Rubber Stiffness Optimization for Floor Vibration Attenuation of a Light Bus Based on Matrix Inversion TPA

Hui Shi,Zhaomeng Fan,Changhai Yang,Wenku Shi,Zhiyong Chen,Guozheng Liu,Jiaxi Zhou

doi:10.1155/2020/6648065

Abstract

The NVH characteristics of light buses are a very important performance for market competitiveness. To solve the serious floor vibration of a light bus at speed of 60 km/h and 90 km/h, we first derive the matrix inversion TPA (MITPA) method, and then transfer path contribution is analyzed by applying matrix inversion TPA with TPA model establishment, operational vibration test, and FRF measurement. Next, the energy decoupling rate of the powertrain mount system (PMS) is optimized by rubber stiffness optimization based on the path contribution analysis taking both amplitude and phase into consideration. The optimized natural frequencies and energy decoupling rate indicate that energy decoupling rate (EDR) of each DoF of the powertrain mount system is improved. Finally, to verify the optimization effect, this paper implements an operational vibration test with optimized mount installed. The results indicate that floor vibration of postoptimization is improved significantly compared with that of preoptimization. This paper offers a method for engineers to improve vibration problem of vehicle by combining experimental TPA for identification of dominant paths with optimization procedure.

Highlights

Introduction e automotiveNVH characteristics are one of the main performances, which affects the vehicle quality and directly determines its market competitiveness
The techniques to improve the NVH performance of vehicles are generally divided into numerical methods (such as multibody dynamic method [1, 2] (MBD), finite element method [3] (FEM), and boundary element method (BEM)) and experimental methods [4] (such as the spectrum analysis and transfer path analysis (TPA) methods [5,6,7]); the numerical methods are usually used to analyze or predict the vibration and noise response (N&V) under some excitation sources by numerical models
E goal of this paper is to present a solution method to solve the floor vibration problem of light buses, in which the method combines matrix inversion TPA for identification of path contribution with the optimization of energy decoupling rate of powertrain mount system (PMS). e paper derives the theory of matrix inversion TPA by dynamic substructuring theory first, and MITPA is applied to analyze the dominant path contribution of the floor vibration problem in light buses

Summary

Introduction

Introduction e automotiveNVH characteristics are one of the main performances, which affects the vehicle quality and directly determines its market competitiveness. The techniques to improve the NVH performance of vehicles are generally divided into numerical methods (such as multibody dynamic method [1, 2] (MBD), finite element method [3] (FEM), and boundary element method (BEM)) and experimental methods [4] (such as the spectrum analysis and transfer path analysis (TPA) methods [5,6,7]); the numerical methods are usually used to analyze or predict the vibration and noise response (N&V) under some excitation sources by numerical models. The numerical models are established based on some condition assumptions, which cannot reflect the real conditions of a physical automotive system. Experimental methods are more accurate, which are all based on physical automotives, especially the TPA method. For component-based TPA, the first step is to solve blocked force or equivalent force, which characterizes the source by measurements in situ [9, 10]. erefore, it is

Methods

Results

Conclusion