Browse Topic: Suspension linkages

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Neural-Network-Based Suspension Kinematics and Compliance Characteristics and Its Implementation in Full Vehicle Dynamics Model2022-01-033503/29/2022
Suspension kinematics and compliance strongly influence the handling performance of the vehicle. The kinematics and compliance characteristics are determined by the suspension geometry and stiffness of suspension linkage and elastic components. However, it is usually inefficient to model all the joints, bushings, and linkage deformation in a full vehicle model. By transforming the complex modeling problem into a data-driven problem tends to be a good solution. In this research, the neural-network-based suspension kinematics and compliance model is built and implemented into a 17 DOF full vehicle model, which is a hybrid model with state variables expressed in the global coordinate system and vehicle coordinate system. The original kinematics and compliance characteristics are derived from multibody dynamics simulation of the suspension system level. The comparison of the neural network model and traditional interpolation methods is also given out to illustrate the advantages and
Duan, Yupeng, Zhang, Yunqing, Wu, Jinglai
Front Axle Kingpin Bush - Evaluation of Wear Rate in Operating Conditions2021-26-047309/22/2021
In automobiles, front axle assembly is a main load bearing member and houses steering linkages. Front axle assembly has two main parts viz. axle beam and axle arm, interconnected by a kingpin. This kingpin allows the rotation of axle arm during steering events. To avoid metal to metal contact between axle arm and kingpin, bushes are housed on the top and bottom half of the axle arm & in axle beam. Due to radial load and steering rotation, as a weak member, bushes will wear out faster. This affects the proper functioning of steering mechanism. Hence, the bushes need to be evaluated prior to its implementation in vehicle. In general, bushes are evaluated using Pin-On-Disc test as a comparative study, but it does not simulate exact boundary conditions as in vehicle. Next option is vehicle level validation but leads to more lead time and testing cost. Hence, as an optimized solution, the same vehicle operating conditions can be replicated in component level testing. Considering the
Bakthavachalam, Sathish Kumar, N, Gopi Kannan, Narasimman, Obuli Karthikeyan, R, Suresh
Light Weight Tubular Suspension Frame Design for Light Commercial Vehicle2021-26-039809/22/2021
Front Suspension frame is an integral part of automobile chassis which acts as a major load carrying structural member and connects different suspension components with body. It provides the required stiffness for achieving desired vehicle dynamics performance. Acting as a major road load path from tire to body, it also acts as a mounting base for suspension arm, steering gearbox and compression rod. Considering the competitive market conditions, increased FE demand along with enhanced structural durability, it is important to evaluate suspension frame for stiffness and durability using CAE methodology so as to reduce product development time and First Time Right cost effective design. In this paper focus is given on developing CAE methodology used to design a light weight tubular kind of suspension frame for Light Commercial Vehicle with stiffness comparable to conventional sheet metal suspension frame. Aim of developing CAE methodology is to obtain similar durability performance of
Thomas, Mithun, Dhawan, Rishabh, L, DineshBabu, Prakash, Anupam
A McPherson Lightweight Suspension Arm2020-01-077204/14/2020
The paper deals with the design and manufacturing of a McPherson suspension arm made from short glass fiber reinforced polyamide (PA66). The design of the arm and the design of the molds have been made jointly. According to Industry 4.0 paradigms, a full digitalization of both the product and process has been performed. Since the mechanical behavior of the suspension arm strongly depends on constraints which are difficult to be modelled, a simpler structure with well-defined mechanical constraints has been developed. By means of such simple structure, the model for the behavior of the material has been validated. Since the suspension arm is a hybrid structure, the associated simple structure is hybrid as well, featuring a metal sheet with over-molded polymer. The issues referring to material flow, material to material contact, weld lines, fatigue strength, high and low temperature behavior, creep, dynamic strength have been investigated on the simple structure. The detailed
Belingardi, Giovanni, Bernasconi, Andrea, Chessari, Marcello, Maccarinelli, Silvia, Mastinu, Giampiero, Previati, Giorgio, Scattina, Alessandro, Spini, Erico
Numerical optimization of independent suspension hardpoint2019-36-015401/13/2020
The present work aims to use complex tools for the calculation of vehicle dynamics, using optimization analysis. The study was applied to a single seat off-road prototype that has independent suspension, Double A or WishBones type, both on the front and rear axles and whose main objective will be the analysis of the prototype suspension arms fixing points. A multi-body model was created by MotionView software and straight-line acceleration and deceleration analyzes were applied to obtain better longitudinal load transfer ratios for the axes, besides the force measurements for the arm connections during these events. After the creation of the multi-body model, some studies using optimization tools, through HyperStudy software, were performed in order to obtain the new positions of the attachment points in the chassis, achieving a better dynamic suspension design. The new points change the longitudinal load transfer design and generate controlled alteration between predefined parameters
Alvim, Olavo Fava Furtado, Silveira, Marcio Eduardo
System Level Design of a Self-Stabilizing Two-Wheeler Suspension Concept2019-28-012710/11/2019
Two-wheeler represent one of the most used mode of transport in countries like India. The data from NCRB shows that most injuries to two-wheeler motorists are after being thrown off the vehicle. A self-stabilized combined with enclosure prevents serious injury in case of a skidding of the two-wheeler. The primary objective of the work is to create a suspension system for the enclosed self-balancing two-wheeler such that it can withstand the load of the vehicle itself and the extra payload. Ride comfort was primary objective of the work. The suspension system was modeled from the first principles, solved using MATLABTM SIMULINKTM and kinematics simulation was performed to learn the behavior of the system in MSC ADAMSTM. Dynamic simulations were also carried out to check if the forces were under permissible levels for overall design. The parameters considered for the work were hard-points, suspension stiffness and damping. With manual parameter iterations, suspension parameters were
Sankarasubramanian, Hariharan, Prabhahar, Dhurai
Considerations for Suspension ModificationJ2492_201910 (Current)10/09/2019
The scope of this document is limited specifically to the following types of passenger vehicles: automobiles, light trucks, and sport/utility vehicles. This document addresses modifications as they apply to legal use of the vehicle, and examines suspension modification as it applies to stock (as manufactured) ride height, and changed (raised or lowered) ride height. Note that modifications of ride height are considered, exclusive of wheel and/or tire modifications, which can also have potentially serious side effects, and are outside the scope of this document.
Motor Vehicle Council
Plastic Bearings Redefine the WheelchairTBMG-3458006/01/2019
For wheelchair users, the feeling of uneven ground can seem all too familiar. Determined to make ride discomfort a thing of the past, Israel-based SoftWheel has completely reinvented the wheel for a float-like experience.
Development of Block Cycle Test Load for Structural Durability Validation of MacPherson Strut2019-26-031501/09/2019
The MacPherson strut is a simple and common across all automotive’s front suspension of passenger cars. It is an independent suspension type, including a single suspension arm (spring and damper), an anti-roll bar and a lower arm. The MacPherson strut must have sufficient stiffness to support cornering force and fore/aft loads. Fatigue test of MacPherson strut suspension can be done in multiple ways. Most common method is laboratory testing/rig test. The objective of laboratory testing is to validate the MacPherson strut physically for all possible real-time events. Replicating all real-time events in lab environment is a challenging task. For many years this limitation was addressed through experience, however it has often led to either over or inferior design. The expected life span of automotive components like MacPherson strut varies considerably but it can be measurable in years/miles. It becomes virtually challenging to prove the product under service conditions over its whole
Murthy, Nuli Veda, Gopal, Sritharan, T, Siddeshwaran, Kilburn, Kevin
Modeling and Simulation of Steady State Handling Characteristics of Formula Vehicle with Antiroll Bars2019-26-006801/09/2019
Antiroll bar plays an important role in rollover stability of the vehicle. But not only does it limit the vehicle roll during cornering, but also alters the lateral load transfer between the tracks, which in turn affects the cornering performance of the vehicle. This paper deals with the design and mathematical modeling of antiroll bars to reduce the body roll of the vehicle from 1.5°/g to less than 1.0°/g. Rear bar uses a conventional torsion type bar but the front anti roll mechanism is an unconventional antiroll bar using a rotating double cantilever mechanism. Mathematical modeling is done for pushrod rod actuated antiroll mechanisms to simulate its non-linear roll rates. Antiroll bars for front and rear are designed for the calculated stiffness. Finite Element Analysis of antiroll bar and its components is done and the mechanism is tested on the vehicle. Steady state tire model parameters are generated by curve fitting tire testing data into pacejka coefficients. Then the vehicle
Gupta, Amit, Jadhav, Suraj, Mane, Ramchandra, Vora, Kamalkishore, Agrewale, Mohammad Rafiq
In-Wheel Suspension on SoftWheels Provides Smooth Ride for Wheelchair UsersTBMG-3245108/01/2018
Daniel Barel's initial objective was straightforward. He wanted to make life more comfortable for people who are confined to wheelchairs. Curbs, different surfaces, and the energy required to propel a wheelchair took a tremendous toll on one of Barel's friends, who had tried his own hand at an improvised solution for the discomfort.
Suspension Systems: Some New Analytical Formulas for Describing the Dynamic Behavior2018-01-055404/03/2018
The paper presents some new and unreferenced analytical formulae describing the dynamic behaviour of the suspension system of road or off-road vehicles. The quarter car model (2 degrees of freedom) is considered, the suspension can be either passive or active. Passive suspensions can be simplified as the spring-damper combination or the spring-damper combination with an additional in series spring (representing, e.g., the rubber bushing at the top of a McPherson strut or the rubber bushing at the end joints of the damper). The mathematical system is linear and the excitation is given by a random stationary and ergodic process. The standard deviations in analytical form are given referring to, respectively, the vehicle body acceleration, the relative displacement between sprung and unsprung mass, and the force at the ground. The so called invariant points of the frequency response functions are derived for both active and passive suspension. Unreferenced sub-invariant points are derived
Mastinu, Giampiero, Gobbi, Massimiliano, Yang, Liunan, Ramakrishnan, Kesavan, Ballo, Federico
Design and Simulated Analysis of Regenerative Suspension System with Hydraulic Cylinder, Motor and Dynamo2017-01-128403/28/2017
With the ever increasing number of vehicles on road and the rise of the electric and automated vehicles, it is important to minimize the consumption of energy by each vehicle, regenerative braking is in wide use today, however, the research in the field of regenerative suspension is limited. The regenerative suspension has huge capabilities in power generation especially on third world roads having rather bumpy rides. A huge amounts of energy is wasted in shock absorbers due to friction. This study emphasizes on the implementation of the energy present in the suspension system by replacing the Shock Absorber with a Energy transfer system Involving Hydraulic cylinder, Hydraulic Motor and Dynamo. The energy which is usually lost as heat due to friction in conventional Suspension is used to drive a dynamo through Hydraulic System designed in this paper and electricity is generated. This approach involves design and simulation of regenerative suspension system with specialized hydraulic
Ahmad, Khushal, Alam, Monis
Study of Different Twist-Beam Axle Configurations in Elastokinematics and Handling Behavior of a Vehicle2016-36-018410/25/2016
The twist-beam suspension is widely used in vehicles due to the simplicity of its construction, less occupied space and its low manufacturing cost in comparison with multi-link suspension. The difficulties related to the design of a twist-beam axle concern the large number of possible configurations for twist-beam profile and the stiffness adjustment of axle beam and suspension arms. However, design process can be done with the aid of multibody dynamics simulations, by testing several configurations in a virtual way. In this work, a simplified twist-beam suspension model is studied, and the influence of variation of its parameters is analyzed in its elastokinematics behavior and in handling performance of a vehicle.
Morales, Eduardo Domingo
Application Study of Nonlinear Viscoelastic Constitutive Model for Dynamic Behavior of Suspension Arm Bushing2016-01-137504/05/2016
Ride quality is an important purchasing consideration for consumers. It is typically defined in terms of noise, vibration and harshness. These phenomena are a result of vibrations caused at the engine/powertrain and from the road surface, which are transmitted to the passenger cabin. To minimize such vibrations, rubber parts are used extensively at mounting points for the cabin, such as engine mountings and suspension bushings. The vehicle development process increasingly requires performance testing, including rubber parts using CAE, prior to prototype evaluation. This in turn requires a rubber material model that can accurately describe dynamic characteristics of rubber components, particularly frequency and amplitude dependency. Conventional rubber models using commercially available structural analysis solvers cannot solve for both frequency and amplitude dependency at the same time, and are unable to predict transient phenomena such as harshness that involve inputs of varying
Ueda, Masahiro, Ito, Satoshi, Suzuki, Daichi
Design and Control of a Novel Geared Electromagnetic Active Suspension2016-01-155404/05/2016
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. The performance comparisons of both controllers mentioned above are carried out in the ADAMS/MATLAB co-simulation to reflect the
Gu, Cheng, Chen, Xinbo, Yin, Jun
Experimental Investigation of Effect of Driveline Torsional Fluctuations on Overall NVH Performance of the Vehicle2015-01-219206/15/2015
Meeting various customer(s) requirements with the given automotive product portfolio within the stipulated time period is a challenge. Design of product configuration matrix is an intelligent task and it requires information about vehicle performance for different configurations which helps in deciding the level of new development. Most often the situation arises, particularly in the field of NVH, to strike the right balance between engine power and structural parameters of the body. The sensitivity of engine power on the overall NVH behavior is the key information necessary to take major business decisions. In this paper, the effect of change in torsional fluctuation of the engine on the NVH behavior of the rear wheel drive vehicle is experimentally studied. The torsional fluctuation of the driveline is given as an input with the help of an electric motor to the existing test vehicle at its differential end and the current NVH levels are measured. A test rig is built to change the
Rao, Manchi Venkateswara, Frank, Jos, Raghavendran, Prasath
Relative Performance Analyses of Independent Front Axle Suspensions for a Heavy-Duty Mining Truck2014-01-232009/30/2014
A range of axle suspensions, comprising hydro-pneumatic struts and diverse linkage configurations, have evolved in recent years for large size mining trucks to achieve improved ride and higher operating speeds. This paper presents a comprehensive analysis of different independent front suspension linkages that have been implemented in various off-road vehicles, including a composite linkage (CL), a candle (CA), a trailing arm (TA), and a double Wishbone (DW) suspension applied to a 190 tons mining truck. Four different suspension linkages are modeled in MapleSim platform to evaluate their kinematic properties. The relative kinematic properties of the suspensions are evaluated in terms of variations in the kingpin inclination, caster, camber, toe-in and horizontal wheel center displacements considering the motion of a hydro-pneumatic strut. The results revealed the CL and DW suspensions yield superior kinematic response characteristics compared to the CA and TA suspensions. Toe-in and
Kang, Yiting, Rakheja, Subhash, Zhang, Wenming
Formula SAE Frame Torsional Stiffness Study using FEA2014-36-023409/30/2014
The Formula SAE competition has the purpose to stimulate the engineering students to work in teams to develop a concept, design and build small racing vehicles. In this competition, students are motivated to build a high performance car, reliable and with low development cost. The success of the team in the competition is determined with a detailed analysis of all aspects involved. Considering the frame development, some key points must be considered for the structural performance: stiffness, durability, modal and safety response. This papers focus on the stiffness analysis to verify if the frame torsional stiffness is compatible with the respective suspension for the level of performance required. The study was performed using the frame of 2012 Formula SAE from Instituto Mauá de Tecnologia using beam elements to model the frame structure in a FEA (Finite Elements Model) software to simulate the system stiffness. The vehicle mass and CG properties to support the studies were obtained
Costa, João Augusto da, Vilela, Daniel
Mercedes anticipates the future with new S-Class13AEID1001_0510/01/2013
Mercedes-Benz, using networked electronic systems (sensor fusion), is introducing on its new S-Class a step-change suspension system that can “see” (via a stereo camera) the road surface ahead and make ultra-high-speed decisions on how to deal with it. The letters “IFS” once represented the pinnacle of suspension development. They stood not just for independent front suspension but also were used by automotive marketers to establish a certain elitism for a product: a step-change ride-and-handling solution about which customers could boast. Earle S. MacPherson's renowned strut was-literally-at the forefront of this advance, using a coil spring and damper to great effect on monocoque cars from 1949; it remains an independently sprung suspension member still favored by many of today's chassis engineers.
Birch, Stuart
Mathematical Modeling of Hydropneumatic Suspension System2013-01-192805/13/2013
Mathematical modeling of any system plays an important role in research and engineering applications. Development of hydropneumatic suspension system requires a complete understanding of physical phenomenon and generating governing equations of the same. In this paper, mathematical model of a typical hydropneumatic suspension system is made and simulation of such a complex multi domain system is programmed in MATLAB Simulink software. Vibration isolation potential of hydropneumatic suspension system is investigated through mathematical modeling, incorporating nonlinearity due to polytropic nature of gas spring.
Kinagi, Ganesh Vijaykumar, Wadkar, Suresh, Sonawane, Dnyanesh
Evaluation of Human Body Response for Different Vehicle Seats Using a Multibody Biodynamic Model2013-01-099404/08/2013
A valid human biodynamic model is very useful for studying the human body's response to whole body vibration. Whole body vibration is one of the important factors in the study of vehicle ride comfort. The environmental vibrations are transferred to the human body through floor and seat. Seated posture is the most commonly used position in automobiles. Therefore, studying the human body response in a seated position has attracted a lot of attention. Because the human body is in direct contact with the seat, its design plays a very important role in vibration transmission. In seat design, two important components are seat suspension and cushion. The mechanical properties of these components are stiffness, damping and mass. These properties can be changed by adjusting cushion material and seat suspension linkages. In this paper, three types of seat models are used. The first one is a hard seat. The second one has only cushion, and the third one is called an isolated seat which has seat
Kumbhar, Prasad, Xu, Peijun, Yang, James
Lightening Approach for Small Vehicles by Developing Extruded Aluminum Suspension Arm2012-32-009410/23/2012
This paper shows the lightening approach for small vehicles by developing lower arm of the hollow extruded aluminum, which is the low cost material and has closed cross section. The manufacturing cost was reduced by developing the industrial method to form the developed lower arm of the extruded aluminum by cold press, without welding. In addition, the developed method forming of the heat-treated extruded aluminum reduces the manufacturing cost more, compared to the conventional method forming before the heat treating. The structure of the developed lower arm has the wide center part receiving the coil spring and the narrow end part connecting to the vehicle body with the bush. The center part has the same cross section as the extruded aluminum, and the end part was formed by shrinking the extruded aluminum by cold press. In addition, the original expanding clinching method was developed to joint the aluminum outer tube of the bush for the prevention action against the galvanic
Yotsuya, Gouki, Yamauchi, Ryo
Steering System Optimization of a Ford Heavy-Commercial Vehicle Using Kinematic & Compliance Analysis2012-01-193709/24/2012
The basic scope of heavy-commercial vehicle (HCV) development which was just concentrated on fuel-economy, durability and performance feel is not capable of fulfilling the increasing customer expectations anymore. HCV developers concentrate on additional vehicle attributes such as steering, ride comfort, NVH, braking, ergonomics and exterior-interior design in order to provide the passenger-car like perception to HCV drivers during long distance drives. The objective of this paper is to present the model validation methodology and the optimization study on suspension & steering hard points of a HCV. The results of the optimization study on suspension kinematics and steering performance of the vehicle is verified using both full vehicle simulations and vehicle testing. A full vehicle ADAMS/Car model is used for the validation and optimization study which has beam-element leaf springs on solid axle and air springs on drive axle for front and rear, respectively. The steering system of the
Oz, Yahya, Ozan, Berzah, Uyanik, Eren
Hydropneumatic Suspension Design for Light Military Tracked Vehicle2012-01-191109/24/2012
In this paper hydropneumatic suspension system design methodology for light military tracked vehicle is discussed in detail. A guide to locate the major impact factor & its effect on the system level design is demonstrated. Spring & damping characteristics of hydropneumatic suspension have significant bearing on the tracked vehicle mobility characteristics. A methodology has been derived to optimize the kinematics of the suspension system by optimizing the load transferring leverage ratio resulting in enhanced system life. The paper also discusses the analytical method used for prediction of spring & damping characteristics and the factors affecting them.
Kinagi, Ganesh Vijaykumar, Pitchuka, Syam Prasad, Sonawane, Dnyanesh
Development of a New Multi-link Rear Suspension2012-01-097804/16/2012
The requirements of suspension systems have become increasingly complex in recent years due to the expansion of global markets and diversification of the conditions under which vehicles are used in different parts of the world. It is also becoming increasingly important to ensure that vehicles offer the secure handling stability which are expected by drivers, but can also provide an adequate level of ride comfort when driving on a wide diversity of road surfaces in all parts of the world. From an environmental viewpoint, it is also essential to achieve weight reductions for better fuel economy. To meet these wide-ranging requirements, we have developed a new multi-link rear suspension that has a simple link configuration and a lower link that features a connecting bushing mechanism developed by Nissan. This innovative new connecting bushing mechanism not only helps to provide better handling stability by ensuring high stiffness and an adequate level of compliance steer, but also helps
Koide, Reo, Kawabe, Yoshihiro, Nakajima, Keiichi, Kazuhiro, Kiriyama
Development of NV Performance of New Rear Suspension and New Drivetrain for Rear-Drive Vehicles2012-01-072904/16/2012
This paper describes the design measures taken to develop the noise and vibration performance of a new rear suspension and a new drivetrain system for rear-wheel-drive vehicles. The new rear suspension is designed to solve trade-off issues between road noise and handling performance. Despite higher drive torque, booming noise is greatly reduced by the new rear suspension and drivetrain without increasing the vehicle weight or sacrificing fuel economy.
Miyakawa, Takayuki, Akamatsu, Hiromichi, Enomoto, Toshio, Suzuki, Atsushi, Kageyama, Yusuke, Matsuoka, Hisayoshi
Mathematical Model to Find Piercing Point in McPherson Strut Suspension and Design of profile for Side Force Control Spring2012-28-001401/09/2012
The cost pressure experienced by the automotive industry and the necessity to reduce the vehicle weight have resulted in a renewed and growing interest in axle systems fitted with McPherson struts. They nevertheless have some drawbacks, well known to car-makers, with regard to their road-holding qualities. In particular, we may mention the problem of friction and drift. Undesired lateral force inevitably exists in a McPherson suspension system, which is liable to damper rod's side wear and promote the damper's inner friction decreasing the ride performance from the suspension system. Already it is proven that side load control spring is best solution on the problem. In this paper the attempt is made to build the mathematical model to find the piercing points which is input for design of side load control spring using vectors and explains detailed mathematical procedure for design of side force control spring. The mathematical model is validated with practical prototype testing and
Joshi, Amol H., Singh Chhabra, Harvinder
Passenger Car and Light Truck AxlesJ2200_201109 (Current)09/06/2011
This SAE Recommended Practice is intended to outline basic nomenclature for axle designs in common use for automotive drives. Over a period of years, there have been many different designs; however, for the purpose of this report, only the most common designs have been selected and only their general construction is illustrated to show the nomenclature of the various parts.
SAE IC Powertrain Steering Committee
Transfer Function Analysis of Rear Multi-Link Suspension to Improve Ride Vibration and Road Noise2011-01-157105/17/2011
The expectation of customers on ride comfort is very high and vehicle engineers also have keen interesting to improve ride vibration and road noise. As the conventional tuning parameters for the ride vibration and road noise, vibration characteristics of tire, body structure, bushing, suspension members etc. are mainly considered. But these conventional tuning parameters are sometimes not enough due to the side effects such like handling performances and durability. Therefore, instead of these conventional design and tuning parameters, suspension geometry and alignment characteristics of suspension system are selected as the alternative parameters to compromise ride vibration, road noise and vehicle dynamic performance. In this research, multi-link type rear suspension is selected for the integrated analysis of ride vibration, road impact noise and handling performance. Transfer function, transfer force analysis of rear multi link suspension system and reaction forces variations
Kim, Myung-Gyu
Dual Rate Jounce Bumper Design2011-01-079104/12/2011
Jounce bumpers are the primary component by which vertical wheel travel is limited in our suspensions. Typically, the jounce bumper is composed of closed or open cell urethane material, which has relatively low stiffness at initial compression with highly progressive stiffness at full compression. Due to this highly progressive stiffness at high load, peak loads are extremely sensitive to changes in input energy (affected by road surface, tire size, tire pressure, etc.) A “Dual Rate Jounce Bumper” concept is described that reduces this sensitivity. Additionally, various mechanizations of the concept are described as well as the specific program benefits, where applicable.
Schudt, Joseph A., Tsai, Maolin, Patil, Ravindra, Geisler, Robert
Synthesis of a Vehicle Suspension with Constrained Lateral Space using a Roll-plane Kineto-dynamic Model2010-01-064104/12/2010
The larger chassis space requirements of hybrid vehicles necessitates considerations of the suspension synthesis with limited lateral space, which may involve complex compromises among performance measures related to vehicle ride and handling. This study investigates the influences of suspension linkage geometry on the kinematic and dynamic responses of the vehicle including the wheel load in order to facilitate synthesis of suspension with constrained lateral space. A kineto-dynamic half-car model is formulated incorporating double wishbone suspensions with tire compliance, although the results are limited to kinematic responses alone. An optimal synthesis of the suspension is presented to attain a compromise among the different kinematic performance measures with considerations of lateral space constraints. In the kineto-dynamic model, the struts comprising linear springs and viscous dampers are introduced as force elements. Kinematic formulations of the proposed model are derived
Balike, Krishna Prasad, Rakheja, Subhash, Stiharu, Ion
Influence of Suspension Kinematics and Damper Asymmetry on the Dynamic Responses of a Vehicle under Bump and Pothole Excitations2010-01-113504/12/2010
Automotive suspensions invariably exhibit asymmetric damping properties in compression and rebound, which is partly attributed to asymmetric damping and in-part to the suspension linkage kinematics together with tire lateral compliance. Although automotive suspensions have invariably employed asymmetric damping, the design guidelines and particular rationale for such asymmetry has not been explicitly defined. The influences of damper asymmetry together with the suspension kinematics and tire lateral compliance on the dynamic responses of a vehicle are investigated analytically under bump and pothole excitations, and the results are interpreted in view of potential design guidance. A quarter-car kineto-dynamic model of the road vehicle employing a double wishbone type suspension comprising a strut with linear spring and multiphase asymmetric damper is formulated for the analyses. The simulation results revealed conflicting sprung mass acceleration responses under idealized bump and
Balike, Krishna Prasad, Rakheja, Subhash, Stiharu, Ion
An Optimal Design of the Suspension Linkage2009-01-292310/06/2009
This paper proposes an optimal method for the air suspension linkages design, which takes multiple critical geometric dimensions of the linkage as design variables, takes the maximum stress of critical areas in certain parts and the total mass of the assembly as objective functions, normalizes those objectives, and combines them together to evaluate the design. A design flow is developed to integrate the proposed method with a 3-D modeling software and a finite element software, and to expedite the design process. The effect of design variables on the stress of each part and on the mass is analyzed. Based on the sensitivity analysis and the objectives' values, the best design is determined from several available candidate schemes. The stress at critical areas is decreased significantly, as well as the total mass, which improve the safety and cut the cost. The optimization method is also applicable to any multi-parameter multi-objective mechanical part design.
Jiang, Hong, Liao, Xueliang, Zhu, Jingjing, Li, Lin
A New Method to Evaluate Bump Steer and Steering Influence on Kinematic Roll and Pitch Axes for All Independent Suspension Types2008-01-294912/02/2008
Does steering and bump steer modify the location of the kinematic roll and pitch axes? If so, by how much? How to calculate and appreciate such differences? The effects of bump steer and steering are often neglected when determining the kinematic roll and pitch axes of a particular independent suspension. This is caused by the inherent limitations of the “classic” kinematic analysis method. A new method is proposed that addresses the limitations of the “classic” method. The new method derives the kinematic roll and pitch axes through synthesis of the wheel movement in six degrees of freedom, and thus includes the effects of bump steer and steering. The new method can also be applied to any independent suspension types, including the multi-link suspension.
Mohan, Ganesh, Rouelle, Claude, Hugon, Emmanuel
Test Rig for Characterization of Automotive Suspension Systems2008-01-069204/14/2008
A test rig (named RuotaVia) is presented for the in-door testing of road vehicle suspension systems. It is basically a drum (ϕ 2.6 m) providing a running surface for testing the dynamic performance of a single tire or suspension system (corner). The suspension system is instrumented for the measurement of the forces and the moments acting at each joint connecting the suspension to the car body. A new 6 axis load cell was designed and manufactured for this purpose. The accelerations in various locations of the system (wheel carrier, suspension arms, …) and the wheel centre displacements in the longitudinal and vertical directions are monitored. The effect of the dynamic interaction between the test rig and the suspension system is discussed in the paper. The direct measurement of the forces and moments at the suspension-chassis joints is still an effective way for understanding the vibration and harshness (VH) suspension performances. The proposed experimental set-up allows to perform
Gobbi, Massimiliano, Guarneri, Paolo, Mastinu, Gianpiero, Rocca, Gianpiero
Consideration of Suspension Mechanism with High Cornering Performance for a Formula Car2008-01-060704/14/2008
In the cornering performance of a formula car, turning is performed at a considerably high level. However, few studies have investigated the control of the camber angle. Therefore, a mechanism that swings to the negative camber side of the suspension in cornering was examined in the present study. A swinging suspension member structure was assumed when a lateral force acted on the tires, and the momentary rotation center of the swing suspension member was controlled so that the direction of the swing would be to the negative camber side. As a result, compliance of the negative camber was achieved. The layout of a preferable mechanism was first determined by geometrical analysis. The negative camber angle obtained with this mechanism changes according to the length of the link for the fixation of the swing suspension member, the installation position, and the angle. The specifications for achieving a proper compliance negative camber were then clarified. Next, the fastest running
Nozaki, Hiromichi, Kizu, Masahito
The Suspension of the Newly Developed Hyundai ELANTRA2006-01-153404/03/2006
This paper introduces a newly developed suspension system for new Elantra model of Hyundai Motor Company which will be on the market this year. The new chassis of Elantra has been developed to give more driving pleasure and confidence to a driver. To achieve these driving targets, the suspension has been changed and finely adjusted to achieve better ride and handling performance compared with the previous generation. Especially, a new multi-link suspension which has two upper links has been developed. The kinematics and compliance characteristics have been contrasted to those of the previous model. Also, the crashworthiness and package efficiency has been considered without limitation of suspension performance. Based on the customer's voice of market, the suspension of new Elantra has tried to fit the all kind of the customer's demand.
Ko, Young Eun, Park, Young Wook, Cho, Young Gun, Lee, Un Koo
Magneto-Rheological Fluid Semiactive Suspension System Performance Testing on a Stryker Vehicle2006-01-137904/03/2006
A Magneto-Rheological (MR) Fluid Semiactive Suspension System was tested on a Stryker vehicle, Infantry Carrier Variant (ICV), to determine the performance improvements compared to a standard ICV Stryker vehicle. In January 2005, the testing was conducted at the U.S. Army Yuma Proving Grounds located in Yuma, Arizona. The testing was conducted under the guidance of the U.S. Army Tank-Automotive Research, Development, and Engineering Center (TARDEC) of Warren, Michigan and MillenWorks of Tustin, California. The core of the system tested is comprised of 8 dampers and controllers using proprietary algorithms to modulate individual wheel forces in response to terrain inputs and body motion. Functionality of the Standard Stryker vehicle’s pressurized gas spring and ride height management system was fully retained while maintaining the physical envelope of the original damper. The systems low power consumption (80 watts idle, estimated 250 watts cross-country, and 800 watts theoretical peak
Wray, Andrea C., Jimenez, Alexander R., Anderfaas, Eric, Hopkins, Brian, LeNoach, Peter
An Off-Road Suspension Design2005-01-402411/22/2005
This paper consists in a definition and analysis of rear suspension geometry to an off-road vehicle. The suspension selection was accomplished through the study of its geometric characteristics to design its dimensions and position of installation in the vehicle according to the expected behavior. The current suspension of the vehicle, on the front and rear axles, was analysed for understanding its dynamic behavior. The vehicle submitted to analysis was a “Mini-Baja”, off-road prototype, which is used to run nationals competitions between engineering colleges. Its top speed is 50 km/h and its turn diameter is 8.2 m.
Gertz, Luiz Carlos, Martelo, Leonardo, Laranja, Rafael Antônio Comparsi, Rech, Charles, Balbinot, Alexandre, Brusamarello, Valner João
Optimum Design of Suspension Systems Under Kinematical Constraints2005-01-360811/01/2005
Suspension systems are designed by considering comfort and durability issues. If suspension systems are analyzed from the view point of acceleration and force transmission, two design criteria are obtained that can be used in optimum design of these suspension systems. For individual links of these suspension systems, these criteria are minimum transmissibility condition and percussion center of the links, which are derived through kinematical analysis. While minimum transmissibility condition can be imposed geometrically, location of percussion center of a link can be optimized by using finite element model of the link. It is shown that accelerations and reaction forces that are transmitted to the chassis of the vehicle can be reduced by considering these issues.
Atik, Engin, Karadeniz, Murat, Muğan, Ata, Keşli, Bülent, Kanbolat, Ahmet
Non-Linear Characteristics Suspension System for Tracked Vehicle2005-26-06401/19/2005
An Armoured Fighting Vehicle (AFV) is a cross-country vehicle, which needs to be designed to operate under sever conditions. The vehicle has to negotiate through all surfaces during actual operation at high speeds. Due to the movement of the vehicle, if the loads applied to the road wheels of the AFV were transmitted directly to the chassis, not only would it occupants suffer severely but also its structure would be subjected to an excessive degree of fatigue loading. A very fundamental requirement of high wheel travel, high energy to be stored can be easily achieved with a non linear characteristics suspension system like Hydro Gas Suspension System (HGSS) which is highly compact and having inbuilt damper. Ever though the design is highly complicated, the system can absorb maximum energy, making the ride of the vehicle highly comfortable. The HGSS also ensures the suspension system is soft at lower loading and stiffer at higher loading which cannot be achieved by any linear
LAKSHMANAN, K. S.
An Integrated Approach for an Articulated Bus Development. Durability and Dynamics Simulations2004-01-345511/16/2004
This paper describes the application of structural and dynamic analysis of a new articulated bus developed by Daimler-Chrysler do Brasil. Structural analysis is carried out using both static and dynamic finite element analysis. The simulation of the vehicle running on a road track gives input for structural dynamic analysis that is followed by durability calculation. Dynamics analyses are carried out using the multibody dynamic methodology and the software Adams/View. Initially, a detailed numerical model is developed, including all the major non-linearities of the actual vehicle, such as air spring and shock absorber curves, suspension bump stops and tire model. Also the representation of the suspension geometry and articulation properties is introduced. Using this model, the first dynamic analysis performed is the calculation of forces acting on suspension elements when the bus is running on a road track with severe profile. Handling analysis of the articulated bus is then conducted
Saracho, Cristina Minioli, Nogueira, Celso Figueiredo, Miyoshi, Carlos Shigueru, Argentino, Marcos Antonio
Impact of Suspension Design on the Strain Field in a Truck Auxiliary Axle2004-01-271510/26/2004
This paper investigates eight suspension design factors used to support non-driven axles and their impact on suspension strain field. The particular suspensions are of a trailing arm and air spring design. These auxiliary suspensions are commonly added to give extra weight carrying capacity to medium and heavy commercial vehicles. Eight design factors were studied. From the investigation, the main factors and seven two-way interactions were ranked by their effect on the strain in the axle according to strain gage location and road test type. Two approaches were taken to study the impact of the design factors. The first approach was to develop computer code to model a two-degree of freedom (2DOF) bi-linear system. The design factors of the suspension that can be modeled in the simplified 2DOF system were input into the computer code using a full factorial design of experiment. The mathematical model uses road displacement input to predict the motions of the axle mass and the trailer
Power, Andrew
A Suspension System suitable for Wheels or Tracks2004-01-158703/08/2004
In the moves to transform armed forces both in the United States and Europe a common feature has been the trend towards lighter armored vehicles. This has brought forward all the old arguments of wheels versus tracks as the weight category of interest is right in the area where there is a convergence, whether perceived or real, in the performance capabilities of the two technologies. The reality is that each has its particular attributes and disadvantages. It is acknowledged that the optimum solution from a performance standpoint is a mix of tracks and wheels. The negative consequence of this is the increased logistic and maintenance burden. This paper describes a novel, though proven, suspension system which is equally suited to both wheels and tracks, permitting an identical platform to be used and so eliminating the logistic and maintenance issue.
Timoney, Eanna
The Use of Semi-Solid Rheocasting (SSR) for Aluminum Automotive Castings2003-01-043303/03/2003
Semi-solid metal (SSM) casting has long been identified as a high-volume process for producing safety-critical and structural automotive castings, but cost and complexity issues have limited its widespread commercial acceptance. Rheocasting, an SSM process that creates semi-solid slurry directly from liquid metal, eliminates the cost disadvantages of the process. However, the majority of rheocasting processes are complex and difficult to operate in the foundry environment. Recent work at MIT has led to the fundamental discovery that application of heat removal and convection as a molten alloy cools through the liquidus creates a non-dendritic, semi-solid slurry. A new process based on this understanding, S.S.R.™ (Semi-Solid Rheocasting), simplifies the rheocasting process by controlling heat removal and convection of an alloy during cooling using an external device. Solution heat treatable castings have been produced in a horizontal die casting machine with the S.S.R.™ process. This
Yurko, James A., Martinez, Raul A., Flemings, Merton C.
Testing a Formula SAE Racecar on a Seven-Poster Vehicle Dynamics Simulator2002-01-330912/02/2002
Vehicle dynamics simulation is one of the newest and most valuable technologies being applied in the racing world today. Professional designers and race teams are investing heavily to test and improve the dynamics of their suspension systems through this new technology. This paper discusses the testing of one of Clemson University's most recent Formula SAE racecars on a seven-poster vehicle dynamics simulator; commonly known as a “shaker rig.” Testing of the current dampers using a shock dynamometer was conducted prior to testing and results are included for further support of conclusions. The body of the paper is a discussion of the setup and testing procedures involved with the dynamic simulator. The results obtained from the dynamic simulator tests are then analyzed in conjunction with the shock dynamometer results. Conclusions are formed from test results and methods for future improvements to be applied in Formula SAE racing are suggested.
Miller, Andrew
Algorithm Computes Kinematics of a Rover on Rocky TerrainTBMG-643906/01/2002
The Rover Analysis Modeling and Simulation (ROAMS) algorithm is to solve the kinematics of a wheeled mo- bile robot (rover) traversing on a rocky terrain. The rover is constructed using a “rocker-bogey-differential” type suspension and steering system as shown in the figure. By exploring the mechanical symmetry and the wheeled-terrain contact characteristics on a rough terrain profile, we developed a novel algorithm to carry out the rover’s configuration, including the vehicle’s wheels, steering and suspension linkages, and the position and orientation of the chassis. Because of its efficient and reliable numerical results, the ROAMS algorithm is well suited for the real-time simulation test bed, e.g., a simulation software system, of the mobile robotic vehicles in the planetary surface exploration missions. Currently, it is used to support the development of simulation and operation tools for the Mars Exploration Rover (MER) in the Mars ‘03 mission.
4-DOF Vehicle Ride Model2002-01-158005/07/2002
Ride quality is one of the most important criteria by which people judge the design of a car. At the most basic level, ride isolation properties are investigated using a quarter vehicle model. But the input from road roughness would excite not only bounce motions, but also pitch motions. Understanding the pitch and bounce motions is essential because it is their combination that determines the vertical and longitudinal vibrations at any point on the vehicle [2]. In this paper, a 4-degree-of-freedom (4-DOF) Vehicle Ride Model, which is shown in Figure 1, is used to investigate the effect on the ride quality of the dynamic index in pitch, mass ratio, weight distribution and flat ride tuning. A Lagrange equation is used to derive the equations of motion. A state-space formulation is obtained by using state variables. From these, the characteristic equation, natural frequency and damping ratio are obtained. Through an analytical and numerical study of the ride quality of a 4-DOF model, the
Sun, Tianbing, Zhang, Yubo, Barak, Pinhas
CAE Methodologies for Virtual Prototyping of Cast Aluminum Suspension Components2002-01-067703/04/2002
This work describes numerical methodologies used for both fatigue life prediction and impact load analysis of automotive suspension components made of a cast aluminium alloy. Some issues related with finite element (FE) discretization are discussed, and the main guidelines for fatigue analysis and critical load determination are presented. FE stress results have been validated through comparison with experimental strain gauges measurements, and a good agreement is shown between the predicted fatigue and impact behaviour of the component, and experimental data obtained from bench tests. Such an agreement concerns, in particular, the failure locations, the fatigue lifetime, the critical load and the post-buckling behaviour.
Knani, K. Bel, Bologna, P., Duni, E., Villari, G., Armando, G., Tortone, M., Leghissa, M., Barone, S.
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