Crack Size Tolerance of Under-Matched Joints of Hull Steel with Different Weld Toughness

Abstract

In order to investigate the safety performance of welding structure of 10CrNi3MoV hull steel, with the application of FAD method provided by SINTAP, this paper made safety assessment for 2 joints with the same yield stress under-matching ratio but different weld toughness. Based on tensile test and CTOD test results, assessment was carried out. Several different sizes (2a) of weld central crack were given. Then the crack size tolerance for each joint can be found. Through relative analysis, a few conclusions were gained. As long as the assessment level is selected, FAD shape changed little. Weld toughness influenced weakly on a joint’s resistance to plastic instability, but significantly on its anti-brittle capacity. The higher weld toughness is, the more likely assessment point located within failure assessment curve, i.e. the safety performance is correspondingly better.