Analysis of thermal-mechanical coupling  strength and fatigue life of cylinder head

ZHU Xiaoping，LIU Zhentao，YU Xiaoli
（Department of Energy Engineering， Zhejiang University， Hangzhou 310027，China）

Abstract：Aiming that the cylinder head is easy to form fatigue damage when under the alternating load， a rapid and effective method to calculate the fatigue life of the cylinder head was introduced. Firstly， the FEMmodel of the cylinder head was built by using Hypermesh software with arranging different density of elements and the element quality was guaranteed with the mesh parameters. And the temperature field， the steadystate stress field and the coupling stress field of the cylinder head were calculated by using Abaqus software. In the calculation of the temperature field， the combustion chamber firepower surface was divided into three areas to improve the calculation accuracy. In the calculation of the steadystate stress， the accuracy and the efficiency of the subsequent fatigue analysis could be improved when the thermal stress field was regarded as steadystate field. Finally， the fatigue life of the cylinder head was calculated by the fatigue analysis software MSCFatigue. The results indicate that the fatigue damage is easily occurred on the side of the combustion chamber firepower surface， and this should make an especially consideration for design.
Key words：cylinder head; thermalmechanical coupling; fatigue