Reliability evaluation of brittle structures under thermal shocks

J. Ocean Eng. Technol. 1998;12(1):58-64.

열충격이 작용하는 취성구조의 신뢰성 평가

이치우,장건익,김종태

경남대학교 공과대학 기계설계학과,전주공전 기계과,통일중공업 차축개발부

Keywords: Brittle Sturcture, Weakest Link Hypothesis Model, Weibull Distribution, Thermal Shoke, Reliability

핵심용어: 취성구조, 최약 링크 가설 모델, 웨이블 분포, 열충격, 신뢰도

Abstract

An analysis method for the reliability of ceramic structures subjected to thermal shocks is presented. Flaws with the size of given probability distribution function are assumed to be distributed at random with a certain density per unit volume in the structures. Criterions for crack instability are derived for brittle solids under general thermal stresses. A probabilistic failure model is presented to study the probability of crack instability for brittle solids containing cracks with uncertain size. The reliabilities of brittle structures are evaluated based on the weakest-link hypothesis, which states that a structure fails when the cracks in any differential volume become unstable. A numerical example is given to demonstrate the application of the proposed method.