Calculation of Stress Intensity Factors for Cracked Piston
更新时间：2019-05-21
访问次数：
作者联系方式：School of Traffic and Vehicle Engineering,Shandong University of Technology,Zibo 255049,Shandong,China.
会议名称：2007年国际机械工程与力学会议
会议地点：江苏无锡
召开年：2007
摘要：The 1/2 rational 3-dimensional solid model of the piston is introduced to the powerful FEA software ANSYS 10.0 to analyze the thermal, mechanical and coupling stress fields of the piston. The calculation results indicate that the great tensile stress generates at the upper end of the piston pin seat, and show that thermal loads have little effect on the fatigue and damage, whereas mechanical loads are the dominant factors. Then the crack is produced at the stress concentration place through the long time working. These results are tallied with the experiments. Based on the theory of rupture and the experiments, the crack is considered to be type I, and the crack location and expansion direction also have been confirmed. The stress intensity factors of different crack depths between 0.15mm to 1.0mm are computed by using "top-down" substructure model method and J-integral. The calculation results are extremely tallied with the academic values offered by the handbook, the limiting error is less than 6％.Thereby the expression of the shape geometry factor for the given engine piston is obtained by curve fitting. This paper can afford a theoretical foundation for the fatigue and reliability analyses of this type of the pistons.
