Session: 12-23-01: Symposium on Multiphysics Simulations and Experiments for Solids

Paper Number: 146142

146142 - Graded Ceramic Matrix Composite Design Though Multi-Physics Finite Element Analysis 

Developing high-performance coatings for ceramic matrix composites (CMC) to withstand high temperatures and harsh gas environments in hydrogen-fueled turbines is indeed a challenging task.  An ideal high-performance coating material must exhibit strong bonding with the CMC substrate to prevent delamination under the harsh environment. It should serve as superior thermal barrier and environmental barrier, reducing heat transfer to the CMC substrate while with standing high temperatures, pressures, and aggressive gas environments without degradation. It should also minimize the thermal stress generation to ensure long-term performance and durability of the coating.

To achieve this goal, we adopted Multiphysics finite element analysis software COMSOL to design and optimize the compositions of graded Y2Si2O7-Gd2Zr2O7 coating layer to achieve the desired thermal and mechanical performance as protection of the CMC substrate. The design criteria includes (1) minimize the temperature on the substrate, (2) minimize the thermal stress and thermal stress gradients within the coating layers, and (3) minimize the thermal stress difference between coating layers to avoid delamination. The heat transfer model and structural mechanics model are explicitly coupled. We first solve the heat transfer governing equation , where  is the heat flux by convection, k is thermal conductivity, T is temperature. After the temperature distribution is obtained, we solve the structural mechanics model by consider the thermal strain and thermal stress. We have quantitively analyzed the temperature distribution and stress distribution along the coating depth direction under various graded coating design by considering the design parameters such as material properties variation and layer thickness variation.  An optimized design has been identified to guide the experimental fabrication of the graded Y2Si2O7-Gd2Zr2O7 coatings on CMC substrates.

Presenting Author: Jingzhe Qiao Clemson University

Presenting Author Biography: Jingzhe Qiao is a Ph.D. student at Mechanical Engineering Department, Clemson University. His research interest is in the area of computational mechanics and computational materials.

Authors:

Jingzhe Qiao Clemson University
Huijuan Zhao Clemson University