Experimental study on CFRP-to-steel bonded interfaces

• Published in: Composites. Part B, Engineering Engineering, 2012-07, Vol.43 (5), p.2279-2289
• Main Authors: Yu, T., Fernando, D., Teng, J.G., Zhao, X.L.
• Format: Article
• Language: English
• Subjects: A. Carbon fibre reinforced polymer; Adhesive bonding; Adhesive strength; adhesives; Applied sciences; B. Bond strength; B. Debonding; B. Interfacial shear stress; Bonded joints; Bonding; CFRP-to-steel bonded interface; Composites; energy; Exact sciences and technology; Forms of application and semi-finished materials; Fracture mechanics; Fracture toughness; Laminates; Mathematical models; modulus of elasticity; Nonlinearity; Physicochemistry of polymers; Polymer industry, paints, wood; shear stress; Technology of polymers; tensile strength
• ISSN: 1359-8368; 1879-1069
• DOI: 10.1016/j.compositesb.2012.01.024

This paper presents an experimental study on the behaviour of CFRP-to-steel bonded interfaces through the testing of a series of single-lap bonded joints. The parameters examined include the material properties and the thickness of the adhesive layer and the axial rigidity of the CFRP plate. The test results demonstrate that the bond strength of such bonded joints depends strongly on the interfacial fracture energy among other factors. Nonlinear adhesives with a lower elastic modulus but a larger strain capacity are shown to possess a much higher interfacial fracture energy than linear adhesives with a similar or even a higher tensile strength. The variation of the interfacial shear stress distribution in a bonded joint as the applied load increases clearly illustrates the existence of an effective bond length. The bond–slip curve is shown to have an approximately triangular shape for a linear adhesive but to have an approximately trapezoidal shape for a nonlinear adhesive, indicating the necessity of developing different forms of bond–slip models for different adhesives.