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Standard
2014-05-07
These performance requirements have been established for manual slack adjusters when tested to SAE J1461. To establish acceptable levels of performance for manual slack adjusters.
Technical Paper
2014-05-07
Eraldo de Jesus Soares, Alan M. Oliva, Camilo A. Adas, Fernando C. Dusi, Paulo Sergio P. Santos, Marco A. Fogaça Accurso, Marcus Kliewer
Abstract The purpose of this paper is to show a multiaxial bench test for static and dynamic testing of leaf springs for suspension of commercial vehicles. The bench test simulates the critical operating conditions (track, ramp, speed bump on track, curves and braking), with stroke control for strength and deformation analysis. One of the main advantages in bench test is to reduce the time of the test, its repeatability, its cost saving and monitoring its performance through inspections and graphic records. The aim of the test is to evaluate the behavior in durability of the components, to analyze the possible failure mode and to be able to approve or reject the component based on the test's results. Criteria were set to accelerate the test by comparing signals measured on the field and bench test with deflection by stress curves. These criteria were maintained under extreme conditions for longer than the observed in previous and real applications. With this, the low incidence of strength and stroke is measured by optimizing the time of the test.
Technical Paper
2014-05-07
Marcos dos Santos, Ricardo Guedes Manini, Jayme B. Curi, Cleber Chiqueti
Abstract ”U” bolts are fixing elements and they are used to clamp an elastic joint. From the past, they still looking as an old design and unfortunately, suspension engineers are not specialists in fasteners and elastic joints. That is why we will show important assumptions and concepts to design and specifications this clamp element “U” bolt and its influence over leaf-springs. Currently, “U” bolt is used to clamp an elastic or elastic-plastic joint of heavy duty suspension, formed by leaf-spring, axle, spring pad, “U” bolt plate. This kind of suspension is typically used to trucks, buses and trailers. We are wondering, which one important assumption that an engineer must be careful when designs a new suspension changing from old designs to an updated technology. We provide a theoretical analysis and a FEA analysis to compare torque efficacy x leaf-spring reactions and what are effects this relationship can cause in a suspension. To have a shortest development time and provide back an expected result from the suspension system, engineers should to consider more and new assumptions, evaluate virtual and practical performance of leaf-springs with “U” bolt designed to clamp all elastic joint and even the correct torque specification to the “U” bolt.
Technical Paper
2014-05-07
Claudio Gomes Fernandes, Eric Noguchi, Rômulo Castro, Uilian Almeida
Abstract Automotive industry has shown, in the recent years, a dramatically increase of competition at emergent markets. The incoming of new Brands, for example in the Brazilian market, is causing the OEMs to decrease costs while increase quality, which represents a big challenge nowadays. In this challenging scenario, virtual simulation has become mandatory. While cutting costs since no physical prototypes are required, virtual models also reduces development time. Time to time, as computers processing capacity grows, virtual models are becoming more and more accurate, being able to capture even high non-linear phenomena, which ten years ago would not be feasible. It is also known the natural tendency of vehicle dynamics engineers to develop shock absorber tuning only by means of subjective evaluation. Many reasons can be raised to this tendency, but one of them is the lack of representation of the entire shock absorber behavior in the virtual models. In this sense, the present work shows an attempt to capture the main non-linearities of shock absorbers that affect the most the vehicle behavior in terms of ride and handling.
Technical Paper
2014-05-07
Alfred Memmel, Anibal Berberich
Abstract Variable Damping systems for commercial vehicle applications have been in the market for several years now. The systems modify damping according to the actual demand within milliseconds. This reduces vertical accelerations which lead to improved comfort while maintaining vehicle stability and safety at the same time. Driver, cargo and vehicle are better protected. The technical effort for variable damping systems was in the past rather high and affected a limited market penetration. On the other side the used control algorithms did not tap the full potential of the system performance. New concepts, like integration of sensors or concentration on the most relevant axle, in combination with new control algorithms, simplifies the systems architecture and improves the performance. Besides the functional advantages, the system improves vehicle efficiency as it reduces the energy dissipated by the dampers. This energy would have to be generated by the engine. Less damping also relates to reduction of fuel consumption.
Technical Paper
2014-05-07
Saulo Machado Rodrigues, André Soares, Henrique Zambon, Odair Berti, Rudimar Mazzochi
During the field tests of a prototype of a cabin suspension assembly applied in a commercial vehicle it has been evidenced the premature failure in the torsion bar. Due to this failure, which happened with 20% of approval total test, one verified that the adding of a lateral displacement control bar (Panhard), attached to the torsion bar, promoted a significant additional force to it, which was not predicted in the initial dimensioning. Due to that, it was executed a re-design of the assembly, paying a special attention to the torsion bar, considering the influence of Panhard bar. To do that, several numerical simulations were carried out, using the finite element software Abaqus, whose boundary conditions were determined based on data collected in the field tests. Lately, the new concepts developed were submitted to bench tests, applying hydraulic actuators to apply the loads, in which one executed an experimental verification of stresses to calibrate the numerical models.
Technical Paper
2014-05-07
Frederico A. A. Barbieri, Vinicius de Almeida Lima, Leandro Garbin, Joel Boaretto
Abstract Brazil presents a very diverse road and traffic conditions and due to several factors the number of truck accidents is very high. Inside truck accidents group, the one that causes the highest number of losses and fatalities is the rollover crash and understanding rollover dynamics is very important to prevent such events. The diversity of cargo vehicles arrangements requires a detailed study regarding the dynamic behavior these vehicle combinations in order to increase operation safety. The same tractor unit can be used with different types and numbers of trailers and/or semi-trailers, each one with different suspension configurations. These truck combinations have distinct dynamic performances that need evaluation. In this sense, this work presents a first phase study on the dynamic behavior of different types of cargo vehicle configuration. A 6×2 tractor is combined with a two distinct grain semi-trailer with different types of suspension: pneumatic and leaf spring. The study is conducted in order to verify the difference in dynamic behavior and the resulting stability of the two configurations in different conditions of speed and maneuvers.
Technical Paper
2014-05-07
Fabio Augusto Schuh, Leandro Luís Corso, Leonardo Hoss
Abstract Applying knowledge available at technical literature for cycle counting, damage caused by each load cycle through S-N curve, and fatigue damage accumulation by Palmgren-Miner rule, durability prediction is performed for a leafspring of a commercial vehicle with 6×4 suspension system. Max principal tension is measured by means of strain gages in the most representative points for fatigue life of the leafspring, determined with FEA, while vehicle runs over off-road track in a proving ground. Load and tension are also measured in a laboratory bench test for this component. Correlation between off-road track and bench test is then performed. Finally, representative samples of the component are tested with dynamic loading until fatigue fracture in bench test, and using data from these tests, statistical analysis is performed with application of Weibull distribution, allowing life prediction in statistical terms.
Article
2014-04-29
Despite the burgeoning success of highly effective single platform modular solutions, hardware variation is not falling, warns BWI Group global technology executive Olivier Raynauld.
WIP Standard
2014-04-29
This SAE Aerospace Standard (AS) sets forth criteria for the selection and verification processes to be followed in providing tires that will be suitable for intended use on civil aircraft. This document encompasses new and requalified radial and bias aircraft tires.

This document establishes the minimum recommended performance standards for new tires to be used on civil aircraft. All new or requalified tires shall meet these standards.

Standard
2014-04-28
This SAE Recommended Practice is intended for testing of manual slack adjusters as they are used in service, emergency, or parking brake systems for vehicles that can be licensed for on-road use. Purpose This document establishes an accelerated laboratory test procedure for manual slack adjusters to determine their integrity and durability in various functional modes and environmental conditions.
Technical Paper
2014-04-28
Y. S. Thipse
Abstract Hyperelastic material simulations are commonly performed in commercial FE codes due to availability of sophisticated algorithms facilitating virtual characterization of such materials in FEA easily. However, the solution time required is longer in FEA. Especially when excitation frequencies do not interfere with structural modes, flexible multibody simulation offers a lucrative and computationally inexpensive alternative. However, it is difficult to directly characterize hyperelastic materials in commercial MBS simulation codes, so the reduced solution time comes at the cost of decreased simulation accuracy, especially if the designer is provided with crude stress - strain test data. Hence, the need is to overcome the drawbacks in FEA and multibody codes, as well as to leverage best of both these codes simultaneously. A methodology is presented where non-linear stiffness properties of the hyperelastic materials are expressed as an analytical function in terms of constants of hyperelastic constitutive material models.
Technical Paper
2014-04-28
Shital M. Kalikate, Satyajit R. Patil, Suresh M. Sawant
Abstract Magneto-rheological (MR) fluid is a type of smart material which has ability to change its flow resistance on the application of magnetic field. This property of changing viscosity of the fluid due to application of magnetic field is utilized in the MR brake. MR brake typically consists of multiple rotating disks immersed in MR fluid and an enclosed electromagnet. The controllable yield stress produces shear friction on the rotating disks, generating the braking torque. Of late MR brakes have been explored for automotive applications. Literature review reveals that the torque output of MR brake is not sufficient for braking of mid-sized car. Hence, it is worthwhile to investigate its application for a two-wheeler where the braking torque requirement is low. This paper presents design and simulation of MR brake performance for its torque output. Design of MR brake involves deciding the configuration of MR brake in terms of number and sizing of disks, selection of MR fluid and design of magnetic circuit.
Technical Paper
2014-04-28
Ashok KK, Bade Simhachalam, Dhanooj Balakrishnan, Krishna Srinivas
Abstract In this paper, the application of tube Extrusion for the development of stepped tubular components is discussed. Thickness increase with respect to cold reduction of diameter is predicted with reasonable accuracy. Thickness increase, length increase and strain hardening coefficient for a given cold reduction of diameter of tube are obtained using LS-DYNA Software. True stress-plastic strain curves from the tensile test are used in the forming simulation using LS-DYNA. A special purpose machine is developed for the production of steering shaft components. Considerable reduction in weight is achieved by using stepped tubular components.
Technical Paper
2014-04-28
Rohitt Ravi, Sivasubramanian, Bade Simhachalam, Dhanooj Balakrishnan, Krishna Srinivas
Abstract Tubular stabilizer bar for commercial vehicle is developed using advanced high strength steel material. Tubular section is proposed to replace the existing solid section. The tubular design is validated by component simulation using ANSYS Software. The tubes are then manufactured of the required size. The bend tool is designed to suit the size of the profile stabilizer bar and the prototypes are made using the tube bending machine. The strength of the tubular stabilizer is increased by using robotic induction hardening system. The tubular stabilizer bar is tested for fatigue load using Instron actuators. Higher weight reduction is achieved by replacing the existing solid stabilizer bar with the tubular stabilizer bar.
WIP Standard
2014-04-21
This SAE Recommended Practice was prepared by the Motor Vehicle Brake Fluids Subcommittee of the SAE Hydraulic Brake Systems Actuating Committee to provide engineers, designers, and manufacturers of motor vehicles with a set of minimum performance standards in order to assess the suitability of silicone and other low water tolerant type brake fluids (LWTF) for use in motor vehicle brake systems. These fluids are designed for use in braking systems fitted with rubber cups and seals made from natural rubber (NR), styrene-butadiene rubber (SBR), or a terpolymer of ethylene, propylene, and a diene (EPDM). In the development of the recommended requirements and test procedures contained herein, it is concluded that the LWTFs must be functionally compatible with existing motor vehicle brake fluids conforming to SAE J1703 and with braking systems designed for such fluids. To utilize LWTFs to the fullest advantage, they should not be mixed with other brake fluids. Inadvertent mixtures of LWTFs with fluids meeting SAE J 1703 are not known to have any adverse effects on performance, but all combinations have not been tested.
Standard
2014-04-16
This SAE Information provides information applicable to production Original Equipment Manufacturer antilock braking systems found on some past and current passenger cars and light trucks. It is intended for readers with a technical background. It does not include information about aftermarket devices or future antilock brake systems. Information in this document reflects that which was available to the committee at the time of publication.
Book
2014-04-11
Today’s designers seek to integrate sensor technology, electronic and mechatronic systems in progressively introducing Electric Power Steering (EPS) systems. However, from a customer perspective on the one hand steering is one of the most visible or tangible aspects of vehicle quality in driving when quality is compromised (through NVH issues), while on the other hand, when executed well, a steering system is all but transparent to the driver. To a number of commentators and OEMs ‘steering feel’ has become termed as contributing to the essential ‘DNA” of the vehicle, and it is therefore an essential aspect of competitive advantage or position. This report examines steering feel and the increasing effect of vehicle electrification, and looks at steering and chassis performance. It also considers the key drivers including fuel efficiency and CO2 emissions, steering design, materials considerations and the packaging dilemma. Furthermore the report looks at the latest steering system trends, in particular electrically power assisted steering (EPAS), electro-hydraulic power steering (EHPS), electric power steering (EPS), active front steering (AFS), four-wheel steering, steer-by-wire, automated parking and NVH reduction.
WIP Standard
2014-04-10
This SAE Recommended Practice provides a method for testing the speed performance of light truck tires under controlled conditions in the laboratory on a test wheel.
WIP Standard
2014-04-10
This Recommended Practice describes the determination of tire pull force properties for an uninclined tire (SAE J670e) on a laboratory flat surface tire force and moment machine. It is suitable for accurately determining pull forces and residual aligning moments for passenger and light-truck tires. These properties are important determinants of vehicle trim. They describe steady-state, free-rolling pull effects ascribable to tires. The test method described in this document is suitable for comparative evaluation of tires for research and development purposes. The method is also suitable for modeling when followed carefully.
WIP Standard
2014-04-10
This SAE Recommended Practice describes the determination of passenger car and light truck tire force and moment properties on a belt-type flat surface test machine. It is suitable for accurately determining five tire forces and moments in steady-state under free-rolling conditions as a function of slip angle and normal force which are incrementally changed in a given sequence. Heavy-duty tires are not considered in this document, because the measuring system would have force and moment ranges too large to meet sensitivity requirements for passenger and light truck tire force and moment measurements. A standard for heavy-duty truck tires would have many of the same features as this document, but the measuring system, would have to be extensively altered. Inclination angle combined with slip angle, pull forces, and any combination with spindle torque are not considered in this document. Standards needed for these topics will be considered separately. The test method described in this document is suitable for comparative evaluations of tires for research and development purposes.
WIP Standard
2014-04-10
This SAE Recommended Practice provides a method for testing the speed performance of passenger car tires under controlled conditions in the laboratory on a test wheel. This procedure applies to "standard load," "extra load," and "T-type high-pressure temporary-use spare" passenger tires.
WIP Standard
2014-04-10
This SAE Recommended Practice provides performance and sampling requirements, test procedures, and marking requirements for aftermarket wheels intended for normal highway use on passenger cars, light trucks, and multipurpose passenger vehicles. For aftermarket wheels on trailers drawn by passenger cars, light trucks or multipurpose vehicles, see SAE J1204. These performance requirements apply only to wheels made of materials included in Table 1 and Table 2. New nomenclature and terms are added to clarify wheel constructions typically not used in OEM applications. The testing procedures and requirements are based on SAE standards listed in the references.
WIP Standard
2014-04-07
This SAE Standard covers performance requirements and methods of test for master cylinder reservoir diaphragm gaskets that will provide a functional seal and protection from outside dirt and water.
WIP Standard
2014-04-01
This SAE Standard applies to the usage of tires of the same nominal size and tread type, but with different outside diameter for articulated front-end loaders. Articulated four-wheel-drive front-end loader performance and component life can be affected by excessive differences in the tire outside circumference and/or diameter. The purpose is to provide specific guidelines for the usage of tires with different outside circumference and/or diameter on articulated front-end loaders.
Technical Paper
2014-04-01
Robert Lloyd
Abstract A hydro-mechanical transmission is described that approximates the “gearing” performance of a continuously variable transmission and incorporates all functions required for hydraulic regenerative braking. Other characteristics such as efficiency, noise, and responsiveness, match or exceed that of present day conventional automatic transmissions. Performance and physical sizing are shown for passenger vehicle, bus and truck transmissions.
Technical Paper
2014-04-01
Yao Fu, Yulong Lei, Ke Liu, Yuanxia Zhang, Huabing Zeng
Abstract In a traditional shift control strategy, the gear range is selected based on the throttle opening and the vehicle speed. The disadvantage of two-parameter based system is that the shift map is lack of adaptability in certain special conditions. The driving environment and the true intentions of the drivers are not fully taken into account by the shift control system. Therefore, improving the feasibility of the shift control strategy for the true intentions of the driver and driving environment is of great significance. Under braking conditions, Automatic transmission shift map with two parameters is unable to use engine braking effectively, which affects the drivability and safety of vehicles greatly. This paper presents a newly developed shift control strategy under braking conditions. First of all, the necessity of engine braking was analyzed. Then, this paper proposed a shift control strategy based on fuzzy inference of braking duration, load, braking deceleration and the vehicle speed.
Technical Paper
2014-04-01
Jiageng Ruan, Paul Walker
Abstract Regenerative braking energy recovery bears significance in extending the driving mileage of electric vehicles (EVs) while fulfilling real-time braking demands. Braking energy strategy plays a significant role in improving the regenerative braking performance and ensuring braking safety. This paper presents a regenerative braking energy recovery strategy for an example EV with a two-speed Dual Clutch Transmission (DCT). The two-speed DCT, with simple structure, can effectively extend the active vehicle speed-range for regenerative braking. Meanwhile, a shifting strategy is proposed for the DCT, working with the presented braking energy recovery strategy, to optimize the brake force distribution between front and rear wheels, motor and friction brake force. The EVs' model with the proposed regenerative braking strategy and the optimal shifting schedule was established and implemented in Matlab/Simulink. A testing rig based on an example EV was then set up in our laboratory to experimentally validate the proposed strategy.
Technical Paper
2014-04-01
Quan Zhou, Gangfeng Tan, Xuexun Guo, Zhigang Fang, Bian Gong
Abstract Focusing the vehicle riding safety and global environmental problems, plenty of solutions on vehicle braking systems appeals during the recent period. Criteria and standards set up for commercial vehicles which should have equipped assisted braking systems were established by amounts of governments. Since eddy current retarders plays an important role in the area of assisted braking system, this article presents an energy-recuperation retarder, which is parallel connected with the driveline through a planet gear system. This paper offers a particular Energy-Recuperation Eddy Current Retarder (ERECR) system with a pedal control system and its characteristics is presented, either. Initially, the constitution of the energy-recuperation eddy current retarder system is established whereas the working principle of the energy-recuperation eddy current retarder is presented by modeling the system and simulation. According to the characteristics presented by simulation, the newly designed mechanical control system is established, and the characteristics of it is analysis.
Technical Paper
2014-04-01
Yoshiharu Inaguma, Naohito Yoshida
Abstract This article describes the friction torque caused by pushing vanes on a cam contour and its influence on a variation of pump driving torque in a balanced vane pump. In the vane pump, the friction torque of the vane is significant to discuss a variation in the driving torque as well as an improvement in the mechanical efficiency. In this work, the influence of the thickness of a vane and the number of vanes on the friction torque of the vane and their additional effect on the variation in the pump driving torque are theoretically and experimentally investigated. The friction torque of the vane occupies a large part of the total friction torque in the vane pump and strongly depends on the number of vanes existing in a suction area as well as the thickness of the vane. The variation in the pump driving torque is composed of the variation of the ideal torque and that of the friction torque of the vane. The former is determined by vane arrangement in the suction area, and the latter is caused by a change in the number of vanes in the suction area.
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