基于APDL语言的活塞热应力分析

Thermal stress analysis of piston based on APDL language

活塞是发动机的核心,工作环境极其恶劣.活塞顶部直接承受高温燃气作用,容易形成不均匀的温度梯度,产生较大的热应力造成活塞受损,活塞的运行可靠性直接影响发动机的使用寿命.基于ANSYS的APDL语言,建立了活塞有限元模型,应用第三类边界条件施加活塞边界温度和换热系数,对活塞进行温度场和热应力分析,分析计算结果,得到活塞温度场、热流密度和热应力分布规律.结果表明活塞燃烧室边缘温度最高,第一环槽处热流密度最大,活塞环槽处和燃烧室边缘热应力相对较大.为活塞的结构设计和可靠性分析提供了参考.

The piston as the core of the engine,its working environment is extremely harsh.The top of the piston directly bears the effect of high temperature gas,which is easy to form uneven temperature gradient and generate large thermal stress,thus causing damage to the piston.The running reliability of piston directly affects the service life of engine.The finite element model of piston was established based on APDL language of ANSYS.The piston boundary temperature and heat transfer coefficient were applied by the third kind of boundary conditions.The temperature field and thermal stress of the piston were analyzed,and the results were obtained.The results show that the temperature at the edge of the piston combustion chamber and the heat flux in the first ring groove are the highest.The thermal stress at the piston ring groove and the edge of the combustion chamber is large.It provides a reference for the structural design and reliability analysis of the piston.