Farshad Zahedi - CAE Expert, Irankhodro Powertrain Company (IPCo.);
Mohammad Azadi - PhD Candidate, Sharif University of Technology and Irankhodro Powertrain Company (IPCo

In the present paper, low cycle fatigue analysis of a magnesium alloy cylinder head of a diesel engine is performed. Due to this target, a finite element model is considered for the cylinder head in ABAQUS software. Loads are applied to the model in 2 steps, including the press-fit of valve seats and the cyclic thermal loads by performing an independent thermal analysis to obtain the temperature distribution. It is assumed that thecylinder head is securely fixed to the engine block through the bolt holes. Therefore, thermo-mechanical stresses are calculated to predict the low cycle fatigue life and damage by using an energy approach to consider both strain and stress effects. The stress and fatigue results of magnesium alloy are compared to aluminum alloy results. As an attractive result, although the strain range for magnesium alloy is more aluminum alloy, but also the fatigue strength of aluminum alloy is almost the same as magnesium alloy due to have less values of stresses. In this case, by using magnesium alloy for cylinder heads, the weight can be reduced up to 40 percents which causes lower fuel consumption.

cylinder head, magnesium alloy, low cycle fatigue, finite element method