最弱リンク説に基づいた不均一材破壊靭性試験の確率論的評価方法

抄録

Scatter of fracture toughness of welds is significantly large due to intrinsic nature of cleavage fracture and stochastic nature of fatigue-crack sampling of a local brittle zone. Under such circumstance, it is often desired to predict a distribution of fracture toughness of the local brittle zone, only. The present paper proposes a method of predicting critical CTOD distribution of a specific microstructure, e.g. coarse-grained HAZ, from weld HAZ CTOD tests. The method is based on the weakest-link assumption and uses a likelihood function which is defined by considering critical CTOD values, as well as crack initiation sites. The proposed method was examined by Monte-Carlo simulations.