基于刚柔耦合多体系统的发动机曲轴疲劳分析

在LMS(Leuven Measurement&System)中建立某型V8发动机曲轴系统的多体动力学模型,通过刚柔耦合动力学计算,得到部件的模态参与因子,将模态参与因子与模态进行线性叠加,得到部件的载荷历程,并将其作为疲劳分析的输入数据;利用LMS.Virtual.Lab的Durability模块对曲轴进行有限元疲劳分析,获得精确的曲轴疲劳寿命值和损伤分布.结论是:通过系统多柔体动力学仿真可以得到各阶模态参与因子的时间历程曲线和部件的载荷历程,同时保证了模态参与因子与有限元模型匹配;曲轴集中应力最大且寿命最短处为轴颈与曲柄的过渡圆角处.

Fatigue analysis on engine crankshaft based on rigid-flexible coupling multi-body systems

A multi-body system dynamical model for a specific V8 engine crankshaft is established based on the Leuven measurement and system(LMS).Through the rigid-flexible coupling dynamical computation,the modal participation factors of components are obtained.With linear superposition of modal participation factors and modals,the loading progresses are used as the inputs to fatigue analysis.By using LMS.Virtual.Lab and Durability modules for finite-element fatigue analysis,the crankshaft fatigue life and damage distribution can be accurately attained.To this end,it is concluded that the time history curve of each modal participation factor and component loading progress are detected via system multi-flexible-body dynamical simulation.Meanwhile,the matching between modal participation factor and finite-element model is guaranteed,whereas the crankshaft maximum stress and the shortest fatigue life are located at the fillet between crankshaft neck and handle.