Analysis of the bearing response test for polymer matrix composite laminates: bearing stiffness measurement and simulation

This paper is the first part of a project that aims to investigate the mechanical and fracture behaviour of bolted joints in general purpose glass fibre-reinforced polyesters (GRP). In the present study a procedure is set up to measure the bearing stiffness of a GRP laminate in a single-bolt double lap joint. With a three-dimensional finite element model it is shown that the bolt and fixture deformations affect the stiffness results. Hence the experimental displacement data were corrected before calculating the coupon bearing stiffness. The coupon bearing stiffness was also simulated by a two-dimensional finite element model. Provided that bolt–hole clearance, material non-linearity and bolt–hole friction are taken into account, good agreement is observed with experimental data. Bearing strain and bearing stiffness are based on the bearing deformation of the coupon, not on the hole elongation. This makes the stiffness data useful for design and allows an easy installation of the displacement measurement devices.