Effect of Intensity of Bending Restraint on Lamellar Tearing and Root Cracking in Corner Joint

Abstract

In corner joints, the occurrence of lamellar tearing of opening type (which implies here that the tearing reaches to the surface) is sometimes observed in addition to root cracking.
In this paper, the effect of the intensity of bending restraint on the lamellar tearing and root cracking in corner joints is investigated with the aid of a newly developed method of test which is named here "Corner Joint Weld Cracking Test (CJC-test)." The result of the CJC-test is compared with that obtained from an experiment carried out in this study on a large structural model.
The main results are as follows :
1) The lamellar tearing occurs where the intensity of bending restraint is above the critical value. Therefore, "the critical intensity of bending restraint for lamellar tearing" can be obtained for the specified materials and welding conditions from the CJC-test.
2) As the critical value is influenced by several factors, the following methods are effective to reduce the possibility of the occurrence of the lamellar tearing : to use steel plates of good ductility through thickness and to make the throat depth as small as possible.
3) The occurrence of the lamellar tearing in actual structures can be predicted by use of the intensity of bending restraint of the structures on the basis of the result of the CJC-test.