TENSILE STRENGTH OF STEEL PLATE WELDED CONNECTION BY WELDERS IN NAKHON RATCHASIMA PROVINCE

Abstract

The experimental results on the tensile strength of the steel plate welded connections by the welders in Nakhon Ratchasima were presented and compared with the EIT welding connection design equations. The weld joints were classified into three types: butt joint with groove weld, lab joint with fillet weld subjected to tensile load parallel to the weld joint, lab joint with fillet weld subjected to tensile load perpendicular to the weld joint. It was found that the obtained factors of safety, which was the ratio between the test specimen tensile strength and the tensile strength based on the EIT design equations, were generally lower than the factors of safety specified in EIT specification. Also, for the specimens in a given weld joint pattern welded by a welder, the tensile strength of the test specimens had a high variation, indicating that the qualification of the welder in Nakhon Ratchasima province was not uniform. Thus, an urgent controlling measure must be developed to improve the welder qualification to an acceptable standard, such as the American Welder Society standard.