010-07-01 2010-07-01 false Brakes for rail equipment. 56.14102 Section 56.14102 Mineral...Devices and Maintenance Requirements § 56.14102 Brakes for rail equipment. Braking systems on railroad cars...

  4. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Brake and Signal Equipment § 230.77 Foundation brake...part of the foundation brake gear of the steam locomotive or tender shall be less than 21/2 inches above the...

  5. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.57 Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent of its cross-sectional area, cracked,...

  6. Hydropneumatic energy reservoir for accumulating the braking energy recovered on a vehicle

    Microsoft Academic Search

    1985-01-01

    Hydropneumatic energy reservoir for accumulating the braking energy recovered on a vehicle by means of a hydrostatic energy recovery-restoration device, combined or not with the vehicle transmission and working between a high-pressure accumulator and a low-pressure accumulator, characterized in that it comprises several oblong cylindrical hydropneumatic accumulators connected hydraulically in parallel and placed side by side inside a single casing

  7. Braking index of isolated pulsars

    NASA Astrophysics Data System (ADS)

    Hamil, O.; Stone, J. R.; Urbanec, M.; Urbancová, G.

    2015-03-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities ? , and their time derivatives that show unambiguously that the pulsars are slowing down. Although the exact mechanism of the spin-down is a question of detailed debate, the commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. Other processes, including the emission of gravitational radiation, and of relativistic particles (pulsar wind), are also being considered. The calculated energy loss by a rotating pulsar with a constant moment of inertia is assumed proportional to a model dependent power of ? . This relation leads to the power law ? ? =-K ?n where n is called the braking index. The MDR model predicts n exactly equal to 3. Selected observations of isolated pulsars provide rather precise values of n , individually accurate to a few percent or better, in the range 1 braking index within the MDR model. Four microscopic equations of state are employed as input to two different computational codes that solve Einstein's equations numerically, either exactly or using the perturbative Hartle-Thorne method, to calculate the moment of inertia and other macroscopic properties of rotating neutron stars. The calculations are performed for fixed values of MB (as masses of isolated pulsars are not known) ranging from 1.0 - 2.2 M? , and fixed magnetic dipole moment and inclination angle between the rotational and magnetic field axes. The results are used to solve for the value of the braking index as a function of frequency, and find the effect of the choice of the EoS, MB. The density profile of a star with a given MB is calculated to determine the transition between the crust and the core and used in estimation of the effect of core superfluidity on the braking index. Our results show conclusively that, within the model used in this work, any significant deviation of the braking index away from the value n =3 occurs at frequencies higher than about ten times the frequency of the slow rotating isolated pulsars most accurately measured to date. The rate of change of n with frequency is related to the softness of the EoS and the MB of the star as this controls the degree of departure from sphericity. Change in the moment of inertia in the MDR model alone, even with the more realistic features considered here, cannot explain the observational data on the braking index and other mechanisms have to be sought.

  8. A-REI Braking Distance

    NSDL National Science Digital Library

    This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Suppose that a particular model of car has a braking distance that can be computed as follows: When the car is traveling at $v$ miles per hour, its bra...

  9. BRAKE SQUEAL NOISE: FINITE ELEMENT ANALYSIS

    Microsoft Academic Search

    MUHAMMAD ZAHIR HASSAN

    This paper investigated the brake disc squeal phenomenon using finite element analysis (FEA). The modal analysis has been used in this work to determine the natural frequency and mode shape pattern. The study on four different types of material properties is carried out to shows the effect of vibration mode and natural frequency as the source of brake squeal contribution.

  10. Performance of a disc brake friction material

    Microsoft Academic Search

    Pradnya Kosbe; Chittaranjan More

    2010-01-01

    The friction materials used in brakes are required to provide a stable coefficient of friction and a lower wear rate at various operating speeds, pressures, temperatures and environmental conditions. These friction materials must also be compatible with the rotor material in order to reduce its extensive wear, vibration and noise during braking. All of these requirements need to be achieved

  11. TMV Technology Capabilities Brake Stroke Monitor

    E-print Network

    TMV Technology Capabilities Brake Stroke Monitor Brake monitoring systems are proactive maintenance This technology allows for CMV operators to have knowledge of their steer, drive, and tandem axle group weights setup is required. Current Safety/Enforcement Technologies EOBR (electronic on-board recorder) On

  12. Accelerometer-controlled automatic braking system

    NASA Technical Reports Server (NTRS)

    Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

    1973-01-01

    Braking system, which employs angular accelerometer to control wheel braking and results in low level of tire slip, has been developed and tested. Tests indicate that system is feasible for operations on surfaces of different slipperinesses. System restricts tire slip and is capable of adapting to rapidly-changing surface conditions.

  13. ELASTIC DEFORMATION OF DISC BRAKE FRICTION LINING

    Microsoft Academic Search

    Guntars Uzkli

    2008-01-01

    There are the analysis and estimation of disc brake friction linings deformation value and impact on the friction body (friction lining on steel base) loading given in this article. It allows to modulate the wear of friction lining in the future research. Such friction body construction was analyzed in this research - the friction body and brake lever are linked

  14. 49 CFR 229.46 - Brakes: general.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...the following: (1) The locomotive brakes and devices for regulating pressures, including but not limited to the automatic and...in trailing position adequately isolates the non-functional valves so as to allow safe operation of the brake systems from...

  15. 49 CFR 229.46 - Brakes: general.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...the following: (1) The locomotive brakes and devices for regulating pressures, including but not limited to the automatic and...in trailing position adequately isolates the non-functional valves so as to allow safe operation of the brake systems from...

  16. 49 CFR 229.46 - Brakes: general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...the following: (1) The locomotive brakes and devices for regulating pressures, including but not limited to the automatic and...in trailing position adequately isolates the non-functional valves so as to allow safe operation of the brake systems from...

  17. Orbital-Transfer Vehicle With Aerodynamic Braking

    NASA Technical Reports Server (NTRS)

    Scott, C. D.; Nagy, K.; Roberts, B. B.; Ried, R. C.; Kroll, K.; Gamble, J.

    1986-01-01

    Vehicle includes airbrake for deceleration into lower orbit. Report describes vehicle for carrying payloads between low and high orbits around Earth. Vehicle uses thin, upper atmosphere for braking when returning to low orbit. Since less propellant needed than required for full retrorocket braking, vehicle carries larger payload and therefore reduces cost of space transportation.

  18. Some wear studies on aircraft brake systems

    NASA Technical Reports Server (NTRS)

    Ho, T. L.

    1975-01-01

    An initial investigation of worn surfaces in friction pads and steel rotors used in current aircraft brakes was carried out using electron microprobe and X-ray diffraction analysis. It consists of the topographical study and the analysis of chemical element distribution. Based upon this initial examination, two approaches, microscopic and macroscopic have been conducted to interpret and formulate the wear mechanism of the aircraft brake materials. Microscopically, the wear particles were examined. The initiation and growth of surface cracks and the oxidation were emphasized in this investigation. Macroscopically, it has been found that, for the current copper based brake material sliding against 17-22 AS steel in a caliper brake, the surface temperature raised due to frictional heat is nonlinearly proportional to the load applied and slide time with speed at 1750 rpm. The wear of brake materials is then proportional to this temperature and is also a function of the melting temperature for copper.

  19. Method and apparatus for electromagnetically braking a motor

    NASA Technical Reports Server (NTRS)

    Davis, Donald R. (Inventor); Radford, Nicolaus A (Inventor); Permenter, Frank Noble (Inventor); Parsons, Adam H (Inventor); Mehling, Joshua S (Inventor)

    2011-01-01

    An electromagnetic braking system and method is provided for selectively braking a motor using an electromagnetic brake having an electromagnet, a permanent magnet, a rotor assembly, and a brake pad. The brake assembly applies when the electromagnet is de-energized and releases when the electromagnet is energized. When applied the permanent magnet moves the brake pad into frictional engagement with a housing, and when released the electromagnet cancels the flux of the permanent magnet to allow a leaf spring to move the brake pad away from the housing. A controller has a DC/DC converter for converting a main bus voltage to a lower braking voltage based on certain parameters. The converter utilizes pulse-width modulation (PWM) to regulate the braking voltage. A calibrated gap is defined between the brake pad and permanent magnet when the brake assembly is released, and may be dynamically modified via the controller.

  20. Hydraulic Car

    NSDL National Science Digital Library

    Watsonville Environmental Science Workshop

    2011-01-01

    In this activity, learners build cars using syringes and water-powered hydraulics. Learners construct the car frame out of cardboard and set up a hydraulic system to raise and lower the car. Use this project to introduce learners to incompressible fluids and Pascal's Principle.

  1. Screw-released roller brake

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1999-01-01

    A screw-released roller brake including an input drive assembly, an output drive assembly, a plurality of locking sprags, a mechanical tripper nut for unlocking the sprags, and a casing therefor. The sprags consist of three dimensional (3-D) sprag members having pairs of contact surface regions which engage respective pairs of contact surface regions included in angular grooves or slots formed in the casing and the output drive assembly. The sprags operate to lock the output drive assembly to the casing to prevent rotation thereof in an idle mode of operation. In a drive mode of operation, the tripper is either self actuated or motor driven and is translated linearly up and down against a spline and at the limit of its travel rotates the sprags which unlock while coupling the input drive assembly to the output drive assembly so as to impart a turning motion thereto in either a clockwise or counterclockwise direction.

  2. Statistical analysis of brake squeal noise

    NASA Astrophysics Data System (ADS)

    Oberst, S.; Lai, J. C. S.

    2011-06-01

    Despite substantial research efforts applied to the prediction of brake squeal noise since the early 20th century, the mechanisms behind its generation are still not fully understood. Squealing brakes are of significant concern to the automobile industry, mainly because of the costs associated with warranty claims. In order to remedy the problems inherent in designing quieter brakes and, therefore, to understand the mechanisms, a design of experiments study, using a noise dynamometer, was performed by a brake system manufacturer to determine the influence of geometrical parameters (namely, the number and location of slots) of brake pads on brake squeal noise. The experimental results were evaluated with a noise index and ranked for warm and cold brake stops. These data are analysed here using statistical descriptors based on population distributions, and a correlation analysis, to gain greater insight into the functional dependency between the time-averaged friction coefficient as the input and the peak sound pressure level data as the output quantity. The correlation analysis between the time-averaged friction coefficient and peak sound pressure data is performed by applying a semblance analysis and a joint recurrence quantification analysis. Linear measures are compared with complexity measures (nonlinear) based on statistics from the underlying joint recurrence plots. Results show that linear measures cannot be used to rank the noise performance of the four test pad configurations. On the other hand, the ranking of the noise performance of the test pad configurations based on the noise index agrees with that based on nonlinear measures: the higher the nonlinearity between the time-averaged friction coefficient and peak sound pressure, the worse the squeal. These results highlight the nonlinear character of brake squeal and indicate the potential of using nonlinear statistical analysis tools to analyse disc brake squeal.

  3. Finite element analysis of transient thermoelastic behaviors in disk brakes

    Microsoft Academic Search

    Ji-Hoon Choi; In Lee

    2004-01-01

    A transient analysis for thermoelastic contact problem of disk brakes with frictional heat generation is performed using the finite element method. To analyze the thermoelastic phenomenon occurring in disk brakes, the coupled heat conduction and elastic equations are solved with contact problems. The numerical simulation for the thermoelastic behavior of disk brake is obtained in the repeated brake condition. The

  4. Reaction times to neon, LED, and fast incandescent brake lamps

    Microsoft Academic Search

    MICHAEL SIVAK; MICHAEL J. FLANNAGAN; TAKASHI SATO; ERIC C. TRAUBE; MASAMI AOKI

    1994-01-01

    Standard incandescent brake lamps have a relatively slow rise time. It takes approximately a quarter of a second for them to reach 90% of asymptotic light output, causing potential delays in responses by following drivers. The present study evaluated reaction times to brake signals from standard incandescent brake lamps and from three alternative brake lamps with substantially faster rise times:

  5. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...the rivet heads, or the brake shoe on bonded linings or pads. Brake linings and pads shall not have cracks or breaks that...minor cracks that do not impair attachment. Drum brake linings shall be securely attached to brake shoes....

  6. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...one-sixteenth of an inch over the brake shoe on bonded linings or pads. Brake linings and pads shall not have cracks or breaks that...not be visible on the friction surface. Drum brake linings shall be securely attached to brake shoes....

  7. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...one-sixteenth of an inch over the brake shoe on bonded linings or pads. Brake linings and pads shall not have cracks or breaks that...not be visible on the friction surface. Drum brake linings shall be securely attached to brake shoes....

  8. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...one-sixteenth of an inch over the brake shoe on bonded linings or pads. Brake linings and pads shall not have cracks or breaks that...not be visible on the friction surface. Drum brake linings shall be securely attached to brake shoes....

  9. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...one-sixteenth of an inch over the brake shoe on bonded linings or pads. Brake linings and pads shall not have cracks or breaks that...not be visible on the friction surface. Drum brake linings shall be securely attached to brake shoes....

  10. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...one-sixteenth of an inch over the brake shoe on bonded linings or pads. Brake linings and pads shall not have cracks or breaks that...not be visible on the friction surface. Drum brake linings shall be securely attached to brake shoes....

  11. Brakes. Auto Mechanics Curriculum Guide. Module 6. Instructor's Guide.

    ERIC Educational Resources Information Center

    Allain, Robert

    This module is the sixth of nine modules in the competency-based Missouri Auto Mechanics Curriculum Guide. Eight units cover: introduction to automotive brake systems; disc and drum brake system components and how they operate; properties of brake fluid and procedures for bleeding the brake system; diagnosing and determining needed repairs on…

  12. Performance of an aircraft tire under cyclic braking and of a currently operational antiskid braking system

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.

    1972-01-01

    An experimental investigation was conducted to study the performance of an aircraft tire under cyclic braking conditions and to study the performance of a currently operational aircraft antiskid braking system. Dry, damp, and flooded runway surface conditions were used in the investigation. The results indicated that under cyclic braking conditions the braking and cornering-force friction coefficients may be influenced by fluctuations in the vertical load, flexibility in the wheel support, and the spring coupling between the wheel and the tire-pavement interface. The cornering capability was shown to be negligible at wheel slip ratios well below a locked-wheel skid under all test surface conditions. The maximum available brake-force friction coefficient was shown to be dependent upon the runway surface condition, upon velocity, and, for wet runways, upon tire differences. Moderate reductions in vertical load and brake system pressure did not significantly affect the overall wet-runway performance of the tire.

  13. Stochastic hydraulics

    NASA Astrophysics Data System (ADS)

    The Fourth IAHR International Symposium on Stochastic Hydraulics, cosponsored by AGU and the American Society of Civil Engineers, will be held July 31-August 2, 1984, at Urbana, 111. About 40 papers selected from submitted abstracts will be presented in the symposium.Topics covered will include (but not be limited to) the following areas: risk and reliability analysis; safety of dams and other hydraulic structures; stochastic models; and stochastic processes of hydraulic and hydrologic phenomena such as turbulence, sediment transport, dispersion and diffusion, and random waves.The proceedings of the Second International Conference, held in Urbana, Illinois, in June 1981, are available from Water Resources Publications, Littleton, Colo., under the title, “Urban Stormwater Hydraulics and Hydrology” and “Urban Stormwater Quality, Management, and Planning.”

  14. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...must not be less than the kinetic energy absorption requirements determined under either...methods: (1) The brake kinetic energy absorption requirements must be based on a conservative...rational analysis, the kinetic energy absorption requirements for each main wheel...

  15. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...must not be less than the kinetic energy absorption requirements determined under either...methods: (1) The brake kinetic energy absorption requirements must be based on a conservative...rational analysis, the kinetic energy absorption requirements for each main wheel...

  16. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...must not be less than the kinetic energy absorption requirements determined under either...methods: (1) The brake kinetic energy absorption requirements must be based on a conservative...rational analysis, the kinetic energy absorption requirements for each main wheel...

  17. Effect of frictional heating on brake materials

    NASA Technical Reports Server (NTRS)

    Ho, T.-L.; Peterson, M. B.; Ling, F. F.

    1974-01-01

    An exploratory study of the properties of aircraft brake materials was made to determine ways of improving friction and wear behavior while minimizing surface temperatures. It is found that frictional variation at high temperature involves material softening and metal transfer, formation of oxides, and surface melting. The choice of proper materials to combat these effects is discussed. Minimum surface temperatures are found to result from use of materials with large density-specific heat and density-specific heat-conductivity factors, use of a higher load-lower friction system, and maximization of the contact area. Some useful trade-off criteria for the size of brake disks against weight considerations are suggested. Additional information on material behavior and peak braking temperatures was gathered from an inspection of used brake pads and rotor disks.

  18. 14 CFR 27.921 - Rotor brake.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations on the use of...

  19. 14 CFR 29.921 - Rotor brake.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations on the use of...

  20. An engine air-brake integration study

    E-print Network

    Mulchandani, Hiten

    2011-01-01

    The feasibility of operating an engine air-brake (EAB) integrated with a pylon duct bifurcation in a realistic aircraft engine environment has been analyzed. The EAB uses variable exit guide vanes downstream of a high ...

  1. Rotary Speed Sensor for Antilocking Brakes

    NASA Technical Reports Server (NTRS)

    Berdahl, C. M.

    1986-01-01

    Sensor based on fluidic principles produces negative pressure approximately proportional to rotational speed. Sensor developed as part of antilocking brake system for motorcycles. Uses inlet pressure rather than outlet pressure as braking-control signal, eliminating pressure pulsations caused by pump vanes and ensuring low-noise signal. Sensor is centrifugal air pump turned by one of motorcycle wheels. Air enters pump through orifice plates, and suction taken off through port in pump inlet plenum.

  2. Oscillatory flow braking: inner magnetosphere observations

    NASA Astrophysics Data System (ADS)

    Panov, E. V.; Nakamura, R.; Baumjohann, W.; Angelopoulos, V.

    2013-12-01

    We search for damped oscillatory flow braking events observed by THEMIS/ARTEMIS in the near-Earth plasma sheet when their counterpart in the inner magnetosphere was observed. By comparing the particle and magnetic field data in the two locations we analyze the feedback of the inner magnetosphere to plasma sheet oscillatory flow braking. We discuss the possible role of the oscillatory flow events for plasma injection into the inner magnetosphere.

  3. Friction and wear of sintered metallic brake linings on a C\\/C-SiC composite brake disc

    Microsoft Academic Search

    Zmago Stadler; Kristoffer Krnel; Tomaž Kosma?

    2008-01-01

    The friction and wear of sintered metallic brake linings on a C\\/C-SiC composite brake disc were studied. This paper reports on the friction and wear properties of sintered metallic (MMC) brake linings, which appear to combine well with a C\\/C-SiC brake disc. The friction characteristics were examined with a dynamometer on two different commercial motorcycle brake systems, differing in terms

  4. Experimental Identification of Brake Pad Material Properties-A Step Towards a Better Prediction of Brake Squeal

    Microsoft Academic Search

    Sylwia Hornig; Daniel Hochlenert; Utz von Wagner

    2010-01-01

    Automotive brake squeal is a disruptive high frequency sound radiation phenomenon generated by friction-induced self-excited vibrations of the brake system. The brake system loses its stability and starts oscillating in a limit cycle with amplitudes limited by nonlinearities, the main origin of the nonlinearities being brake lining material. In order to perform a reliable brake squeal prediction using established mathematical-mechanical

  5. Consideration of Materials for Aircraft Brakes

    NASA Technical Reports Server (NTRS)

    Peterson, M. B.; Ho, T.

    1972-01-01

    An exploratory investigation was conducted concerning materials and their properties for use in aircraft brakes. Primary consideration was given to the heat dissipation and the frictional behavior of materials. Used brake pads and rotors were analyzed as part of the investigation. A simple analysis was conducted in order to determine the most significant factors which affect surface temperatures. It was found that where size and weight restrictions are necessary, the specific heat of the material, and maintaining uniform contact area are the most important factors. A criterion was suggested for optimum sizing of the brake disks. Bench friction tests were run with brake materials. It was found that there is considerable friction variation due to the formation and removal of surface oxide films. Other causes of friction variations are surface softening and melting. The friction behavior at high temperature was found to be more characteristic of the steel surface rather than the copper brake material. It is concluded that improved brake materials are feasible.

  6. Magnetic braking in galactic flows

    SciTech Connect

    Sparke, L.S.

    1982-09-01

    The nuclear fireworks of active galaxies are believed to derive their power from the kinetic energy of gas falling onto a massive central objects; mass shed from evolving galactic stars is an obvious source of fuel for this process. But this ejected material shares the galactic rotation, and a centrifugal barrier will prevent it from reaching the nucleus, if its angular momentum is not removed. This paper shows that, if the large-scale galactic magnetic field has a strong enough radial component, magnetic torques can act to spin down the infalling matter. Rotation of the interstellar gas induces a toroidal magnetic field, and Maxwell stresses remove angular momentum from the flow; gas can then fall inward to the galactic center. In this way, the monster in the nucleus can be fed on gas from a galaxy's own stars. The magnetic fields in M87 and NGC 1275, giant elliptical galaxies which are accreting from an intracluster medium, appear to be strong enough to allow magnetic braking.

  7. Electromagnetic brake/clutch device

    NASA Astrophysics Data System (ADS)

    Vranish, John M.

    1994-01-01

    An electromagnetic brake/clutch device includes a drive shaft supported by at least one bearing for transmitting torque, a housing, affixed to prevent its rotation, surrounding the drive shaft, and an electromagnetically activated device within the housing to selectively prevent and allow rotation of the drive shaft. The electromagnetically activated device includes a plurality of cammed rollers to prevent counter-clockwise rotation of the drive shaft. The drive shaft includes a circumferential disk and the housing includes a reaction ring for engagement with the plurality of cammed rollers. The plurality of cammed rollers are released from engagement with the circumferential disk and the reaction ring by a plurality of tripping mechanisms within the housing. The tripping action uses the locking force to act as a release force merely by changing the boundary conditions of the roller interface angles. The tripping mechanisms include trippers for disengaging the plurality of cammed rollers and an anvil shaped portion for providing lateral movement of the trippers. The plurality of cammed rollers is preloaded to engagement with the circumferential disk and reaction ring by a spring, and is located with respect to an adjacent tripping mechanism with another spring.

  8. Modelling and validation of magnetorheological brake responses using parametric approach

    NASA Astrophysics Data System (ADS)

    Z, Zainordin A.; A, Abdullah M.; K, Hudha

    2013-12-01

    Magnetorheological brake (MR Brake) is one x-by-wire systems which performs better than conventional brake systems. MR brake consists of a rotating disc that is immersed with Magnetorheological Fluid (MR Fluid) in an enclosure of an electromagnetic coil. The applied magnetic field will increase the yield strength of the MR fluid where this fluid was used to decrease the speed of the rotating shaft. The purpose of this paper is to develop a mathematical model to represent MR brake with a test rig. The MR brake model is developed based on actual torque characteristic which is coupled with motion of a test rig. Next, the experimental are performed using MR brake test rig and obtained three output responses known as angular velocity response, torque response and load displacement response. Furthermore, the MR brake was subjected to various current. Finally, the simulation results of MR brake model are then verified with experimental results.

  9. Experimental analysis of brake squeal noise on a laboratory brake setup

    Microsoft Academic Search

    Oliviero Giannini; Adnan Akay; Francesco Massi

    2006-01-01

    The present paper is the first of two papers dealing with brake squeal instability. An experimental setup is specifically designed for this purpose and is characterized by a simple design to aid measurements and modeling. This first paper describes the experimental setup called “laboratory brake” and presents the measurements performed on it to characterize its dynamical behavior and its squeal

  10. Speciation of Sb in airborne particulate matter, vehicle brake linings, and brake pad wear residues

    E-print Network

    Short, Daniel

    : XAS XANES EXAFS Antimony Particulate matter Brake linings a b s t r a c t Insights into the speciation the brake abrasion process is easily decomposed forming more stable compounds such as antimony mixed oxidic., 2001; Takaoka et al., 2005). In addition, antimony trioxide has been classified by the International

  11. Brake squeal reduction of vehicle disc brake system with interval parameters by uncertain optimization

    NASA Astrophysics Data System (ADS)

    Lü, Hui; Yu, Dejie

    2014-12-01

    An uncertain optimization method for brake squeal reduction of vehicle disc brake system with interval parameters is presented in this paper. In the proposed method, the parameters of frictional coefficient, material properties and the thicknesses of wearing components are treated as uncertain parameters, which are described as interval variables. Attention is focused on the stability analysis of a brake system in squeal, and the stability of brake system is investigated via the complex eigenvalue analysis (CEA) method. The dominant unstable mode is extracted by performing CEA based on a linear finite element (FE) model, and the negative damping ratio corresponding to the dominant unstable mode is selected as the indicator of instability. The response surface method (RSM) is applied to approximate the implicit relationship between the unstable mode and the system parameters. A reliability-based optimization model for improving the stability of the vehicle disc brake system with interval parameters is constructed based on RSM, interval analysis and reliability analysis. The Genetic Algorithm is used to get the optimal values of design parameters from the optimization model. The stability analysis and optimization of a disc brake system are carried out, and the results show that brake squeal propensity can be reduced by using stiffer back plates. The proposed approach can be used to improve the stability of the vehicle disc brake system with uncertain parameters effectively.

  12. Performance of ceramic enhanced phenolic matrix brake lining materials for automotive brake linings

    Microsoft Academic Search

    K. W. Hee; P. Filip

    2005-01-01

    Despite the number of research studies completed on the mechanism of friction in automotive brake lining materials, the phenomenon is still not fully understood. Complex mechano-chemical processes occurring on the friction interface of a composite friction material make it difficult to understand the correlation between the formulation of brake lining and the frictional performance. This paper concentrates on (i) the

  13. Adaptive controller for regenerative and friction braking system

    DOEpatents

    Davis, Roy I. (Ypsilanti, MI)

    1990-01-01

    A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

  14. Adaptive controller for regenerative and friction braking system

    DOEpatents

    Davis, R.I.

    1990-10-16

    A regenerative and friction braking system for a vehicle having one or more road wheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the road wheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the road wheels of the vehicle without skidding or slipping will not be exceeded. 8 figs.

  15. Hydraulic system for a ratio change transmission

    DOEpatents

    Kalns, Ilmars (Northville, MI)

    1981-01-01

    Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

  16. Design and experimental evaluation of a fuzzy logic pressure controller for the Airbus 310\\/320 braking control system

    Microsoft Academic Search

    P. J. Costa Branco; J. A. Dente

    2010-01-01

    We show here the design and preliminary experimental evaluation steps of a fuzzy controller for the pressure loop of a proposed new Airbus A310\\/A320 modular braking system. The results indicated that two main requirements of this system could be achieved:•pressure control with high robustness in the case of hydraulic load fluctuations, and;•highly modular characteristics, since the same fuzzy controller can

  17. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Strength Requirements Ground Loads § 29.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  18. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Strength Requirements Ground Loads § 29.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  19. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Strength Requirements Ground Loads § 29.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  20. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Strength Requirements Ground Loads § 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  1. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Strength Requirements Ground Loads § 29.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  2. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...AIRPLANES Structure Ground Loads § 23.493 Braked roll conditions. Under braked roll conditions, with the shock absorbers and tires in their static positions, the following apply: (a) The limit vertical load factor must be...

  3. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...AIRPLANES Structure Ground Loads § 23.493 Braked roll conditions. Under braked roll conditions, with the shock absorbers and tires in their static positions, the following apply: (a) The limit vertical load factor must be...

  4. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...AIRPLANES Structure Ground Loads § 23.493 Braked roll conditions. Under braked roll conditions, with the shock absorbers and tires in their static positions, the following apply: (a) The limit vertical load factor must be...

  5. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...Strength Requirements Ground Loads § 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  6. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Strength Requirements Ground Loads § 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  7. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Strength Requirements Ground Loads § 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  8. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...Strength Requirements Ground Loads § 29.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  9. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...AIRPLANES Structure Ground Loads § 23.493 Braked roll conditions. Under braked roll conditions, with the shock absorbers and tires in their static positions, the following apply: (a) The limit vertical load factor must be...

  10. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Strength Requirements Ground Loads § 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  11. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...AIRPLANES Structure Ground Loads § 23.493 Braked roll conditions. Under braked roll conditions, with the shock absorbers and tires in their static positions, the following apply: (a) The limit vertical load factor must be...

  12. 30 CFR 56.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Emergency braking for electric hoists. 56.19017 Section 56.19017 Mineral... Hoists § 56.19017 Emergency braking for electric hoists. Each electric hoist shall be equipped with a...

  13. A pressure control scheme for air brakes in commercial vehicles

    E-print Network

    Bowlin, Christopher Leland

    2007-04-25

    for providing the ground work for future systems such as forward collision avoidance systems, advanced anti-lock brake systems and differential braking systems. The development of this controller involves two tasks. The first task was the development of a...

  14. P iezoelectric Sensors and Actuators in Disk Brakes

    Microsoft Academic Search

    Peter Hagedorn; Daniel Hochlenert; Reg Dunlop

    In recent years new mathematical models for mechanical disk brakes in passenger cars were developed in the authors' laboratory, mainly with view to brake squeal and these models were validated in a test rig. For this application \\

  15. 2. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE SHOES, BRAKE HANDLE, AND REDUCTION GEARS, LOOKING SOUTHWEST - Buffalo Coal Mine, Vulcan Cable Hoist, Wishbone Hill, Southeast end, near Moose Creek, Sutton, Matanuska-Susitna Borough, AK

  16. THERMAL HYDRAULICS KEYWORDS: thermal hydraulics,

    E-print Network

    Smith, Barton L.

    -fluid modeling of nuclear reactor systems. Thermal-hydraulic analysis codes such as RELAP5-3D ~Ref. 1! and FLICA regions of the system. In fact, the CFD code FLUENT has previously been coupled to RELAP5-3D ~Refs. 3 parameter model of the thermally limiting core locations. However, these codes are not intended to pre- dict

  17. Improvements in the inspection procedure of brake disc warping

    Microsoft Academic Search

    D. García-Pozuelo; A. Gauchía; B. L. Boada; V. Díaz

    2009-01-01

    \\u000a Abstract  The warping of brake discs and ovality of brake drums is one of the main causes of vibration and noise during the braking\\u000a of a vehicle and of diminishing brake efficiency. Nowadays, the International Motor Vehicle Inspection Committee (CITA) demands\\u000a an inspection of the warping and ovality during the Periodic Motor Vehicle Inspection (PMVI). However, the measurement is\\u000a not always

  18. Nonlinear stability analysis of a disk brake model

    Microsoft Academic Search

    Daniel Hochlenert

    2009-01-01

    It has become commonly accepted by scientists and engineers that brake squeal is generated by friction-induced self-excited\\u000a vibrations of the brake system. The noise-free configuration of the brake system loses stability through a flutter-type instability\\u000a and the system starts oscillating in a limit cycle. Usually, the stability analysis of disk brake models, both analytical\\u000a as well as finite element based,

  19. Development of the brake system design program for a vehicle

    Microsoft Academic Search

    S. P. Jung; K. J. Jun; T. W. Park; J. H. Yoon

    2008-01-01

    It is quite challenging to estimate the braking performance of a vehicle because the brake system is comprised of many parts,\\u000a including a booster, master cylinder, and caliper. Calculation of characteristics such as braking force through vehicle tests\\u000a requires much time and money. Therefore, the development of a method to estimate the braking performance of a vehicle using\\u000a qualitative methods

  20. Motion capture of a pad measured with accelerometers during squeal noise in a real brake system

    NASA Astrophysics Data System (ADS)

    Renaud, Franck; Chevallier, Gaël; Dion, Jean-Luc; Taudière, Guillaume

    2012-11-01

    The operating deflection shape of a pad during squeal noise is measured on a real brake system with three-axis accelerometers. A time-frequency analysis is performed that highlights the dependency of squeal on the hydraulic pressure of the system and shows that squeal occurs simultaneously with harmonic components. The operating deflection shape of this pad before and during squeal is then visualized using interpolation, showing the predominance of bending motion. Finally, the pad motions observed are compared to the real modal basis of a detailed Finite Element model.

  1. Hydropneumatic energy reservoir for accumulating the braking energy recovered on a vehicle

    SciTech Connect

    Michel, R.

    1985-06-04

    Hydropneumatic energy reservoir for accumulating the braking energy recovered on a vehicle by means of a hydrostatic energy recovery-restoration device, combined or not with the vehicle transmission and working between a high-pressure accumulator and a low-pressure accumulator, characterized in that it comprises several oblong cylindrical hydropneumatic accumulators connected hydraulically in parallel and placed side by side inside a single casing of small height, the space included between the said casing and the said accumulators forming the low-pressure accumulator.

  2. Predictive model of squeal noise occurring on a laboratory brake

    Microsoft Academic Search

    Oliviero Giannini; Aldo Sestieri

    2006-01-01

    This paper on brake squeal instability presents a reduced order model of a laboratory brake considered in a previous paper, and presents a description of the squeal mechanism occurring during experiments.The model uses the modal parameters of the laboratory brake components, the disc and the caliper, when they are not in contact between them. Successively, the caliper and the disc

  3. Disk brake squeal prediction using the ABLE algorithm

    Microsoft Academic Search

    G. Lou; T. W. Wu; Z. Bai

    2004-01-01

    Disk brake squeal noise is mainly due to unstable friction-induced vibration. A typical disk brake system includes two pads, a rotor, a caliper and a piston. In order to predict if a disk brake system will generate squeal, the finite element method (FEM) is used to simulate the system. At the contact interfaces between the pads and the rotor, the

  4. Thermomechanical processes in the friction heating of disk brakes

    Microsoft Academic Search

    A. A. Evtushenko; N. V. Gorbacheva; E. G. Ivanik

    1997-01-01

    Thermomechanical processes are studied at the contact area of a metal brake disk and brake block during braking. Expressions\\u000a are obtained for both the temperature and the thermal displacement in the center of the contact area caused by the effect\\u000a of the friction heat source, whose power is a linear function of time.

  5. Regenerative braking system for a hybrid electric vehicle

    Microsoft Academic Search

    S. R. Cikanek; K. E. Bailey

    2002-01-01

    This paper discusses a regenerative braking system (RBS) for a parallel hybrid electric vehicle (PHEV) that performs regenerative energy recovery based on vehicle attributes, thereby providing improved performance, efficiency and reliability at minimal additional cost. A detailed description of the regenerative braking algorithm is presented along with simulation results from a dynamic model of the PHEV exhibiting the regenerative braking

  6. Design of an optimal fuzzy controller for antilock braking systems

    Microsoft Academic Search

    A. Mirzaei; M. Moallem; B. Mirzaeian; B. Fahimi

    2005-01-01

    Antilock braking systems (ABS) have been developed to improve vehicle control during sudden braking especially on slippery road surfaces. The objective of such control is to increase wheel tractive force in the desired direction while maintaining adequate vehicle stability and steerability and also reducing the vehicle stopping distance. In this paper, an optimized fuzzy controller is proposed for antilock braking

  7. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Single car air brake tests. 232.305 Section 232.305...and Testing Requirements § 232.305 Single car air brake tests. (a) Single car air brake tests shall be performed by a...

  8. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Single car air brake tests. 232.305 Section 232.305...and Testing Requirements § 232.305 Single car air brake tests. (a) Single car air brake tests shall be performed by a...

  9. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Single car air brake tests. 232.305 Section 232.305...and Testing Requirements § 232.305 Single car air brake tests. (a) Single car air brake tests shall be performed by a...

  10. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Single car air brake tests. 232.305 Section 232.305...and Testing Requirements § 232.305 Single car air brake tests. (a) Single car air brake tests shall be performed by a...

  11. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Single car air brake tests. 232.305 Section 232.305...and Testing Requirements § 232.305 Single car air brake tests. (a) Single car air brake tests shall be performed by a...

  12. The influence of braking time on heat flow through the friction surfaces of the friction elements of disk brakes for railway vehicles

    Microsoft Academic Search

    Liviu Sevastian Bocîi

    2011-01-01

    Disk brakes were first introduced on the suburban and urban coaches and high speed freight cars (V > 120 km\\/h) for the following reasons: shoe brakes reached their potential limits, especially at high speeds; the maintenance of disc brakes is cheaper; greater comfort; the friction coefficient of disk brake elements (friction pad and brake disc) presents lower variation in velocity

  13. The design of aircraft brake systems, employing cooling to increase brake life

    NASA Technical Reports Server (NTRS)

    Scaringe, R. P.; Ho, T. L.; Peterson, M. B.

    1975-01-01

    A research program was initiated to determine the feasibility of using cooling to increase brake life. An air cooling scheme was proposed, constructed and tested with various designs. Straight and curved slotting of the friction material was tested. A water cooling technique, similar to the air cooling procedure, was evaluated on a curved slotted rotor. Also investigated was the possibility of using a phase-change material within the rotor to absorb heat during braking. Various phase-changing materials were tabulated and a 50%, (by weight) LiF - BeF2 mixing was chosen. It was shown that corrosion was not a problem with this mixture. A preliminary design was evaluated on an actual brake. Results showed that significant improvements in lowering the surface temperature of the brake occurred when air or water cooling was used in conjunction with curved slotted rotors.

  14. Measurements of radio pulsar braking indices

    NASA Astrophysics Data System (ADS)

    Chukwude, A. E.; Baiden, A. A.; Onuchukwu, C. C.

    2010-06-01

    A quantitative analysis of radio pulsar timing noise is presented. Our analysis employs the recently reported strong correlation (with correlation coefficient r = 0.95) between the observed second time derivative of the pulse rotation frequency (ddot?obs), obtained from fully phase-coherent timing analyses, and a timing noise statistic (?R23), used to quantify the amount of pulsar rotational fluctuations absorbed by the coefficient of the cubic term, to isolate the presumed deterministic braking index from the effects attributable to pulsar timing activity. Application of this method to a sample of 27 radio pulsars, whose timing data span 9-13 years, reveals that (i) for 22 pulsars, a sensible braking index measurement was impossible: with numerical values of the braking index either appreciably less than the corresponding uncertainty or anomalously large; (ii) save for the relatively large uncertainties, the braking index appears to be significantly measured in five pulsars. Current results are discussed in the context of the prevailing standard model for radio pulsar spin-down.

  15. Asbestos free friction composition for brake linings

    Microsoft Academic Search

    Arnab Ganguly; Raji George

    2008-01-01

    An asbestos free friction material composite for brake linings is synthesized containing fibrous reinforcing constituents,\\u000a friction imparting and controlling additives, elastomeric additives, fire retarding components and a thermosetting resin.\\u000a The composite shows exemplary friction characteristics and has great resistance to wear and shows good temperature stability.

  16. Wind-Tunnel Investigations of Diving Brakes

    NASA Technical Reports Server (NTRS)

    Fucha, D.

    1942-01-01

    Unduly high diving speeds can be effectively controlled by diving brakes but their employment involves at the same time a number of disagreeable features: namely, rotation of zero lift direction, variation of diviving moment, and, the creation of a potent dead air region.

  17. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...of each wheel with brakes. The limit loads must be equal to 0.55 times the vertical load at each wheel or to the load developed by 1.2 times the nominal...ground reactions must pass through the center of gravity of the...

  18. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...of each wheel with brakes. The limit loads must be equal to 0.55 times the vertical load at each wheel or to the load developed by 1.2 times the nominal...ground reactions must pass through the center of gravity of the...

  19. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...of each wheel with brakes. The limit loads must be equal to 0.55 times the vertical load at each wheel or to the load developed by 1.2 times the nominal...ground reactions must pass through the center of gravity of the...

  20. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...of each wheel with brakes. The limit loads must be equal to 0.55 times the vertical load at each wheel or to the load developed by 1.2 times the nominal...ground reactions must pass through the center of gravity of the...

  1. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...of each wheel with brakes. The limit loads must be equal to 0.55 times the vertical load at each wheel or to the load developed by 1.2 times the nominal...ground reactions must pass through the center of gravity of the...

  2. Brake and speed responsive controlled transmission

    Microsoft Academic Search

    M. Maezono; T. Shimizu; K. Ishikawa

    1987-01-01

    A control apparatus is described for multi-speed, oil pressure operated vehicle transmission having an oil pressure operated clutch for each speed drive train, a lowest and a highest speed drive train, and a one-way clutch in the lowest speed drive train. The apparatus comprises means for detecting a brake actuated condition and a stopped condition of the vehicle including means

  3. Experimental investigation of an accelerometer controlled automatic braking system

    NASA Technical Reports Server (NTRS)

    Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

    1972-01-01

    An investigation was made to determine the feasibility of an automatic braking system for arresting the motion of an airplane by sensing and controlling braked wheel decelerations. The system was tested on a rotating drum dynamometer by using an automotive tire, wheel, and disk-brake assembly under conditions which included two tire loadings, wet and dry surfaces, and a range of ground speeds up to 70 knots. The controlling parameters were the rates at which brake pressure was applied and released and the Command Deceleration Level which governed the wheel deceleration by controlling the brake operation. Limited tests were also made with the automatic braking system installed on a ground vehicle in an effort to provide a more realistic proof of its feasibility. The results of this investigation indicate that a braking system which utilizes wheel decelerations as the control variable to restrict tire slip is feasible and capable of adapting to rapidly changing surface conditions.

  4. Hybrid Electric Vehicle (HEV) Braking and Steering Systems

    NSDL National Science Digital Library

    2013-04-11

    This module consists of a PowerPoint presentation, lab sheet, and syllabi discussing HEVs' braking and steering systems. These materials are derived from three courses offered at Lewis and Clark Community College on automotive alignment, braking, and steering systems and were developed through a seed grant from the CAAT. The presentation discusses the circuitry and operations for HEV braking and steering systems, variations from traditional braking and steering power assist, and how to service brake pads on a Ford Escape Hybrid. The lab sheet should familiarize students with the variations and similarities between hybrid and conventional systems when servicing a HEV's brake pads such as placing the vehicle in “Pad Service Mode.” The provided syllabi includes highlighted sections where these HEV technologies were incorporated into alignment, brakes, and suspension courses at Lewis and Clark Community College.

  5. Hydraulic fracturing-1

    SciTech Connect

    Not Available

    1990-01-01

    This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

  6. Downhole hydraulic seismic generator

    SciTech Connect

    Gregory, D.L.; Hardee, H.C.; Smallwood, D.O.

    1992-05-19

    This patent describes a downhole seismic source for operation within a borehole to produce seismic energy waves through surrounding earth strata. It includes an elongated housing adapted for lowering into the borehole by a cable means; a hydraulic oscillator means carried by the housing for producing seismic vibrations in the housing; a hydraulic pressure source carried by the housing for providing a flow of high pressure hydraulic fluid, comprising a pump means for recycling the hydraulic fluid and for recharging the downhole seismic source and an electric motor for driving the pump means, the hydraulic pressure source further comprising a low pressure fluid accumulator which receives spent hydraulic fluid from the hydraulic oscillator means and from the clamp valve means and outputs hydraulic fluid to any pump means which outputs a high pressure hydraulic fluid, a heat exchanger means for receiving the high pressure fluid from the pump means and for dissipating heat produced by the pump means in the hydraulic fluid, and a high pressure accumulator for receiving the high pressure hydraulic fluid from the heat exchanger means and for providing the high pressure fluid as an output to an electro-hydraulic servovalve means, whereby the downhole seismic source is recharged for future operation; an electro-hydraulic servovalve means operably connected between the hydraulic pressure source and the hydraulic oscillator means for controlling the flow of high pressure hydraulic fluid from the hydraulic pressure source into the hydraulic oscillator means which thus produces the seismic vibrations; and a clamping means.

  7. Brake and speed responsive controlled transmission

    SciTech Connect

    Maezono, M.; Shimizu, T.; Ishikawa, K.

    1987-02-24

    A control apparatus is described for multi-speed, oil pressure operated vehicle transmission having an oil pressure operated clutch for each speed drive train, a lowest and a highest speed drive train, and a one-way clutch in the lowest speed drive train. The apparatus comprises means for detecting a brake actuated condition and a stopped condition of the vehicle including means responsive to the throttle opening and governor of the vehicle engine. It also includes means responsive to the detecting means for supplying oil pressure to the clutch for the highest speed drive train during the continuance of either the brake actuated or stopped vehicle condition for minimizing the torque transmitted through the transmission.

  8. From the Kinetic Energy Recovery System to the Thermo-Hydraulic Hybrid Motor Vehicle

    NASA Astrophysics Data System (ADS)

    Cristescu, Corneliu; Drumea, Petrin; Guta, Dragos; Dumitrescu, Catalin

    2011-12-01

    The paper presents some theoretical and experimental results obtained by the Hydraulics and Pneumatics Research Institute INOE 2000-IHP with its partners, regarding the creating of one hydraulic system able to recovering the kinetic energy of the motor vehicles, in the braking phases, and use this recovered energy in the starting and accelerating phases. Also, in the article is presented a testing stand, which was especially designed for testing the hydraulic system for recovery the kinetic energy. Through mounting of the kinetic energy recovering hydraulic system, on one motor vehicle, this vehicle became a thermo-hydraulic hybrid vehicle. Therefore, the dynamic behavior was analyzed for the whole hybrid motor vehicle, which includes the energy recovery system. The theoretical and experimental results demonstrate the possible performances of the hybrid vehicle and that the kinetic energy recovery hydraulic systems are good means to increase energy efficiency of the road motor vehicles and to decrease of the fuel consumption.

  9. The effect of friction on drum brakes

    SciTech Connect

    Huang, Y.M.; Shyr, J.S. [National Taiwan Univ. (China)

    1995-12-31

    The boundary element method (BEM) has been developed for a long period of time. Cruse and Wilson developed an isoparametric quadratic element. Rizzo, Cruse, Rizzo and Shippy, and Swedlow and cruse applied the method to various problems. It shows that the BEM can provide a very good analytical result in the linear problem and it can reduce time in preparation of numerical data. Watson and Newcomb pointed out that the pressure distribution on the contact surface of the brake drum and the lining plate do not vary significantly along the axis. The deflection can be reduced by an appropriate design of the web; therefore, two dimensional analysis with the BEM is used in this analysis. Based on the authors` knowledge, this is the first paper to analyze the drum brake by using the BEM. The assumptions are the brake drum to be a rigid body, perfect interface contact between the drum and the shoe, the constant friction coefficient of the friction material and the thermal effect to be neglected. The two dimensional equations are derived based on the Somigliana`s identity. Since there is no shape function and no need of the Jacobin for the coordinate transform, to integrate numerically is easier and to write a computer code is simpler for the constant value element than the second order element. The linear element is inappropriate to treat the comer problem. Using the linear elements or second order elements creates discontinuous phenomena along the irregular boundary. The common nodal point has different normal vector and boundary conditions. It is necessary to have an extra equation to provide a unique solution for the final linear equation. Using the constant value element can get rid of this problem. The effect of the friction on the pressure distribution at the friction interface is studied. The calculated results of the pressure distribution are compared with the available data. The mathematical model can be used as a design tool to predict the performance of drum brakes.

  10. Effect of lateral run-out on calliper drag in automotive disc brakes

    Microsoft Academic Search

    S. H. Masood; Lakhwinder Singh

    2007-01-01

    Efficiency of an automotive disc brake system is affected by several factors such as lateral run out (LRO), caliper housing stiffness, lining compressibility, seal\\/groove design, brake fluid, and pad material. A minor deviation in any of these factors may lead to problems like brake noise, vibration and off-brake caliper drag in the brake system. This paper presents an experimental study

  11. Analysis Of The Friction Brake Lining Including Heat Transfer System And Thermal Analysis

    Microsoft Academic Search

    Osman KOÇ

    2009-01-01

    Kinetic energy during braking of the moving mass is converted into heat energy through friction. This heat energy cause brake pads to be exposed to excessive temperature. The breaking efficiency reduces in time and in this case some problems (reducing in brake performance, defect run ning, rapid brake pad wear and noise) occur. Five different brake pad materials were subjected

  12. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...and pads. The thickness of the brake linings or pads shall meet the applicable...Steering axle brakes. The brake lining/pad thickness on the steering...drum brakes. The steering axle brake lining/pad thickness shall not be...

  13. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...and pads. The thickness of the brake linings or pads shall meet the applicable...Steering axle brakes. The brake lining/pad thickness on the steering...drum brakes. The steering axle brake lining/pad thickness shall not be...

  14. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...and pads. The thickness of the brake linings or pads shall meet the applicable...Steering axle brakes. The brake lining/pad thickness on the steering...drum brakes. The steering axle brake lining/pad thickness shall not be...

  15. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...and pads. The thickness of the brake linings or pads shall meet the applicable...Steering axle brakes. The brake lining/pad thickness on the steering...drum brakes. The steering axle brake lining/pad thickness shall not be...

  16. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...the front wheel and at least one brake operating on the rear wheel...with a parking brake system plus one of the following service brake...operates the brakes on all wheels by way of either: (1) A split service...common brake, if a failure in one system does not affect the...

  17. Design and Experimental Evaluation of a Magnetorheological Brake

    Microsoft Academic Search

    W. H. Li; H. Du

    2003-01-01

    A new magnetorheological (MR) brake prototype was designed, fabricated and tested. Firstly, the rheological properties of\\u000a MR fluids, in particular the dynamic yield stress, were experimentally investigated based on a Bingham plastic model. The\\u000a working principles of the MR brake were then analysed and discussed. The equations for transmitted torque were derived and\\u000a used to evaluate the disc-shaped MR brake.

  18. Tau as a Potential Control Variable for Visually Guided Braking

    ERIC Educational Resources Information Center

    Rock, Paul B.; Harris, Mike G.

    2006-01-01

    D. N. Lee (1976) described a braking strategy based on optical expansion in which the driver brakes so that the target's time-to-contact declines around a constant slope in the range -0.5 less than or equal to tau less than 0. The present results from a series of braking simulations confirm and extend earlier reports (E. H. Yilmaz & W. H. Warren,…

  19. Evaluation of Corrosion Failure in Tractor-Trailer Brake System

    Microsoft Academic Search

    2002-01-01

    As reported to ORNL, concomitant with the introduction of different deicing and anti-icing compounds, there was an increase in the brake failure rate of tractor-trailer trucks. A forensic evaluation of a failed brake system was performed. Optical and scanning electron microscopic evaluation showed corrosion to be mostly confined to the brake table\\/lining interface. The corrosion is non-uniform as is to

  20. Predicting the Braking Indices of Nulling and Intermittent Pulsars

    NASA Astrophysics Data System (ADS)

    Rusul, Abdujappar; Zheng, Xiao-Ping; Esamdin, Ali

    2014-04-01

    The braking index is an important factor when examining the pulsar braking mechanism. Measuring braking indices requires measuring the pulsar period and its first and second derivatives. Among them, the second derivative is easily contaminated by timing noise and an unresolved glitch effect. The absence of data bounding a given transition into (or out of) a radio-on phase is another disadvantage in measuring the second derivatives of intermittent pulsars, as was recently demonstrated by Young and coworkers. But, the observed period first derivatives, in the "on" and "off" states of the intermittent pulsars, give us a possible way to predict their braking indices even though they are hard to observe. In this paper, we will give a simple and useful method to study the braking indices of intermittent pulsars. As an application of our method, we will calculate the possible braking indices of three intermittent pulsars and one nulling pulsar, namely, PSR B1931 + 24, PSR J1841 - 0500, PSR J1832 + 0029 and PSR B0823 + 26, under three different magnetospheric conditions, which include polar cap size variation, charge density variation and the combination of the above two cases. We have found that all the braking indices we predicted are almost within the observed domain. It is concluded that, in a relatively short observation period, in which the variation of the braking index can be ignored, we can accurately predict the braking indices of intermittent pulsars, under a specific magnetosphere model, by using the observed "on" and "off" state period first derivatives.

  1. Antimony in brake pads-a carcinogenic component?

    Microsoft Academic Search

    Ole von Uexküll; Staffan Skerfving; Reed Doyle; Michael Braungart

    2005-01-01

    Antimony trisulfide (Sb2S3) is used as a lubricant in friction material. X-ray diffraction analysis revealed Sb in 3\\/3 disc brake pads (range 41,000–46,000 mg\\/kg) and in 2\\/2 disc brake dust samples (21,000 and 17,000 mg\\/kg) from trucks. Considerably lower concentrations were found in drum brake pads (3\\/5, 59–6400 mg\\/kg) and in drum brake dust (4\\/18, 78–2800 mg\\/kg). Other toxic metals

  2. Dynamic Properties of Disk Brake Based on Thermoelastic Instability Theory

    Microsoft Academic Search

    Xun Yang; Jixin Wang; Ying Liu

    2010-01-01

    Based on the thermo-elastic instability (TEI) theory and direct thermal-structural coupling method, the temperature increment and deformation of disk brake during an emergency braking process are analyzed. The simulation results indicate that the disc brake, before running-in, takes 3.35sec to decelerate from the initial speed of 100km\\/h to 0km\\/h, with 207°C maximum temperature increment, 8.29m\\/s2 average deceleration, 0.624 braking torque

  3. Evaluation of materials and design modifications for aircraft brakes

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Kennedy, F. E.; Peterson, M. B.

    1975-01-01

    A test program is described which was carried out to evaluate several proposed design modifications and several high-temperature friction materials for use in aircraft disk brakes. The evaluation program was carried out on a specially built test apparatus utilizing a disk brake and wheel half from a small het aircraft. The apparatus enabled control of brake pressure, velocity, and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The results of the design evaluation program showed that some improvement in brake performance can be realized by making design changes in the components of the brake containing friction material. The materials evaluation showed that two friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary since both materials show a significant negative slope of the friction-velocity curve at low velocities.

  4. Aerodynamic braking of high speed ground transportation vehicles.

    NASA Technical Reports Server (NTRS)

    Marte, J. E.; Marko, W. J.

    1973-01-01

    The drag effectiveness of aerodynamic brakes arranged in series on a train-like vehicle was investigated. Fixed- and moving-model testing techniques were used in order to determine the importance of proper vehicle-ground interference simulation. Fixed-model tests were carried out on a sting-mounted model: alone; with a fixed ground plane; and in proximity to an image model. Moving-model tests were conducted in a vertical slide-wire facility with and without a ground plane. Results from investigations of one brake configuration are presented which show the effect of the number of brakes in the set and of spacing between brakes.

  5. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Handling of defective equipment with ECP brake systems. 232.609 Section 232.609 Transportation...DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER...Electronically Controlled Pneumatic (ECP) Braking Systems § 232.609 Handling of...

  6. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Handling of defective equipment with ECP brake systems. 232.609 Section 232.609 Transportation...DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER...Electronically Controlled Pneumatic (ECP) Braking Systems § 232.609 Handling of...

  7. Measurement and control of brake pedal feel quality in automobile manufacturing

    E-print Network

    Cerilles, Jeffrey T. (Jeffrey Thomas)

    2005-01-01

    Customer perception of brake pedal feel quality, as related to the perception of the brake pedal feeling soft or mushy, depends on both the customer's subjective judgment of quality and the actual build quality of the brake ...

  8. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...equipment 30-75 (6) Reducing valve for independent or straight air brake 30-50 (7) Self-lapping portion for electro-pneumatic brake (minimum full application pressure) 50 (8) Self-lapping portion for independent air brake...

  9. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Process to introduce new brake system technology. 232.503 Section 232.503... Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the...

  10. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Process to introduce new brake system technology. 232.503 Section 232.503... Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the...

  11. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Process to introduce new brake system technology. 232.503 Section 232.503... Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the...

  12. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Process to introduce new brake system technology. 232.503 Section 232.503... Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the...

  13. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Process to introduce new brake system technology. 232.503 Section 232.503... Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the...

  14. UNIVERSITY OF CALIFORNIA, SAN DIEGO Brake Rotor Design and Comparison using Finite Element Analysis

    E-print Network

    Wang, Deli

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Chapter 2 Disk Brake Overview . . . . . . . . . . . . . . . . . . . . . . . 5 Chapter 3 Two WheelUNIVERSITY OF CALIFORNIA, SAN DIEGO Brake Rotor Design and Comparison using Finite Element Analysis Vehicle Dynamics . . . . . . . . . . . . . . . . . . 8 3.1 Stability Under Braking

  15. 77 FR 46633 - Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-06

    ...Necessary for Safe Operation: Brakes; Adjustment Limits AGENCY...as follows: Sec. 393.47 Brake actuators, slack adjusters, linings/pads, and drums/rotors...bolt-type, and rotochamber brake actuator readjustment...

  16. 76 FR 54721 - Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ...Necessary for Safe Operation: Brakes; Adjustment Limits AGENCY...as follows: Sec. 393.47 Brake actuators, slack adjusters, linings/pads, and drums/rotors...bolt-type, and rotochamber brake actuator readjustment...

  17. 49 CFR 571.122a - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...requirements of S5 without detachment of brake linings from the shoes or pad, detachment...condition, for compliance with the brake lining inspection requirements. Disassemble...fracture of any component. (b) Brake linings for detachment from the shoe...

  18. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Handling of defective equipment with ECP brake systems. 232.609 Section 232.609 Transportation...DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER...Electronically Controlled Pneumatic (ECP) Braking Systems § 232.609 Handling of...

  19. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Handling of defective equipment with ECP brake systems. 232.609 Section 232.609 Transportation...DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER...Electronically Controlled Pneumatic (ECP) Braking Systems § 232.609 Handling of...

  20. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Handling of defective equipment with ECP brake systems. 232.609 Section 232.609 Transportation...DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER...Electronically Controlled Pneumatic (ECP) Braking Systems § 232.609 Handling of...

  1. Speciation of Sb in airborne particulate matter, vehicle brake linings, and brake pad wear residues

    NASA Astrophysics Data System (ADS)

    Varrica, D.; Bardelli, F.; Dongarrà, G.; Tamburo, E.

    2013-01-01

    Insights into the speciation of Sb in samples of brake linings, brake pad wear residues, road dust, and atmospheric particulate matter PM10 and PM2.5 were obtained combining several well established and advanced characterization techniques, such as scanning electron microscopy - energy dispersive spectrometry (SEM-EDS), inductively coupled plasma mass spectrometry (ICP-MS) and synchrotron radiation X-ray absorption spectroscopy (SR-XAS). The advantage of SR-XAS is that samples do not undergo any chemical treatment prior to measurements, thus excluding possible alterations. These analyses revealed that the samples of wheel rims dust, road dust, and atmospheric particulate matter are composed by an admixture of Sb(III) and Sb(V) in different relative abundances. Brake linings turned out to be composed by Sb(III) oxide (Sb2O3) and stibnite (Sb2S3). Stibnite was also detected in some of the particulate matter samples. The obtained data suggest that Sb2S3 during the brake abrasion process is easily decomposed forming more stable compounds such as antimony mixed oxidic forms. Sb redox speciation, in particular and well studied circumstances, may enhance the potential and selectivity of this element as a tracer of motor vehicle emissions in apportioning studies.

  2. Pulsar Braking Index and Mass Accretion

    E-print Network

    P. D. Morley

    1993-11-15

    I show that the braking index, $N$, a fundamental pulsar experimental quantity, naturally differs from the canonical value of 3 by terms which involve mass accretion. Using the measured values of $N$ for PSR1509-58 and PSR0531+21, I determine that for constant density neutron stars their present mass accretion rates are $(3.10\\pm.51)\\times10^{-5}$ M year$^{-1}$ and $(9.946\\pm.089)\\times10^{-5}$ M year$^{-1}$ respectively, where M is the mass of each pulsar. Finally, I demonstrate that mass accretion removes the outstanding problem of the origin of the big glitches of the Vela Pulsar.

  3. Do Si stars undergo any magnetic braking?

    E-print Network

    P. North

    1998-02-23

    The old question of rotational braking of Ap Si stars is revisited on the empirical side, taking advantage of the recent Hipparcos results. Field stars with various evolutionary states are considered, and it is shown that the loose correlation between their rotational period and their surface gravity is entirely compatible with conservation of angular momentum. No evidence is found for any loss of angular momentum on the Main Sequence, which confirms earlier results based on less reliable estimates of surface gravity. The importance of reliable, fundamental Teff determinations of Bp and Ap stars is emphasized.

  4. Dynamic Simulation on the Belt Conveyor on Emergency Braking

    Microsoft Academic Search

    Xi Pingyuan; Song Yandong

    2009-01-01

    In order to control reasonably the acceleration and dynamic tension in emergency braking process so as to assure smooth braking and the security of conveyor system, accurate design techniques should be adopted, thus the dynamic simulation methods are required to research precisely the baking performances of belt conveyor. By comparing dynamic performances of some kinds of models, the Vogit model

  5. Thermally induced roughness of tread-braked railway wheels

    Microsoft Academic Search

    T Vernersson

    1999-01-01

    Roughness (corrugation, waviness) on the tread of a rolling railway wheel leads to vibrations in wheels, bogies and superstructure and also in rails, sleepers and roadbed. These vibrating components radiate noise to the surroundings. A lowering of the noise levels from tread-braked freight cars is of utmost importance for the future of rail traffic. The thermomechanical interaction between brake block

  6. STABILITY ANALYSIS OF DISC BRAKE SQUEAL CONSIDERING TEMPERATURE EFFECT

    Microsoft Academic Search

    Abd Rahim; Abu Bakar; Mohd Kameil Abdul Hamid; Afandi Dzakaria; Badri Abdul Ghani; Maziah Mohamad

    2006-01-01

    Passenger cars have become one of the main transportations for people travelling from one place to another. Indeed, vehicle quietness and passenger comfort issues are a major concern. One of vehicle components that occasionally generate unwanted vibration and unpleasant noise is the brake system. Brake squeal noise is the most troublesome and irritant one to both car passenger and the

  7. Judder vibration in disc brakes excited by thermoelastic instability

    Microsoft Academic Search

    Oscar Altuzarra; Enrique Amezua; Rafael Avilés; Alfonso Hernández

    2002-01-01

    Friction vibrations and noises which are common in brakes, have attracted a great deal of attention lately. This paper analyses low frequency vibrations in disc brakes excited at high car speed. This vibration, called judder, has a frequency in the range 10 to 300 Hz and usually comes in association with hum noises. The dynamic phenomenon shows two principal components,

  8. Thermally induced roughness of tread braked railway wheels

    Microsoft Academic Search

    T. Vernersson

    1999-01-01

    Roughness (corrugation, waviness) on the tread of a rolling railway wheel leads to vibrations in wheels, bogies and superstructure and also in rails, sleepers and roadbed. These vibrating components radiate noise to the surroundings. A lowering of the noise levels from tread braked freight cars is of utmost importance for the future of rail traffic. The thermomechanical interaction between brake

  9. Suppression of Brake Squeal Noise Applying Viscoelastic Damping Insulator

    Microsoft Academic Search

    Jun Hou; Xuexun Guo; Guohui Sun; Jie Zhang

    2009-01-01

    Squeal noise in vehicle disc brakes is perceived by consumers as both annoying and warranty cost. Among the methods that have been used to control squeal noise, increasing the system damping has been shown to be very effective. The most commonly used method to increase system damping consists of attaching multi-layer laminates on the back of the brake pads. As

  10. Braking system for use with an arbor of a microscope

    DOEpatents

    Norgren, Duane U. (Orinda, CA)

    1984-01-01

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling device causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  11. On the nature of tribological contact in automotive brakes

    Microsoft Academic Search

    Mikael Eriksson; Filip Bergman; Staffan Jacobson

    2002-01-01

    The tribological contact in automotive brakes involves dry sliding contact at high speeds and high contact forces. The commonly used organic binder-type brake pad friction materials are extremely inhomogeneous and exhibit very low bulk strengths. Despite the low strength, the specific contact surfaces that form during the use render the pads very good friction and wear characteristics. This paper gives

  12. TRANSIENT THERMOELASTIC ANALYSIS OF DISK BRAKES IN FRICTIONAL CONTACT

    Microsoft Academic Search

    Ji-Hoon Choi; In Lee

    2003-01-01

    The transient analysis of the thermoelastic contact problem of automotive disk brakes with frictional heat generation is performed using the finite element method. To analyze the thermoelastic phenomenon occurring in disk brakes, the coupled heat conduction and elastic equations are solved with contact problems. In the present work, the fully implicit transient scheme for the thermoelastic analysis is used to

  13. Different Control Strategies for the Active Suppression of Brake Squeal

    Microsoft Academic Search

    Peter Hagedorn; Daniel Hochlenert

    The present paper is devoted to the modeling and the active suppression of brake squeal. Two different control strategies are described and tested on the basis of a four degree of freedom disk brake model. The first control law is based on optimal control and includes a filter to estimate the system’s state. The second law maximizes the energy dissipated

  14. Determination of heat and thermal distortion in braking systems

    Microsoft Academic Search

    A. Yevtushenko; E. Ivanyk

    1995-01-01

    A model is proposed which enables the surface friction temperature of disk brakes and the value of normal temperature displacements in braking to be found. The change of the heat flow generated by friction forces with time and with respect to coordinate is taking into account.The model predicts fairly well the literature experimental data. It is shown that the change

  15. EVEN WEAR PROVIDING OF DISC BRAKE FRICTION LINING

    Microsoft Academic Search

    Aldis Paeglis

    2008-01-01

    The article analyzes practical research of even wear of disc brake friction linings. The research was carried out to test the theoretical research regarding providing of even wear changing the pressing force application coordinates. Two kinds of the friction body (friction lining on steel base) construction were tested in experimental work. The friction body and brake lever are linked with

  16. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...apply and remain applied on each car in the train until a release of...brakes has been initiated on each car in response to train line electric, pneumatic, or other signals...verification that each side of each car's brake system responds...

  17. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...apply and remain applied on each car in the train until a release of...brakes has been initiated on each car in response to train line electric, pneumatic, or other signals...verification that each side of each car's brake system responds...

  18. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...apply and remain applied on each car in the train until a release of...brakes has been initiated on each car in response to train line electric, pneumatic, or other signals...verification that each side of each car's brake system responds...

  19. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...apply and remain applied on each car in the train until a release of...brakes has been initiated on each car in response to train line electric, pneumatic, or other signals...verification that each side of each car's brake system responds...

  20. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...apply and remain applied on each car in the train until a release of...brakes has been initiated on each car in response to train line electric, pneumatic, or other signals...verification that each side of each car's brake system responds...

  1. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...one track to another within a terminal complex while not in passenger...train's departure from the terminal complex with passengers...in passenger service from a terminal or yard where a Class II brake...from the engineer's brake valve or controller of the...

  2. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...one track to another within a terminal complex while not in passenger...train's departure from the terminal complex with passengers...in passenger service from a terminal or yard where a Class II brake...from the engineer's brake valve or controller of the...

  3. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...procedure. Insert a low range (0 to 25 amperes for most 2- and 4-brake systems and 0 to 40 amperes for a 6-brake system) d.c. ammeter into...full off” and observe return to zero amperes. Divide the maximum ammeter reading...

  4. Optimal design of a hybrid controller for antilock braking systems

    Microsoft Academic Search

    A. Mirzaei; M. Moallem; B. Mirzaeian

    2005-01-01

    Antilock braking systems (ABS) have been developed to reduce tendency of wheel lock and to improve vehicle control during sudden braking especially on slippery road surfaces. The objective of such control is to increase wheel tractive force in the desired direction while maintaining adequate vehicle stability and steerability and also reducing the vehicle stopping distance. In this paper, an optimized

  5. Simultaneous hydraulic fracturing

    SciTech Connect

    Uhri, D.C.

    1989-05-16

    A process is described for simultaneous hydraulic fracturing of a hydrocarbonaceous fluid-bearing formation comprising: (a) determining a hydraulic pressure necessary to fracture the formation from at least two wells which penetrate the formation; (b) injecting a hydraulic fracturing fluid into both wells under the determined hydraulic pressure; and (c) applying simultaneously the determined hydraulic pressure to the hydraulic fluid contained in both wells which pressure is sufficient to fracture the formation thereby causing a fracture to be propagated from each well in a curved manner sufficient to intersect at least one natural hydrocarbonaceous fluid-bearing fracture.

  6. Eigenvalue optimization against brake squeal: Symmetry, mathematical background and experiments

    NASA Astrophysics Data System (ADS)

    Spelsberg-Korspeter, Gottfried

    2012-09-01

    Brake squeal is still a challenge for design engineers and scientists. Due to cost reasons for the avoidance of brake noise only passive measures are meaningful for a broad industrial range. Many countermeasures against squeal are based on the introduction of damping, for example by using shims. In the literature on the modeling of brake squeal, the structural properties of the brake disc are most often not considered. It has however been shown analytically and experimentally that the stiffness properties of the disc are important and that splitting of double modes of the disc has a stabilizing effect. This knowledge can be used for structural optimization of brake rotors. The goal of this paper is to exploit the potential and to discuss some mathematical difficulties. Furthermore, experimental evidence for the relation of rotor asymmetry and squeal is given.

  7. Asbestos exposures during reprocessing of automobile brakes and clutches.

    PubMed

    Sakai, Kiyoshi; Hisanaga, Naomi; Shibata, Eiji; Ono, Yuichiro; Takeuchi, Yasuhiro

    2006-01-01

    Asbestos exposures of workers in three small factories reprocessing automobile brakes and clutches in Japan were investigated. Airborne asbestos was collected on a membrane filter using an air sampler. From 1982 to 1989, asbestos counting was performed on 295 samples (198 personal and 97 stationary), using phase contrast microscopy. Only chrysotile asbestos was detected. Workers who reprocessed automobile brakes and clutches were exposed to asbestos concentrations of 0.025-76.4 fibers/cm3. Geometric mean asbestos concentrations during attaching linings to brake shoes and attaching facings to clutch disks were 0.859 fibers/cm3 and 0.780 fibers/cm3, respectively. Concentrations during stripping worn brake linings and clutch facings were 0.484 fibers/cm3 and 0.382 fibers/cm3, respectively. Machine grinding and leveling of new brake-lining surfaces represent potential sources of heavy asbestos exposures, unless enclosures and local ventilation are efficient. PMID:16722188

  8. PROTOBINARY EVOLUTION DRIVEN BY MAGNETIC BRAKING

    NASA Astrophysics Data System (ADS)

    Zhao, Bo; Li, Z.; Kratter, K. M.

    2014-01-01

    The majority of stars are in multiple systems, especially binaries. Such objects form in dense cores of molecular clouds that are observed to be strongly magnetized. Most previous studies of binary formation have either ignored magnetic fields or focused on the initial core fragmentation into binary seeds. Here I focus on the effects of the magnetic field on the orbital evolution of the protobinary during the main accretion phase, after a pair of stellar seeds have formed. By simulating a 'seed' binary system with the sink particle treatment, we show that magnetic field plays a crucial role in removing the gas angular momentum and shrinking the binary separation. Through magnetic braking, strong magnetic field is very effective in suppressing the formation of circumstellar disks and circumbinary disk along with its spiral arm structures. The magnetic field can also be responsible for the population of the low mass-ratio binaries in the observed distribution. The magnetically-braked material will have equal chance of being accreted onto either binary seed, instead of the preferential accretion onto the secondary when magnetic field is absent. Furthermore, large field mis-alignment helps to produce rotationally-supported circumbinary disks even for relatively strong magnetic fields, by weakening the magnetically-dominated structure close to the binary. Hence to explain the observed properties of binaries, the magnetic effects deserve more careful considerations in the larger context of binary formation in future studies.

  9. Protobinary Evolution Driven By Magnetic Braking

    NASA Astrophysics Data System (ADS)

    Zhao, Bo; Li, Zhi-Yun

    2013-07-01

    The majority of stars are in multiple systems, especially binaries. Such objects form in dense cores of molecular clouds that are observed to be strongly magnetized. Most previous studies of binary formation have either ignored magnetic fields or focused on the initial core fragmentation into binary seeds. Here I focus on the effects of the magnetic field on the orbital evolution of the protobinary during the main accretion phase, after a pair of stellar seeds have formed. By simulating a 'seed' binary system with the sink particle treatment, we show that magnetic field plays a crucial role in removing the gas angular momentum and shrinking the binary separation. Through magnetic braking, strong magnetic field is very effective in suppressing the formation of circumstellar disks and circumbinary disk along with its spiral arm structures. The magnetic field can also be responsible for the population of the low mass-ratio binaries in the observed distribution. The magnetically-braked material will have equal chance of being accreted onto either binary seed, instead of the preferential accretion onto the secondary when magnetic field is absent. Furthermore, large field mis-alignment helps to produce rotationally-supported circumbinary disks even for relatively strong magnetic fields, by weakening the magnetically-dominated structure close to the binary. Hence to explain the observed properties of binaries, the magnetic effects deserve more careful considerations in the larger context of binary formation in future studies.

  10. Suppression of brake squeal noise applying finite element brake and pad model enhanced by spectral-based assurance criteria

    Microsoft Academic Search

    Yi Dai; Teik C. Lim

    2008-01-01

    An enhanced dynamic finite element (FE) model with friction coupling is applied to analyze the design of disc brake pad structure for squeal noise reduction. The FE model is built-up from the individual brake component representations. Its interfacial structural connections and boundary conditions are determined by correlating to a set of measured frequency response functions using a spectral-based assurance criterion.

  11. Engineering report. Part 3: NASA lightweight wheel and brake sub-system. Lightweight brake development. [for application to space shuttle

    NASA Technical Reports Server (NTRS)

    Bok, L. D.

    1973-01-01

    The development of light weight wheel and brake systems designed to meet the space shuttle type requirements was investigated. The study includes the use of carbon graphite composite and beryllium as heat sink materials and the compatibility of these heat sink materials with the other structural components of the wheel and brake.

  12. Control of Hydraulic Robots

    Microsoft Academic Search

    Wen-Hong Zhu

    \\u000a Hydraulic actuation has been widely used in industrial applications, attributed to its characteristic of having a large power\\u000a to mass ratio. Although this feature dramatically increases the operational capability of a hydraulically driven robot, the\\u000a inherent nonlinear dynamics associated with hydraulic cylinders substantially challenge the controller design. It is obvious\\u000a that the specific difficulties existed in the control of hydraulically

  13. EEG potentials predict upcoming emergency brakings during simulated driving

    NASA Astrophysics Data System (ADS)

    Haufe, Stefan; Treder, Matthias S.; Gugler, Manfred F.; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin

    2011-10-01

    Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h-1 driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed.

  14. Airborne asbestos exposure during light aircraft brake replacement.

    PubMed

    Blake, Charles L; Johnson, Giffe T; Harbison, Raymond D

    2009-08-01

    Asbestos containing materials are a component of many vehicle brake systems, including those found in some light aircraft. To characterize the asbestos exposure that results from the installation and maintenance of these components, an aircraft fitted with asbestos containing brake pads had brake changes performed while both area and personal air samples were taken. The brake changing process took place in a closed, unventilated aircraft hanger and all operations were performed according to the manufacturer's recommended procedure. Personal air samples did not detect any measurable amount of asbestos fibers during the brake changing or subsequent cleanup procedures. Analysis of personal samples (n=9) using phase contrast microscopy indicated airborne fiber concentrations at or below 0.003f/ml as 8-h time weighted averages (TWAs) and less than 0.069f/ml averaged over 28-30min sampling periods. Airborne chrysotile fibers were detected by two area air samples with fiber concentrations remaining at or below 0.0013f/ml over an 8-h TWA. These results indicate that normal brake changing work practices on aircraft with asbestos containing brake pads does not produce a harmful level of asbestos exposure for aircraft mechanics. PMID:19409949

  15. Braking formula for electrons of relativistic speed

    NASA Astrophysics Data System (ADS)

    Bethe, H.; Bartschat, Klaus

    2014-12-01

    The current translation is by Klaus Bartschat, Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311, USA. An attempt has been made to preserve Bethe's writing style as much as possible, including his use of "Volt" instead of "electron volt". Even though the term "stopping power" is quite common in present scientific English, we generally use "braking [capability]" rather than "stopping [power]", in order to emphasize the act [and ability] of slowing down the particle rather than the ultimate result of bringing it to a complete halt. Also, a few typographical errors were kept in the English translation to ensure the translation replicates the original paper. Please, see Section 3 of the annotation to Bethe's article [Fontes, C.J., Bostock, C.J. and Bartschat, K. 2014. Eur. Phys. J. H, 39: 517-536] for a list. The references were converted to EPJH style, and the footnotes are numbered consecutively.

  16. Tribomaterial factors in space mechanism brake performance

    NASA Technical Reports Server (NTRS)

    Hawthorne, H. M.

    1990-01-01

    The asbestos/phenolic pads of Shuttle Remote Manipulator System (SRMS) brakes are unsuitable for use in long life space mechanisms because their friction decreases on extended sliding in high vacuum. Dehydration of the material and accumulation of wear debris in the conforming interface of this tribosystem induces the permanent friction changes. Other polymer and some ceramic based materials exhibit similar frictional torque behavior due to the development of minimal contact patches by the interfacial debris. In contrast, high friction occurs when other ceramics form many small contacts throughout fine debris beds. Generating this latter interfacial structure during run-in ensures that the in-vacuo friction remains stable thereafter. Such materials with low wear rates are potential candidates for friction elements in SSRMS and similar mechanisms.

  17. Process Optimization for the Improvement of Brake Noise: A Case Study

    Microsoft Academic Search

    Hee Seong Sohn; Tae Won Park

    2006-01-01

    This study improves brake noise by optimizing the manufacturing processes of brake discs and pads. Taguchi techniques and designed experiments were used for the optimization. The signal-to-noise ratios of the key output responses, such as runouts of brake discs and compressibility of brake pads, were maximized to optimize the mean and variation. Analysis of the variance was performed to obtain

  18. Numerical study on the vibration characteristics of automobile brake disk and pad

    Microsoft Academic Search

    Xianjie Meng; Guangqiang Wu; Lin He

    2009-01-01

    Based on the review of researches on the vibration and noise related to automobile brake, a four degrees of freedom nonlinear dynamics model of brake disk and pads is established, the stability of vibration system at the equilibrium points is analyzed. Finally the numerical method is taken to study the impacts of brake pressure, shape parameter and the brake disk's

  19. Study of hysteresis of disk brake mechanism for heavy-duty vehicles

    Microsoft Academic Search

    D. V. Tretyak; V. G. Ivanov

    2007-01-01

    The paper describes the new method of the calculation of the disk brake and the model of the pneumatic disk brake mechanism\\u000a developed with the simulation package ADAMS. The modeling of the mechanical system (brake) serves to predict the behavior\\u000a of the braking system member consisting of contacting movable parts.

  20. Design considerations for an automotive magnetorheological brake Kerem Karakoc, Edward J. Park *, Afzal Suleman

    E-print Network

    Park, Edward

    fluid, transfer lines and brake actuators (e.g. disk or drum brakes). When the driver pressesDesign considerations for an automotive magnetorheological brake Kerem Karakoc, Edward J. Park February 2008 Available online xxxx Keywords: Mechatronic design Magnetorheological fluid Automotive brake

  1. Tribological properties prediction of brake lining for automobiles based on BP neural network

    Microsoft Academic Search

    Yan Yin; Jiusheng Bao; Lei Yang

    2010-01-01

    By many tribological experiments of brake lining for automobiles, the original experimental data were firstly obtained, which contains the influencing rules of braking conditions on tribological performance. Based on the artificial neural network technology and the experimental data specimens, the BP neural network model was established to predict the tribological properties. Three parameters of braking conditions (braking pressure, sliding velocity

  2. Optimization of manufacturing parameters for a brake lining using Taguchi method

    Microsoft Academic Search

    Seong Jin Kim; Kwang Seok Kim; Ho Jang

    2003-01-01

    The Taguchi method, a robust experimental design, is used to optimize manufacturing parameters of a brake lining. In this work, a brake lining containing 15 ingredients is employed to find the best manufacturing parameters for wear resistance and friction stability of a brake lining. According to the parameter design, brake linings produced from 16 different manufacturing conditions are examined for

  3. Asbestos exposure during routine brake lining manufacture.

    PubMed

    Kakooei, Hossein; Sameti, Mahmod; Kakooei, Ali Akbar

    2007-12-01

    Occupational exposure to asbestos fiber and total dust of workers of a major brake lining manufacture plant in a developing country were examined and compared with those in developed countries. Time weighted average of total dust and asbestos fiber concentration in the potential sources of exposure were monitored. All personal air sampling were collected on membrane filters and analyzed by phase contrast optical microscopy (PCM) for comparison with the occupational safety and health administration (OSHA) permissible exposure limit (PEL) of 0.1 f/cc, 8-h time--weighted average. This study demonstrates that routine mixing, polishing and beveling process in the brake lining production can result in elevated levels of airborne asbestos. Greater releases of airborne asbestos were observed during mixing process and mixer machine. The results also showed that the employees working in the process had the exposure to total dust concentrations ranging from 2.08 to 16.32 mg/m(3) that is higher than OSHA, recommendation. According to OSHA definition of fibers, it has been indicated that from 3,000 counted particles, 90% of particles are in the form of non-fiber and reaming have fiber-shaped. The particle analyze gives the geometric mean diameter as 6.02 mum, and also indicated that the arithmetic mean of the number distribution for the particle population was 8.4 mum. Approximately 60.4% of the counted fibers were lower than 10 mum in length, from which only 8% consists of fibers (>5 mum in length). In conclusion, the analysis showed a presence in the air of only chrysotile asbestos and an absence of other types of asbestos. During an 8-h shift, the average asbestos fiber exposure (0.78 f/cc) were 7.8 time in excess of OSHA PEL. Additional studies in occupational exposure to asbestos are needed. PMID:18212474

  4. Wear formulation for aircraft brake material sliding against steel

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Peterson, M. B.

    1977-01-01

    Predictions of wear on contemporary copper-based brake material sliding against 17-22 AS grade steel, wear testing equipment, formulation of wear, and test results are discussed. An initial investigation of worn surfaces of the brake material and a mating steel rotor was carried out. A wear model proposed suggests initiation of cracks at a hard particle inclusion site in the surface layer of the brake material; crack propagation allows particles to be removed by intersection of cracks. Mutual relations between sliding variables, load, time, hardness, and surface temperature are studied. Empirical formulas are exhibited.

  5. Brake lock mechanism for the two axis pointing system

    NASA Technical Reports Server (NTRS)

    Posey, Alan; Clark, Mike; Mignosa, Larry

    1991-01-01

    Six months prior to shipment of the Broadband X-ray Telescope to the Kennedy Space Center for flight aboard the Space Shuttle Columbia, a major system failure occurred. During modal survey testing of the telescope's gimbal pointing system, the roll axis brake unexpectedly released. Low level vibration and static preloads present during the modal survey were within the expected flight environment. Brake release during shuttle liftoff or ascent was an unacceptable risk to mission success; thus, a Brake Lock Mechanism (BLM) was developed.

  6. A 6-DOF vibration isolation system for hydraulic hybrid vehicles

    NASA Astrophysics Data System (ADS)

    Nguyen, The; Elahinia, Mohammad; Olson, Walter W.; Fontaine, Paul

    2006-03-01

    This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHVs). The HHVs are designed to combine gasoline/diesel engine and hydraulic power in order to improve the fuel efficiency and reduce the pollution. Electric hybrid technology is being applied to passenger cars with small and medium engines to improve the fuel economy. However, for heavy duty vehicles such as large SUVs, trucks, and buses, which require more power, the hydraulic hybridization is a more efficient choice. In function, the hydraulic hybrid subsystem improves the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. Since the operation of the main component of HHVs involves with rotating parts and moving fluid, noise and vibration are an issue that affects both passengers (ride comfort) as well as surrounding people (drive-by noise). This study looks into the possibility of reducing the transmitted noise and vibration from the hydraulic subsystem to the vehicle's chassis by using magnetorheological (MR) fluid mounts. To this end, the hydraulic subsystem is modeled as a six degree of freedom (6-DOF) rigid body. A 6-DOF isolation system, consisting of five mounts connected to the pump/motor at five different locations, is modeled and simulated. The mounts are designed by combining regular elastomer components with MR fluids. In the simulation, the real loading and working conditions of the hydraulic subsystem are considered and the effects of both shock and vibration are analyzed. The transmissibility of the isolation system is monitored in a wide range of frequencies. The geometry of the isolation system is considered in order to sustain the weight of the hydraulic system without affecting the design of the chassis and the effectiveness of the vibration isolating ability. The simulation results shows reduction in the transmitted vibration force for different working cycles of the regenerative system.

  7. View of main hoist wire rope drum and brakes, open ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of main hoist wire rope drum and brakes, open contact boards are in view at the far right wall - Puget Sound Naval Shipyard, Portal Gantry Crane No. 42, Pier 5, Farragut Avenue, Bremerton, Kitsap County, WA

  8. Implementation Of Fuzzy Automated Brake Controller Using TSK Algorithm

    NASA Astrophysics Data System (ADS)

    Mittal, Ruchi; Kaur, Magandeep

    2010-11-01

    In this paper an application of Fuzzy Logic for Automatic Braking system is proposed. Anti-blocking system (ABS) brake controllers pose unique challenges to the designer: a) For optimal performance, the controller must operate at an unstable equilibrium point, b) Depending on road conditions, the maximum braking torque may vary over a wide range, c) The tire slippage measurement signal, crucial for controller performance, is both highly uncertain and noisy. A digital controller design was chosen which combines a fuzzy logic element and a decision logic network. The controller identifies the current road condition and generates a command braking pressure signal Depending upon the speed and distance of train. This paper describes design criteria, and the decision and rule structure of the control system. The simulation results present the system's performance depending upon the varying speed and distance of the train.

  9. Evaluation strategy of regenerative braking energy for supercapacitor vehicle.

    PubMed

    Zou, Zhongyue; Cao, Junyi; Cao, Binggang; Chen, Wen

    2015-03-01

    In order to improve the efficiency of energy conversion and increase the driving range of electric vehicles, the regenerative energy captured during braking process is stored in the energy storage devices and then will be re-used. Due to the high power density of supercapacitors, they are employed to withstand high current in the short time and essentially capture more regenerative energy. The measuring methods for regenerative energy should be investigated to estimate the energy conversion efficiency and performance of electric vehicles. Based on the analysis of the regenerative braking energy system of a supercapacitor vehicle, an evaluation system for energy recovery in the braking process is established using USB portable data-acquisition devices. Experiments under various braking conditions are carried out. The results verify the higher efficiency of energy regeneration system using supercapacitors and the effectiveness of the proposed measurement method. It is also demonstrated that the maximum regenerative energy conversion efficiency can reach to 88%. PMID:25311161

  10. Metals associated with stormwater-relevant brake and tire samples

    PubMed Central

    McKenzie, Erica R.; Money, Jon E.; Green, Peter G.; Young, Thomas M.

    2009-01-01

    Properly apportioning the loads of metals in highway stormwater runoff to the appropriate sources requires accurate data on source composition, especially regarding constituents that help to distinguish among sources. Representative tire and brake samples were collected from privately owned vehicles and aqueous extracts were analyzed for twenty-eight elements. Correlation principal components analysis (PCA) revealed that tires were most influenced by Zn, Pb, and Cu, while brakes were best characterized by Na and Fe followed by Ba, Cu, Mg, Mn, and K; the latter three may be due to roadside soil contributions. Notably elevated Cd contributions were found in several brake samples. A targeted Cd-plated brake rotor was sampled, producing results consistent with the elevated levels found in the larger sample population. This enriched source of Cd is of particular concern due to high toxicity of Cd in aquatic ecosystems. PMID:19709720

  11. Why Brake-By-Wire (BBW) ? Advantages of BBW

    E-print Network

    Yao, Bin

    Conventional Brake System http://www.conti-online.com #12;BBW Survey [ SKF (Motor + PGT +Ball Screw)] [ DELPHI (Motor + PGT +Ball Screw)] [Continental Teves (Motor + PGT + Roller Screw)] [Continental Teves installed

  12. 11. STOVE NUT USED IN THE MILL WHEN THE BRAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. STOVE NUT USED IN THE MILL WHEN THE BRAKE WHEEL DROVE ONE PAIR OF MILLSTONES DIRECTLY; FOUND ON THE FIRST FLOOR OF THE WINDMILL AT WATERMILL - Windmill at Water Mill, Montauk Highway & Halsey Lane, Water Mill, Suffolk County, NY

  13. Regenerative braking on bicycles to power LED safety flashers

    E-print Network

    Collier, Ian M

    2005-01-01

    This work develops a method for capturing some of the kinetic energy ordinarily lost during braking on bicycles to power LED safety flashers. The system is designed to eliminate: (a) battery changing in popular LED flashers, ...

  14. 54. West emergency brake in the south machinery room (interior ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. West emergency brake in the south machinery room (interior of both machinery rooms is identical). Facing west. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  15. 4. FLOOR 3; GENERAL VIEW LOOKING NORTH SHOWS WALLOWER, BRAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. FLOOR 3; GENERAL VIEW LOOKING NORTH SHOWS WALLOWER, BRAKE LEVER, CASE FOR SCREENER, TOP OF GRAIN ELEVATOR, LAYSHAFT WHICH POWERS THE SCREENER AND ELEVATOR - Hayground Windmill, Windmill Lane, East Hampton, Suffolk County, NY

  16. Driver Behavioral Changes through Interactions with an Automatic Brake System for Collision Avoidance

    NASA Astrophysics Data System (ADS)

    Itoh, Makoto; Fujiwara, Yusuke; Inagaki, Toshiyuki

    This paper discusses driver's behavioral changes as a result of driver's use of an automatic brake system for preventing a rear-end collision from occurring. Three types of automatic brake systems are investigated in this study. Type 1 brake system applies a strong automatic brake when a collision is very imminent. Type 2 brake system initiates brake operation softly when a rear-end crash may be anticipated. Types 1 and 2 are for avoidance of a collision. Type 3 brake system, on the other hand, applies a strong automatic brake to reduce the damage when a collision can not be avoided. An experiment was conducted with a driving simulator in order to analyze the driver's possible behavioral changes. The results showed that the time headway (THW) during car following phase was reduced by use of an automatic brake system of any type. The inverse of time to collision (TTC), which is an index of the driver's brake timing, increased by use of Type 1 brake system when the deceleration rate of the lead vehicle was relatively low. However, the brake timing did not change when the drivers used Type 2 or 3 brake system. As a whole, dangerous behavioral changes, such as overreliance on a brake system, were not observed for either type of brake system.

  17. Numerical Analysis of Car Disc Brake Squeal Considering Thermal Effects

    Microsoft Academic Search

    Lijie Li; Huajiang Ouyang; A. R. AbuBakar

    Friction-induced vibration and noise emanating from car disc brakes is a source of considerable discomfort and leads to customer\\u000a dissatisfaction. The high frequency noise above 1 kHz, known as squeal, is most annoying and is very difficult to eliminate.\\u000a It was recently estimated that noise, harshness and vibration (together known as the NVH problem), including disc brake squeal,\\u000a generated warranty

  18. Modeling of air brakes for onboard diagnostics of heavy trucks

    E-print Network

    Kankanala, Penchala N

    2000-01-01

    OF SCIENCE August 2000 Major Subject: Mechanical Engineering MODELING OF AIR BRAKES FOR ONBOARD DIAGNOSTICS OF HEAVY TRUCKS A Thesis By PENCHALA N KANKANALA Submitted to the Office of Graduate Studies of Texas A&M University In partial fulfillment...: Mechanical Engineering ABSTRACT Modeling of Air Brakes for Onboard Diagnostics of Heavy Trucks ( August 2000 ) Penchala N. Kankanala, B. E. , Mangalore University Chair of Advisory Committee: Dr Darbha Swaroop Accidents involving commercial vehicles...

  19. Analysis of heat conduction in a disk brake system

    Microsoft Academic Search

    Faramarz Talati; Salman Jalalifar

    2009-01-01

    In this paper, the governing heat equations for the disk and the pad are extracted in the form of transient heat equations\\u000a with heat generation that is dependant to time and space. In the derivation of the heat equations, parameters such as the\\u000a duration of braking, vehicle velocity, geometries and the dimensions of the brake components, materials of the disk

  20. Thermoelastic analysis for chattering phenomenon of automotive disk brake

    Microsoft Academic Search

    Chongdu Cho; Sooick Ahn

    2001-01-01

    This study investigates the effects of operating conditions on the chattering of an automotive disk brake by experimental\\u000a and computational methods. Design factors, which cause chattering in automobiles, have attracted great attentions for long\\u000a time; but they are not well understood yet. For this study, we construct a brake dynamometer for measuring the disk surface\\u000a temperature during chattering, and propose

  1. The T.G.V. disk brake squeal

    Microsoft Academic Search

    X. Lorang; Q. S. Nguyen; F. Margiocchi; P. E. Gautier

    Discomfort problems due to the noise emittence of braking systems in trains have suggested recently several mechanical analyses.\\u000a This paper gives some of our results obtained from the numerical modelling of TGV brakes in relation with some experimental\\u000a data. The numerical discussion is based upon the Coulomb’s law of contact with a constant coefficient of friction. A dynamic\\u000a stability analysis

  2. Research study on antiskid braking systems for the space shuttle

    NASA Technical Reports Server (NTRS)

    Auselmi, J. A.; Weinberg, L. W.; Yurczyk, R. F.; Nelson, W. G.

    1973-01-01

    A research project to investigate antiskid braking systems for the space shuttle vehicle was conducted. System from the Concorde, Boeing 747, Boeing 737, and Lockheed L-1011 were investigated. The characteristics of the Boeing 737 system which caused it to be selected are described. Other subjects which were investigated are: (1) trade studies of brake control concepts, (2) redundancy requirements trade study, (3) laboratory evaluation of antiskid systems, and (4) space shuttle hardware criteria.

  3. Investigation of aerodynamic braking devices for wind turbine applications

    SciTech Connect

    Griffin, D.A. [R. Lynette & Associates, Seattle, WA (United States)

    1997-04-01

    This report documents the selection and preliminary design of a new aerodynamic braking system for use on the stall-regulated AWT-26/27 wind turbines. The goal was to identify and design a configuration that offered improvements over the existing tip brake used by Advanced Wind Turbines, Inc. (AWT). Although the design objectives and approach of this report are specific to aerodynamic braking of AWT-26/27 turbines, many of the issues addressed in this work are applicable to a wider class of turbines. The performance trends and design choices presented in this report should be of general use to wind turbine designers who are considering alternative aerodynamic braking methods. A literature search was combined with preliminary work on device sizing, loads and mechanical design. Candidate configurations were assessed on their potential for benefits in the areas of cost, weight, aerodynamic noise, reliability and performance under icing conditions. As a result, two configurations were identified for further study: the {open_quotes}spoiler-flap{close_quotes} and the {open_quotes}flip-tip.{close_quotes} Wind tunnel experiments were conducted at Wichita State University to evaluate the performance of the candidate aerodynamic brakes on an airfoil section representative of the AWT-26/27 blades. The wind tunnel data were used to predict the braking effectiveness and deployment characteristics of the candidate devices for a wide range of design parameters. The evaluation was iterative, with mechanical design and structural analysis being conducted in parallel with the braking performance studies. The preliminary estimate of the spoiler-flap system cost was $150 less than the production AWT-26/27 tip vanes. This represents a reduction of approximately 5 % in the cost of the aerodynamic braking system. In view of the preliminary nature of the design, it would be prudent to plan for contingencies in both cost and weight.

  4. Asbestos-free brake-lining materials for hydrogenerators

    SciTech Connect

    Lalonde, S.; Lanteigne, J. [Hydro-Quebec, Varennes, Quebec (Canada)

    1995-11-01

    Three different asbestos-free materials currently considered as new lining materials for hydrogenerator brakes were tested and compared to the original asbestos lining. Results show that these substitutes not only vary greatly from the original material in terms of mechanical properties and physical characteristics but also exhibit significantly different performances in braking tests. Consequently, these new materials are not entirely suitable for the intended application.

  5. Hall drift and the braking indices of young pulsars

    NASA Astrophysics Data System (ADS)

    Gourgouliatos, K. N.; Cumming, A.

    2015-01-01

    Braking index measurements of young radio pulsars are all smaller than the value expected for spin-down by magnetic dipole braking. We investigate magnetic field evolution in the neutron star crust due to Hall drift as an explanation for observed braking indices. Using numerical simulations and a semi-analytic model, we show that an ?1014 G quadrupolar toroidal field in the neutron star crust at birth leads to growth of the dipole moment at a rate large enough to agree with measured braking indices. A key factor is the density at which the crust yields to magnetic stresses that build up during the evolution, which sets a characteristic minimum Hall time-scale. The observed braking indices of pulsars with inferred dipole fields of ? 1013 G can be explained in this picture, although with a significant octupole component needed in some cases. For the stronger field pulsars, those with Bd ? 1013 G, we find that the magnetic stresses in the crust exceed the maximum shear stress before the pulsar reaches its current age, likely quenching the Hall effect. This may have implications for the magnetar activity seen in the high magnetic field radio pulsar PSR J1846-0258. Observations of braking indices may therefore be a new piece of evidence that neutron stars contain subsurface toroidal fields that are significantly stronger than the dipole field, and may indicate that the Hall effect is important in a wider range of neutron stars than previously thought.

  6. The application of hydraulics in the 2,000 kW wind turbine generator

    NASA Technical Reports Server (NTRS)

    Onufreiczuk, S.

    1978-01-01

    A 2000 kW turbine generator using hydraulic power in two of its control systems is being built under the management of NASA Lewis Research Center. The hydraulic systems providing the control torques and forces for the yaw and blade pitch control systems are discussed. The yaw-drive-system hydraulic supply provides the power for positioning the nacelle so that the rotary axis is kept in line with the direction of the prevailing wind, as well as pressure to the yaw and high speed shaft brakes. The pitch-change-mechanism hydraulic system provides the actuation to the pitch change mechanism and permits feathering of the blades during an emergency situation. It operates in conjunction with the overall windmill computer system, with the feather control permitting slewing control flow to pass from the servo valve to the actuators without restriction.

  7. Development of aircraft brake materials. [evaluation of metal and ceramic materials in sliding tests simulation of aircraft braking

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Peterson, M. B.

    1974-01-01

    The requirements of brake materials were outlined and a survey made to select materials to meet the needs of high temperature brakes. A number of metals and ceramic materials were selected and evaluated in sliding tests which simulated aircraft braking. Nickel, molybdenum tungsten, Zr02, high temperature cements and carbons were tested. Additives were then incorporated into these materials to optimize their wear or strength behavior with particular emphasis on nickel and molybdenum base materials and a high temperature potassium silicate cement. Optimum materials were developed which improved wear behavior over conventional brake materials in the simulated test. The best materials are a nickel, aluminum oxide, lead tungstate composition containing graphite or molybdenum disulphite; a molybdenum base material containing LPA100 (an intermetallic compound of cobalt, molybdenum, and silicon); and a carbon material (P5).

  8. Thermal measurement of brake pad lining surfaces during the braking process

    NASA Astrophysics Data System (ADS)

    Pi?tkowski, Tadeusz; Polakowski, Henryk; Kastek, Mariusz; Baranowski, Pawel; Damaziak, Krzysztof; Ma?achowski, Jerzy; Mazurkiewicz, ?ukasz

    2012-06-01

    This paper presents the test campaign concept and definition and the analysis of the recorded measurements. One of the most important systems in cars and trucks are brakes. The braking temperature on a lining surface can rise above 500°C. This shows how linings requirements are so strict and, what is more, continuously rising. Besides experimental tests, very supportive method for investigating processes which occur on the brake pad linings are numerical analyses. Experimental tests were conducted on the test machine called IL-68. The main component of IL-68 is so called frictional unit, which consists of: rotational head, which convey a shaft torque and where counter samples are placed and translational head, where samples of coatings are placed and pressed against counter samples. Due to the high rotational speeds and thus the rapid changes in temperature field, the infrared camera was used for testing. The paper presents results of analysis registered thermograms during the tests with different conditions. Furthermore, based on this testing machine, the numerical model was developed. In order to avoid resource demanding analyses only the frictional unit (described above) was taken into consideration. Firstly the geometrical model was performed thanks to CAD techniques, which in the next stage was a base for developing the finite element model. Material properties and boundary conditions exactly correspond to experimental tests. Computations were performed using a dynamic LS-Dyna code where heat generation was estimated assuming full (100%) conversion of mechanical work done by friction forces. Paper presents the results of dynamic thermomechanical analysis too and these results were compared with laboratory tests.

  9. Friction behavior of sintered metallic brake pads on a C\\/C–SiC composite brake disc

    Microsoft Academic Search

    Zmago Stadler; Kristoffer Krnel; Tomaz Kosmac

    2007-01-01

    In this study we report on the frictional and wear properties of sintered metallic (MMC) brake linings in combination with a C\\/C–SiC brake disc. The influence of additives, such as graphite, and abrasives in the metallic matrix on the formation of the friction layer was investigated using a scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX) and Auger

  10. Hydraulic fracture design optimization

    SciTech Connect

    Lee, Tae-Soo; Advani, S.H.

    1992-06-01

    This research and development investigation, sponsored by US DOE and the oil and gas industry, extends previously developed hydraulic fracture geometry models and applied energy related characteristic time concepts towards the optimal design and control of hydraulic fracture geometries. The primary objective of this program is to develop rational criteria, by examining the associated energy rate components during the hydraulic fracture evolution, for the formulation of stimulation treatment design along with real-time fracture configuration interpretation and control.

  11. Hydraulic fracture design optimization

    SciTech Connect

    Lee, Tae-Soo; Advani, S.H.

    1992-01-01

    This research and development investigation, sponsored by US DOE and the oil and gas industry, extends previously developed hydraulic fracture geometry models and applied energy related characteristic time concepts towards the optimal design and control of hydraulic fracture geometries. The primary objective of this program is to develop rational criteria, by examining the associated energy rate components during the hydraulic fracture evolution, for the formulation of stimulation treatment design along with real-time fracture configuration interpretation and control.

  12. Intelligently Controllable Walker with Magnetorheological Fluid Brake

    NASA Astrophysics Data System (ADS)

    Kikuchi, Takehito; Tanida, Sosuke; Tanaka, Toshimasa; Kobayashi, Keigo; Mitobe, Kazuhisa

    Caster walkers are supporting frames with casters and wheels. These tools are regularly utilized as life support tools or walking rehabilitation tools in hospitals, nursing homes and individual residences. Users of the walkers can easily move it thanks to its wheels and casters. However falling accidents often happen when it moves without users. The falling accident is very serious problem and one of leading causes of secondary injuries. In the other case, it is hard to move to desired directions if users have imbalance in their motor functions or sensory functions, e.g., hemiplegic patients. To improve safeness and operability of the walkers, we installed compact MR fluid brakes on the wheels and controlled walking speed and direction of the walker. We named this intelligently controllable walker, “i-Walker” and discussed on the control methods and experimental results in this paper. Preliminary trials for direction control of the first-generation of the i-Walker (i-Walker1) are presented. On the basis of the results, we improved the control method and hardware of the i-Walker1, and developed the second-generation (i-Walker2). System description and experimental results of the i-Walker2 are also described. The i-Walker2 has better operability and lower energy consumption than that of the i-Walker1. The line-tracing controller of the i-Walker2 well controls human motions during walking experiments on the target straight line.

  13. Airborne asbestos concentrations associated with heavy equipment brake removal.

    PubMed

    Madl, A K; Gaffney, S H; Balzer, J L; Paustenbach, D J

    2009-11-01

    Asbestos-containing brake linings were used in heavy-duty construction equipment such as tractors, backhoes, and bulldozers prior to the 1980s. While several published studies have evaluated exposures to mechanics during brake repair work, most have focused on automobiles and light trucks, not on heavy agricultural or construction vehicles. The purpose of this study is to characterize the airborne concentration of asbestos to workers and bystanders from brake wear debris during brake removal from 12 loader/backhoes and tractors manufactured between 1960 and 1980. Asbestos content in brake lining (average 20% chrysotile by polarized light microscopy) and brake wear debris [average 0.49% chrysotile by transmission electron microscopy (TEM)] was also quantified. Breathing zone samples on the lapel of mechanics (n = 44) and area samples at bystander (n = 34), remote (n = 22), and ambient (n = 12) locations were collected during 12 brake changes and analyzed using phase contrast microscopy (PCM) [National Institute for Occupational Safety and Health (NIOSH) 7400] and TEM (NIOSH 7402). In addition, the fiber distribution by size and morphology was evaluated according to the International Organization for Standardization method for asbestos. Applying the ratio of asbestos fibers:total fibers (including non-asbestos) as determined by TEM to the PCM results, the average airborne chrysotile concentrations (PCM equivalent) were 0.024 f/cc for the mechanic and 0.009 f/cc for persons standing 1.2-3.1 m from the activity during the period of exposure ( approximately 0.5 to 1 h). Considering the time involved in the activity, and assuming three brake jobs per shift, these results would convert to an average 8-h time-weighted average of 0.009 f/cc for a mechanic and 0.006 f/cc for a bystander. The results indicate that (i) the airborne concentrations for worker and bystander samples were significantly less than the current occupational exposure limit of 0.1 f/cc; (ii) approximately 2% of respirable fibers were >20 microm in length; and (iii) approximately 95% of chrysotile in the brake linings degraded in the friction process. The industrial hygiene data presented here should be useful for conducting retrospective and current exposure assessments of individuals, as well as hazard assessments of work activities that involve repairing and replacing asbestos-containing brakes in heavy construction equipment. PMID:19692501

  14. Wear Modalities and Mechanisms of the Mining Non-asbestos Composite Brake Material

    NASA Astrophysics Data System (ADS)

    Bao, Jiusheng; Yin, Yan; Zhu, Zhencai; Tong, Minming; Lu, Yuhao; Peng, Yuxing

    2013-08-01

    The mining brake material is generally made of composite materials and its wear has important influences on the braking performance of disc brakes. In order to improve the braking reliability of mine hoisters, this paper did some tribological investigations on the mining brake material to reveal its wear modalities and mechanisms. The mining non-asbestos brake shoe and 16Mn steel were selected as braking pairs and tested on a pad-on-disc friction tester. And a SEM was used to observe the worn surface of the brake shoe. It is shown that the non-asbestos brake material has mainly five wear modalities: adhesive wear, abrasive wear, cutting wear, fatigue wear and high heat wear. At the front period of a single braking the wear modality is mainly composed of some light mechanical wear such as abrasive, cutting and point adhesive. With the temperature rising at the back period it transforms to some heavy mechanical wear such as piece adhesive and fatigue. While in several repeated brakings once the surface temperature rises beyond the thermal-decomposition point of the bonding material, the strong destructive high heat wear takes leading roles on the surface. And a phenomenon called friction catastrophe (FC) occurs easily, which as a result causes a braking failure. It is considered that the friction heat has important influences on the wear modalities of the brake material. And the reduction of friction heat must be an effective technical method for decreasing wear and avoiding braking failures.

  15. Thermally Actuated Hydraulic Pumps

    NASA Technical Reports Server (NTRS)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research vessels. Heretofore, electrically actuated hydraulic pumps have been used for this purpose. By eliminating the demand for electrical energy for pumping, the use of the thermally actuated hydraulic pumps could prolong the intervals between battery charges, thus making it possible to greatly increase the durations of undersea exploratory missions.

  16. Experimental analysis of brake squeal noise on a laboratory brake setup

    NASA Astrophysics Data System (ADS)

    Giannini, Oliviero; Akay, Adnan; Massi, Francesco

    2006-04-01

    The present paper is the first of two papers dealing with brake squeal instability. An experimental setup is specifically designed for this purpose and is characterized by a simple design to aid measurements and modeling. This first paper describes the experimental setup called "laboratory brake" and presents the measurements performed on it to characterize its dynamical behavior and its squeal behavior. The tests are aimed at identifying the key parameters controlling the squeal phenomenon that are necessary to build a model of the setup. The experimental analysis on squeal presented here identifies several characteristics that lead to instabilities and correlates them with the operating parameters as well as with the dynamic behavior of the system. Measurements also highlight that the pad dynamics have a key role in the selection of the squealing modes at one of the out-of-plane eigenfrequency of the system. Finally, the experimental results provide a better understanding of the physics of the squeal mechanism and suggest guidelines to build a representative model of the setup.

  17. Leaf Hydraulics Lawren Sack1

    E-print Network

    Holbrook, N. Michele

    Leaf Hydraulics Lawren Sack1 and N. Michele Holbrook2 1 Department of Botany, University of Hawai influence rates of transpiration and photosynthesis. Leaf hydraulic conductance (Kleaf) varies more than 65. #12;Contents INTRODUCTION. . . . . . . . . . . . . . . . . 362 LEAF HYDRAULIC CONDUCTANCE

  18. Environmentally adapted hydraulic oils

    Microsoft Academic Search

    Elisabet Kassfeldt; Göran Dave

    1997-01-01

    A comparison has been carried out between one mineral based hydraulic oil and three environmentally adapted hydraulic oils. Two of these are semi-synthetic oils, i.e. mixtures of vegetable base oil and synthetic esters, and the last is based on synthetic esters only. Technical properties such as viscosity, pour point etc., and chemical properties such as phosphorus and sulphur content etc.

  19. Bud development and hydraulics

    PubMed Central

    Cochard, Hervé

    2008-01-01

    The distal zone of one-year-old apple (Malus domestica) shoots was studied on five cultivars for bud size and composition (number of appendages) and hydraulic conductance before bud burst. Our hypothesis was that bud development was related to hydraulic conductance of the sap pathway to the bud independent of an acrotonic (proximal vs. distal) effect. Bud size and composition, and hydraulic conductance, were highly variable for all cultivars. A positive correlation was demonstrated between both the number of cataphylls and green-leaf primordia and hydraulic conductance. Cultivar and bud size affected the intercept of these relationships more than the slope suggesting similar scaling between these variables but different hydraulic efficiencies. A great proportion of small buds were also characterized by null values of hydraulic conductance. Our study suggests that hydraulically mediated competitions exist between adjacent buds within a same branching zone prefiguring the variability of lateral types in the following growing season. It is hypothesized that this developmental patterning is driven by hydraulic characteristics of the whole-metamer, including the subtending leaf, during bud development. PMID:19704779

  20. Downhole hydraulic seismic generator

    DOEpatents

    Gregory, Danny L. (Corrales, NM); Hardee, Harry C. (Albuquerque, NM); Smallwood, David O. (Albuquerque, NM)

    1992-01-01

    A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a double-actuating piston whose movement is controlled by an electro-servovalve regulating a high pressure hydraulic fluid flow into and out of upper and lower chambers surrounding the piston. The spent hydraulic fluid from the hydraulic oscillator is stored and pumped back into the system to provide high pressure fluid for conducting another run at the same, or a different location within the borehole.

  1. Downhole hydraulic seismic generator

    SciTech Connect

    Gregory, D.L.; Hardee, H.C.; Smallwood, D.O.

    1990-12-31

    A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a double-actuating piston whose movement is controlled by an electro-servovalve regulating a high pressure hydraulic fluid flow into and out of upper and lower chambers surrounding the piston. The spent hydraulic fluid from the hydraulic oscillator is stored and pumped back into the system to provide high pressure fluid for conducting another run at the same, or a different location within the borehole. 4 figs.

  2. Downhole hydraulic seismic generator

    SciTech Connect

    Gregory, D.L.; Hardee, H.C.; Smallwood, D.O.

    1990-01-01

    A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a double-actuating piston whose movement is controlled by an electro-servovalve regulating a high pressure hydraulic fluid flow into and out of upper and lower chambers surrounding the piston. The spent hydraulic fluid from the hydraulic oscillator is stored and pumped back into the system to provide high pressure fluid for conducting another run at the same, or a different location within the borehole. 4 figs.

  3. An analysis of the annual probability of failure of the waste hoist brake system at the Waste Isolation Pilot Plant (WIPP)

    SciTech Connect

    Greenfield, M.A. [Univ. of California, Los Angeles, CA (United States); Sargent, T.J.

    1995-11-01

    The Environmental Evaluation Group (EEG) previously analyzed the probability of a catastrophic accident in the waste hoist of the Waste Isolation Pilot Plant (WIPP) and published the results in Greenfield (1990; EEG-44) and Greenfield and Sargent (1993; EEG-53). The most significant safety element in the waste hoist is the hydraulic brake system, whose possible failure was identified in these studies as the most important contributor in accident scenarios. Westinghouse Electric Corporation, Waste Isolation Division has calculated the probability of an accident involving the brake system based on studies utilizing extensive fault tree analyses. This analysis conducted for the U.S. Department of Energy (DOE) used point estimates to describe the probability of failure and includes failure rates for the various components comprising the brake system. An additional controlling factor in the DOE calculations is the mode of operation of the brake system. This factor enters for the following reason. The basic failure rate per annum of any individual element is called the Event Probability (EP), and is expressed as the probability of failure per annum. The EP in turn is the product of two factors. One is the {open_quotes}reported{close_quotes} failure rate, usually expressed as the probability of failure per hour and the other is the expected number of hours that the element is in use, called the {open_quotes}mission time{close_quotes}. In many instances the {open_quotes}mission time{close_quotes} will be the number of operating hours of the brake system per annum. However since the operation of the waste hoist system includes regular {open_quotes}reoperational check{close_quotes} tests, the {open_quotes}mission time{close_quotes} for standby components is reduced in accordance with the specifics of the operational time table.

  4. Prosthetic leg powered by MR brake and SMA wires

    NASA Astrophysics Data System (ADS)

    Nguyen, The; Munguia, Vicente; Calderon, Jose

    2014-04-01

    Current knee designs for prosthetic legs rely on electric motors for both moving and stationary states. The electric motors draw an especially high level of current to sustain a fixed position. The advantage of using magnetorheological (MR) fluid is that it requires less current and can have a variable braking torque. Besides, the proposed prosthetic leg is actuated by NiTinol wire, a popular shape memory alloy (SMA). The incorporation of NiTinol gives the leg more realistic weight distribution with appropriate arrangement of the batteries and wires. The prosthesis in this research was designed with MR brake as stopping component and SMA wire network as actuating component at the knee. The MR brake was designed with novel non-circular shape for the rotor that improved the braking torque while minimizing the power consumption. The design also helped simplify the control of braking process. The SMA wire network was design so that the knee motion was actively rotated in both directions. The SMA wires were arranged and played very similar role as the leg's muscles. The study started with the overall solid design of the knee including both MR and SMA parts. Theoretical models were derived and programmed in Simulink for both components. The simulation was capable of predicting the power required for moving the leg or hold it in a fixed position for a certain amount of time. Subsequently, the design was prototyped and tested to validate the theoretical prediction. The theoretical models were updated accordingly to correlate with the experimental data.

  5. Thermophysical Properties of Automotive Metallic Brake Disk Materials

    NASA Astrophysics Data System (ADS)

    Kim, S. W.; Park, K.; Lee, S. H.; Kang, K. H.; Lim, K. T.

    2008-12-01

    The temperature distribution, the thermal deformation, and the thermal stress of automotive brake disks have quite close relations with car safety; therefore, much research in this field has been performed. However, successful and satisfactory results have not been obtained because the temperature-dependent thermophysical properties of brake disk materials are not sufficiently known. In this study, the thermophysical properties (thermal diffusivity, the specific heat, and the coefficient of thermal expansion) of three kinds of iron alloy series brake disk materials, FC250, FC170, and FCD50, and two kinds of aluminum alloy series brake disk materials, Al MMC and A356, were measured in the temperature range from room temperature to 500 °C, and the thermal conductivity was calculated using the measured thermal diffusivity, specific heat capacity, and density. As expected, the results show that the two series have significant differences in respect of the thermophysical properties, and to reduce the thermal deformation of the brake disk, the aluminum alloys with a high thermal conductivity and the iron alloys with low thermal expansion are recommended.

  6. Regenerative braking device with rotationally mounted energy storage means

    DOEpatents

    Hoppie, Lyle O. (Birmingham, MI)

    1982-03-16

    A regenerative braking device for an automotive vehicle includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (30) and an output shaft (32), clutches (50, 56) and brakes (52, 58) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. In a second embodiment the clutches and brakes are dispensed with and the variable ratio transmission is connected directly across the input and output shafts. In both embodiments the rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft rotates faster or relative to the output shaft and are torsionally relaxed to deliver energy to the vehicle when the output shaft rotates faster or relative to the input shaft.

  7. Arsenic species and leachability in the fronds of the hyperaccumulator Chinese brake (Pteris vittata L.)

    E-print Network

    Ma, Lena

    Arsenic species and leachability in the fronds of the hyperaccumulator Chinese brake (Pteris June 2002; accepted 9 December 2002 ``Capsule'': Arsenic was predominantly present as inorganic arsenite in the fronds of the hyperaccumulator Chinese brake. Abstract Arsenic speciation is important

  8. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...high temperatures. (c) Nonmetallic brake tubing. Coiled nonmetallic brake tubing may be used for connections between towed and...axle of the motor vehicle if— (1) The coiled tubing has a straight segment (pigtail) at...

  9. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...high temperatures. (c) Nonmetallic brake tubing. Coiled nonmetallic brake tubing may be used for connections between towed and...axle of the motor vehicle if— (1) The coiled tubing has a straight segment (pigtail) at...

  10. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...high temperatures. (c) Nonmetallic brake tubing. Coiled nonmetallic brake tubing may be used for connections between towed and...axle of the motor vehicle if— (1) The coiled tubing has a straight segment (pigtail) at...

  11. Evaluation of Corrosion Failure in Tractor-Trailer Brake System

    SciTech Connect

    Wilson, DF

    2002-10-22

    As reported to ORNL, concomitant with the introduction of different deicing and anti-icing compounds, there was an increase in the brake failure rate of tractor-trailer trucks. A forensic evaluation of a failed brake system was performed. Optical and scanning electron microscopic evaluation showed corrosion to be mostly confined to the brake table/lining interface. The corrosion is non-uniform as is to be expected for plain carbon steel in chloride environments. This initial analysis found no evidence for the chlorides of calcium and magnesium, which are the newly introduced deicing and antiicing compounds and are less soluble in water than the identified chlorides of sodium and potassium, in the scale. The result could be as a result of non-exposure of the examined brake table to calcium and magnesium chloride. The mechanisms for the increased failure rate are postulated as being an increased rate of corrosion due to positive shifts in the corrosion potential, and an increased amount of corrosion due to an increased ''time of wetness'' that results from the presence of hygroscopic salts. Laboratory scale evaluation of the corrosion of plain carbon steel in simulated deicing and anti-icing solutions need to be performed to determine corrosion rates and morphological development of corrosion product, to compare laboratory data to in-service data, and to rank economically feasible replacement materials for low carbon steel. In addition, the mechanical behavior of the lining attached to the brake shoe table needs to be assessed. It is opined that an appropriate adjustment of materials could easily allow for a doubling of a brake table/lining lifetime. Suggestions for additional work, to clarify the mechanisms of rust jacking and to develop possible solutions, are described.

  12. Characterization of the high-frequency squeal on a laboratory brake setup

    Microsoft Academic Search

    Oliviero Giannini; Francesco Massi

    2008-01-01

    This paper presents an experimental investigation on high-frequency brake squeal noise conducted on an appropriately designed experimental rig, called laboratory brake.Brake squeal is one of the major issues in the design process of an automotive brake and the development of a robust procedure for a “squeal-free” design is still under investigation. The high-frequency squeal is the most frequent noise generated

  13. Torque regulation with the General Motors ABS VI electric brake system

    Microsoft Academic Search

    J. K. Hurtig; S. Yurkovich; K. M. Passino; D. Littlejohn

    1994-01-01

    The primary goal of an automotive brakes system is to achieve a complete and safe stop as fast as possible. Anti-lock braking systems (ABS) seek to avoid wheel lock-up and skidding to minimize stopping distances and maximize lateral stability during braking (i.e., to make it possible for the driver to steer out of a problem during an emergency braking scenario).

  14. Disc brake squeal characterization through simplified test rigs

    NASA Astrophysics Data System (ADS)

    Akay, A.; Giannini, O.; Massi, F.; Sestieri, A.

    2009-11-01

    This paper presents a review of recent investigations on brake squeal noise carried out on simplified experimental rigs. The common theme of these works is that of approaching the study of squeal noise on experimental set-ups that are much simpler than commercial disc brakes, providing the possibility of repeatable measurements of squeal occurrence. As a consequence, it is possible to build consistent and robust models of the experimental apparatus to simulate the squeal events and to understand the physics behind squeal instabilities.

  15. Transient analysis of thermoelastic contact problem of disk brakes

    NASA Astrophysics Data System (ADS)

    Belhocine, Ali; Bouchetara, Mostefa

    2013-06-01

    The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disk and pads during the braking phase. The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles. The thermal-structural analysis is then used with coupling to determine the deformation established and the Von Mises stresses in the disk, the contact pressure distribution in pads. The results are satisfactory compared to those found in the literature.

  16. Thermal-mechanical coupled analysis of a brake disk rotor

    NASA Astrophysics Data System (ADS)

    Belhocine, Ali; Bouchetara, Mostefa

    2013-08-01

    The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disk and pads during the braking phase. The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles The thermal-structural analysis is then used with coupling to determine the deformation and the Von Mises stress established in the disk, the contact pressure distribution in pads. The results are satisfactory when compared to those of the specialized literature.

  17. Aluminum runway surface as possible aid to aircraft braking

    NASA Technical Reports Server (NTRS)

    Miller, C. D.; Pinkel, I. I.

    1973-01-01

    Several concepts are described for use singly or in combination to improve aircraft braking. All involve a thin layer of aluminum covering all or part of the runway. Advantage would derive from faster heat conduction from the tire-runway interface. Heating of tread surface with consequent softening and loss of friction coefficient should be reduced. Equations are developed indicating that at least 99 percent of friction heat should flow into the aluminum. Preliminary test results indicate a coefficient of sliding friction of 1.4, with predictably slight heating of tread. Elimination of conventional brakes is at least a remote possibility.

  18. The effect of temperature rise of the fuzzy logic-controlled braking resistors on transient stability

    Microsoft Academic Search

    M. H. Ali; T. Murata; J. Tamura

    2004-01-01

    Braking resistor is a very powerful tool to improve transient stability in a power system. Usually, a fixed value of the braking resistor is considered for the transient stability analysis. However, when the braking resistor is in operation, temperature of the resistor material rises above ambient temperature which ultimately causes the resistance value to increase. This paper analyzes the effect

  19. Reduction of squeal noise from disc brake systems using constrained layer damping

    Microsoft Academic Search

    M. Triches Jr; S. N. Y. Gerges; R. Jordan

    2004-01-01

    Squeal noise generation during braking is a complic ated dynamic problem which automobile manufacturers have confronted for decade s. Customer complaints result in significant yearly warranty costs. More importantly , customer dissatisfaction may result in rejection of certain brands of brake systems. In or der to produce quality automobiles that can compete in today's marketplace, the occurrence of disc brake

  20. 49 CFR 238.17 - Movement of passenger equipment with other than power brake defects.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...equipment with other than power brake defects. Beginning...equipment with other than a power brake defect. (Passenger cars...this part, other than a power brake defect, may be moved only... (ii) It makes any unusual noise when its wheel set is spun...

  1. 49 CFR 238.17 - Movement of passenger equipment with other than power brake defects.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...equipment with other than power brake defects. Beginning...equipment with other than a power brake defect. (Passenger cars...this part, other than a power brake defect, may be moved only... (ii) It makes any unusual noise when its wheel set is spun...

  2. 49 CFR 238.17 - Movement of passenger equipment with other than power brake defects.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...equipment with other than power brake defects. Beginning...equipment with other than a power brake defect. (Passenger cars...this part, other than a power brake defect, may be moved only... (ii) It makes any unusual noise when its wheel set is spun...

  3. Study of the nonlinear stationary dynamic of single and multi instabilities for disc brake squeal

    E-print Network

    Boyer, Edmond

    and prediction of squeal noise arising due to friction-induced vibrations in brake systems. To study the squealStudy of the nonlinear stationary dynamic of single and multi instabilities for disc brake squeal-jacques.sinou@ec-lyon.fr Abstract : The focus of this article is to show and discuss the nonlinear dynamical behaviors of brake

  4. Motion capture of a pad measured with accelerometers during squeal noise in a real brake system

    E-print Network

    Paris-Sud XI, Université de

    Motion capture of a pad measured with accelerometers during squeal noise in a real brake system during squeal noise is measured on a real brake system with three-axis ac- celerometers. A time Brakes - 126 Rue de Stalingrad - 93700 DRANCY - FRANCE Abstract The operating deflection shape of a pad

  5. 49 CFR 238.17 - Movement of passenger equipment with other than power brake defects.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...equipment with other than power brake defects. Beginning...equipment with other than a power brake defect. (Passenger cars...this part, other than a power brake defect, may be moved only... (ii) It makes any unusual noise when its wheel set is spun...

  6. 49 CFR 238.17 - Movement of passenger equipment with other than power brake defects.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...equipment with other than power brake defects. Beginning...equipment with other than a power brake defect. (Passenger cars...this part, other than a power brake defect, may be moved only... (ii) It makes any unusual noise when its wheel set is spun...

  7. Analysis of brake squeal noise using the finite element method: A parametric study

    Microsoft Academic Search

    Mário Trichês Júnior; Samir N. Y. Gerges; Roberto Jordan

    2008-01-01

    Brake squeal noise has been under investigation by automotive manufacturers for decades due to consistent customer complaints and high warranty costs. J.D. Power surveys consistently show brake noise as being one of the most critical vehicle quality measurements. Furthermore, the development of methods to predict noise occurrence during the design of a brake system has been the target of many

  8. Instabilities in the sliding of continua with surface inertias: An initiation mechanism for brake noise

    Microsoft Academic Search

    M. Graf; G.-P. Ostermeyer

    2011-01-01

    This paper presents a model for friction-induced vibration in brake systems, which takes a homogeneous tribological layer on the brake pad into account. The derived model consists of two flat elastic bodies sliding against each other with a constant coefficient of friction. In brake tribology, like in most tribological processes, a surface structure is observed, which can be modeled as

  9. Thiol synthesis and arsenic hyperaccumulation in Pteris vittata (Chinese brake fern)

    E-print Network

    Ma, Lena

    Thiol synthesis and arsenic hyperaccumulation in Pteris vittata (Chinese brake fern) Weihua Zhanga in arsenic detoxification. Abstract Pteris vittata (Chinese brake fern) has potential for phytoremediation to be a supplement. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Pteris vittata; Chinese brake fern; Thiols

  10. Design electronic control unit of blend brake system for heavy vehicle

    Microsoft Academic Search

    Wang Tianxu; Gong Mingde

    2011-01-01

    Electronic control unit(ECU) of blend brake system based on electro-hydra ulic servo control for heavy vehicle is designed and analyzed in this paper. The study makes full consideration of the requirements of high speed, heavy weight and fast braking for heavy vehicle. Through collected speed signals and pressure signals output by the main brake cylinder, the ECU analyses and judges

  11. An active control method to reduce the effect of negative damping in disk brake system

    Microsoft Academic Search

    Sayed-Mahdi Hashemi-Dehkordi; Musa Mailah; A. R. A. Bakar

    2009-01-01

    In this paper, a novel approach to reduce the effect of negative damping that causes brake noise is proposed by applying an active force control (AFC) based strategy to a two degree-of-freedom model of a disk brake system. At first, the disc brake model is simulated and analyzed using a closed loop pure PID controller. Later, it is integrated with

  12. On Dissipation-Induced Destabilization and Brake Squeal: A Perspective using Structured

    E-print Network

    Zworski, Maciej

    such as damping coefficients in follower force systems, and lining stiffness co- efficients in models for brakesOn Dissipation-Induced Destabilization and Brake Squeal: A Perspective using Structured and models for squealing brakes. In this paper, it is shown that a pseudospectral analysis can illuminate

  13. Wear mechanism in automotive brake materials, wear debris and its potential environmental impact

    Microsoft Academic Search

    J. Kukutschová; V. Roubí?ek; K. Malachová; Z. Pavlí?ková; R. Holuša; J. Kuba?ková; V. Mi?ka; D. MacCrimmon; P. Filip

    2009-01-01

    A model semi-metallic brake lining was subjected to full-scale automotive brake dynamometer tests. The structural properties and surface topography of brake linings were analyzed at different stages of wear testing and correlated to frictional performance. Characteristics of released wear particles were also addressed. A combination of abrasive and adhesive wear with oxidative processes dominated the friction process. Formation of a

  14. Effects of ingredients on tribological characteristics of a brake lining: an experimental case study

    Microsoft Academic Search

    Min Hyung Cho; Seong Jin Kim; Daehwan Kim; Ho Jang

    2005-01-01

    A brake lining containing 16 ingredients was investigated to study the effect of ingredients on various aspects of friction properties. The composite was developed for a non-asbestos organic based friction material for an automotive brake system and contained typical ingredients for commercial brake friction materials. Based on a basic formulation, 32 different friction material specimens were produced according to an

  15. A study on the friction characteristics and durability of band brakes

    Microsoft Academic Search

    Yasushi Mori; Yoshiaki Kato; Ryoukou Akasaka

    1995-01-01

    A band brake is often used as a braking device in an automatic transmission because it fits around the clutch drum and does not require additional space. Its friction characteristics vary depending on the oil film between the brake band and the drum. Less friction force occurs under lower pressure and greater lubrication. In this study, the relationship between friction

  16. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...brake systems. (a) The primary brake system of a train...consistent with prevailing adhesion, train safety, and brake...shall develop and implement a process or procedure to verify that...shall adopt and comply with a process or procedures to...

  17. Department of Mechanical Engineering Fall 2012 Bell Helicopter Rotor Brake Redesign, Optimization, and Analysis

    E-print Network

    Demirel, Melik C.

    PENNSTATE Department of Mechanical Engineering Fall 2012 Bell Helicopter Rotor Brake Redesign, Optimization, and Analysis Overview Bell Helicopter uses a rotor brake to stop the rotors from spinning for safety reasons, once the helicopter has landed. When the rotor brake is engaged, chatter occurs and can

  18. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

  19. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

  20. Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker

    ERIC Educational Resources Information Center

    Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

    2014-01-01

    The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in…

  1. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

  2. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

  3. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

  4. 49 CFR 232.209 - Class II brake tests-intermediate inspection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...has not previously received a Class I brake test or that has been...defective equipment. (b) A Class II brake test shall consist...release is performed, train speed shall not exceed 10 MPH, and the...block of cars that receives a Class II brake test pursuant to...

  5. 49 CFR 232.205 - Class I brake test-initial terminal inspection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...defective equipment. (c) A Class I brake test of a train shall...release is performed, train speed shall not exceed 10 MPH and the...locomotive engineer that the Class I brake test was satisfactorily...test and the location where the Class I brake test was...

  6. Hydraulic Fracturing Sand

    USGS Multimedia Gallery

    Fine-grained silica sand is mixed with chemicals and water before being pumped into rock formations to prevent the newly created artificial fractures from closing after hydraulic fracturing is completed....

  7. Automatic emergency hydraulic switch

    Microsoft Academic Search

    B. T. Sitnikov; I. B. Matveev; V. N. Denisov

    1972-01-01

    tem automatically when large leaks appear in the system, or when the process piping ruptures suddenly, has been developed and tested at Penza Polytechnic Institute. This emergency hydraulic switch can be employed in various hydraulic systems serviug process machinery and equipment. It is designed to handle maximum flowrates at i00 liters\\/min, and to take pressures up to 200 kgf\\/cm 2.

  8. Portable Hydraulic Powerpack

    NASA Technical Reports Server (NTRS)

    Anderson, L. A.; Henry, R. L.; Fedor, O. H.; Owens, L. J.

    1986-01-01

    Rechargeable hydraulic powerpack functions as lightweight, compact source of mechanical energy. Self-contained hydraulic powerpack derives energy from solid chemical charge. Combustion of charge initiated by small hammer, and revolving feeder replaces charges expended. Combustion gases cool during expansion in turbine and not too hot for release to atmosphere. Unit has applications driving wheelchairs and operating drills, winches, and other equipment in remote areas. Also replaces electric motors and internal-combustion engines as source of power in explosive atmospheres.

  9. 27. Historic drawing, Marine Railway. Detail of Emergency Brake, 1917. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. Historic drawing, Marine Railway. Detail of Emergency Brake, 1917. Photographic copy of original. Boston National Historical Park Archives, Charlestown Navy Yard. BOSTS 13439, #551-16 - Charlestown Navy Yard, Marine Railway, Between Piers 2 & 3, on Charlestown Waterfront at west end of Navy Yard, Boston, Suffolk County, MA

  10. Wind braking of magnetars: To understand magnetars' multiwave radiation properties

    NASA Astrophysics Data System (ADS)

    Tong, H.; Xu, R. X.

    2014-09-01

    Magnetars are proposed to be peculiar neutron stars powered by their super-strong magnetic field. Observationally, anomalous X-ray pulsars and soft gamma-ray repeaters are believed to be magnetar candidates. While more and more multiwave observations of magnetars are available, we see unfortunately an accumulation of failed predictions of the traditional magnetar model. These challenges urge a reconsidering of the magnetar phenomenon. Wind braking of magnetars is one of the alternative modelings. The release of magnetic energy may generate a particle outflow (i.e., particle wind) which results in both an anomalous X-ray luminosity (L_X) and a significantly high spindown rate (\\dot P). In this wind braking scenario, only a strong multipole field is necessary for a magnetar (a strong dipole field is no longer needed). Wind braking of magnetars may help us to understand their multiwave radiation properties, including (1) non-detection of magnetars in the Fermi-LAT observations, (2) timing behaviors of low magnetic field magnetars, (3) nature of anti-glitches, (4) criterion for magnetar radio emission, etc. In the wind braking model of magnetars, timing events of magnetars should always be accompanied by radiative events.

  11. A Laboratory Activity on the Eddy Current Brake

    ERIC Educational Resources Information Center

    Molina-Bolivar, J. A.; Abella-Palacios, A. J.

    2012-01-01

    The aim of this paper is to introduce a simple and low-cost experimental setup that can be used to study the eddy current brake, which considers the motion of a sliding magnet on an inclined conducting plane in terms of basic physical principles. We present a set of quantitative experiments performed to study the influence of the geometrical and…

  12. Real-time brake torque estimation for internal combustion engines

    NASA Astrophysics Data System (ADS)

    Franco, Javier; Franchek, Matthew A.; Grigoriadis, Karolos

    2008-02-01

    Presented is a real-time engine brake torque estimation model where the instantaneous measured engine speed serves as the model input. The model is comprised of notch filters executed in the crank-angle domain to extract mean engine speed and the nth frequency component from the instantaneous engine speed signal in real-time. Here n denotes the number of engine cylinders. Moreover, the engine brake torque estimation is separated into two parts: steady-state and transient. It will be shown that the nth harmonic (in units of periods per engine cycle) of engine speed and mean engine speed are sufficient to estimate the engine brake torque. The steady-state portion of the model is developed using orthogonal least-squares estimation and results in a model with 15 regressors for our particular case. The transient portion is identified using a time domain identification method. Validation of the engine brake torque model is provided using a computational engine model for a 6-cylinder heavy duty diesel engine. Transient engine speed and torque conditions in the presence of sensor noise are evaluated as well as cylinder power imbalance scenarios.

  13. Three Dimensional Animation of a Disc Brake System Generating Noise

    Microsoft Academic Search

    Chris Talbot; Kamal-al Banawi; John D Fieldhouse

    Brake noise investigations using the whole body visual technique of double pulsed holographic interferometry have been extended so that a series of time related interferograms may be recorded over a cycle of excitation. The main disadvantage of such a technique is that the extraction of the valuable information contained within the holograms requires a degree of expertise in the interpretation

  14. DISC BRAKE SYSTEM (CENTER), INCLUDING BELT DRIVE TO SECONDARY GENERAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DISC BRAKE SYSTEM (CENTER), INCLUDING BELT DRIVE TO SECONDARY GENERAL MOTORS ENGINE (LEFT)AND FERREL REDUCTION GEAR CONNECTION TO ALLIS-CHALMERS DIESEL ENGINE (RIGHT), LOOKING NORTH. NOTE TORQUE CONVERTER (TOP) AND THROTTLE (BELOW) LINES CONNECTING TO PRIMARY ENGINE. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

  15. Analytic Methods for Thermal Calculation of Brakes (Review)

    Microsoft Academic Search

    O. O. Evtushenko; E. H. Ivanyk; N. V. Horbachova

    2000-01-01

    In the present review, we discuss works that have been published in the last 15–20 years that are devoted to the analysis of mathematical computational models of thermal properties of braking friction systems of various types. New applications of the theory of heat conduction and thermoelasticity as well as the rapid development of computer engineering have led to a considerable

  16. TRANSIENT ANALYSIS OF THERMOELASTIC CONTACT BEHAVIORS IN COMPOSITE MULTIDISK BRAKES

    Microsoft Academic Search

    Ji-Hoon Choi; Jae-Hung Han; In Lee

    2004-01-01

    The transient analyses of the thermoelastic contact problem are performed for carbon–carbon composite multidisk brakes subject to mechanical and frictionally excited thermal loads. The finite element method, based on the coupled theory in which displacement and temperature fields are mutually affected, is applied for the numerical simulations. In the present study, to improve the accuracy of computations and stabilize the

  17. Application of Fractional Derivatives in Thermal Analysis of Disk Brakes

    Microsoft Academic Search

    Om Prakash Agrawal

    2004-01-01

    This paper presents a Fractional Derivative Approach for thermal analysis of disk brakes. In this research, the problem is idealized as one-dimensional. The formulation developed contains fractional semi integral and derivative expressions, which provide an easy approach to compute friction surface temperature and heat flux as functions of time. Given the heat flux, the formulation provides a means to compute

  18. Vibrational instabilities in pad-disk braking system

    Microsoft Academic Search

    L. Baillet; S. D'Errico; B. Laulagnet

    This paper describes a numerical model which enable the generation of braking instabilities, for a disk and a pad in contact. The use of a calculation code with dynamic finite elements is necessary to reproduce the transitory phenomena. The finite elements code PLAST3 in three dimension, based upon the formulation of Lagrange multipliers, uses an explicit dynamic formulation and includes

  19. Grey relation analysis on fuzzy fault tree of disk brake

    Microsoft Academic Search

    Dezhong Ma; Yongqing Jang; Zhen Zhou; Tonghui Zhao; Dawei Lin

    2011-01-01

    The fault states are fuzzy and the relationship between the primary and the secondary factor leading to the fault is uncertain in the course of the reliability analysis of disk brake. To solve these problems, the fuzzy grey relation analysis is used to improve the traditional method, Fault Tree Analysis (FTA). The triangle fuzzy number is used to represent the

  20. Fleet study evaluation of an advance brake warning system.

    PubMed

    Shinar, D

    2000-01-01

    The advance brake warning system (ABWS) is a mechanism that activates the brake lights in response to a rapid disengagement of the gas pedal, before the driver's foot reaches the brake pedal. Two previous studies showed that (a) such rapid releases of the gas pedal are typically followed by brake activation, and (b) the ABWS can prevent a high percentage of rear-end collisions in which an attentive following driver maintains a headway of 1.0 s or less from the vehicle ahead. In the present study the crash involvement of 764 government cars and light trucks was tracked over an average period of 35 months. The vehicles were matched in pairs--one of each pair with the ABWS and one without it. Data analyses focused on collisions in which the government vehicles were rear-ended. Overall, ABWS-equipped vehicles were not significantly less involved in rear-end collisions. However, an examination of the struck vehicles only showed that the ABWS-equipped vehicles were involved in fewer rear-end collisions per kilometer driven than were the vehicles without the ABWS. In conclusion, despite the theoretical appeal and the results of earlier studies, the fleet study failed to demonstrate that such a system is a cost-effective safety device for the prevention of rear-end crashes. Actual or potential applications include the evaluation of new in-vehicle technologies by a hierarchy of multiple validation studies prior to consideration. PMID:11132809

  1. The stability of motorcycles under acceleration and braking

    Microsoft Academic Search

    D J N Limebeer; R S Sharp; S Evangelou

    2001-01-01

    A comprehensive study of the e Vects of acceleration and braking on motorcycle stability is presented. This work is based on a modi® ed version of a dynamic model presented earlier, and is thought to be the most comprehensive motorcycle dynamic model in the public domain. Extensive use is made of both non-linear and linearized models. The models are written

  2. Oxygen-Diffused Titanium as a Candidate Brake Rotor Material

    SciTech Connect

    Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Jolly, Brian C [ORNL

    2009-01-01

    Titanium alloys are one of several candidate materials for the next generation of truck disk brake rotors. Despite their advantages of lightweight relative to cast iron and good strength and corrosion resistance, titanium alloys are unlikely to be satisfactory brake rotor materials unless their friction and wear behavior can be significantly improved. In this study, a surface engineering process oxygen diffusion was applied to titanium rotors and has shown very encouraging results. The oxygen diffused Ti-6Al-4V (OD-Ti) was tested on a sub-scale brake tester against a flat block of commercial brake lining material and benchmarked against several other Ti-based materials, including untreated Ti-6Al-4V, ceramic particle-reinforced Ti composites (MMCs), and a thermal-spray-coated Ti alloy. With respect to friction, the OD-Ti outperformed all other candidate materials under the imposed test conditions with the friction coefficient remaining within a desirable range of 0.35-0.50, even under the harshest conditions when the disk surface temperature reached nearly 600 ?C. In addition, the OD-Ti showed significantly improved wear-resistance over the non-treated one and was even better than the Ti-based composite materials.

  3. An improved automotive brake lining using fibrous potassium titanate

    NASA Technical Reports Server (NTRS)

    Mansfield, J. A.; Halberstadt, M. L.; Riccitiello, S. R.; Rhee, S. K.

    1976-01-01

    Simultaneous fade reduction and wear improvement of a commercial automotive brake lining were achieved by adding fibrous potassium titanate. The dependence of friction and wear characteristics on quantitative variations in potassium titanate, asbestos, phenolic binder, and organic and inorganic modifiers was evaluated.

  4. Magnetic Braking and Protostellar Disk Formation: Ambipolar Diffusion

    E-print Network

    Richard R. Mellon; Zhi-Yun Li

    2008-09-21

    It is established that the formation of rotationally supported disks during the main accretion phase of star formation is suppressed by a moderately strong magnetic field in the ideal MHD limit. Non-ideal MHD effects are expected to weaken the magnetic braking, perhaps allowing the disk to reappear. We concentrate on one such effect, ambipolar diffusion, which enables the field lines to slip relative to the bulk neutral matter. We find that the slippage does not sufficiently weaken the braking to allow rotationally supported disks to form for realistic levels of cloud magnetization and cosmic ray ionization rate; in some cases, the magnetic braking is even enhanced. Only in dense cores with both exceptionally weak fields and unreasonably low ionization rate do such disks start to form in our simulations. We conclude that additional processes, such as Ohmic dissipation or Hall effect, are needed to enable disk formation. Alternatively, the disk may form at late times when the massive envelope that anchors the magnetic brake is dissipated, perhaps by a protostellar wind.

  5. 6. OBLIQUE VIEW OF HOIST, SHOWING WOODEN BRAKE SHOES, REDUCTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. OBLIQUE VIEW OF HOIST, SHOWING WOODEN BRAKE SHOES, REDUCTION GEARS AND BED FOR (MISSING) CLUTCH/DRIVE GEAR UNIT, LOOKING NORTHWEST - Buffalo Coal Mine, Vulcan Cable Hoist, Wishbone Hill, Southeast end, near Moose Creek, Sutton, Matanuska-Susitna Borough, AK

  6. Thermal cracking in disc brakes Thomas J. Mackin *,1

    E-print Network

    Salvaggio, Carl

    that rotor failure is a consequence of low cycle thermo-mechanical fatigue. An analysis of the vehicle and the proposed theoretical approach # 2002 Elsevier Science Ltd. All rights reserved. Keywords: Thermal fatigue; Heat cracks; Brake failures; Thermal stress; Fatigue 1350-6307/02/$ - see front matter # 2002 Elsevier

  7. Brakes Specialist. Teacher Edition. Automotive Service Series. Second Edition.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This curriculum guide for automatic brakes service is one in a series of automotive service speciality publications that is based on the National Institute of Automotive Service Excellence task lists. The curriculum is composed of four units. Each unit of instruction may contain some or all of the following components: objective sheet, suggested…

  8. Driver Behavior and Situation Aware Brake Assistance for Intelligent Vehicles

    Microsoft Academic Search

    Joel C. McCall; Mohan M. Trivedi

    2007-01-01

    This paper deals with the development of Human-Centric Intelligent Driver Assistance Systems. Rear-end collisions account for a large portion of traffic accidents. To help mitigate this problem, predictive braking systems and adaptive cruise control systems have been developed. However, these types of systems usually rely solely on the vehicle and vehicle surround sensors, either ignoring the human component of driving

  9. Wear and related characteristics of an aircraft tire during braking

    NASA Technical Reports Server (NTRS)

    Mccarty, J. L.

    1972-01-01

    Wear and related characteristics of friction and temperature developed during braking of size 22 x 5.5, type aircraft tires are studied. The testing technique involved gearing the tire to a driving wheel of a ground vehicle to provide operations at constant slip ratios on asphalt, concrete, and slurry-seal surfaces. Data were obtained over the range of slip ratios generally attributed to an aircraft braking system during dry runway operations. The results show that the cumulative tire wear varies linearly with distance traveled and the wear rate increases with increasing slip ratio and is influenced by the runway-surface character. Differences in the wear rates associated with the various surfaces suggest that runways can be rated on the basis of tire wear. The results also show that the friction coefficients developed during fixed-slip-ratio operations are in good agreement with those obtained by other investigators during cyclic braking, in that the dry friction is insensitive to the tire tread temperature is shown to increase with increasing slip ratio and, at the higher ratios, to be greater during braking on asphalt and slurry seal than on concrete.

  10. 53. Drive shaft, motors, eddie currents, brakes, and differential gears ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    53. Drive shaft, motors, eddie currents, brakes, and differential gears in south machinery room (interior of both machinery rooms is identical). Facing east. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  11. 5. FLOOR 3; SHOWS BRAKE LEVER, BLOCK FORMERLY USED TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. FLOOR 3; SHOWS BRAKE LEVER, BLOCK FORMERLY USED TO RAISE IT AND HOOK WHICH KEPT IT IN THE 'OFF' POSITION; ALSO SEEN ARE THE LARGE BLOCKS SUSPENDED FROM THE CAP FRAME WHICH HOLD THE TRUCK WHEELS TO CENTER THE CAP - Hayground Windmill, Windmill Lane, East Hampton, Suffolk County, NY

  12. Interaction Control for a Brake Actuated Manipulator Brian Dellon

    E-print Network

    Matsuoka, Yoky

    workspace is required. One way to mitigate these safety concerns is through the use of a passively actuated with an environment and to extract/augment/assist human movement and sensing. One key issue is to ensure safe haptic display. Passive actuation through clutches [1], steerable mechanisms [2], or brakes [3] presents

  13. SO?UTMA KANALLI FREN D?SKLER?N?N FRENLEME KUVVETLER?NE VE ISI DE????M?NE ETK?LER? IMPACTS OF SELF COOLING BRAKE DISKS ON BRAKING FORCES AND HEAT CHANCING

    Microsoft Academic Search

    Mesut DÜZGÜN; Yakup YILDIZ

    b Abstract Brake systems are converting kinetic energy that a vehicle has to thermal energy. Heat should be transferred to the environment in a short period during this converting. Brake parts being imposed continuously excessive heat impacts brake performance negatively. Disks having different cooling structure were produced, heat change occurring on these disks and impacts on brake forces were investigated.

  14. Main braking phase for a soft moon landing as a form of trajectory correction

    NASA Astrophysics Data System (ADS)

    Likhachev, V. N.; Sikharulidze, Yu. G.; Fedotov, V. P.

    2013-12-01

    Rationale is given for the braking profile of a spacecraft making a soft landing on the Moon's surface, including the following four phases: main braking, free fall, repeated braking, and descent at a constant speed. Due to the large altitude differential over the braking path in near-polar regions of the Moon, main braking is proposed as a type of trajectory correction impulse using no altimeter. The boundary problem solution and statistical calculations are used to give the potential energy costs and characteristics of the dispersion characteristics for this phase and choose an optimal thrust-to-weight ratio for the phase.

  15. Laboratory sandbox validation of transient hydraulic tomography

    Microsoft Academic Search

    X. Liu; W. A. Illman; A. J. Craig; J. Zhu; T.-C. J. Yeh

    2007-01-01

    (1) Hydraulic tomography is a method that images the hydraulic heterogeneity of the subsurface through the inversion of multiple pumping or cross-hole hydraulic test data. Transient hydraulic tomography is different from steady state hydraulic tomography in that it utilizes transient hydraulic head records to yield the distribution of hydraulic conductivity (K) as well as specific storage (Ss) of an aquifer.

  16. Theoretical and experimental studies on a magnetorheological brake operating under compression plus shear mode

    NASA Astrophysics Data System (ADS)

    Sarkar, C.; Hirani, H.

    2013-11-01

    The torque characteristics of magnetorheological brakes, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnetic casing, are controlled by regulating the yield stress of the MR fluid. An increase in yield stress increases the braking torque, which means that the higher the yield strength of the MR fluid, the better the performance of the MR brake will be. In the present research an application of compressive force on MR fluid has been proposed to increase the torque capacity of MR brakes. The mathematical expressions to estimate the torque values for MR brake, operating under compression plus shear mode accounting Herschel-Bulkley shear thinning model, have been detailed. The required compressive force on MR fluid of the proposed brake has been applied using an electromagnetic actuator. The development of a single-plate MR disk brake and an experimental test rig are described. Experiments have been performed to illustrate braking torque under different control currents (0.0-2.0 A). The torque results have been plotted and compared with theoretical study. Experimental results as well as theoretical calculations indicate that the braking torque of the proposed MR brake is higher than that of the MR brake operating only under shear.

  17. Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker

    NASA Astrophysics Data System (ADS)

    Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

    2014-12-01

    The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in obtaining their estimates of these quantities before and after watching a video recording of a car braking from various initial speeds to a complete stop and subsequent application of mathematical statistics to the obtained sets of students' answers. The results revealed that the difference between the value of the car braking distance estimated before watching the video and the real value of this distance was not caused by a random error but by a systematic error which was due to the incorrect students' conceptions about the car braking process. Watching the video significantly improved the students' estimates of the car braking distance, and we show that in this case, the difference between the estimated value and the real value of the car braking distance was due only to a random error, i.e. the students' conceptions about the car braking process were corrected. Some of the students subsequently performed video analysis of the braking processes of cars of various brands and under various conditions by means of Tracker that gave them exact knowledge of the physical quantities, which characterize a motor vehicle braking. Interviewing some of these students brought very positive reactions to this novel method of learning.

  18. Analytica Chimica Acta 504 (2004) 199207 Arsenic speciation in Chinese brake fern by ion-pair high-performance

    E-print Network

    Ma, Lena

    2004-01-01

    Analytica Chimica Acta 504 (2004) 199­207 Arsenic speciation in Chinese brake fern by ion-pair high) and arsenate [As(V)] in Chinese brake fern (Pteris vittata L.). The separation was performed on a reverse in the Chinese brake fern, indicating that Chinese brake fern can convert MMA to DMA by methylation. © 2003

  19. Guidelines for numerical vibration and acoustic analysis of disc brake squeal using simple models of brake systems

    NASA Astrophysics Data System (ADS)

    Oberst, S.; Lai, J. C. S.; Marburg, S.

    2013-04-01

    Brake squeal has become of increasing concern to the automotive industry but guidelines on how to confidently predict squeal propensity are yet to be established. While it is standard practice to use the complex eigenvalue analysis to predict unstable vibration modes, there have been few attempts to calculate their acoustic radiation. Here guidelines are developed for numerical vibration and acoustic analysis of brake squeal using models of simplified brake systems with friction contact by considering (1) the selection of appropriate elements, contact and mesh; (2) the extraction of surface velocities via forced response; and (3) the calculation of the acoustic response itself. Results indicate that quadratic tetrahedral elements offer the best option for meshing more realistic geometry. A mesh has to be sufficiently fine especially in the contact region to predict mesh-independent unstable vibration modes. Regarding the vibration response, only the direct, steady-state method with a pressurised pad and finite sliding formulation (allowing contact separation) should be used. Comparison of different numerical methods suggest that a obroadband fast multi-pole boundary element method with the Burton-Miller formulation would efficiently solve the acoustic radiation of a full brake system. Results also suggest that a pad lift-off can amplify the acoustic radiation similar to a horn effect. A horn effect is also observed for chamfered pads which are used in practice to reduce the number and strength of unstable vibration modes. These results highlight the importance of optimising the pad shape to reduce acoustic radiation of unstable vibration modes.

  20. Shuttle Rudder/Speed Brake Power Drive Unit (PDU) Gear Scuffing Tests With Flight Gears

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P.; Oswald, Fred B.; Krants, Timothy L.

    2005-01-01

    Scuffing-like damage has been found on the tooth surfaces of gears 5 and 6 of the NASA space shuttle rudder/speed brake power drive unit (PDU) number 2 after the occurrence of a transient back-driving event in flight. Tests were conducted using a pair of unused spare flight gears in a bench test at operating conditions up to 2866 rpm and 1144 in.-lb at the input ring gear and 14,000 rpm and 234 in.-lb at the output pinion gear, corresponding to a power level of 52 hp. This test condition exceeds the maximum estimated conditions expected in a backdriving event thought to produce the scuffing damage. Some wear marks were produced, but they were much less severe than the scuffing damaged produced during shuttle flight. Failure to produce scuff damage like that found on the shuttle may be due to geometrical variations between the scuffed gears and the gears tested herein, more severe operating conditions during the flight that produced the scuff than estimated, the order of the test procedures, the use of new hydraulic oil, differences between the dynamic response of the flight gearbox and the bench-test gearbox, or a combination of these. This report documents the test gears, apparatus, and procedures, summarizes the test results, and includes a discussion of the findings, conclusions, and recommendations.

  1. TU Delft: Hydraulic Engineering

    NSDL National Science Digital Library

    Given the Dutch reputation for water management, it's no surprise that one of their leading technical institutes, The Technische Universiteit Delft, offers a program in Hydraulic Engineering. The website, in both Dutch and English, describes their program as an attempt "to bridge the gap between basic sciences (fluid mechanics and soil mechanics in particular) and practical engineering applications in the design, construction, maintenance, management and eventually the demolition of hydraulic structures." The Education section of the website posts MSc theses completed by their students. The research section describes current and recently completed research projects and includes a listing of publications, some of which are available to download. The website also has a link to a Hydraulic Engineering portal, which offers various publication databases (some in Dutch only), and the Civil Engineering Knowledge Centre, which provides library access and discussion forums for students and staff of Civil Engineering.

  2. Investigation of temperature and thermal stress in ventilated disc brake based on 3D thermo-mechanical coupling model

    Microsoft Academic Search

    Pyung Hwang; Xuan Wu

    2010-01-01

    Ventilated disc brakes are widely used for reducing velocity due to their braking stability, controllability and ability to\\u000a prove a wide-ranging brake torque. During braking, the kinetic energy and potential energies of a moving vehicle are converted\\u000a into thermal energy through friction heating between the brake disc and the pads. The object of the present study is to investigate\\u000a the

  3. Hydraulics of wells

    USGS Publications Warehouse

    McLaughlin, Thad G.

    1955-01-01

    Although the subject of this lecture is supposed to be concerned primarily with the hydraulics of wells, Professor Weers has asked that I also discuss the effects tat geological formations have on the quantity and quality of water available to wells. I will discuss the geology of Colorado in relation to the availability and quality of water with particular reference to the most productive aquifers or water-bearing formations in the State. I will then discuss the hydraulics of wells with the aim of emphasizing the differences between water-table and artesian conditions.

  4. What Is Hydraulic Fracturing?

    NSDL National Science Digital Library

    2012-01-01

    Hydraulic fracturing is a process used in nine out of 10 natural gas wells in the United States, where millions of gallons of water, sand and chemicals are pumped underground to break apart the rock and release the gas. Scientists are worried that the chemicals used in fracturing may pose a threat either underground or when waste fluids are handled and sometimes spilled on the surface. This poster presentation illustrates the under surface process of hydraulic fracking and the distribution flow to the market.

  5. Geostatistical inference of hydraulic conductivity and dispersivities from hydraulic heads and tracer data

    E-print Network

    Cirpka, Olaf Arie

    Geostatistical inference of hydraulic conductivity and dispersivities from hydraulic heads; accepted 25 April 2006; published 10 August 2006. [1] In groundwater, hydraulic heads and solute arrival times depend primarily on the hydraulic conductivity field and hydraulic boundary conditions. The spread

  6. Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report

    SciTech Connect

    Lascurain, Mary Beth [ORNL; Capps, Gary J [ORNL; Franzese, Oscar [ORNL

    2013-10-01

    The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data revealed a linear relationship between brake application pressure and was used to develop an algorithm to normalize stopping data for weight and initial speed.

  7. Laboratory Determination of Hydraulic Conductivity

    NSDL National Science Digital Library

    From D.B. McWhorterand D. K. Sunda's 1977 Ground-Water Hydrology and Hydraulics, this two page excerpt outlines and details Laboratory Determination of Hydraulic Conductivity. Here, visitors will find illustrations and formula to understand the concept.

  8. 46 CFR 28.880 - Hydraulic equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  9. 46 CFR 28.405 - Hydraulic equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  10. 46 CFR 28.405 - Hydraulic equipment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  11. 46 CFR 28.405 - Hydraulic equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  12. 46 CFR 28.405 - Hydraulic equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  13. 46 CFR 28.405 - Hydraulic equipment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  14. 46 CFR 28.880 - Hydraulic equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  15. 46 CFR 28.880 - Hydraulic equipment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  16. 46 CFR 28.880 - Hydraulic equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  17. Inductive braking of thermomagnetic avalanches in superconducting films

    NASA Astrophysics Data System (ADS)

    Vestgården, J. I.; Mikheenko, P.; Galperin, Y. M.; Johansen, T. H.

    2014-05-01

    The stabilizing effect of placing a normal metal layer adjacent to a thermomagnetically unstable superconducting film is investigated. By solving the coupled Maxwell and heat transfer equations numerically it is shown that the metal, via inductive braking of the rapidly propagating flux avalanches, strongly reduces their impact. It is found that with increasing thickness and/or electrical conductivity of the metal layer, the number of avalanche events increases, while the amount of flux involved in each avalanche is strongly reduced, resulting in an overall more stable thermomagnetic system. The numerical results provide detailed insight into the braking process, and explain both previous dc magnetometry measurements and new magneto-optical imaging results obtained for a superconducting NbN film coated with a Cu-layer.

  18. Magnetic Braking and Protostellar Disk Formation: The Ideal MHD Limit

    E-print Network

    Richard R. Mellon; Zhi-Yun Li

    2007-09-04

    Magnetic fields are usually considered dynamically important in star formation when the dimensionless mass-to-flux ratio is close to, or less than, unity (lambda~100, they merge together to form a more or less contiguous, rotationally supported disk. Even though the magnetic field in such a case is extremely weak on the scale of dense cores, it is amplified by collapse and differential rotation, to the extent that its pressure dominates the thermal pressure in both the disk and its surrounding region. For relatively strongly magnetized cores with lambdalines. For rotationally supported disks to appear during the protostellar mass accretion phase of star formation in dense cores with realistic field strengths, the powerful magnetic brake must be weakened, perhaps through nonideal MHD effects and/or protostellar winds. We discuss the possibility of observing a generic product of the magnetic braking, an extended circumstellar region that is supported by a combination of toroidal magnetic field and rotation - a "magnetogyrosphere".

  19. Bohmian quantization of the big-brake singularity

    NASA Astrophysics Data System (ADS)

    Pinto-Neto, Nelson; Pantoja, Diego Moraes

    2014-04-01

    The aim of this paper is to study the quantum aspects of the big-brake singularity. This is a singularity where the expansion of the universe stops abruptly, with infinity deceleration, caused by the divergence of the pressure of the fluid which describes the matter content of the model. In order to obtain our results, we interpret the quantum solutions of the Wheeler-DeWitt equation obtained from the canonical quantization of the classical model using the de Broglie-Bohm (dBB) quantum theory. Analyzing the Bohmian trajectories, we show that when one approaches the big-brake singularity, the universe still stops expanding, but now with finite deceleration, and initiates a smooth contracting phase. The pressure and the curvature never diverge.

  20. Integration in Hydraulics.

    ERIC Educational Resources Information Center

    Sworder, Steven C.

    This paper presents an application of integration to the field of hydraulics. An integral relation for the time required to drop the fluid contained in a cylindrical tank from one level to another using a hole in the tank wall is derived. Procedures for constructing the experimental equipment and procedures for determining the coefficient of…