Fracture evaluation method, fracture evaluation apparatus, program and computer readable recording medium

摘要

A method of determining fractures to determine a fracture of a metal structure, the method comprising: a stage (S21, S22, S23) of deformation analysis performing deformation analysis from the beginning of the deformation to the end of the deformation deformation of the metal structure; and a step (S24, S25, S26) of determining the extraction fracture of an objective portion of fracture determination from a state of deformation of the metal structure obtained in the step (S21, S22, S23) of analysis of deformation, and when the objective portion of determination of the extracted fracture has returned from a plastic state to an elastic state, since a tension when the portion that has returned to the elastic state is (x, y) = (σ2, σ1) (maximum main tension: σ1, minimum main tension: σ2) in a coordinate plane (x, y), and perform the fracture determination of the target portion of the fracture determination using a creep stress determined by a intersection between a straight line that satisfies a relationship y = (σ1 / σ2) x and a creep curve obtained from the plastic state of the target portion of the fracture determination, in which at the stage (S24, S25, S26 ) of determin At the end of the fracture, a fracture boundary tension determined by an intersection between the straight line that satisfies the ratio y = (σ1 / σ2) x and a fracture boundary tension line of the target portion of the fracture determination is obtained, the fracture limit tension and the re-creep tension are converted to an equivalent tension respectively, an equivalent plastic fracture limit deformation corresponding to the fracture limit tension and an equivalent plastic deformation corresponding to the re-creep limit are obtained, a from the respective equivalent stresses by using an equivalent stress curve - equivalent plastic deformation based on a metal structure material, and a fracture risk of the target portion of fracture determination is calculated using the equivalent plastic limit deformation of fracture and equivalent plastic deformation.