Mechanical properties of the riveted connecting forming of CFRP plates

Mechanical properties of the unidirectional CFRP sheets connected by various rivet formations are experimentally investigated to propose the suitable riveted connection of the CFRP sheets. In this approach, the rivet connection is conducted with different position and different number. The connecting strength is dependent on the fracture mode. In basic, two different fracture modes are obtained: rivet- and CFRP-based fracture, where the high and the low strength are obtained for the sample fractured mainly by rivet and CFRP, respectively. However, in addition to the two fracture modes, rivet failures with micro-crack in CFRP are detected. The micro-cracks make change of the stress-strain curve although, like the rivet fractured sample, the high strength is still obtained. The failure in CFRP is attributed to the fiber/matrix interfacial debonding. The failure characteristics of CFRP can be monitored during the shear loading test with variation of the electric current in the CFRP plates. The concept of this approach is to examine the change of the electric resistance due to the material failure. In this case, the decrement of the current value is related to the failure in the rivet and CFRP. With the rivet formation, the fracture mode is altered; and appropriate rivet positions are determined to make the high connecting strength of the CFRP plates.