基于虚拟样机技术的机车车辆结构疲劳寿命仿真

提出一种多体系统仿真和有限元分析相互结合进行虚拟样机疲劳寿命预测的方法.该法用于处理随机动载荷作用下转向架构架的疲劳设计.作用在复杂结构上的时变动载荷历程可以通过应用多体系统分析软件SIMPACK的多体仿真技术获得.在ANSYS中利用单位载荷作用下的准静态应力/应变分析技术计算结构危险节点应力及关键区域.模态分析技术用来获得结构固有频率和模态振型.基于危险应力状态(包括单轴,成比例和非比例多轴)、动载荷时间历程以及Palmigren-Miner损伤理论.最后利用FE-FATIGUE软件的安全强度因子分析法进行标准时域的结构疲劳寿命预测,其中包括应力应变的循环计数,损伤预测和最终寿命估计.

Structure of locomotive and vehicle fatigue life simulations based on virtual prototyping technology

A virtual Prototyping fatigue life prediction method based on multi-body system(MBS) simulation and finite element analysis(FEA) was proposed.The method was implemented to handle with the difficulties of a locomotive bogie frame fatigue design under random dynamic loads.The time varying dynamic load histories acting on the bogie frame structure can be evaluated by applying the Multi-body System analysis technique in software SIMPACK.The quasi-static stress/strain analysis technology in software ANSYS yields the danger nodes' stresses in the critical locations of the structure depending on the unite loads.And modal analysis was used to determine frequencies and mode shapes.Based on these danger stresses state(uniaxial or proportional or non-proportional multiaxial)and dynamic load time histories,fatigue life can be estimated with Palmigren-Miner theory.This method also involves stress or strain cycle counting,damage prediction,and finally life estimation in software FE-FATIGUE with safety factor technology.