Control of Welding Distortion for Thin Panel Block Structure Using Plastic Counter-Deforming Method

J. Ocean Eng. Technol. 2009;23(2):87-91.

Kim Sang-Il

Okpo Office Lloyd's Register Asia

소성 역변형법을 이용한 박판 평 블록의 용접변형 제어

김상일

로이드선급협회 아시아 옥포사무소

Keywords: Welding distortion, Geometric inaccuracy, Adjusting work, Distortion control method, Plastic counter-deforming method (PCDM)

핵심용어: 용접변형, 기하학적 부정확성, 재작업, 변형 제어법

Abstract

The welding distortion of a hull structure in the shipbuilding industry is inevitable at each assembly stage. The geometric inaccuracy caused by welding distortion tends to preclude the introduction of automation and mechanization and requires additional man-hours for adjustment work during the following assembly stage. To overcome this problem, a distortion control method should be applied. For this purpose, it is necessary to develop an accurate prediction method that can explicitly account for the influence of various factors on the welding distortion. The validity of this prediction method must also be clarified through experiments. For the purpose of reducing the weld-induced bending deflection, this paper proposes the plastic counter-deforming method (PCDM), which uses line heating as the optimum distortion control method. The validity of this method was substantiated by a number of numerical simulations and actual measurements.