Strength of laser welded thick plate lap joint

Abstract

The purpose of the present study is to evaluate the static strength of thick plate laser welded lap joints. The strength of thin sheet laser welded lap joints of thickness less than 1·6 mm has already been reported, but the strength of thick plate laser welded lap joints having a thickness greater than 10 mm is not known. It is the opinion of the present authors that application of such a thick laser welded lap joint to sandwich panel fabrication presents revolutionary opportunities for heavy industry. Mechanical tests have been conducted on 10 mm–6 mm thickness laser welded lap joints to determine their static strength. The measured nominal shear stress is found to be almost the same as the tensile strength of the weld metal. This result is significantly different to that for thin sheet laser welded lap joints. In the present report, the fracture criteria for thick plate laser welded lap joints are clarified.