Identification of Organic Compounds Released from Low-Metallic Automotive Model Brake Pad and its Non-Airborne Wear Particles
Abstract The brake wear contribution to the environmental pollution has been extensively discussed, with major focus on asbestos and heavy metals released to the environment. Only limited attention was paid to released organic compounds generated during friction processes, although the organic and carbonaceous components are not the minor part in brake lining formulations. Friction processes in brakes are associated with relatively high temperatures and high pressures on the friction surfaces which relates to the thermal decomposition of the organic components in friction materials and to brake lining thermal fade. Thus, this study focuses on the identification of organic compounds released from a model low metallic brake material.
Abstract Brake linings have complex microstructure and consist of different components. Fast growing automotive industry requires new brake lining materials to be developed at considerably shorter time periods. The purpose of this research was to generate the knowledge for optimizing of brake friction materials formula with mathematical methods which can result in minimizing the number of experiments/test, saving development time and costs with optimal friction performance of brakes. A combination of processing methods, raw materials and testing supported with the Artificial Neural Network (ANN) and Taguchi design of experiment (DOE) allowed achieving excellent results in a very short time period. Friction performance and wear data from a series of Friction Assessment and Screening Test (FAST) were used to train an artificial neural network, which was used to optimize the formulations. The averaged COF, COF variation and wear were used as the output parameters.
Promaxon® D in NAO Non Steel Disc Pad Fromulations: the Importance in the Third Body Layer and its Effect on Brake Noise
Abstract Friction performance is the result of the interaction between rotor and friction material surfaces. Kinetic energy has to be transformed into heat, plastic deformations, chemical reactions and wear debris. The later generates the formation of the so-called third body layer and its initiation, growth and degradation will generate the actual friction coefficient and vibrations behavior. Some raw materials seem to promote third body layer formation more than others. The composition of plateaus usually contains iron oxide, copper, carbon, silicon and calcium. Since copper free materials are under development, the importance of understanding the third body layer formation has become bigger. Promaxon® D is widely used in NAO non steel formulations. It is a calcium silicate with a special morphology that influences friction material at two levels: the macro -bulk- scale and the micro -surface- scale. Bulk effect is related to the volume and porosity degree of the friction material.
Abstract An aspect of high performance brake design that has remained strikingly empirical is that of determining the correct sizing of the brake pad - in terms of both area and volume - to match well with a high performance vehicle application. Too small of a pad risks issues with fade and wear life on the track, and too large has significant penalties in cost, mass, and packaging space of the caliper, along with difficulties in maintaining adequate caliper stiffness and its impact on pedal feel and response time. As most who have spent time around high performance brakes can attest to, there methods for determining minimum brake pad area, usually related in some form or another to the peak power the brake must absorb (functions of vehicle mass and top speed are common). However, the basis for these metrics are often lost (or closely guarded), and provide very little guidance for the effects of the final design (pad area) deviating from the recommended value.
The new Joint Light Tactical Vehicle program, worth $30 billion, brings superior survivability to the U.S. Army and Marine Corps. most prolific multi-mission mobility platform.
Without idling the truck’s main engines, an auxiliary power unit can provide heating and cooling to maintain a comfortable temperature in the cab and sleeper, as well as power laptops, gaming machines, and microwaves. Fleets need to provide drivers with the ability to maintain their wanted comfort level on the road while also ensuring resources are being used wisely.
This document proposes methods for the testing and evaluation of aluminum wheel and wheel trim surface finishes for compatibility with various types of tire, wheel and car wash cleaning materials, and other chemicals that might come into contact with these automotive components. It is recognized that each end user of this methodology might seek answers to questions that are unique to his business or situation. Therefore, the procedure is written in a generic sequence that could be strictly followed, repeated, or modified in order to provide the user with the best results. Example decision tree are provided to help the user select a sequence of exposure steps that would best suit his needs, (reference Figures 1, 2). This procedure should not be utilized if the intent is to evaluate the compatibility of wheel finishes to any flammable products, because those chemistries would require special laboratory safety and handling precautions.
This SAE Recommended Practice describes a test method for determination of heavy truck tire force and moment properties under combined cornering and braking conditions. The properties are acquired as functions of slip angle, normal force, and slip ratio. Slip angle and normal force are changed incrementally using a sequence specified in this document. At each increment, the slip ratio is continually changed by application of a braking torque ramp. The data are suitable for use in vehicle dynamics modeling, comparative evaluations for research and development purposes, and manufacturing quality control.
Endurica targets tire and rubber product developers with new software release. CAE software adds features for the analysis of rolling structures, self-heating, wrinkling, and cavitation.
This SAE Recommended Practice describes a test method for determination of heavy truck (Class VI, VII, and VIII) tire force and moment properties under free-rolling cornering conditions. The steady-state properties are acquired as functions of slip angle and normal force, which are changed incrementally using a sequence specified in this document. The data are suitable for use in vehicle dynamics modeling, comparative evaluations for research and development purposes, and manufacturing quality control. This document addresses two principal topics; a) the description of a hypothetical “Ideal Machine,” and b) a standard directly applicable to testing practices currently common to the industry. The references to the “Ideal Machine” are meant to provide a roadmap for the testing machine manufacturer, providing direction and goals for the next generation of testing capabilities.
This set is comprised of two titles, Advances in Aircraft Landing Gear and Advances in Aircraft Brakes and Tires both edited by Robert Kyle Schmidt, a mechanical engineer and known expert in this subject. Advances in Aircraft Landing Gear is a collection of eleven hand-picked technical papers focusing on the significant advancements that have occurred in this field concerning numeric modeling, electric actuation, and composite materials. Advances in Aircraft Brakes and Tires focuses on the aircraft’s interface with the ground – through its wheels, tires and brakes – a critical part of a safe and reliable operation. It presents a selection of the most relevant papers published by SAE International on these matters in the past fifteen years.
This SAE Standard covers two types of hose fabricated from textile reinforcement and synthetic rubber, assembled with end fittings for use in high-temperature automotive power steering applications as flexible connections within the temperature range of -40 to +150 °C (-40 to +302 °F) maximum and 10.3 MPa (1500 psi) maximum working pressure. These hoses are intended for use in applications where reduction in amplitude of pump pressure pulsation is required. Class A hose has a nominal OD of 19.84 mm (0.781 in). Class B hose is a lightweight hose with a nominal OD of 17.91 mm (0.705 in). This specification defines the minimum performance levels of a flexible connector in the hydraulic steering system to convey power steering fluid from the steering pump to the steering gear.
Abstract The vertical force generated from terrain-tire interaction has long been of interest for vehicle dynamic simulations and chassis development. To improve simulation efficiency while still providing reliable load prediction, a terrain pre-filtering technique using a constraint mode tire model is developed. The wheel is assumed to convey one quarter of the vehicle load constantly. At each location along the tire's path, the wheel center height is adjusted until the spindle load reaches the pre-designated load. The resultant vertical trajectory of the wheel center can be used as an equivalent terrain profile input to a simplified tire model. During iterative simulations, the filtered terrain profile, coupled with a simple point follower tire model is used to predict the spindle force. The same vehicle dynamic simulation system coupled with constraint mode tire model is built to generate reference forces.
Hardness measurements are used as a quality control check of the consistency of formulation and processing of brake linings. This hardness method is nondestructive. NOTE-This method is not a measure of friction level. The hardness and the range of hardness are characteristic of each formulation; therefore, the acceptable values and ranges must be established for each formulation and may be affected by processing. NOTE-The hardness of sintered powder metal lining is usually determined with Rockwell superficial hardness equipment. (See ASTM B 347)
Semi-solid casting is a near-net shape casting process that is capable of producing extremely high-quality castings. It differs from all other casting processes as it does not use fully liquid metal to produce the castings, instead using a feed material that is preferably about 50% solid and 50% liquid.
The aircraft landing gear system is relatively unique on board an aircraft—it is both structure and machine, supporting the aircraft on the ground, yet providing functions such as energy absorption during landing, retraction, steering, and braking. Advances in Aircraft Landing Gear is a collection of eleven hand-picked technical papers focusing on the significant advancements that have occurred in this field concerning numeric modeling, electric actuation, and composite materials. Additionally, papers discussing self-powered landing gear and more electrical overall aircraft architectures have been included. The content of Advances in Aircraft Landing Gear is divided into two sections: Analysis and Design Methods; and Electric Actuation, Control, and Taxi.
An aircraft’s interface with the ground—through its wheels, tires, and brakes—is critical to ensure safe and reliable operation, demanding constant technology development. Significant advancements have occurred with almost all civil airliners entering service with radial tires, and with the Boeing 787 having entered service in 2011 with electrically actuated carbon-carbon brakes. This book is divided into three sections: tires, control systems, and brakes, presenting a selection of the most relevant papers published by SAE International on these matters in the past fifteen years. They have been chosen to provide significant interest to those engineers working in the landing gear field. With almost all current large civil aircraft (and many smaller aircraft) opting exclusively for carbon-carbon brakes, a number of papers addressing the challenges of this technology are included. Papers touching on tire behavior and papers discussing brake control strategies are provided.
Hyundai enhances NVH with 2016 Tucson’s re-engineered suspension—including ‘world first’ dual-member damper housing
No area of the third-generation Tucson crossover utility vehicle was left untouched by Hyundai engineers, but particular attention was placed on re-engineering the chassis for improved ride and handling, and importantly, better NVH characteristics. The CUV employs a dual-reinforcing panel rear wheelhouse design, which optimizes panels that are prone to vibration, resulting in a 109% increase in rigidity.
The SAE J2530 provides performance, sampling, test procedures, and marking requirements for wheels intended for normal highway use on passenger cars, light trucks, and multipurpose passenger vehicle. This Recommended Practice (which is separate from SAE J2530) specifies the workflow of the Wheel Conformity Assessment Program. This program allows wheel manufacturers to register their product compliant to SAE J3010. The following items precede display of “SAE J3010” on any particular wheel design: a. Manufacturer registration All manufactures with the objective to pursue registration, shall complete the registration as an individual manufacturer via the registrar’s website http://wheeldb.registrar.domain. The registration includes company contact information, wheels produced, and company identification marks. b.
This recommended practice shall apply to all on-highway trucks and truck-tractors equipped with air brake systems and having a GVW rating of 26 000 lb or more.
The SAE Recommended Practice specifies a standardize method and test procedure to measure low pressure differential (< 1bar) brake component brake fluid flow performance. The standard can be utilized for flow measurements across hydraulic brake components such as master cylinders, apply system to chassis controls piping, or other sources of flow restriction in the low pressure side of the hydraulic brake system. It covers materials, manufacturing processes, and general properties required to meet the wide range of service encountered in automotive application. This specification covers only low pressure differential fluid flow and does not include measurement recommended practice for High Pressure differential (> 1 bar) flows.
This SAE Aerospace Information Report (AIR) applies to landing gear tires and airframe structure for all types and models of civil and military aircraft having tires as part of the landing gear.
Performance Analysis of the ABS Control on Parallel Hybrid Electric Vehicle Equipped with Regenerative Braking System
Abstract Anti-lock brake system (ABS) prevents the vehicle wheels from locking up and reduces the total stopping distance as far as possible. The current implementation is based on a traditional hydraulic disk brake and small wheel inertia. Seen the need for making vehicles cleaner in the future, it can be expected that an increasing the amount of vehicles will be equipped with electric motors able to regenerate energy during braking. The addition of this electric motor changes the properties of the brake actuation and has an influence on the wheel inertia. However, the objective of this paper is to study the change of the dynamics induced by the regenerative braking which assess the performance of traditional ABS systems on the parallel hybrid electric vehicles. The MATLAB software to establish the simulation model, which include the single wheel dynamic model, hydraulic brake system model, electric motor brake system model and traditional ABS controller were used.
This procedure describes a method for measuring the fraction of underlayer (also referred to as backing layer) existing at any given height above the a disc brake friction materials shoe plate. Measuring underlayer distribution is useful for computing useable lining thickness and for friction material quality management.
This SAE Standard covers motor vehicle brake fluids of the nonpetroleum type, based upon glycols, glycol ethers, and borates of glycolethers, and appropriate inhibitors, for use in the braking system of any motor vehicle such as a passenger car, truck, bus, or trailer. These fluids are not intended for use under arctic conditions. These fluids are designed for use in braking systems fitted with rubber cups and seals made from styrene-butadiene rubber (SBR), or a terpolymer of ethylene, propylene, and a diene (EPDM).
This SAE Standard covers motor vehicle brake fluids of the nonpetroleum type, based upon glycols, glycolethers and appropriate inhibitors, for use in the braking system of any motor vehicle such as a passenger car, truck, bus, or trailer. These fluids are not intended for use under arctic conditions. These fluids are designed for use in braking systems fitted with rubber cups and seals made from styrene-butadiene rubber (SBR), or a terpolymer of ethylene, propylene, and a diene (EPDM).
This SAE Aerospace Information Report (AIR) provides information on the parking brake system design for a variety of aircraft including part 23, 25, 27, and 29. The document includes a discussion of key technical issues with parking brakes. This document does NOT provide recommended practices for parking brake system design.
A New Semi-Empirical Method for Estimating Tire Combined Slip Forces and Moments during Handling Maneuvers
Modeling the tire forces and moments (F&M) generation, during combined slip maneuvers, which involves cornering and braking/driving at the same time, is essential for the predictive vehicle performance analysis. In this study, a new semi-empirical method is introduced to estimate the tire combined slip F&M characteristics based on flat belt testing machine measurement data. This model is intended to be used in the virtual tire design optimization process. Therefore, it should include high accuracy, ease of parameterization, and fast computational time. Regression is used to convert measured F&M into pure slip multi-dimensional interpolant functions modified by weighting functions. Accurate combined slip F&M predictions are created by modifying pure slip F&M with empirically determined shape functions. Transient effects are reproduced using standard relaxation length equations. The model calculates F&M at the center of the contact patch.
Off-highway machine mounting systems, especially the cab mounting system, significantly affect the operator comfort in the cab by providing enough damping for a good ride and isolating the structure-borne forces from traveling into the cab.
This document applies to direct acting vacuum power assist brake boosters only, exclusive of the master cylinder or other brake system prime mover devices for passenger cars and light trucks [4500 kg GVW (10 000 lb)]. It specifies the test procedure to determine minimum performance and durability characteristics.