Failure analysis of thermal barrier coatings based on cohesive element and XFEM

In order to better understand the failure mechanism of the thermal barrier coating, the ABAQUS finite element software was used to analyze the failure of the thermal barrier coating. Cohesive element and extended finite element (XFEM) were used to study the cracking of the TGO interface in the thermal barrier coating and the initiation and propagation of random cracks in the ceramic coating (TC) and the oxidation layer (TGO). The relationship between vertical cracks and horizontal cracks was studied. The results shown that the cracking of the TGO interface of the thermal barrier coating first occurred at the TGO/TBC trough, and the initiation of the random cracks in the ceramic coating and the oxidation layer also occurred at the TGO/TBC trough. The existence of the vertical crack could inhibit the initiation and propagation of the horizontal crack, and the propagation lengths at the TGO/TBC trough was longer than that of the TGO/TBC crest. It indicated that the TGO/TBC trough area was a dangerous area, which was likely to cause crack initiation and propagation in this area.