基于多体动力学的479Q发动机连杆载荷与强度分析  

Load and Strength Analysis of Connecting Rod in 479Q Engine Based on Multibody Dynamics

作　　者：何柏岩[1] 陈寺专[1] 裴毅强[2] 刘翾[3] 董正身[3] 

机构地区：[1]天津大学机械工程学院,天津300072 [2]天津大学内燃机燃烧学国家重点实验室,天津300072 [3]河北工业大学车辆工程系,天津300132

出　　处：《内燃机工程》2011年第4期39-45,共7页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金项目(E050605046);天津市应用基础及前沿技术研究计划资助项目(10JCYBJC25400)

摘　　要：以479Q汽油机为研究对象,建立了曲轴、连杆和活塞的三维几何模型和多体动力学模型。载荷边界条件采用真实示功图和负载数据,得到了做功行程中作用于连杆两端的载荷谱。采用惯性释放技术计及惯性力对连杆应力的影响,计算得到了做功行程中任意时刻连杆的动态应力场。对静力计算方法和惯性释放方法进行了对比,后者得到的动态应力场更加接近真实情况。根据曲轴转速为2 000 r/min时的气缸压力测试曲线(最高燃烧压力4.6 MPa)和对应的发动机扭矩(165 N.m),计算得到连杆最大轴向载荷为26 kN,最大工作应力为259MPa。根据局部应力应变法,该工况下的寿命为2.941×1016转,连杆近似为无限寿命。Three dimensional geometry model and multibody dynamics model for crankshaft,connecting rod and piston of model 479Q gasoline engine were built up.The load boundary conditions were determined by measured actually indicated diagram and load data to calculate the load spectrum acting on connecting rod ends in working stroke.Based on inertia relief method and finite element analysis,the dynamic stress field of the connecting rod was obtained,which was closer to real conditions than obtained using conventional static method.In conditions of crankshaft speed 2 000 r/min and output torque 165 N·m,the calculated max.axial load is 26 kN and its corresponding Von Mises stress 259 MPa.Based on local stress-strain method,the predicted connecting rod fatigue life is 2.941×1016 revolutions,nearly infinite.

关 键 词：内燃机 多体系统 连杆 惯性释放 强度 

分 类 号：TK402[动力工程及工程热物理—动力机械及工程]