Improvement of the shape of ceramic piston head by optimization and FEM

In the present study, the shape of ceramic piston head was improved by optimization methods. The objective function used was failure probability. The polyaxiality of the stress field was in principle taken into account by the Principle of Independent Action, which is based on Weibull's theory. However because of the large differences in principal stresses, the expression could be simplified. According to the results obtained the probability of failure decreased to 1/10 of the original the volume was reduced by 20 percent principal stress decreased.