MacPherson Strut Suspension Research Articles

The influence of the anti-roll bar on the vehicle’s roll angle

This study investigates the impact of the anti-roll bar (ARB) on the roll angle of a Toyota Prius vehicle. The vehicle is equipped with a front independent MacPherson strut suspension incorporating a P-shaped stabilizer bar, and a rear semiindependent torsion beam suspension. The methodology involves determining the stiffness of the ARB and analyzing its influence on the vehicle’s roll angle using both theoretical and experimental approaches. The results indicate that the mathematical model, which takes into account the stiffness of the stabilizer bar, effectively predicts and explains the vehicle’s roll behavior. Keywords: unsprung mass displacement, vehicle stability, anti-roll bar

Topology optimization of a MacPherson control arm

One of the most important systems in ground vehicles is the suspension system, which is responsible for the ride comfort, the road holding and handling. A crucial part of a passenger car passive suspension system is the control arm or wishbone arm or A-arm. Its main function is to provide a link between the body of the vehicle and the wheels. In this paper, the studied control arm is a part of a MacPherson strut suspension and its dimensions correspond to a front right suspension of a SUV vehicle. Two geometrical models of the control arm were developed in Solidworks® CAD-CAE Software, one with the measured dimensions and one with the outline dimensions of the control arm. A finite element model of the first one was built, using typical loading conditions, in order to determine the deformation and the stress contours. Then a topology optimization analysis was carried out to the second one in order to obtain a new design for the control arm. The FE results of the existing control arm and the optimized one were compared in terms of weight and structural integrity in different loading conditions leading to conclusions regarding the optimization procedure.

Piezo impedance-based monitoring of loosening of bolts: Experimental and numerical study

The suspension strut mount plays a crucial role in any vehicular suspension system, where it acts as a connector (bolted) to the vehicular body and suspension strut. The mount’s purpose is to cushion the Vehicular impacts and reduce the jarring effect, noise, and vibration caused due to vehicle movement over the undulated roads. The self-loosening of bolts results because of the up and down impact of the spring cause the jounce bouncer to push and pull action at the mount interface, cause vibrations transmitted to the vehicle camber. Self-loosening leads to damage of mount followed by clunking noises, noisy steering, tire misalignment, and can cause discomfort to the passenger. Therefore, condition monitoring and assessment of an upper strut mount is necessary for vehicles. This paper studies the feasibility of the piezo Impedance-based Structural health monitoring (SHM) technique to monitor the self-loosening bolts in the upper strut mount of the suspension system (MacPherson strut suspension) of passenger car. The piezo coupled signatures were obtained experimentally by loosening all the three bolts (connected to strut bearing) through control torques through a digital torque wrench. All the experimental signatures were acquired with a single PZT patch bonded to the surface of the upper strut mount for loosening bolts with pre-tight loss. Progressive damage scenarios are simulated along with preload loss of either single bolt or all three bolts, respectively. Three different statistical damage indices were evaluated for damage quantification raised due to bolt loosening. A 3D numerical modeling of strut mount is done using ANSYS WORKBENCH, and piezo impedance signatures were acquired (hence converted to admittance) for validating the experimental signatures. In an overall, this study provides an insight into the loss of structural integrity due to the self-loosening of suspension bolts, which can be threatful to vehicular integrity.

Design of end coil angular position and centerline shape of C-type side load coil spring for reducing side load of MacPherson strut suspension

MacPherson strut suspension, which is widely used vehicle suspension type, decreases the riding comfort and durability of strut module due to the side load generated at the damper. In this study, a method for designing a C-type side load coil spring is proposed to reduce the side load, considering not only the centerline shape, but also the end coil angular position of the spring. The effect of end coil angular position as well as centerline shape on the force axis are analyzed through finite element analysis (FEA) and regression analysis. Formulas are established based on the analyses and the C-type coil spring was designed considering the effects of both design variables on the force axis. Then, the side load of the MacPherson strut suspension on which the designed C-type side load coil spring was mounted was calculated by using the flexible multibody dynamic analysis method. Finally, a side load reduction effect of C-type side load coil spring is analyzed by comparing with that of helical-type coil spring.

Performance Analysis of Helical Compression spring And Banana or C Shaped Coil Spring Under Various Loading Conditions

Suspension system is one of the major and indispensable subsystems for land vehicles and has functions of providing better road holding, handling, and ride comfort. There are many suspension system types used for automobiles, and MacPherson strut suspension is one of the most widely used suspension system type due to its favorable features like simplicity, low cost, and high performance. However, there exists a drawback of this suspension type; since the coil springs have no ability to absorb lateral forces, undesired dry friction effects on the damper may degrade the ride comfort. As remedy to this drawback, the most popular and contemporary application is the use of coil spring forms which are called side load springs.It is observed that, the vehicle drifts towards one side due to high weight of suspension system. This problem can be solved by implementation of banana-C shaped coil spring. A banana,C-shaped coil spring is designed in such a way that it, when fitted correctly, exerts an opposing force compensating for the aforementioned side load pressure. This creates a balance and leads to the best possible working conditions for the shock absorber, ensuring a longer lifetime. Creo software was utilized to design the helical compression spring. The static analysis using finite element method has been done in order to find out the detailed load vs. defection of the helical compression spring and banana-shaped coilspring.

다물체 동역학 해석을 통한 맥퍼슨 스트럿 서스펜션 사이드 로드 스프링의 승차감 개선 효과 분석

맥퍼슨 스트럿 서스펜션에 적용되는 사이드 로드 스프링을 해석하기 위해서는 일반적으로 비선형 유한요소 해석이 사용된다. 그러나 비선형 유한요소 해석은 모델링 및 해석에 많은 시간이 소요되는 경우가 많다. 본 논문에서는 절대절점좌표계를 이용하여 비선형 유한 요소를 모델링하고, 이를 다물체 동역학 모델에 적용하여 해석하는 방법을 설명한다. 그리고 하중을 받지 않은 상태로 설계된 사이드 로드스프링을 차량에 장착된 상태로 전환하기 위한 지그 모델을 구성하는 방법을 제시하고, 이 결과를 반차량 및 전차량 모델에 적용하여 다물체 동역학 해석을 수행한다. 이러한 해석들을 통하여, 기존의 유한요소 해석을 통해서는 구현하기 힘들거나 시간이 많이 걸리는 사이드 로드 스프링의 효과 분석을 보다 쉽고 빠르게 수행할 수 있다.

Failure study as a physical component in mechanical suspensions of two automobile models of an automotive company

Car suspensions are a key element for the good behavior of cars. There are many types with their advantages and disadvantages, but among them, the most used and known today is the MacPherson strut suspension. The MacPherson strut is a system devised by Earle S. MacPherson in the 40s and patented by Ford in 1953, which today is used for the front axle of most cars. This type of suspension is very versatile because it can be used on the rear as well as front axles, and because of its low cost. These types of vehicles present many breakdowns on these pieces in the municipality of “Ocaña, Norte de Santander, Colombia” since the type of terrain is very complex (steep slopes, poor condition of the roads, among others), which leads to breakdowns on the pieces due to shear stresses, which could cause a traffic accident and high repair costs. This work seeks to show the identification of the vehicles that use the MacPherson strut and its possible failures. Subsequently, the analysis of the stresses on the lower arm system of the MacPherson strut is carried out in compact cars using simulation software. to perform the physical analysis behavior.

Kinematic and Dynamic Analysis for a New MacPherson Strut Suspension System

Abstract The present paper undertakes kinematic and dynamic analysis of front suspension system. The investigated model is a full-scale Macpherson which is a multibody system. Two degree of freedom model is considered here to illustrate the vertical displacement of sprung mass and unsprung mass with using displacement matrix. Ride and handling parameters including displacement of sprung and unsprung masses, camber/caster angle, and track changes are derived from the relationships. Moreover, geometrical model and equations are validated by Adams/Car software. The kinematic and dynamic results have been compared in both analytical and numerical outputs for verification. The proposed analytical model shows less than 5% differences with a complicated multibody model.

Design optimization of minivan MacPherson-strut suspension system based on weighting combination method and neighborhood cultivation genetic algorithm

In this paper, the kinematic characteristic analysis and optimization design of a minivan MacPherson-strut suspension system are performed. Design requirements of a minivan suspension system are described first, and then the design process is presented. A typical MacPherson suspension model of the minivan is conducted. Through the established model, the simulation of parallel wheel travel of the suspension system of the minivan is carried out and analyzed. After initial analysis, wheel alignment parameters especially the toe angle and camber angles need to be optimized to meet the requirements of the desired design value. The characteristic curves of wheel alignment parameters are drawn and the corresponding non-ideal characteristics are found. The optimization objective is to reduce the variation of the unreasonable alignment parameters, and the design variables are given through the sensitivity analysis. The design parameters are reasonably grouped according to different kinematic characteristics, thus, a unified objective function is established by direct weighing combination method. Finally, the established objective function is optimized and designed with neighborhood cultivation genetic algorithm. By comparing the original and optimized results, the better wheel alignment parameters are obtained and the system performances of suspension are further improved.

Kriging Model Based Optimization of MacPherson Strut Suspension for Minimizing Side Load using Flexible Multi-Body Dynamics

In a MacPherson strut suspension, which is one of the most popularly used vehicle suspension type, the side load is inevitably generated at the damper when wheel moves in the vertical direction. Since the side load causes friction at the damper and reduces riding comfort, it is important to reduce the side load for improving riding comfort. In this paper, an optimal design is performed to minimize the side load by using Kriging model. Before performing the optimal design, a flexible multi-body dynamics (FMBD) analysis, which can consider both multi-body dynamics and finite element method, is performed to verify the side load generated at the top of damper rod. As a result of optimal design, spring setting positions that minimize the side load are obtained and by using optimal spring setting positions, the suspension FMBD model was constructed.

Sequential Approximate Optimization of MacPherson Strut Suspension for Minimizing Side Load by Using Progressive Meta-Model Method

In a MacPherson strut suspension, the side load is inevitably generated and it causes friction at the damper reducing riding comfort. In this paper, to solve this problem, progressive meta-model based sequential approximate optimization (SAO) is performed to minimize the side load. To calculate the side load, a wheel travel analysis is performed by using flexible multi-body dynamics (FMBD) model of suspension, which can consider both finite element method (FEM) and multi-body dynamics (MBD). In the optimal design process, meta-model is generated by using extracted sampling points and radial basis function (RBF) method. As a result of optimal design, spring setting positions that minimize the side load are obtained and by using optimal spring setting positions, the suspension FMBD model was constructed.

Investigation of passenger car using Macpherson strut for suspension system pt.1: Vehicle behaviour variation of time response

It has been decade, researchers has been conducting researches on the topics concerning vehicle behavior. Suspension system, driving maneuver and road profile are the particular parameters in order to achieve the aim in vehicle behavior understanding. This paper combined these three criteria by means of using a passenger car equipped with MacPherson strut front suspension undergoes different driving behavior. The objective of this paper is to study the effect of passenger car equipped with MacPherson strut front suspension system vehicle behavior based on different driving maneuvers. For this study, Proton Persona Sedan 1.6 Manual Transmission Base Line was used to investigate the MacPherson strut suspension system. Data were collected using DEWESoft Software. As the velocity and direction varies with time, the vehicle response subjected to stationary excitation, while it varies with different velocity and different type of road. Acceleration, deceleration and bumpy test the suspension mechanism support the weight of the vehicle yet to cushion bumps and holes in the road. It can be concluded that the MacPherson strut suspension system has an effect on not only vehicle behavior but also comfort ride. These findings provide the following insights for future research in suspension vibration in order to optimize the performance of the MacPherson strut suspension system.

A comprehensive kinematic analysis of the double wishbone and MacPherson strut suspension systems

The double wishbone (DWB) and the MacPherson strut (MPS) suspension systems are commonly used independent suspensions in passenger cars. Their kinematics are complicated, and have not been analysed comprehensively in existing literature. This paper presents an analysis of the position kinematics of the complete spatial model of these suspension systems. The presented solution is built upon two key elements: the use of Rodrigue's parameters to develop an algebraic set of equations representing the kinematics of the mechanisms, and the computation of Gröbner basis as a method of solving the resulting set of equations. It is found that the final univariate equation representing all the kinematic solutions for a given pair of steering and road-profile inputs, in the general case, is of 64 degree, for both the suspension mechanisms. It is also shown that in certain special cases, both the suspensions generate 28 solutions, instead of 64. Numerical accuracy of the solutions obtained is established by computing the residuals of the original set of kinematic constraint equations. The configurations of the mechanisms for the real solutions are depicted graphically. Finally, the responses of the suspensions to continuously varying steering and road-profile inputs are computed using a branch-tracking technique.

A new adaptive sliding mode control for Macpherson strut suspension system with magneto-rheological damper

This work proposes a new adaptive sliding mode controller to enhance ride comfort and steering stability of automobile associated with a semi-active magneto-rheological damper. In this study, a Macpherson strut type suspension system which is widely used in light vehicles is considered. The dynamic model of the Macpherson strut with magneto-rheological damper is obtained and the governing equations are then formulated using kinematic properties of the suspension system following Lagrange’s formulation. In the formulation of the model, both the rotation of the wheel assembly and the lateral stiffness of the tire are considered to represent the nonlinear characteristic of Macpherson type suspension system. Subsequently, in order to effectively reduce unwanted vibrations, a new adaptive sliding mode controller is designed by adopting moving sliding surface instead of conventional fixed sliding surface. In order to demonstrate the effectiveness of the proposed controller, a cylindrical magneto-rheological damper is designed and manufactured on the basis of practical application conditions such as required damping force. Then, ride comfort, suspension travel, and road handling are evaluated and some benefits of the proposed controller such as enhanced ride comfort are evaluated.

A nonlinear kinematic and dynamic modeling of Macpherson suspension systems with a magneto-rheological damper

It is well known that Macpherson strut suspension systems are widely used in light and medium weight vehicles. The performance of these suspension systems can be enriched by incorporating magneto-rheological (MR) dampers and an appropriate dynamic model is required in order to find out the ride comfort and other performances properly in the sense of practical environment conditions. Therefore, in this work the kinematic and dynamic modeling of Macpherson strut suspension system with MR damper is presented and its responses are evaluated. The governing equations are formulated using the kinematic properties of the suspension system and adopting Lagrange’s equation. In the formulation of the model, both the rotation of the wheel assembly and the lateral stiffness of the tire are considered to represent the nonlinear characteristic of Macpherson type suspension system. The formulated mathematical model is then compared with equivalent conventional quarter car suspension model and the different dynamic responses such as the displacement of the sprung mass are compared to emphasize the effectiveness of the proposed model. Additionally, in this work the important kinematic properties of suspension system such as camber angle, king-pin angle and track width alteration, which cannot be obtained from conventional quarter car suspension model, are evaluated in time and frequency domains. Finally, vibration control responses of the proposed suspension system are presented in time and frequency domains which are achieved from the semi-active sky-hook controller.

Multi-objective optimization of LQR control quarter car suspension system using genetic algorithm

In this paper, genetic algorithm (GA) based multi-objective optimization technique is presented to search optimum weighting matrix parameters of linear quadratic regulator (LQR). Macpherson strut suspension system is implemented for study. GA is implemented to minimize vibration dose values (VDV), RMS sprung mass acceleration, sprung mass displacement and suspension working space. Constraints are put on RMS sprung mass acceleration, maximum sprung mass acceleration, tyre deflection, unsprung mass displacement and RMS control force. Passive suspension system and LQR control active suspension system are simulated in time domain. Results are compared using class E road and vehicle speed 80 kmph. For step response, GA based LQR control system is having minimum oscillations with good ride comfort. VDV is reduced by 16.54%, 40.79% and 67.34% for Case I, II and III respectively. Same trend is observed for RMS sprung mass acceleration. Pareto-front gives more flexibility to choose optimum solution as per designer's need.

Sliding-mode control for semi-active suspension with actuator dynamics

A sliding-mode controller (SMC) is proposed for semi-active suspensions to achieve ride comfort and handling performance simultaneously. First, a nonlinear quarter-car model of Macpherson strut suspension is established in Matlab/Simulink. Constrained damper force and actuator dynamics are considered for the damper model. System identification is applied to the nonlinear model for obtaining the linear model parameters. Kalman filter is designed based on the linear model and the actuator dynamics to estimate the state responses required for SMC. The sliding surface consists of tyre deflection and sprung mass acceleration. The proposed SMC is evaluated using the nonlinear model for both time and frequency domain responses. Robustness due to the increased sprung mass and deteriorated suspension is also investigated in this paper. Preliminary simulation results show improved ride comfort without sacrificing the road holding performance.

An insight into linear quarter car model accuracy

The linear quarter car model is the most widely used suspension system model. A number of authors expressed doubts about the accuracy of the linear quarter car model in predicting the movement of a complex nonlinear suspension system. In this investigation, a quarter car rig, designed to mimic the popular MacPherson strut suspension system, is subject to narrowband excitation at a range of frequencies using a motor driven cam. Linear and nonlinear quarter car simulations of the rig are developed. Both isolated and operational testing techniques are used to characterise the individual suspension system components. Simulations carried out using the linear and nonlinear models are compared to measured data from the suspension test rig at selected excitation frequencies. Results show that the linear quarter car model provides a reasonable approximation of unsprung mass acceleration but significantly overpredicts sprung mass acceleration magnitude. The nonlinear simulation, featuring a trilinear shock absorber model and nonlinear tyre, produces results which are significantly more accurate than linear simulation results. The effect of tyre damping on the nonlinear model is also investigated for narrowband excitation. It is found to reduce the magnitude of unsprung mass acceleration peaks and contribute to an overall improvement in simulation accuracy.

New model and simulation of Macpherson suspension system for ride control applications

The main purpose of this paper is to propose a new nonlinear model of the Macpherson strut suspension system for ride control applications. The model includes the vertical acceleration of the sprung mass and incorporates the suspension linkage kinematics. This two-degree-of-freedom (DOF) model not only provides a more accurate representation of the Macpherson suspension system for control applications in order to improve the ride quality, but also facilitates evaluation of the suspension kinematic parameters, such as camber, caster and king-pin angles as well as track alterations on the ride vibrations. The performances of the nonlinear and linearised models are investigated and compared with those of the conventional model. Besides, it is shown that the semi-active force improves the ride quality better than active force, while the opposite is true in terms of improving the performance of the kinematic parameters. The results of variations of the kinematic parameters based on the linear model subject to road disturbances are compared with those of a virtual prototype of Macpherson suspension in ADAMS software. The analytical results in both cases are shown to agree with each other.

Mode and design sensitivity analyses for brake judder reduction

Brake judder is a phenomenon that occurs when the steering wheel vibrates abnormally owing to braking at a high speed. It is classified into cold and hot judders. The former is generated because of an initial uneven disc surface and the latter results from uneven heat spots on the disc surface by braking repeatedly. There are two ways to reduce the judder. One is to reduce the excitation by modification of the disc shapes and pad ingredients. The other is to improve modal characteristics of the suspension system. The latter approach is used in this research. Real vehicle tests and computer simulation are utilized to analyse systematically the judder phenomenon of the vehicle. The Macpherson strut suspension is employed, and the judder sensitivity is calculated on the basis of a design sensitivity analysis. The bush stiffness is reworked and a braking test is carried out to verify the sensitivity result. Judder reduction by the mode control is verified.