Cracks are inevitable in almost all engineering components and structures.The study of thermo-elastic fracture mechanics, which deals with the catastrophic propagation of existing cracks under thermal loading, is considered to be of great importance in the design of structures such as aerospace components, combustion chambers, turbines and nuclear pressure vessels.In the paper, we present a finite element method procedure based on an open source library (libmesh) to evaluate the failure capacity of cracked homogeneous and bi-material media under cyclic thermo-mechanical loads.The control equations of coupled, time-dependent thermo-elasticity are employed to account for the time-varying nature of the thermal load.As the nonlinear control equation, the iteration method has been used.For the thermo-mechanical problem, the temperature field will be get at first.That is then employed as input for the mechanical problem to determine the displacement and stress fields.And then the temperature field will be modified by the displacement and stress fields.The process will be repeated until convergence.If crack closure due to thermal distortion takes place, then the displacement and traction field may affect the heat flux between the crack faces, and the thermal and mechanical parts of the problem will need to be solved repeatedly until thermo-mechanical convergence is achieved.Both isothermal and adiabatic conditions are considered at the crack surfaces.We present results from cases of pure mode-I fracture in homogeneous materials and for interfacial fracture in bi-materials.The present analysis shows that the results obtained by the procedure are in good agreement with those available in the literature.At last, we discuss the influence of crack closure on quasi-static, sub-critical crack extension.The results suggest that the crack closure may have a severe impact on the predicted failure capacity of cracked structures and should be considered in the evaluation of fatigue life.