Adaptability Study of an Ideal Linear Elastic Constitutive Model for a Plasma Sprayed Ceramic Thermal Barrier Coating

A finite element simulation of a plasma sprayed thermal barrier coating(TBC) system was conducted. Plasma sprayed thermal barrier ceramic coating was treated as either a simple elastic model or an advanced viscoplastic model which includes rate dependence and unequal flow stresses in tension and compression. Predicted tensile stresses emerging in the ceramic plane at the elevated temperature never become large enough to cause surface cracks based on elastic analysis, so does using the viscoplastic model. At the low temperature, these two models identically show that the ceramic coat will locally cracks at the "peak" location. It is shown that although there are some numerical differences in these two models' predictions, elastic analysis predicts accurate in failure mechanism analysis based on stresses.