PREDICTION OF FRACTURE RESISTANCE CURVES FROM TENSILE DATA

摘要

In order to perform Ieak-before-break design of nuclear piping systems and integrity evaluation of reactor vessels, full stress-strain (σ-ε) curves and fracture resistance(J-R) curves are required. However it is time-consuming and expensive to obtain the J-R curves experimentally. The objective of this paper is to develop two methods for the J-R curve prediction from tensile data. In the first method, elastic-plastic finite element analyses for a series of crack length/specimen width values were performed. Accordingly the load vs. load line displacement curves corresponding to the fracture strain are obtained and the J-R curves based on the generalized locus method are obtained. In the second method, the correlation between σ-ε curves and J-R curves was statistically analyzed and an empirical equation for the J-R curve prediction from the tensile data is proposed. A good correlation between the predicted results based on the proposed methods and the experimental ones is obtained.