Polymers are one of the most important types of engineering materials used with reinforcing fibers in various industries in order to improve the mechanical properties. One of the most widely used composites is the carbon fiber reinforced plastic owning excellent mechanical properties such as high specific stiffness and specific strength. In addition epoxy resins is extensively used as a matrix in fiber reinforced plastics due to its high strength and modulus, low contraction, excellent heat resistance, and high chemical and corrosive resistance. The fatigue performances imposed by standards have to be performed by means of experimental campaigns in laboratory on specimens. Classical procedures to evaluate the fatigue limit of material involve expensive and time-consuming tests because of the high number of specimens being tested. In the last decades, with an aim to reduce testing times and costs of fatigue tests, different techniques and methods have been proposed in order to study the various damage phenomena rapidly and consistently. Infrared thermography is considered as a promising method to investigate the fatigue behavior focusing on the metals and fiber reinforced plastic. The identification procedure of this method is based on the use of self-heating measurements and validate by comparing the prediction of the S–N curves given by the model and experimental fatigue results. In this study the thermographic technique based on temperature variation was used to assess the fatigue behavior of carbon fiber reinforced epoxy. The standard composite samples were fabricated by hand lay-up method. To fabricate the composite samples, four layers of woven carbon fibers with an equal weight ratio of epoxy resin were used. The quasi-static tensile tests were conducted to determine the stress levels in classical and self-heating fatigue tests. Maximum cyclic stresses were chosen between 10 % and 90% of the ultimate tensile strengths as load levels. The load-controlled fatigue tests were conducted with a stress ratio of 0.1 and loading frequency of 10 Hz. In fiber reinforced epoxy under cyclic loading the main mechanisms causing energy dissipation are attributed to the matrix cracking, fibers fracture, and interface cracking/friction among others. According to the fatigue tests analysis (evolution of the hysteresis area and Young's modulus) and the results obtained from self-heating tests, the energy dissipation mechanisms were discussed.

It was worth noting that the obtained results from self-heating measurements can propose a good agreement with those attained by the classical methods. In other words an empirical relation could be considered between self-heating and classical fatigue results. Moreover with comparing the dissipated energies and stabilized temperatures in the self-heating measurements, there was a direct relation between them. Finite element simulation using commercially available ABAQUS software was also performed to model the temperature variations in the specimens subjected to cyclic loadings. Using a thermo-mechanical coupled analysis, the generated temperature in the specimens as a function of the applied stress can be obtained. Experimental tensile properties of the composite specimens were used as the input material data for the analysis. In order to validate the model, the obtained numerical results were compared with the experimental data. Employing the verified model, a parametric study on the effective parameter can be performed