Optimum Material Distribution for Maximizing the Load Carrying Capacity of Thick-Walled FGM Circular Pipes Subjected to Thermomechanical Loading

This study deals with the optimization problem of material distributions for maximizing the applied internal pressure of thick-walled functionally graded material (FGM) circular pipes subjected to thermomechanical loading. For the FGM circular pipes without cracks, the ultimate internal pressure is determined using the tensile strength criterion. For the FGM circular pipes with cracks, radial edge cracks emanating from the inner surface of pipe are supposed and the ultimate internal pressure is determined using the fracture toughness criterion. The optimum material distribution for maximizing the applied internal pressure is obtained using a nonlinear mathematical programming method. Numerical results for a thick-walled TiC/Al2O3 FGM circular pipe reveal that the load carrying capacity can be improved markedly by choosing an optimum material distribution profile.