Cylinder Head High/Low Cycle Fatigue CAE Analysis 2012-01-1991

Cyclic firing loading conditions coupled with high thermal loads are the main causes for failure of the cylinder head. A complete thermo-mechanical fatigue analysis of a cast aluminum cylinder head should include both high and low cycle fatigue. Reliable nonlinear material behavior, accurate thermo-mechanical stress analysis, and dependable failure criterion are the keys to successful life prediction. The low cycle fatigue is primarily due to thermal stress resulted from repeated start-up and shut-down cycle of the engines. The high cycle fatigue is mainly due to the firing loads, as amplitude stress, accumulated to the mean stress due to the thermal load. In this paper the required CAE simulations for high/low cycle fatigue of cylinder head will be discussed.