Finite element analysis of thermal and mechanical stresses in diesel engine cylinder head using two-layer elastic-viscoplastic model

The objective of this article is to simulate the thermal and mechanical behavior of the diesel engine cylinder head. This finite element analysis was performed in the ABAQUS software. Thus، to identify the material behavior، results of low cycle fatigue tests at various temperatures (stress- mechanical strain hysteresis curve at the mid-life cycle) were used and material constants of the two-layer elastic-viscoplastic model were extracted. Fatigue tests were performed in the strain-controlled tensile-compressive condition on the aluminum-silicon-magnesium alloy (A356. 0). Then، by using these material constants at 25، 200 and 250°C، thermal and mechanical stresses of the cylinder head were calculated. The validation result illustrated that the elastic-viscoplastic model has a proper accuracy to predict the hysteresis behavior of the aluminum alloy. Finite elements results showed the location of cracking between valves. In addition، the calculated viscous strain cannot be eliminated، although it is less than the plastic strain.