Mechanical Properties of MI SiC/SiC Composites and Their Constituents (Preprint)

摘要

A series of 15 melt infiltrated SiC/SiC composites were fabricated per the standard process arrived at by NASA-GRC (01/01 material). This was done based on the in-situ boron nitride process prior to fiber interface coating and subsequent densification. A series of physical property testing was conducted to determine the mechanical properties, cyclic load response, damage progression, and the effect of temperature on elastic properties. Other tests addressed properties that are typically assumed such as through thickness, elastic modulus, and shear modulus. Additionally, in-situ moduli of constituent materials were experimentally evaluated using nano-indentation techniques at room temperature. An analytical model (pcGINA) was further developed and used to predict the elastic properties of CMC textile reinforced composites. The analytical modeling components were constructed within a unit cell constituent- based geometric model to map the 3D spatial description of the fabric preform. The model implemented a hybrid finite element approach and a virtual work technique.