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2016-12-05 ...
  • December 5, 2016 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
This seminar provides an introduction to several critical aspects of heavy truck dynamics. The comprehensive presentation and discussion will begin with the mechanics and dynamics of heavy truck tires, followed by steering dynamics, and finally moves participants into suspension kinematics and dynamics. Starting at the ground and moving up, this seminar explores the important dynamic aspects of each subsystem and how each is related to the overall truck dynamics.
2016-08-10 ...
  • August 10-12, 2016 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
  • December 12-14, 2016 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
This seminar will present an introduction to Vehicle Dynamics from a vehicle system perspective. The theory and applications are associated with the interaction and performance balance between the powertrain, brakes, steering, suspensions and wheel and tire vehicle subsystems. The role that vehicle dynamics can and should play in effective automotive chassis development and the information and technology flow from vehicle system to subsystem to piece-part is integrated into the presentation. Governing equations of motion are developed and solved for both steady and transient conditions.
2016-06-15
Technical Paper
2016-01-1834
Florian Fink, Gregor Koners
Abstract This paper describes the prediction process of wheel forces and moments via indirect transfer path analysis, followed by an analysis of the influence of wheel variants and suspension modifications. It proposes a method to calculate transmission of noise to the vehicle interior where wheel forces and especially moments were taken into account. The calculation is based on an indirect transfer path analysis with geometrical modifications of the frequency response functions. To generate high quality broadband results, this paper also points out some of the main clearance cutting criteria. The method has been successfully implemented to show the influence of wheel tire combinations as well as the influence of suspension modifications. Case studies have been performed and will be presented in this paper. Operational noise and vibration measurements have been carried out on Daimler NVH test tracks. The frequency response functions were estimated in an acoustic laboratory.
2016-06-15
Journal Article
2016-01-1827
Giorgio Bartolozzi, Marco Danti, Andrea Camia, Davide Vige
Abstract The time to market in the automotive industry is constantly decreasing pushing the carmaker companies to increase the efforts in numerical simulations and to decrease the number of prototypes. In the NVH field, this time constraint reflects in moving the well-established finite element simulations towards the so called “full-vehicle simulations”. Specifically, the CAE techniques should be able to predict the complete behavior of the vehicles in mission conditions, so to reproduce some usual tests, such as the “coast down” test on different roads. The aim of this paper is to present a methodology to improve rolling noise simulations exploiting an integrated full-vehicle approach. An accurate modeling of all the subsystems is needed, with particular attention to the wheels and the suspension systems. Therefore, the paper firstly covers the modeling approach used to obtain the FE models of tires and suspension system.
2016-06-15
Technical Paper
2016-01-1765
Kelly Savva, Ahmed Haris, Eliot Motato, Mahdi Mohammadpour, Stephanos Theodossiades, Homer Rahnejat, Patrick Kelly, Alexander Vakakis, Lawrence Bergman, Donald McFarland
Abstract Legislation on vehicle emissions and the requirements for fuel efficiency are currently the key development driving factors in the automotive industry. Research activities to comply with these targets point to engine downsizing and new boosting technologies, which have adverse effects on the NVH performance, durability and component life. As a consequence of engine downsizing, substantial torsional oscillations are generated due to high combustion pressures. Meanwhile, to attenuate torsional vibrations, the manufacturers have implemented absorbers that are tuned to certain frequency ranges, including clutch dampers, Dual Mass Flywheel (DMF) and centrifugal pendulum dampers. These devices add mass/inertia to the system, potentially introducing negative effects on other vehicle attributes, such as weight, driving performance and gear shiftability.
2016-05-23 ...
  • May 23-25, 2016 (8:00 a.m. - 5:00 p.m.) - Greer, South Carolina
  • November 14-16, 2016 (8:00 a.m. - 5:00 p.m.) - Greer, South Carolina
Training / Education Classroom Seminars
While a variety of new engineering methods are becoming available to assist in creating optimal vehicle designs, subjective evaluation of vehicle behavior is still a vital tool to deliver desired braking, handling, and other dynamic response characteristics. In order to better prepare today’s engineer for this task, this course offers twelve modules devoted to key the fundamental principles associated with longitudinal and lateral vehicle dynamics.
2016-05-09 ...
  • May 9-11, 2016 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
  • November 21-23, 2016 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
Just as the chassis and suspension system provides an ideal framework for the automobile, this popular SAE seminar provides an informative framework for those involved in the design of these important systems. Emphasizing the fundamental principles that underlie rational development and design of suspension components and structures, this course covers the concepts, theories, designs and applications of automotive suspension systems.
2016-04-27
WIP Standard
J773
This SAE Standard covers dimensional, material, and general specifications and methods of test for two types of general purpose conical spring washers, designated type L and type H, for use as loose washers over screws and bolts, and also for use as pre-assembled washers in screw and washer assemblies. Both the type L and type H washers are available in three washer series (narrow, regular and wide), having varied proportions designed to fulfill specific application requirements for load distribution. Where so specified by the user, washers shall be supplied with peripheral teeth. All sizes and types of washers specified in this standard are not necessarily stock production items. Users should consult with manufacturers concerning availability.
2016-04-15
Journal Article
2015-01-9020
Emre Sert, Pinar Boyraz
Abstract Studies have shown that the number of road accidents caused by rollover both in Europe and in Turkey is increasing [1]. Therefore, rollover related accidents became the new target of the studies in the field of vehicle dynamics research aiming for both active and passive safety systems. This paper presents a method for optimizing the rear suspension geometry using design of experiment and multibody simulation in order to reduce the risk of rollover. One of the major differences of this study from previous work is that it includes statistical Taguchi method in order to increase the safety margin. Other difference of this study from literature is that it includes all design tools such as model validation, optimization and full vehicle handling and ride comfort tests. Rollover angle of the vehicle was selected as the cost function in the optimization algorithm that also contains roll stiffness and height of the roll center.
2016-04-13
Event
The purpose of this session is to provide a forum for presentations on steering and suspension related topics as it applies to ground vehicles. Papers for this session should address new approaches as well as advances in application of steering, suspension related technologies.
2016-04-13
Event
The purpose of this session is to provide a forum for presentations on steering and suspension related topics as it applies to ground vehicles. Papers for this session should address new approaches as well as advances in application of steering, suspension related technologies.
2016-04-05
Standard
J230_201604
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.
2016-04-05
Standard
J217_201604
This SAE Recommended Practice covers a high-quality corrosion resisting steel wire, cold drawn, formed, and heat treated to produce uniform mechanical properties. It is magnetic in all conditions. It is intended for the manufacture of springs and wire forms that are to be heat treated after forming to enhance the spring properties. This document also covers processing requirements of the springs and forms fabricated from this wire.
2016-04-05
Standard
J510_201604
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.
2016-04-05
Standard
J1528_201604
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.
2016-04-05
Standard
J1123_201604
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.
2016-04-05
Journal Article
2016-01-0420
Frank Anthony Cuccia, James Pineault, Mohammed Belassel, Michael Brauss
Abstract It is well known that manufacturing operations produce material conditions that can either enhance or debit the fatigue life of production components. One of the most critical aspects of material condition that can have a significant impact on fatigue life is residual stress (RS) [1, 2]. When springs are manufactured, the spring stock may undergo several operations during production. Additional operations may also be introduced for the purpose of imparting the spring with beneficial surface RS to extend its fatigue life and increase its ability to execute the task it was designed to perform. The resultant RS present in production springs as a result of the various fabrication and processing operations applied can be predicted and modeled, however, RS measurements must be performed in order to quantify the RS state with precision.
2016-04-05
Technical Paper
2016-01-0431
Guangqiang Wu, Huwei Wu, Xiang Chen
Abstract The nonlinear characteristics impact of multi-staged stiffness clutch damper on the vehicle creeping is investigated by using the lumped-parameter modeling method as a certain mass-production passenger sedan is taken as the research subject. Firstly, a quasi-transient engine model of an inline four-cylinder and four-stroke engine, based on measured data of cylinder gas pressure versus crankshaft angle, is derived. Effective output torque is acquired and as the input excitation to the driveline system. Secondly, a 12-DOF (Degree of Freedom) nonlinear and branched powertrain system and vehicle longitudinal dynamics model is established. The differential mechanism characteristics and dynamic tire property based on the LuGre tire model are considered. Then, for a traditional two-staged stiffness clutch damper in consideration of hysteresis characteristics, vehicle powertrain system responses in both the time and frequency domain are obtained.
2016-04-05
Technical Paper
2016-01-0430
Joel Metz, Xin Zhang, Xiao Yu
The Front Lower Control Arm (FLCA) is a key part of the automotive suspension for performance and safety. Many FLCA designs attach to the front sub-frame using rubber handling and riding bushings, which determine the vehicle dynamics and comfort. In this paper, a design for a ride bushing using a metal pin structure is discussed. The inner portion of the ride bushing is a hollow metal collar with a layer of rubber, and the FLCA pin structure is pressed into the rubber. For safety requirements, the bushings must meet a pin push-in and push-out force requirement. During the development of the bushing design, different test groups conducted tests to determine if manufactured parts meet the push-out force specification. Each group tested at a different load rate and generated different maximum push out force values. The push-in/out speed was found to have a strong influence on the generated maximum load.
2016-04-05
Technical Paper
2016-01-0429
Paul Augustine, Timothy Hunter, Nathan Sievers, Xiaoru Guo
Abstract The performance of a structural design significantly depends upon the assumptions made on input load. In order to estimate the input load, during the design and development stage of the suspension assembly of a BAJA car, designers and analysts invest immense amount of time and effort to formulate the mathematical model of the design. These theoretical formulations may include idealization errors which can affect the performance of the car as a final product. Due to the errors associated with the assumption of design load, several components might have more weight or may have less strength than needed. This discrepancy between the assumed input load (lab or theoretical studies) and the actual load from the environment can be eliminated by performing a real life testing process using load recovery methodology. Commercial load cells exist in industry to give engineers insight to understanding the complex real world loading of their structures.
2016-04-05
Technical Paper
2016-01-0428
Ruochen Wang, Renkai Ding, Qing Ye
Abstract For coordinating the ride comfort and driving safety, the “inerter-spring-damper” (ISD) system is proposed in this paper, and the “spring-adjustable damper” is adapted to connect with ISD in series, then, a new type of semi-active suspension system is established. In order to verify the system rationality, the ISD semi-active suspension model and robust controller model are established respectively in the AMESim and MATLAB/Simulink environment, which is based on two degrees of freedom suspension model. Then, the co-simulation of ISD semi-active suspension with robust control is analyzed. Compared with the conventional ISD suspension, the results show that, the ISD semi-active suspension with robust control can significantly reduce the body vertical vibration, restrain tire resonance and enhance the tire grounding, that is, this system can coordinate the conflicts between vehicle ride comfort and driving safety.
2016-04-05
Technical Paper
2016-01-1301
Shishuo Sun, David W. Herrin, John Baker
Abstract One of the more useful metrics to characterize the high frequency performance of an isolator is insertion loss. Insertion loss is defined as the difference in transmitted vibration in decibels between the non-isolated and isolated cases. Insertion loss takes into account the compliance on the source and receiver sides. Accordingly, it has some advantages over transmissibility especially at higher frequencies. In the current work, the transfer matrix of a spring isolator is determined using finite element simulation. A static analysis is performed first to preload the isolator so that stress stiffening is accounted for. This is followed by modal and forced response analyses to identify the transfer matrix of the isolator. In this paper, the insertion loss of spring isolators is examined as a function of several geometric parameters including the spring diameter, wire diameter, and number of active coils.
2016-04-05
Journal Article
2016-01-1543
Donald F. Tandy, Scott Hanba, Robert Pascarella
Abstract One important part of the vehicle design process is suspension design and tuning. This is typically performed by design engineers, experienced expert evaluators, and assistance from vehicle dynamics engineers and their computer simulation tools. Automotive suspensions have two primary functions: passenger and cargo isolation and vehicle control. Suspension design, kinematics, compliance, and damping, play a key role in those primary functions and impact a vehicles ride, handling, steering, and braking dynamics. The development and tuning of a vehicle kinematics, compliance, and damping characteristic is done by expert evaluators who perform a variety of on road evaluations under different loading configurations and on a variety of road surfaces. This “tuning” is done with a focus on meeting certain target characteristics for ride, handling, and steering One part of this process is the development and tuning of the damping characteristics of the shock absorbers.
2016-04-05
Journal Article
2016-01-1571
Harsh Patel, Michael Casino, David Noakes, Nicholas Kauffman, Daniel Rohwedder, Jugal Popat, Aneesh Nabar, Peter Thomas Tkacik
Abstract This paper is part of a bigger research effort that aims to capture the influences of static wheel alignment measurement accuracy for road going vehicles. Vehicle alignments can and often are the bottleneck in automotive and truck assembly lines and a greater understanding of the issues are very valuable. The alignment equipment in this research has been tuned and adjusted to minimize external variables and the team of authors have 300+ vehicle measurements. Of the many things that influence the accuracy and repeatability of vehicle suspension alignment measurement and adjustment, the measurement procedures can be the most significant. This includes but is not limited to alignment machine setup and vehicle tire pressures.
2016-04-05
Technical Paper
2016-01-1561
Xinxin Shao, Haiping Du, Fazel Naghdy
Abstract Development of a passive anti-pitch anti-roll hydraulically interconnected suspension (AAHIS) with the advantage of improving vehicle directional stability and handling quality is presented. A 7 degrees-of-freedom full car model and a 20 degrees-of-freedom anti-pitch anti-roll hydraulically interconnected suspension model dynamically coupled together through boundary conditions are developed and used to evaluate vehicle handing dynamic responses under steering/braking maneuvers. The modeling of mechanical subsystem is established based on the Newton’s second law and the fluid subsystem is modelled using a nonlinear finite-element approach. A motion-mode energy method (MEM) based on the calculation of the motion-mode energy is employed to investigate the effects of an anti-pitch anti-roll hydraulically interconnected suspension (AAHIS) system on vehicle body-wheel motion-mode energy distribution.
2016-04-05
Technical Paper
2016-01-1554
Cheng Gu, Xinbo Chen, Jun Yin
Abstract A novel geared electromagnetic active suspension is proposed in this paper. A pushing rod and a rocker are introduced to transfer the suspension vertical motion to the rotational motion of the motor. Comparing with the common ball-screw active suspension, it presents advantages of simple structure, easy manufacturing and module design. As the state variables of the suspension system cannot be all obtained for the sake of cost, taking the suspension deflection as the measurement, an output feedback LQR optimal controller is adopted, and it is concluded that the system can be stable with damping. Considering the nonlinearity of equivalent stiffness and unsprung mass caused by the system structure, parameter perturbation ranges are concluded through dynamic analysis, and robust H∞ control algorithm is proposed to realize the multi-objective optimization.
2016-04-05
Technical Paper
2016-01-1555
Jack Ekchian, William Graves, Zackary Anderson, Marco Giovanardi, Olivia Godwin, Janna Kaplan, Joel Ventura, James R. Lackner, Paul DiZio
Abstract It is widely anticipated that autonomous vehicles will offer increased productivity and convenience by freeing occupants from the responsibility of driving. However, studies indicate that the occurrence of motion sickness in autonomous vehicles will be substantially higher than in conventionally driven vehicles. Occupants of autonomous vehicles are more likely to be involved in performing tasks and activities, such as reading, writing and using a computer or tablet, that typically increase the occurrence of motion sickness. The authors present a novel high bandwidth active suspension system, GenShock®, and tailored control algorithms targeted toward mitigating motion sickness in autonomous vehicles. GenShock actuators can actively push and pull the wheels of a vehicle in order to keep the chassis level and reduce heave, pitch, and roll motion.
2016-04-05
Technical Paper
2016-01-1557
Francesco Castellani, Nicola Bartolini, Lorenzo Scappaticci, Davide Astolfi, Matteo Becchetti
Abstract Shock absorber is one of the most relevant sub-systems of the suspension system for a wide range of vehicles. Although a high level of development and tuning has been reached, in order to ensure high safety standards in almost every situation, some dynamic phenomena affecting vehicle handling or NHV (Noise Vibration Harshness) can appear. The aim of present work is to improve a mathematical model using experimental data from a prototype of monotube shock absorber developed for research purposes. The model takes into account all the main features affecting the global performance of the device, such as non-linear behaviour and the presence of hysteresis loops. Actually, the most important parameters are analyzed, such as flow and orifice coefficients of the valves, coefficients of mechanical compliance of the chambers and oil compressibility, dry and viscous friction coefficients.
2016-04-05
Technical Paper
2016-01-1549
Nicola Bartolini, Lorenzo Scappaticci, Francesco Castellani, Alberto Garinei
Knocking noise is a transient structural noise triggered by piston rod vibrations in the shock absorber that excite the vibration of chassis components. Piston rod vibrations can be caused by valve motion (opening and closing) and dry friction during stroke inversions. This study investigates shock absorber knocking noise in twin tube gas-filled automotive shock absorbers and its aim is to define an acceptance criterion for a sample check of the component. If, in fact, the damper comes from a large mass production, it may happen that small mounting differences lead to different behaviors that result in higher or lower levels of knocking noise. To achieve this goal, experimental tests were carried out using a hydraulic test bench; accelerometers were placed in proximity to the rebound valve and on the piston rod. The vibration phenomenon was then isolated through a post-processing analysis and a damped and unforced lumped mass model was used to characterize the vibration.
2016-04-05
Technical Paper
2016-01-1550
Ming Peng, Xuexun Guo, Junyi Zou, Chengcai Zhang
Abstract This paper presents a novel application of hydraulic electromagnetic energy-regenerative shock absorber (HESA) into commercial vehicle suspension system and vehicle road performance are simulated by the evaluating indexes (e.g. root-mean-square values of vertical acceleration of sprung mass, dynamic tire-ground contact force, suspension deflection and harvested power; maximum values of pitch angle and roll angle). Firstly, the configuration and working principle of HESA are introduced. Then, the damping characteristics of HESA and the seven-degrees-of-freedom vehicle dynamics were modeled respectively before deriving the dynamic characteristics of a vehicle equipped with HESA. The control current is fixed at 7A to match the similar damping effect of traditional damper on the basis of energy conversion method of nonlinear shock absorber.
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