Investigation of Local Failure Criteria of Wall-Thinned Area by Simulated Specimen Tests

The objective of this study is to develop a local failure criterion at wall-thinning defect of piping components. For this purpose, a series of tensile tests was performed using several types of specimens with different stress state under tension, including smooth bars, notched round bars and grooved plates. In addition, finite element (FE) simulations were performed for all tests, and its results were compared to the test results. From the comparisons, the equivalent stress and strain corresponding to maximum load and final failure of the notched round bar specimens were proposed as the local failure criterion which is a function of stress triaxiality at notched area. The criteria were verified by employing them to the estimation of maximum load and final failure of grooved plate specimen tests.