Bimodal bound of system reliability for random composite structures

Abstract

A procedure of system reliability analysis using the stochastic finite element method for composite structures is presented, Composite structure is considered as a random structure, The material properties, fiber angles, laminate thickness, and curvatures are modeled as random parameters, The curvature means initial curvature as a result of manufacturing error for the case of a Rat plate. The random thickness and fiber angles affect the strain-displacement relation and material directions. In the stochastic finite element formulation, these randomnesses are considered to obtain accurate statistical responses. In reliability analysis, composite laminates are assumed to be multicomponent series system, and the correlations between possible failure modes of different components are considered to obtain bimodal bounds of failure probability. The method is verified through comparison of the results with those obtained by the Monte Carlo simulation for two example problems, The developed method is efficient and accurate enough to be applied to engineering problems and can assess the risk of structures quantitatively and logically.