Modern thermal barrier coatings (TBC) are required to not only limit heat transfer through the coating but to also protect engine components from thermal cyclic load and oxidation. Failure mechanism of TBC is important for the safety status of components. To obtain a better understanding of the failure mechanism under thermal cyclic load, a new type of interface elements with three nodes which is based on the idea of interface damage mechanics was proposed. Compared with traditional interface elements, these elements have the quality of indicating the normal direction of interface with arbitrary shape. The modified model was implemented into ABAQUS by user subroutine UEL. The damage and fracture of cosine shape interface were numerical simulated considering the rough interface of the plasma sprayed thermal barrier coating. The calculating results show that, under thermal cycle loadings, the displacement between nodes of the interface elements is not continuous which represents the opening process of the interface crack, the damage increases with the number of thermal cycle loadings and the max damage is caused during the first cycle, the top of the interface is the critical position and the normal separation dominants; under tension loadings, the wavy interface has better capability of load bearing than the linear interface for PS-TBC. Simulation of damage and fracture for different materials with arbitrary interface using the modified interface elements is available, and the results are reasonable. Modern thermal barrier coatings (TBC) are required to not only limit heat transfer through the coating but to also protect engine components from thermal cyclic load and oxidation. Failure mechanism of TBC is important for the safety status of components. the failure mechanism under thermal cyclic load, a new type of interface elements with three nodes which is based on the idea of ​​interface damage mechanics was proposed. Compared with traditional interface elements, these elements have the quality of indicating the normal direction of interface with arbitrary The modified model was implemented into ABAQUS by user subroutine UEL. The damage and fracture of cosine shape interface were numerical simulated on the rough interface of the plasma sprayed thermal barrier coating. The calculation results show that under thermal cycle loadings, the displacement between nodes of the interface elements is not continuous which represents the open ing process of the interface crack, the damage increases with the number of thermal cycle loadings and the max damage is caused during the first cycle, the top of the interface is the critical position and the normal separation dominants; under tension loadings, the wavy interface has better capability of load bearing than the linear interface for PS-TBC. Simulation of damage and fracture for different materials with arbitrary interface using the modified interface elements is available, and the results are reasonable.