A reliability‐based fatigue design for mechanical components under material variability

Abstract

AbstractThe mechanical components subjected cyclic load unusually fail due to fatigue. The traditional deterministic design method still has the risk of failure while the safety factor method sometimes is overconservative and uneconomic. In this study, reliability‐based design optimization is applied in structural design of components under low cycle fatigue. A constitutive model (Jiang and Sehitoglu model) was written into user‐defined material subroutine of finite element software to make simulation more accurate. In addition, an adaptive least squares support vector machines (LS‐SVM)‐based response surface method is employed to improve the efficiency of design process. After constructing the implicit life model, a hybrid directional step method is employed to implement the performance measure approach. Finally, a simple case (thickness optimization for cantilever tube) is used to demonstrate the whole procedure of proposed design procedure.