A comparative numerical-experimental investigation on the tensile behaviour of bonded, rivetted and hybrid composite joints configurations

This paper deals with the development of accurate numerical models to predict the tensile mechanical behaviour of composite joints. The problems of damage initiation and propagation in composite joints for an economic solution with minimized oversizing is addressed. Different types of joints (Single Lap Joint, Single Strap Joint, Joggle Joint) and couplings (bonded, rivetted, hybrid) have been combined to find out the most suitable and reliable joining technique depending on the design constraints. On the basis of preliminary DCB and ENF tests, the characteristics of the adhesive material (stress limits and fracture energies) have been determined. These data have been employed for the numerical simulations on bonded and hybrid (bonded/rivetted) joints. The introduced numerical models, taking into account geometrical non-linearity and progression of damage in composite plies, have been preliminary validated by ad-hoc experimental tests to demonstrate their effectiveness in simulating the mechanical behaviour of general composite joints.