Characterization of adhesive bonded CFRP laminates using full-field digital image stereo-correlation and finite element analysis

In this paper, the full field experimental analysis, and numerical and morphological investigation on two groups of adhesive bonded CFRP laminates are presented. The Digital Image Stereo Correlation (Stereo DIC) technique is used to characterize the out of plane deformation of the specimens under loading. Despite the simplicity of the adopted approach, the analysis and the comparison between the load-displacement curve and the stereo DIC results show that a significant damage in the specimens can be found during the early stages of the test. This first significant failure is the result of out of plane deformation due to the adhesive opening which plays a crucial role in the ultimate failure of the specimen. The stereo DIC and mechanical results prove the phenomena; while the localization of the first significant failure has also been verified using a numerical model. The morphological studies of the adhesive coated specimen after failure shows the nature of the fracture and the load carrying behaviour of the adhesive. It has been quantitatively proved that the thickness of the adherend has a very less substantial role in the failure of specimens in comparison with the thickness of the adhesive.