基于有限元法的柴油机曲轴裂纹扩展模拟研究  

Simulation of Crankshaft Crack Propagation for Diesel Engine Based on FEM

作　　者：李恒宾 

机构地区：[1]青海交通职业技术学院汽车工程系,青海西宁810028

出　　处：《车用发动机》2013年第1期5-8,共4页Vehicle Engine

摘　　要：以某型直列柴油机曲轴为研究对象,建立曲轴的有限元模型,采用子结构技术对有限元模型进行模态缩减。应用AVL.Excite进行曲轴的多体动力学仿真,经过应力恢复得到曲轴的应力分布,确定易产生裂纹的危险截面。采用1/4节点等参退化奇异单元模拟裂纹前沿应力奇异性,建立曲轴表面裂纹扩展的有限元模型,对不同深度椭圆裂纹的应力强度因子进行计算,最后拟合应力强度因子与裂纹深度的近似表达式,预测了其裂纹扩展寿命。For the crankshaft of an inline diesel engine, the finite element model was established, and then the modal reduction of model was carried out by using the substructure technology. With AVL Excite software, the multi-body dynamics simulation of crankshaft was done. Based on the modal stress recovery, the stress distribution of crankshaft was acquired and the critical section of crack initiation was identified. The stress singularity of crank front was simulated with the 1/4-node isoparametric degraded singular element and the finite element model of crack propagation was built. Then the stress intensity factors of ellipse crack with different depth were calculated. Finally, a curve-fitting formula of the stress intensity factor and crack depth was given, and the crack propagation lifetime was predicted.

关 键 词：断裂力学 曲轴 裂纹扩展 寿命 应力强度因子 有限元法 

分 类 号：TK423.3[动力工程及工程热物理—动力机械及工程]