基于有限元和多体动力学的柴油机曲轴强度与应力分析

摘要

以某12V柴油机曲轴为研究对象，利用非线性多体动力学与三维实体有限元法对其进行强度分析。首先建立曲轴等部件的三维实体有限元模型，采用子结构法对其进行结构缩减，导入多体动力学分析软件后添加连接单元，建立轴系非线性多体动力学模型；然后将多体动力学分析结果恢复到曲轴三维实体有限元模型，进行一个工作循环下的曲轴动应力分析；最后校核其疲劳强度。分析结果表明：分析方法合理，所研究的曲轴其疲劳强度满足要求。%Nonlinear multi-body dynamics and 3D finite element method was used to make the strength analysis of a 12 V diesel engine crankshaft. The 3D finite element solid models of crankshaft and other parts were created and reduced by substructure technique. The multi-body dynamics program, considering joints added, was introduced to establish non-linear multi-body dynamics model. The results of multi-body dy- namics calculation were transferred to the 3D finite element model. Then the dynamic stress of the crankshaft was analyzed during one operating cycle. At last, the fatigue strength was checked. Analysis results show that the method is reasonable, and the fatigue strength of crankshaft can meet the requirements.