Environmental barrier coatings (EBCs) are currently developed to protect ceramic matrix composites from extreme environments such as gas turbine engines. It therefore is essential to understand the behavior of the CMC/EBC system under representative thermomechanical loadings. In particular, the creep behavior of EBCs was shown to be one of the lifetime limiting mechanism.  
The main objective of the test considered herein was to identify the creep behavior of the system in a 4-point bending test under thermal loading. It was based on  laser beam inducing 3D thermal gradients in the coating. An infrared camera enabled temperature fields to be quantified at the surface of the coating. Under such conditions, the specimen expanded and deflected. Displacement fields are measured using two visible light cameras on both sides of the sample via digital image correlation. During the test, the mechanical load was first applied. Then, the thermal loading was applied on the center of the coating surface up to  To let the sample creep, the laser was maintained for two hours and then turned off instantaneously. Two cycles were performed following this procedure.
Thermal and kinematic fields were measured for comparison with finite element simulations, using a weighted Finite Element Model Updating method. The identification of thermal boundary conditions showed different results depending on the area of minimization. Mechanical identification allowed the creep behavior of the coating to be quantified. Effects of temperature and stress are key parameters for quantifying the creep behavior of EBCs.