微型客车后驱动桥多轴耦合疲劳试验仿真
Simulation of a multi-axial loading fatigue test of the rear drive axle of a minivan

汽车行驶时悬架系统承受着来自路面的载荷冲击，保证其耐久性是汽车设计中非常重要且急需解决的关键问题之一，多轴向加载的室内道路模拟疲劳试验被广泛采用。为了进一步缩短汽车研发周期，降低研发成本以提高市场竞争力，该文建立了后驱动桥的动态有限元模型，依照实验室道路模拟疲劳试验的基本原理，通过编制MATLAB程序实现了系统频响函数识别、根据目标信号和频响函数反求动态载荷、计算动态响应与目标信号的误差等功能。仿真结果表明：后驱动桥目标信号测点的应力应变时间历程复现综合误差均在5%以内，并预测出该悬架系统的疲劳强度危险点位于截面尺寸突变的区域。
Abstract：When a vehicle is running, its suspension is heavily loaded due to the motion. The durability is then one of the key problems in vehicle design. Multi-axial loading laboratory fatigue tests are widely used to shorten the development process, reduce costs and enhance market competitiveness. This paper presents a practical method for simulating multi-axial fatigue tests of a rear axle using a dynamic finite element model of the rear axle and data processing in MATLAB. The simulation of the laboratory fatigue tests includes system identification, calculation of the input dynamic loads for the finite-element model and calculation of the stress-strain response reproduced and compared with the measured stress-strain response. With the errors of less than 5% with the critical fatigue areas in the rear axle located where the section sizes change.