Extreme Environment Damage Index and Accumulation Model for CMC Laminate Fatigue Life Prediction

Materials Research & Design (MR&D) is proposing in the SBIR Phase II an effort to develop a tool for predicting the fatigue life of C/SiC composite laminates, which incorporates mechanical loading at any minimum stress to maximum stress ratio (i.e., R value), at room and elevated temperatures, in either inert or oxidizing environments. The success of this effort would represent a significant state-of-the-art improvement in fatigue projections of ceramic matrix composites, since no tools capable of accomplishing this have ever been developed. The developed algorithm, implemented via user-defined subroutines operating within the ABAQUS public domain finite element software, will represent a significant new addition to the suite tools currently available to CMC designers.