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2014-05-13
WIP Standard
J1603
This SAE Standard describes the performance and part requirements for elastomeric seals used in highway vehicle disc brake calipers. Seals covered by this specification may be the solid section type (square, rectangular, O-ring, etc.) mounted stationary in the cylinder bore or on the movable piston. The specification contains the following major sections:
2014-05-10
Journal Article
2014-01-9122
Daogao Wei, Peng Wang, Zhijie Pan, Siming Hu, Huaiyang Xiao
Tie rod end clearance is an important parameter influencing automobile stability under slalom maneuver. In this paper the steering mechanism is simplified into a plane linkage mechanism and an analysis of the effects on vehicle stability exerted by kinematic pair clearance under slalom maneuver is also presented. A 4DOF mathematical model of vehicle maneuvering system is thus being built. On the basis of this model, we adopt the numerical analysis method to conduct a simulated analysis about the stability of prototype vehicle side slip angle as the clearance parameter changes. According to the results, vehicle slalom dynamics behaviors manifest itself in shifting from single cycle to chaos directly. With the increase in clearance, nearly no change is displayed in the upper critical frequency of vehicle slalom instability. However, an increasing rise is shown in the lower critical frequency.
2014-05-10
Journal Article
2014-01-9123
Hyeonu Heo, Jaehyung Ju, Doo Man Kim, Harkbong Kim
An understanding of the flow around a tire in contact with the ground is important when designing fuel-efficient tires as the aerodynamic drag accounts for about one third of an entire vehicle's rolling loss. Recently, non-pneumatic tires (NPTs) have drawn attention mainly due to their low rolling resistance associated with the use of low viscoelastic materials in their construction. However, an NPT's fuel efficiency should be re-evaluated in terms of aerodynamic drag: discrete flexible spokes in an NPT may cause more aerodynamic drag, resulting in greater rolling resistance. In this study, the aerodynamic flow around a non-pneumatic tire in contact with the ground is investigated for i) stationary and ii) rotating cases using the steady state Reynolds-Averaged Navier-Stokes (RANS) method. A sensitivity analysis was carried out with a varying mesh density. The flow into cavity by the discrete spoke geometry of the NPT does not significantly affect the overall aerodynamic drag.
2014-05-07
Technical Paper
2014-36-0001
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.
2014-05-07
Technical Paper
2014-36-0018
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.
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
2014-36-0038
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
2014-36-0029
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
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.
2014-05-07
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.
2014-04-29
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
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.
2014-04-10
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.
2014-04-07
WIP Standard
J1605
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.
2014-04-01
Technical Paper
2014-01-1057
Daewon Jang, Sungbae Jang
Abstract Today, all manufacturers of vehicle are up for the challenge to abide in automobile emission control laws. Weight reduction is one of the best solutions to reduce both fuel consumption and emissions. The most effective method for the said idea is to have lightweight materials to some of parts of vehicle using the FRP(Fiber Reinforced Plastics). In order to obtain good mechanical properties of FRP, continuous fiber should be used. But it is difficult to design and manufacture of FRP parts using continuous fiber because of material properties and molding process. In this paper, it is used CF(carbon Fiber) and Epoxy to make a composite material Properties of this CFRP can be predicted through analysis. Tests and simulations of specimen are performed as every steps progress for correlation. And spring can be designed to meet all requirements for specific performance. The CFRP spring is made by new devices and methods and can be applied to vehicle for practical using.
2014-04-01
Technical Paper
2014-01-1050
Massimiliana Carello, Andrea Giancarlo Airale, Alessandro Ferraris
Abstract The use of composite materials is very important in automotive field to meet the European emission and consumption standards set for 2020. The most important challenge is to apply composite materials in structural applications not only in racing vehicles or supercars, but also in mass-production vehicles. In this paper is presented a real case study, that is the suspension wishbone arm (with convergence tie and pull-rod system) of the XAM 2.0 urban vehicle prototype, that it has the particular characteristics that the front and rear, and left and right suspension system has the same geometry. The starting point has been an existing solution made in aluminum to manufacture a composite one.
2014-04-01
Technical Paper
2014-01-0999
Klaus Greven, Manikandan Loganathan
Abstract The Counter Pressure Casting (CPC) process is particularly suited for the production of aluminum suspension components like wheel carriers or steering knuckles. Using a typical AlSi7Mg alloy such as A356 or EN AC-42100, yield strength above 260 MPa and elongation rates above 8% are possible in a high volume production. Although these are very good values for aluminum castings, the yield strength has to be improved to increase the light weight potential of such components. The present work shows how this goal can be achieved by the development of a new aluminum casting alloy. Besides the modification of Si and Mg content, the addition of Cr leads to an additional dispersion hardening effect. In this way, yield strength above 310 MPa combined with an elongation of 7% can be assured in the CPC process after a T6 heat treatment.
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.
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