Thermal barrier coatings (TBCs) operate under high temperature, steep thermal gradients, and repeated thermal cycles. These conditions generate time-varying temperature fields that modify interfacial thermal stresses and their gradients. As a result, stress-concentration sites may migrate and compromise mechanical stability, including interfacial integrity and crack initiation/propagation.
We use finite-element analysis (FEA) to quantify these temperature-field-driven stresses and to assess microstructural and interfacial factors that influence fracture susceptibility. With a 2D model, we track interfacial stress distributions and the movement of stress concentrations under diffusion, thermal-gradient, and uniform-heating conditions.
Parametric studies on porosity indicate a consistent tendency: pores in the bond coat relax compressive stress near the interface, whereas pores in the top coat amplify local stress concentration and increase crack susceptibility. Ongoing work will extend the same loading conditions to a 3D geometry to test the consistency of these trends and to support experimental validation and design guidance for TBCs in high-temperature service.