Three-Dimensional Deformation and Life Prediction Methods for Ceramic Matrix Composite Components

Manufacturing defects in ceramic composite matrix require 3D fiber architectures to reinforce and toughen both in-plane and out-of-plane directions of CMCs. Modeling 3D material properties and evaluating durability of structures made of 3D composites are of great importance in their application in advanced turbine engines. Alpha Star proposes to develop a micro/macro-scale finite element failure method that accounts for both 3-D composite material and structural behaviors subject to the engine service condition. The contribution of 3-D fiber architectures to structural stiffness and strengths in both in-plane and out-of-plane directions will be accounted for in unit cells using micromechanics formulation. Assuming fiber distribution in 3D composites to be statistically uniform, the input information for a unit cell will be the fiber orientation and content in each material direction as well as the manufacturing defect content, which covers the entire family of 3D CMCs and maintains computational efficiency in the micro/macro scale FEM failure analysis. Embedding the unit cell model in the macroscopic structural analysis allows detailed micro damage to be addressed in durability evaluation of turbine engine components made of 3D CMCs. The proposed method will provide a highly efficient analytical tool for 3D CMC turbine engine design and application.