Simulation of failure behavior of 2.5D SiC/SiC variable thickness dovetail joint structures based on mesoscale model

The application of ceramic matrix composites plays an important role in improving the performance of aero engines. However, mesoscopic aperiodicity causes excellent challenges for the performance analysis of ceramic matrix composite structures. It is no longer applicable to obtain the macroscopic properties of materials through experiments or RVE simulations for structural performance analysis. Here an attempt is made to develop a performance analysis method for mesoscopic aperiodic ceramic matrix composite structures based on mesoscale models and apply the method to the strength calculation of 2.5D SiC/SiC variable thickness dovetail joint structures. The established model reasonably approximates and accurately describes the structure's real yarn geometries and orientations, reflecting the differences of yarn architectures in different regions. The yarn stress-strain curve is obtained through experiments, and the yarn constitutive model is established. The failure behavior of the 2.5D woven dovetail joint structure is simulated using the progressive damage analysis method and taking the yarn as the basic load-bearing unit. The simulated results are in good agreement with the experimental data in terms of failure load, load-displacement responses, macroscopic damage evolutions, and failure modes.