The proposed research will develop a probabilistic analysis framework incorporating current aerostructure industry composite laminate design methodologies to predict the reliability of composite structures. The research will consider the reliability ased composite design methodology as being divided into two distinct but closely coupled modeling techniques. The first is the structural model which uses finite element analysis to determine the global and ply level response of the structure. The second modeling technique is the failure models which are closely coupled with the structural model. The failure models which address both initial and progressive damage, may be in the form of maximum stress/strain, interactive criteria, or more specific models which have been developed by the aerostructure manufacturers. Using an iteractive process, the damage states will be incorporated into the structural models to determine the distribution of stiffness reduction and delamination buckling loads. System reliability methods such as branch and bound technique and efficient Monte Carlo simulation will be used with probabilistic finite element methos\ds to determine progressive damage states and residual strength. The research will link state-of-th-art laminate design techniques with failure models. This effort has the potential for applicaiton to the engineering tasks required for the development of new rotorcraft using modern composite materials and technologies, and is especially relevant to the areas of damage tolerance and crashwothiness. The proposed research will yield a methodology and software that would greatly improve both our physical understanding and analytical capability in this area.
Keywords: composite, laminate, impact, dynamic analysis, statistics, probability, progressive failure
