Design Optimization of a Deep-sea Pressure Vessel by Reliability Analysis

J. Ocean Eng. Technol. 2005;19(2):40-46.

JOUNG TAE-HWAN;NHO IN-SIK;LEE JAE-HWAN;HAN SEUNG-HO;

Dept. of Naval Architecture and Ocean Engineering, Chungnam National University;Dept. of Naval Architecture and Ocean Engineering, Chungnam National University;Dept. of Naval Architecture and Ocean Engineering, Chungnam National University;Korea Institute

신뢰성 해석을 이용한 심해용 내압용기의 설계 최적화

정태환;노인식;이재환;한승호;

충남대학교 선박해양공학과;충남대학교 선박해양공학과;충남대학교 선박해양공학과;한국기계연구원 구조연구부 구조안전그룹;

Keywords: Reliability Analysis, Reliability Index, Probability of Failure, AFOSM, RSM, Monte-Carlo Simulation Method

핵심용어: 신뢰성 해석, 신뢰도 지수, 파괴확률, 개선된 1계 2차 모멘트법, 응답면기법, 몬테-카를로 모사법

Abstract

In order to consider the statistical properties of probability variables which are used in structural analysis, the conventional approach of using safety factors based on past experience, are usually used to estimate the safety of a structure. The real structures could only be analyzed with the error in estimation of loads, materials and dimensional characteristics. Errors should be considered systematically in the structural analysis. In this paper, we estimated the probability of failure of two pressure vessels, simultaneously, using computational analysis. One pressure vessel, theoretically, had no stiffener whereas the other had. This paper also discusses sensitivity values of random variables in the rounded parts of the pressure vessel which had ring-style stiffener in the center of the external area which had ring-style stiffener. Finally, we show that the reliability index, and the probability of failure, can be calculated to particular tolerance limits.