铝合金活塞的应力强度因子计算

Stress Intensity Factor Calculation for Aluminum Alloy Piston

基于某汽油机硅铝合金活塞的最大爆发工况,建立了装有活塞销的活塞三维有限元模型。对其进行了热强度和机械强度的有限元分析。计算得到活塞的应力集中点的位置,也即裂纹源的位置,通过在活塞实体模型上增加裂纹面及裂纹体,得到裂纹尖端场的应力强度因子,并分析得出机械负荷作用下的应力强度因子对裂纹的扩展起决定作用。

Based on the piston＇s fatigue experiments, the 3-D FEA model of the piston and the piston pin is built. The thermal and mechanical coupling field of the piston is analyzed. The crack is produced at the stress concentration place through long time working. The crack surface and the crack volume are reflected on the model, and the stress intensity factors are gained. The results show that thermal loads have little effects on stress intensity factors, whereas mechanical loads are the dominant factors.