Prediction of Fracture Damage in and Reliability BasedDesign Optimization of Composite Structures

摘要

A simplified composite analytical life prediction procedure (SAPGEN) is developed for navalrnjoint design that will perform: material constituent analysis (MCA), 2) material uncertainty analysisrn(MUA), fracture damage and the percent contribution of each material constituent to failure mechanisms.rnSAPGEN has the ability to predict 1) constituent/ply mechanical properties, 2) property degradation 3)rndamage modes and mechanisms, 4) failure modes and mechanisms 5) percent damages due to fourteenrnspecified failure criteria and 6) the durability/reliability of a composite joint/structure. The progressivernfailure analysis (PFA) methodology imbedded within SAPGEN utilizes finite element analyses (FEA) andrniteratively updates material properties due to the existing loading conditions. The applied load (force,rntemperature, pressure, etc.) or time is iteratively increased, permitting damage tracking throughout thernstructure for many loading scenarios. SAPGEN predicts failure mechanisms relevant to compositernstructures, such as delamination, with simplified finite element models. As a demonstration, SAPGEN wasrnused to determine damage modes within a typical naval joint and compared to test results and currentrndetailed analytical methods.