On the Study of Restraint and Residual Stress due to Welding on Erecting Butt Joint of Ship's Hull (Repors No. 2)

Abstract

It is usually one of undesirable designs and procedures that a welded construction has mutually two or more abjacent butt joints.But in common ship yards or in repair yards, their designing engineers and manufacturing engineers sometimes would encounter the occasion as above.The minimum mutual distance between two or more adjacent joints for proper and safety welded construction has not been clarified and established.The authors applied for this two mutually adjacent joint test, our “Restrained-Butt-Joint” method, (see Report No. 1) to which the residual stress surrounding the two mutually adjacent butt joints were measured the stress distributions were established.The testing conditions, thickness of plate ; 20 mm, breadth ; 400 mm, restrained distance, (see Report No. 1); 850 mm and distance between two joints ; 40, 80, 150 and 250 mm was applied for this tests.From this experimental results, we could reach the summarized conclusions as follows.1. The intensities of restraint were not hardly varied by the various distnce between two joints, and the values were approximately the same as the one-butted specimen (Report No. 1).2. In the 40 mm joint-specimen, the longitudinal stress distribution along perpendicular direction to weld could be regarded such as the same one on the one-butted specimen.3. in 80 mm, it was appeared that the longitudinal stress had a hump distribution 2 peaks in the surrounding the joints.4. Noticeably, in 150 mm, the longitudinal stress in the initial butt weld, are usually tension at one-butt, became compressive for whicts, was suffered from a influence of the 2 ad welding.5. The 250 mm distance between two joints the two separate peak of longitudinal distribution along perpendicular direction for weld line, was clearly found.