Micromechanical Models for Dielectric Behavior of Ceramic Matrix Composites

The proposed program will enhance material and sensor models to provide improved understanding of dielectric property information regarding Ceramic Matrix Composite (CMC) material condition. These models are to be used to assess thermochemical degradation of CMC’s and also to assess the condition of materials during manufacture. JENTEK has developed a family of electroquasistatic and magnetoquasistatic sensors and arrays that have successfully solved a wide range of previously intractable NDE problems. These sensors and sensor arrays use model-based inverse methods to estimate electromagnetic properties that are correlated with many conditions of interest, such as thermal degradation of component materials. JENTEK’s Interdigitated Electrode Dielectrometer is being adapted for manufacturing quality control of CMC’s. The goals of this Phase I program are to extend standard micromechanical models to predict dielectric behavior of coated fiber CMC’s, to incorporate these models into anisotropic layered material representations for dielectric sensor models, and to relate composite constituent behavior with thermal exposure conditions. To address this need, we will work with CMC thermostructural modelers (MR&D), manufacturers (COI Ceramics), and an end user (Pratt & Whitney). In Phase II, we will refine the models to support in-service material evaluation and self-consistent prediction of dielectric, thermochemical, and structural behavior.