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2014-05-07
Technical Paper
2014-36-0019
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.
2014-05-07
Technical Paper
2014-36-0024
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.
2014-05-07
Technical Paper
2014-36-0029
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.
2014-05-07
Standard
J1512_201405
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.
2014-05-07
Technical Paper
2014-36-0038
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.
2014-05-07
Technical Paper
2014-36-0025
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.
2014-04-29
Article
Despite the burgeoning success of highly effective single platform modular solutions, hardware variation is not falling, warns BWI Group global technology executive Olivier Raynauld.
2014-04-28
Technical Paper
2014-28-0038
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.
2014-04-28
Technical Paper
2014-28-0042
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.
2014-04-28
Technical Paper
2014-28-0006
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.
2014-04-28
Technical Paper
2014-28-0016
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.
2014-04-28
Standard
J1461_201404
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.
2014-04-21
WIP Standard
J1705
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.
2014-04-16
Standard
J2246_201404
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.
2014-04-11
Book
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.
2014-04-10
WIP Standard
J1987
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.
2014-04-10
WIP Standard
J1988
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.
2014-04-10
WIP Standard
J1633
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.
2014-04-10
WIP Standard
J1561
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.
2014-04-10
WIP Standard
J2530
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.
2014-04-01
Technical Paper
2014-01-1009
Yoon Cheol Kim, Seong Jin Kim, Jaeyoung Lee, Jeongkyu Kim, SooHyuk Lee, Kyoungdon Yi, KiJeong Kim
Abstract Reducing unsprung mass of the car is a representative method to enhance the ride & handling performance and fuel efficiency. In this study, brake disc weight is reduced 15∼20% using a hybrid type material. The basis for this study is the separation of the friction surface and HAT(mounting part). Aluminum material is applied in the HAT for a light weight effect. Gray iron is applied in the friction surface section to maintain braking performance. Two types of joining between aluminum and cast iron are developed. One is the aluminum casting method utilizing a gray iron insert and the other is a bolted assembly method. Detailed structure, process and material are optimized using try-out & dynamometer experiments. The Reliability of this development is proved through durability (dynamometer and vehicle) testing.
2014-04-01
Technical Paper
2014-01-1242
Jonathan M. S. Mattson, Michael Mangus, Christopher Depcik
Abstract A timing sweep to correlate the location of Maximum Brake Torque (MBT) was completed on a single-cylinder, direct injected compression ignition engine that was recently upgraded to a high-pressure rail injection system for better engine control. This sweep included emissions monitoring for carbon dioxide, carbon monoxide, particulate matter, hydrocarbons, and oxides of nitrogen for the calibration of a heat release model, as well as the opportunity to relate MBT timing to brake-specific emissions production. The result of this timing sweep was a relatively linear correlation between injection delay and peak pressure timing. In addition, a number of other MBT timing methodologies were tested indicating their applicability for immediate feedback upon engine testing, particularly mass fraction burned correlations. Emissions were either strongly correlated to MBT timing (with emissions being minimized in the vicinity of MBT), or were completely independent of MBT.
2014-04-01
Technical Paper
2014-01-0098
Anthony Barkman, Kelvin Tan, Arin McIntosh, Peter Hylton, Wendy Otoupal-Hylton
This paper discusses a project intended as a design study for a team of college students preparing for careers in motorsports. The project's objective was to conduct a design study on the possible redesign of the suspension for a dirt-track sprint car. The car examined was typical of those which race on one-quarter to one-half mile dirt oval tracks across the United States. The mission of this concept study was to develop a different configuration from the traditional torsion bar spring system, for the front end. The design included moving the dampers inboard with the addition of a rocker to relate the movement through the front suspension system. For the rear end, components were designed to allow the radius rod to be adjustable from the cockpit, thus providing the driver with adjustability to changing track conditions.
2014-04-01
Technical Paper
2014-01-0070
Ralph S. Shoberg, Jeff Drumheller
Abstract Reliable wheel attachment must start with proper tightening of the lug nuts in order to achieve the clamping force necessary to hold the vehicle's wheels securely for all operating conditions. It is the purpose of this paper to provide a complete overview of the theory and practice of using torque-angle signature analysis methods to examine the installation and audits of wheel lug nuts. An accurate estimate of clamp load can be determined without actually measuring the clamp load. The torque-angle signature analysis, known as “M-Alpha”, performed on tightening and loosening curves provides a powerful tool to understand the integrity of a bolted joint when clamp load data is not available. This analysis technique gives insight into the frictional effects, material properties, and geometric factors that can affect the clamp load attained during the installation process.
2014-04-01
Technical Paper
2014-01-0069
Andrew Nevin, Eric Daoud
Abstract Traditional tread depth measurements require manual utilization of a mechanical device to acquire measurements at each location of interest on a tire. Drive-over machine-vision sensors are becoming available as a means for measuring tread depth. These sensors typically consist of a laser and a camera contained in an environmentally-sealed sensor housing. Tires approach the sensor over the supporting surface, while a laser projects an illuminating line across the tread surface for capture in a digital image. This scan is evaluated to provide a single 2D contour of tread depth at the illuminated line. Advanced machine-vision sensors acquire a sequence of images, which results in a multitude of data points over a 3D region of the tread surface. Post-processing of the acquired images illustrates the observed tread pattern and establishes multiple tread depth measurements.
2014-04-01
Technical Paper
2014-01-0066
Ben Wen, Gregory Rogerson, Alan Hartke
Abstract Tire rolling resistance is one of tire performance indicator that represents a force needed to maintain the constant rolling of a tire. There are quite few methods and standards to measure tire rolling resistance, such as ISO-28585, ISO-18164, SAE-J1269, SAE-J2452, …. These tests have been used by tire companies, vehicle manufactures, and government agencies to evaluate tire rolling resistance performance. SAE-J1269 and SAE-J2452 are two popularly used multi-condition rolling resistance tests for passenger and light truck tires. Examining the test conditions and procedures of these two test standards showed that some key procedures and conditions from both standards are similar although there are many difference as well. The study presented here is to analyze test results from both tests and their correlation under certain conditions. If the correlation exists, one test may provide test results for both test conditions, therefore, test efficiency can be improved.
2014-04-01
Technical Paper
2014-01-0928
Daryl R. Poirier, Ravindra Patil, Robert Geisler, Joseph Schudt
Abstract The automotive industry is under great pressure to reduce vehicle mass for both cost and fuel economy gains. A significant contributor to body and suspension structure mass is peak vertical loads, primarily entering the body structure through the jounce bumper to body interface. This paper focuses on the successful development of “Loads Management Striker Caps” for the 2013 Cadillac ATS front and rear suspension. Component design and development of the striker caps was executed using explicit finite element analysis tools. Multi-body dynamics vehicle models were used to set component requirements and confirm striker cap performance for the vehicle during peak vertical events. The “Loads Management Striker Caps” ultimately reduced peak strut/shock tower loads by 40% in the front suspension and 25% in the rear suspension. This resulted in significant body and chassis mass savings, contributing to the Cadillac ATS's class leading curb weight.
2014-04-01
Technical Paper
2014-01-0929
Changxin Wang, Wenku Shi, Qinghua Zu
Abstract Aiming at the difficulty of sovling the stiffness calculation of taper-leaf spring with variable stiffness, a combined method was proposed, which combine superposition method and finite difference method. Then the calculation results of different differential segments were compared with experimental results. The compared results show that the proposed method is effective and simple. So it has some practical significance in designing the taper-leaf spring. In addition, based on the stiffness test of the taper-leaf spring, the proper adjustments to the correction factor of the single parabolic leaf spring stiffness formula was recommended(ξ =0.92-0.96).
2014-04-01
Technical Paper
2014-01-0714
Sanghun Cho, Taewan Gu, Eunyoung Yoo, Youngkyu Jeong, Baegsu Joo
Abstract In automotive software developments, since the types of software functionalities are depending on automotive engineering domains such as powertrain, body, and chassis, software logic and data processing, code complexity, and its reliability are also depending on them. Therefore, it has some challenges that monolithic code quality measures are applied to software code for all domains. In addition, imprecise criteria for the measures also can make software developers and testers confused whether their code verifications are enough or not. This paper proposes domain-specific code quality measures and precise criteria by combining a new functionality model, named Abstract Function Model (AFM), and shows results of automotive software functionality analysis using the model. Using 8 real automotive software projects, we derived statistics of software code on specific automotive engineering domain and identified code quality measures from the statistics.
2014-04-01
Technical Paper
2014-01-0331
Masayuki Naito, Yasuhiro Koike, Shintaro Osaki, Shinichiro Morishita, Nanhao Quan
Abstract HEV and EV markets are in a rapid expansion tendency. Development of low-cost regenerative cooperation brake system is needed in order to respond to the consumers needs for HEV and EV. Regenerative cooperation brake system which HEV and EV are generally equipped with has stroke simulator. We developed simple composition brake system based on the conventional ESC unit without the stroke simulator, and our system realized a low-cost regenerative cooperation brake. The key technologies are the quiet pressurization control which can be used in the service application, which is to make brake force depending on brake travel, by gear pump and the master cylinder with idle stroke to realize regenerative cooperation brake. Thanks to the key technologies, both the high regenerative efficiency and the good service brake feeling were achieved.
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