Near Free-Edge Interfacial Transverse Peeling Stress Analysis of Composite Bonded Joints due to Thermomechanical Loads

In the past six decades, a considerable number of theoretical and experimental investigations have been conducted on the mechanical strength and durability of composite bonded joints. Nevertheless, many issues regarding the debonding behavior of such joints still remain uncertain. However, it is well accepted that the high near free-edge stress fields of these joints are the cause of their debonding failure. In this study, the performance of an externally bonded fiber-reinforced polymer (FRP) fibrous composite to a concrete substrate prism subjected to thermal loading is evaluated by employing the principles of lamination theory. The bond strength is predicted to take place at the peak interfacial transverse peeling stresses, which is the main failure mode of the joint. The proposed criterion is validated through the existing experimental data points. Comparison between the calculated and experimental results show good agreement producing quite a high average ratio. The current approach is applicable for failure modeling analysis, optimal design of bonded joints, and scaling analysis among others.