Mode-II fracture behavior evaluation for adhesively bonded pultruded GFRP/steel joint using four-point bending test

Abstract The pure mode-II fracture behavior of an adhesively bonded glass fiber reinforced polymer (GFRP)/steel joint was experimentally investigated using a four-point end-notched flexure (4ENF) test. Cracking of the 4ENF specimen initiated and propagated in the adhesive-steel surface. The dominant failure mode observed in all specimens was adhesive-steel interface failure. The compliance of the 4ENF specimen was determined with the rigid joint model and finite element method. The extended global method was employed to obtain a simple analytical solution of the mode-II energy release rate, and the corresponding results were compared with that determined by the virtual crack closure technique (VCCT). The full R-curve for the pure mode-II fracture behavior of an adhesively bonded pultruded GFRP/steel joint was obtained. Then, the VCCT was used to determine the load–displacement curves of the 4ENF specimens for validating the accuracy and applicability of the pure mode-II fracture criteria of the adhesively bonded pultruded GFRP/steel joint.