基于有限元和多体动力学联合仿真的疲劳寿命预测

针对运动机构部件多轴疲劳载荷历程提取困难等问题，提出了基于联合仿真的疲劳寿命预测方法.结合有限元方法和多体动力学仿真分析获得部件的工作载荷历程，然后通过有限元方法和疲劳分析联合求解，预测部件的疲劳寿命.在动力学仿真部分，采用模态综合法获取部件的应力及载荷历程信息.寿命预测采用多轴裂纹萌生疲劳分析，其中部件的多轴特性通过二轴分析获得.以发动机曲轴部件为例，叙述了设计流程的应用过程.应用结果表明，该方法可以对疲劳事故的原因进行诊断，并且可以作为采用工艺强化措施的依据

Fatigue life prediction based on finite element and multibody dynamics co-simulation

A method of co-simulation based fatigue life prediction was put forward to resolve the problems of parts operating mechanism analysis,such as load-time-history extracting.The load-time-history of parts was obtained by integrating finite element method(FEM) and multibody dynamics simulation,then its fatigue life was predicted by combining FEM and fatigue calculation.Based on mode synthesis technique,the dynamic stress and load-time-history of parts were obtained through dynamics simulation.Biaxial analysis was used to get the multiaxial information,and fatigue calculation of multiaxial crack initiation was conducted.An example of engine crankshaft was used to illustrate application of the new method.This method not only can identify and locate the cause of fatigue damage,but also can be regarded as the reference of adopting strengthening techniques.