Simulation of lap-shear fracture test of hybrid metal/CFRP laminates

Abstract

Hybrid metal/CFRP laminates are considered for aerospace structural applications since by combining both material classes it is possible to utilize the advantageous properties of both and overcoming their weaknesses. In metal/CFRP hybrid laminate architectures, the metal fraction improves the impact resistance, and metal layers at the outer surface protect the CFRP core from environmental effects, such as ultraviolet radiation, moisture, and abrasive wear. CFRP provides high strength and high stiffness along with low weight. However, the interface between metal and CFRP implicates a higher complexity than interfaces between similar materials. E.g. differences in stiffness lead to shear stresses at free edges promoting delamination fracture. A test configuration considered for characterizing resistance against interfacial fracture is the lap shear test, which is not standardized for hybrid laminates. In order to assure the validity of experimental results, the effects of the chosen specimen geometry and experimental setup has been comprehensively investigated by means of experiments and numerical analyses.