Experimental and numerical investigations have been conducted to evaluate the effect which the clamping force, resulting fromtorque tightening anut andbolt,has onthemixedmode (I andII)fracture strength
and effective stress intensity geometry/loading factor of a plate having an edge crack. The experimental
tests were carried out on three batches of simple edge crack and bolt torque tightened edge crack specimens made from poly methyl-methacrylate (PMMA) rectangular plate. The specimens’ fracture strengths
were obtained using a tensile testing machine in different loading angles using a modified Arcan fixture.
In numerical part, finite element simulations were used to model the three test specimens variants used
and thereby establish their stress intensity geometry/loading factors. The results show thatthe bolttightening torque, and hence the plate clamping force, has a significant effect on reducing the equivalent mixed
mode stress intensity factor of all loading angles and the equivalent factor, and thus the joint fracture
strength compared to bolt-less simple edge crack specimens.