Paper number 912

MEASURING BOLTED JOINT BEARING DEFORMATION AND STIFFNESS

B. Vangrimde¹, R.Boukhili¹

1Centre for Applied Research on Polymers, Ecole Polytechnique de Montréal, CP 6079, succursale Centre-Ville, Montréal, Quebec, H3C 3A7, Canada

Summary

This investigation deals with the stress-strain behaviour of single-bolt double shear bolted joints. The standard test method for bearing response of polymer matrix composite laminates (ASTM D5961) provides a way to measure bearing stress, bearing strain and bearing chord stiffness. Although the bearing strain is clearly defined, obtaining this strain from the measured data is not a straightforward procedure. It is shown that the tensile strain in the coupon, included in the measured data, profoundly influences the bearing strain and bearing chord stiffness. Data for 6 glass fibre-reinforced polyester laminates and 3 coupon geometries are presented. A simple correction procedure is proposed which allows the tensile strain to be excluded from the measured data. Experimental and finite element results are presented to provide insight for future experiments and to show that there is a merit in isolating the deformation caused by coupon tensile strain from the bearing deformation.

Keywords

bolted joints, fastening, bearing deformation, bearing stiffness, GRP.