基于仿真分析的曲轴平衡重动态优化设计

针对现有多缸内燃机曲轴平衡重设计存在的优化目标不明确、动力学模型简单等问题，以四缸内燃机曲柄连杆机构的虚拟样机为设计平台，对曲轴平衡重进行了动力学仿真分析及优化设计，介绍了包括有限元计算、动力学建模、动态优化设计和结构优化设计的整个设计流程.仿真结果表明，采用虚拟样机对曲轴平衡重进行动态优化设计，设计过程的效率和精度都有所提高；选择不同的优化目标会产生差异很大的最终优化方案.经过比较各种目标的优化结果，建议将曲轴主轴承载荷工作周期内的平均值作为动态优化设计的优化目标.

Simulation-based dynamic optimal design of crankshaft counterweights

Aiming at the problems in design of the crankshaft counterweights of multi-cylinder engine,such as the ambiguity in choosing the optimal goals and the simpleness of the dynamic models of cranktrain etc,a dynamic optimal design method was put forward based on a virtual prototype of 4-cylinder engine's cranktrain.The dynamic simulation based optimizing process was presented including the procedures of finite element calculation,dynamic optimal design,and structure optimal design.Calculation results indicate that the efficiency and accuracy of the whole design procedure are improved by conducting a dynamic optimizing simulation with the virtual prototype of cranktrain;and a different choice of optimal goal leads a tremendously different optimal design scheme.By comparing the different optimal schemes for different optimal goals,it is concluded that the mean load of crankshaft's main bearing is an appropriate choice of optimal objective.