A novel experimental methodology to identify fracture envelopes and cohesive laws in mixed-mode I plus III

This work presents a novel methodology to investigate fracture behaviour in mixed-mode I + III experimentally and applies it to elastic-plastic structural adhesive joints. J-integral is separated into contributions from single modes by assuming clear assignment of external loads to one corresponding fracture mode. A proposed evaluation method allows direct calculation of traction vectors at crack tip. Additionally, an indirect method is proposed, which determines traction vectors from experiments at prescribed constant J-integral. First experimental results are presented and both methods seem to be adequate to study dependencies of cohesive laws on loading paths.