Analysis and Optimization of Driveline Bushing for Lateral Ride Vibration under Shock Excitation

Peng Guo,Zefeng Lin,Jinlu Li,Jiewei Lin

doi:10.3390/app11062647

Abstract

Ride comfort is increasingly important for automobile companies due to the increasing concern of the demands of customers. Response to shock at low speed, such as single or consecutive pulse excitations from humps, are one of the greatest assessing indices of vehicle ride related to the ride comfort. This paper aims to study the effect of driveline bushing on ride vibration when the vehicle experiences shock excitation and to improve the ride quality by optimizing the bushing parameters. A vehicle level multibody dynamic model with a differential-subframe subsystem is developed and calibrated against field test data. The sensitivities of the bushing stiffness and damping coefficients are analyzed and the most influential bushing parameters on the seat rail vibration are identified. The relationship between the bushing parameters and the ride vibration is developed by a 5-level response surface design. The fitted response functions are validated and adopted as the optimization objectives. The optimized results, including the acceleration, the running r.m.s. acceleration, the jerk, the running r.m.s. jerk, the VDV and the comfort, are compared with those of the baseline vehicle. Results show that the optimized bushings significantly decrease the vibration at the driver and the rear passenger seats by approximately 50% in the lateral direction. A considerable improvement has been achieved in ride comfort that the weighted vibration at seats is reduced to a level below the median perception threshold of human being in the lateral direction.

Highlights

It is the two main functions of the bushings in automobiles to isolate vibration transmission between structures and reduce noise transmitted to cabin
The results show that the direct relationships obtained through the response surface method (RSM) gave good predictions of the vibration dose value (VDV) at DR, which means the response functions were suitable for the following optimization
Driveline bushings had considerable effects on the ride comfort in the lateral direction while that in the fore-and-aft and vertical directions was found to be insensitive to the driveline bushing properties

Summary

Introduction

It is the two main functions of the bushings in automobiles to isolate vibration transmission between structures and reduce noise transmitted to cabin. Stiffness and damping of bushing have a great influence on the static and dynamic performance of vehicles. As a highly coupled dynamic system, changes of subsystem of vehicle may have considerable impacts on the global responses [1]. Suspensions (of vehicle/seat) and mounts (of engine/suspension) have the most direct effect on ride comfort and have been well studied [2,3,4,5,6]. It was justified that the well-designed mechanical properties of the jounce bumper is able to reduce the vertical acceleration at the vehicle centroid at most speeds [7]. The bushing joints of the front suspension have great influence on the vertical displacements and roll accelerations of the vehicle chassis [8].

Objectives

Methods

Results

Conclusion