Impact damage and residual strength predictions of 2D woven SiC/SiC composites

Abstract

Lightweight, Ceramic Matrix Composites (CMC) are very attractive alternatives to superalloys for applications in hot turbine sections. However, debris, such as dirt, ice and metallic particles may be ingested by aero-engines and impact from them may cause serious damage and/or degradation to CMC components of the engines. It is important to develop predictive models and computational tools that would address this problem. The objective of this paper is to develop a progressive damage model for Ceramic Matrix Composite and implement it into ABAQUS Explicit to numerically predict impact damage and residual strength of a CMC component. To achieve this objective, experimental data on 2D woven SiC/SiC beams subjected to high velocity impact and subsequent four-point-bending tests were used. Modified Hashin–Rotem criteria were assumed for damage initiation and specialized cohesive traction-separation laws were developed to address the fiber toughening mechanism experienced by the CMC in tension and shear modes. Impact damage and four-point-bending of the SiC/SiC specimens were simulated in ABAQUS Explicit, and relatively good agreement was found between FEA predictions and test results, including the impact zone shape and size, as well as the load-deflection response and residual bending strength from the four-point-bending tests.