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Viewing 91 to 120 of 10516
2016-04-05
Technical Paper
2016-01-0433
Tao Sun, Eungkil Lee, Yuping He
This paper presents nonlinear bifurcation stability analysis of articulated vehicles with active trailer differential braking (ATDB) systems. ATDB systems have been proposed to improve stability of articulated vehicle systems to prevent unstable motion modes, e.g., jack-knifing, trailer sway and rollover. Generally, behaviors of a nonlinear dynamic system may change with varying parameters. A stable equilibrium can become unstable and a periodic oscillation may occur or a new equilibrium may appear making the previous equilibrium unstable. The value of a parameter at which these changes occur is known as “bifurcation value” and the parameter is known as the “bifurcation parameter”. Conventionally, nonlinear bifurcation analysis approach is applied to examine the nonlinear dynamic characteristics of single unit vehicles, e.g., cars, trucks, etc.
2016-04-05
Technical Paper
2016-01-0438
Ye Yuan, Junzhi Zhang, Chen Lv, Yutong Li
Due to its importance in energy saving, regenerative braking has become a key technology of various types of electrified vehicles. Regenerative braking system (RBS), converting vehicle’s kinetic energy into electricity during decelerations, improves the energy efficiency of electrified vehicles significantly. In this paper, a new type of RBS is proposed for electric vehicles. To realize the cooperative control of regenerative braking and hydraulic braking, 4 pressure-difference-limit valves, 2 relief valves, and 2 brake pedal simulators, are added to the layout of a conventional 4-channel hydraulic modulator. The cooperation of relief valves and hydraulic pumps provides a stabilized high-pressure source. Pressure-difference-limit valves ensure that the pressure in each wheel cylinder can be modulated separately at a high precision. Besides, the functions of anti-lock braking system (ABS) and electronic stability program (ESP) are also integrated in this RBS.
2016-04-05
Technical Paper
2016-01-0426
Francisco C. Cione, Armando Souza, Luiz Martinez, Jesualdo Rossi, Evandro Giuseppe Betini, Fabio Rola, Marco A. Colosio
Studying the formation and distribution of residual stress fields will improve the operational criteria of wheel safety, among other gains. Many engineering specifications, manufacturing procedures, inspection and quality control have begun to require that the residual stress of a particular component be evaluated. It is known that these residual stress fields could be added to the effects of system load (tare weight plus occupation of vehicle traction, braking and torque combined). The results obtained used X-ray diffraction, drilling method with rosette type strain gages, are convergent with similarity to those obtained using FEA simulation over critical region for global and superficial in principal stresses mode. The mathematical tools for modeling and simulations using finite elements had evolved following the increasing computing power and hardware cost reduction.
2016-04-05
Technical Paper
2016-01-0444
Kemal Çalışkan, Mina M.S. Kaldas, Roman Henze, Ferit Küçükay
This paper presents a performance analysis study for the Rule-optimized Fuzzy-Logic controller of a Semi-active Suspension system. The Rule-optimized controller uses a Fuzzy Logic scheme which offers new opportunities in the improvement of vehicle ride performance. An eleven degree of freedom full vehicle ride dynamics model is constructed and validated through laboratory tests performed on a hydraulic four-poster shaker. An optimization process to obtain the optimum Fuzzy Logic membership functions and the optimum rule-base of the semi-active suspension controller is proposed. Discrete optimization has been performed with a Genetic Algorithm (GA) to find the global optima of the cost function which considers the ride comfort and road holding performance of the full vehicle.
2016-04-05
Technical Paper
2016-01-1298
Shukai Yang, Zuokui Sun, Yingjie liu, Bingwu Lu, Tao Liu, Hangsheng Hou
This work carried out a detailed analysis and optimization regarding a front disc brake squeal issue. Specifically, it explained the stability theory of complex modes for brake squeal simulation, constructed a brake system finite element model, established a simulation analysis methodology, determined the key parameters for evaluating the stability of the brake system complex modes, and carried out a model verification measurement with the SAE 2521 procedure. Finally, in order to resolve a specific 1800 Hz low frequency brake squeal issue, an optimization simulation was carried out. The obtained solutions were validated by the experimental findings.
2016-04-05
Technical Paper
2016-01-0474
Shukai Yang, Bingwu Lu, Zuokui Sun, Yingjie liu, Hangsheng Hou
An low frequency vibration issue around 3.5 Hz surfaces during a truck program development process, and it is linked to uncomfortable driving and riding experiences. This work focuses on an analytical effort to resolve the issue by first building a full vehicle MBS model,and then carrying out a vibration response analysis. The model validation is performed using the full vehicle testing in terms of structural modes and frequency response characteristics. In order to resolve the issue which is considered to be excited mainly by the tire non-uniformity, the influence of the cab suspension, frame modes, front leaf spring system and rear balance suspension are analyzed. The root cause of the issue is found to be the rear balance suspension system, and the final optimization effort establishes the resolution measure for the issue.
2016-03-27
Technical Paper
2016-01-1710
Ek-u thammakornbunjut, Sutee Olarnrithinun
In general, the automotive chassis will be subjected to a combination of dynamic loads. The important one of these loads is an impact load which will be occurred when a vehicle crash to another vehicle or infrastructures. This paper aims to investigate the axial impact strength of a C-shape straight beam reinforced with dented rectangular plates. Only spherical shape of the dent is considered in this study. The effects of dent diameter, dent depth, and number of dented plates are analyzed using nonlinear finite element method. The possibility to use this type of reinforcement is discussed.
2016-02-05
Magazine
Off-highway hybrids: Opportunities and challenges With oil prices declining and emissions regulations in North America 'stabilized,' is there a place for hybrid powertrains in this new world of cheap oil? Looking for a better image Display advances are helping to reduce operator fatigue. Charging up electrified powertrains Control technologies race forward while batteries improve and adopt standard sizes. Measuring and accounting for suspension TARDEC teamed with SEA Ltd. to develop a system to measure the suspension parameters, center of gravity, and moments of inertia of wheeled vehicles in the never ending quest to model and predict vehicle dynamic behavior. Looking at mobility in 2050 Cuneyt L. Oge begins his term as 2016 SAE International President with a vision about the future of auto- and aero-mobility.
2016-02-02
Article
Sensata Technologies introduced its smallest micro-fused strain gauge technology for next-generation brake systems especially designed for hybrid and electric vehicles.
2016-02-01
Technical Paper
2016-28-0035
Shraddhesh Rasal, Jayanth Jaganmohan, Sohan Agashe, Kiran P Wani
Abstract The design of the conventional passive suspension has always been a compromise between vehicle handling and comfort, which led to the development of the modern active and semi active suspension systems. Amongst these, semi-active suspension has been focus of research in recent years owing to its lesser complexity and less power consumption as compared to active suspension. Semi active suspension uses real time variation in damping coefficient which can be achieved by using various control strategies. It is observed from available literature that Skyhook (for better ride comfort), Groundhook (for better vehicle handling) and Hybrid are most widely used strategies. These strategies use ‘On-Off’ control strategy (i.e. two preset values of damping co-efficient) but a better control over damping coefficients can be achieved using Continuous Control strategy. This paper aims to implement Continuous control strategy using Fuzzy logic for the semi active suspension.
2016-02-01
Technical Paper
2016-28-0201
Upendra Kulkarni, Monish M. H. Gowda, Hima Kiran Venna
Abstract Steering and suspension system has to be designed properly to achieve improved handling characteristics. Improper design of steering systems will result in steering errors such as bump steer and roll steer. These steering errors results in reduced steering performance. During the design of steering system the tie rod length has to be properly selected to reduce these steering errors. The purpose of the work is to analyze the effects of tie rod length variation on bump steer. Multi body dynamic model of the selected vehicle was created using MSC ADAMS Car software. Ideal design of steering system to achieve zero bump steer was created. The tie rod length was later varied up to 10% to study the effect of varying length on bump steer. Parallel wheel travel analysis was conducted to study the tie rod length variation on bump steer. Acceleration test was conducted on a flat road having bump to analyze the effect of changing tie rod length on steering performance of the vehicle.
2016-02-01
Technical Paper
2016-28-0184
Aditya Anant Patil
Abstract Kinematic inputs such as camber, caster variation are very important for design of any suspension setup. Usual procedure is to get these inputs from kinematic software. But every designer cannot have this software & one has to learn them too. We have developed a method for kinematic analysis of McPherson strut type suspension which can be implemented on easily available and familiar software like MS Excel. Results obtained are in correlation with results from commercially available mechanism tools such as Pro mechanism. All links in suspension layout are considered as rigid. Vector calculus and other mathematical methods have been used to come up with final solution. Inputs required for mathematical program are suspension hardpoints, Lower arm angle from design orientation as wheel travel input and Rack stroke as steering input.
2016-01-27
Article
A new Michelin tire is an all-season street grabber with technical attributes derived from endurance racing.
2016-01-26
WIP Standard
J1981
The test is designed to evaluate the frontal impact resistance of wheel and tire assemblies used with passenger cars, light trucks and multi-purpose vehicles. The test is specifically related to vehicle pothole tests that are undertaken by most vehicle manufacturers. The scope has been expanded to allow the use of a striker that can be angled to preferentially impact the inboard and outboard wheel flange. For side impact of the outboard rim flange only, please refer to SAE J175. This SAE Recommended Practice provides a procedure to test a wheel or a tire and the test failure critiera. The specific test for a vehicle requires input from a pothole test on that vehicle to establish the drop height of the striker used in this test.
2016-01-25
Standard
ARP1907C
This SAE Aerospace Recommended Practice (ARP) covers the functional, design, construction, and test requirements for Automatic Braking Systems. Installation information and lessons learned are also included.
2016-01-20
Article
System offers fast response and eliminates piston drag, but hydraulic output to front wheels is still needed for larger cars.
2016-01-20
WIP Standard
J840
This SAE Recommended Practice covers equipment capabilities and the test procedure to quantify and qualify the shear strength between the friction material and backing plate or brake shoe for automotive applications. This SAE Recommended Practice is applicable to: bonded drum brake linings; integrally molded disc brake pads; disc brake pads and backing plate assemblies using mechanical retention systems (MRS); coupons from drum brake shoes or disc brake pad assemblies. The test and its results are also useful for short, semi-quantitative verification of the bonding and molding process. This Recommended Practice is applicable during product and process development, product verification and quality control. This Recommended Practice does not replicate or predict actual vehicle performance or part durability.
2016-01-15
WIP Standard
J1121
This recommended practice has been developed to assist engineers and designers in the preparation of specifications for the major types of helical compression and extension springs. It is restricted to a concise presentation of items which will promote an adequate understanding between spring manufacturer and spring user of the major practical requirements in the finished spring. Closer tolerances are obtainable where greater accuracy is required and the increased cost is justified. For the basic concepts underlying the spring design and for many of the details see the SAE Information Report MANUAL ON DESIGN AND APPLICATION OF HELICAL AND SPIRAL SPRINGS, SAE HS 795, which is available from SAE Headquarters in Warrendale, PA 15096. A uniform method for specifying design information is shown in the TYPICAL DESIGN CHECK LISTS FOR HELICAL SPRINGS, SAE J1122.
2016-01-13
Article
Last year's double-digit hiring spree of engineers continues at Schaeffler as demand in North America intensifies for the supplier's engine, transmission, and chassis technologies.
2016-01-12
WIP Standard
J1707
This SAE Recommended Practice provides basic recommendations for dispensing and handling of SAE J1703 and SAE J1704 Brake Fluids by Service Maintenance Personnel to assure their safe and effective performance when installed in or added to motor vehicle hydraulic brake actuating systems. This document is concerned only with brake fluid and those system parts in contact with it. It describes general maintenance procedures that constitute good practice and that should be employed to help assure a properly functioning brake system. Recommendations that promote safety are emphasized. Specific step-by-step service instructions for brake maintenance on individual makes or models are neither intended nor implied. For these, one should consult the vehicle manufacturer’s service brake maintenance procedures for the particular vehicle. Vehicle manufacturer’s recommendations should always be followed.
2016-01-11
WIP Standard
J1122
This SAE Recommended Practice furnishes sample forms for helical compression, extension and torsion springs to provide a uniform method for specifying design information. It is not necessary to fill in all the data, but sufficient information must be supplied to fully describe the part and to satisfy the requirements of its application. For detailed information, see 'Design and Application of Helical and Spiral Springs - SAE HS 795 SEP82', also 'Helical Compression and Extension Spring Terminology - SAE J1121 NOV75.' Both of these documents use SI (metric) units in accordance with the provisions of SAE J916 MAY85, and so does SAE J1122. Here, however, the U.S. Customary Units (in, lb, psi) have been added in parentheses after each SI Unit for the convenience of the user who must furnish specifications on a project where all requirements are listed in non-metric terms.
2016-01-06
WIP Standard
J2059
In this SAE Recommended Practice, attention will be given to passenger cars and light trucks (through Class III). The purpose of this recommended practice is to define standardized symbols that describe the arrangement and function of drivetrain systems and components of all-wheel-drive vehicles. This document presents basic symbols, superimposed symbols and symbols with modifiers. Various vehicle drivetrain schematics are shown with specific component arrangements or general driveline layout to illustrate varying levels of descriptive intent.
2016-01-04
WIP Standard
AIR5552A
This information report provides general guidance for the design considerations, qualification in endurance, strength and fatigue of landing gear using composite components as principle structural elements. The information discussed herein includes the development and evaluation of design data considering: the potential for imbedded manufacturing defects, manufacturing process variations, the component operating environment, potential damage threats in service, rework and overhaul, and inspection processes. This AIR mainly discusses the use of thick composites for landing gear structural components. Considerations and recommendations provided in this AIR may therefore differ greatly from considerations and recommendations found in widely accepted composite design references such as CMH-17 and Advisory Circulars such as AC 20-107(B).
2016-01-04
WIP Standard
J230
This SAE Recommended Practice covers a high-strength corrosion-resisting steel wire, uniform in mechanical properties, intended for the manufacture of springs and wire forms. It covers processing requirements of springs and forms fabricated from this wire.
2016-01-04
WIP Standard
J2800
This lab test procedure should be used when evaluating the combined corrosion and fatigue performance for a particular coating system, substrate, process and design. The test is intended to provide an A to B comparison of a proposed coil spring design versus an existing field validated coil spring when subjected to the combined effects of corrosion and fatigue. The corrosion mechanisms covered by this test include general, cosmetic and pitting corrosion. Fatigue testing covers the maximum design stress and/or stress range of the coil spring design (typically defined as excursion from jounce to rebound positions in a vehicle). The effects of gravel and heat are simulated by pre-conditioning the springs prior to fatigue testing. Time dependant corrosion mechanisms such as stress corrosion cracking are not addressed with this test.
2016-01-04
WIP Standard
J511
This pneumatic spring terminology has been developed to assist engineers and designers in the preparation of specifications and descriptive material relating to pneumatic springs and their components. It does not include gas supply or control systems.
2016-01-04
WIP Standard
J1123
This SAE Standard is limited to concise specifications promoting an adequate understanding between spring maker and spring user on all practical requirements in the finished spring. The basic concepts for the spring design and for many of the details have been fully dealt with in HS J788.
2016-01-04
WIP Standard
J447
This SAE Information Report provides automotive engineers with the basic principles of corrosion, design guidelines to minimize corrosion, and a review of the various materials, treatments, and processes available to inhibit corrosion of both decorative and functional body and chassis components.
2016-01-04
WIP Standard
J510
This SAE Standard is limited to concise specifications promoting an adequate understanding between spring maker and spring user on all practical requirements in the finished spring. The basic concepts for the spring design and for many of the details have been fully addressed in HS-J788, SAE Information Report, Manual on Design and Application of Leaf Springs, which is available from SAE Headquarters. NOTE: For leaf springs made to metric units, see SAE J1123.
2016-01-04
WIP Standard
J1528
Test Material: Only fully processed new springs which are representative of springs intended for the vehicle shall be used for the tests. No complete spring or separate leaf shall be used for more than one test.
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