温度试验与热力耦合仿真对活塞结构的优化

Temperature Test and Thermo-Mechanical Coupling Simulationto Optimize Structure of Piston

为满足增压后汽油机的性能要求,对活塞结构进行改进。基于传热学理论和非线性有限元分析方法对活塞进行仿真分析,先将活塞、活塞销、连杆、缸套进行整体建模,并结合活塞温度测试试验对活塞的模拟温度场进行验证,再导入热载荷和机械载荷的边界条件,计算出在热力耦合作用下活塞的应力大小及分布情况。计算结果表明,结构改进后,活塞的最大应力值降低了129.63MPa,热应力和机械应力明显降低,满足增压后汽油机的使用要求,说明了改进后活塞结构是合理的。

In order to satisfy the performance requirements of turbocharged gasoline engine,the structure of piston should be improved. Based on the heat transfer theory and nonlinear finite element analysis,modeling the overall model with piston,piston pin,connecting rod and cylinder liner,combined with the temperature test experiment of piston to prove the simulating temperature field of piston is viable,import the boundary conditions of thermal load and mechanical load,calculated the coupling field of stress size and distribution of the piston. According to the results of calculation,the structure of piston should be improved. The results showed that the max stress value of improved piston was decreased 129.63 MPa,verifying the rationality of the structure improvement of piston,effectively reducing the piston thermal stress and mechanical stress,and satisfying the using requirement of the turbocharged gasoline engine.