A study on the numerical simulation of thermo-mechanical behavior of the novel functionally graded thermal barrier coating under thermal shock

An attempt was made to investigate the thermal and residual stress distribution in a novel three layer (La۲Zr۲O۷/۸YSZ/NiCrAlY) during a real-like heating regime which includes heating, service time and final cooling. For achieving maximum accuracy and consistency in calculation of thermal and mechanical properties of hybrid coating system, all related and required properties were introduced to the software in temperature-dependent mode. Element modification approaches like mass scaling leads to a considerable reduction in running time while satisfying and not violating accuracy and converging criteria and constrains. Applying adaptive hybrid meshing techniques which applies both mesh–part dependency and independency during numerical iterative solution avoids element distortion and diverging in coupled problem. Heat flux and nodal temperature contours indicated that, most of damaging and harmful thermal load and residual stresses concentrate on ceramic top coats and this may lead less harm and life time reduction in the substrate.

Keywords:

Finite Element Simulation , Residual stress , thermal barrier coating , Thermal Shock