A Study on the Fatigue Strength of Lap Weld of LNG Tank

J. Ocean Eng. Technol. 1999;13(3):29-35.

Kim, Jong-Ho;

LNG탱크 겹침용접부의 피로강도에 관한 연구

김종호;

한국해양대학교 기관시스템공학부;

Keywords: LNG, Fatigue Crack, Variable Load, Membrane, SUS, Safe Life Design, Probability Density Function

핵심용어: 액화천연가스, 피로균열, 변동하중, 멤브레인, 스테인리스강, 안전수명설계, 확률밀도함수

Abstract

At the design of Mark III membrane type LNG tank, an analytical and experimental approach on the fatigue strengths of membrane and its welds are very important in order to assist designers and surveyors. In this study, fatigue tests of lap weld of Mark III membrane type LNG tank were carried out and cumulative damage factor was calculated in order to estimate the fatigue life by probability density function and rule methods. It contained the following tests and reviews : 1) The fatigue tests of lap weld of stainless steel according to statistical testing method recommended by JSME, 2)Preparation of S-N curve for lap welds considering the statistical properties of the results of fatigue tests. 3) Procedure for estimating the initiation life of fatigue crack of lap welds under variable loads by the rule lf classification society and probability density function, 4) Guideline for inspection of lap welds fo membrane type LNG tank.