Influence of joining temperature on damage of warm self-piercing riveted joints in carbon fiber reinforced polymer and aluminum alloy sheets

Abstract

The deformation of and damage to carbon fiber reinforced polymer (CFRP) in warm self-piercing riveted (WSPR) joints with CFRP and AA5754 aluminum alloy are investigated. WSPR experiments were performed at different joining temperatures. A damage constitutive model for composite materials considering the shear effect and temperature effect was established to predict the mechanical properties of CFRP during the WSPR process. The simulation model of WSPR in CFRP and aluminum alloy was established, and the influence of the joining temperature on the delamination failure and macrocracks in the CFRP surface were analyzed by numerical simulations. The results show that the WSPR finite element model can accurately predict the forming section of the joints and the damage to CFRP. The propagation direction of the delamination damage crack is consistent with the laying direction of the underlying fiber. With an increase in joining temperature, the ductility of CFRP in the corresponding direction is enhanced, and the time of the rivet piercing the upper surface layer is delayed. When the forming temperature reaches the matrix glass transition temperature, the evolution trend of each damage mode changes.