Reliability analysis of girth welds by using finite element simulations with uncertain material properties

This research proposes a reliability simulation method combining the finite element simulation technology and stress-strength model to predict the structural reliability of girth welds with the following steps. Firstly, a group of finite element simulations of the girth welds are carried out considering uncertainties of elastic moduli in the weld and core barrel materials. Then the maximum von-Mises stresses over the welds are extracted from those simulations to generate the stress distribution. Finally through a stress-strength model, the structural reliability of the girth weld is calculated by assuming its yield strength following a Normal distribution. In addition, via the proposed method, influences factors such as temperature, pressure and the uncertainty level among the elastic modulus on the weld reliability are discussed in detail.