Soviet Technique for Estimating Post-Welded Deflection: Case of Butt Welding

The hulls of modern ships are almost entirely welded. This makes the prediction of post-welded deformations very important. The number of parameters involved in the process of welding is large, so the exact mathematical theory for prediction of deformations is unavailable. Some researchers have estimated the post-welded deflections based on empirical and semi-empirical equations. The growing literature on the study of postwelded deflections of hull plates enables the estimation of these deflections based on the plate geometry and the plate material. The limited number of critical parameters covered by these experiments makes it difficult to organize the data systematically. This has delayed the introduction of a framework for estimating the influence on the plate deflection from welding speed, current, number of passes, welding rod size and material, etc. The approach adopted in the U.S.S.R. was to develop an integrated framework to include the critical welding parameters. The main results from this approach were published in several books, with the main reference being a book by Kuzminov published in 1974. From the standpoint of ship production, it is useful to understand this Soviet approach as well as to give examples of its use. Therefore, this paper introduces the Soviet procedure for calculation of deflection due to butt welding, presents the graphical aids used in this procedure, and presents a worked example using this procedure for a butt welded plate.