Reliability-Based Optimum Design for Tubular Frame Structures

J. Ocean Eng. Technol. 1988;2(1):95-105.

골조 파이프 구조물의 최적신뢰성 설계

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한국기계연구소 대덕선박분소 선체구조실

Keywords: Realiability-Based Optimum Design, Critical Section, Probability of Failure, Buckling Failure, Plasticity Failure, Fatigue Failure, Reanalysis Method

핵심용어: 최적신뢰성 설계, 주요단면, 파손 확률, 좌굴 파손, 소성 파손, 피로 파손, 재해석법

Abstract

This paper describes the development of a reliability-based optimum design technique for such three dimensional tubular frames as off shore structures. The objective function is formulated for the structural weight. Constraints that probability of failure for the critical sections does not exceed the allowable probability of failure are set up. In the evaluation of the probability of failure, fatigue as well as buckling and plasticity failure are taken into account and the mean-value first-order second-moment method(MVFOSM) is applied for its calculation. In order to reduce the computing time required for the repeated structural analysis in the optimization process, reanalysis method is also applied. Application to two and three dimensional simple frame structures is performed. The influence of material properties, external forces, allowable failure probabilities and interaction between external forces on the optimum design is investigated.