Paper number 541

MATRIX CRACKING IN A (0/90)2S GFRP LAMINATE LOADED IN FLEXURE

P.A.Smith, S.L.Ogin and G.Faulks

School of Mechanical and Materials Engineering
University of Surrey, Guildford, Surrey, GU2 5XH, UK

Summary

Matrix cracking in a (0/90)2s GFRP laminate loaded in four point bending has been studied experimentally and analytically. Experimental data have been obtained for crack accumulation in the single 90° ply near the tensile face of the laminate as functions of applied bending moment and in situ ply strain. The cracks lead to a reduction in the flexural stiffness of the laminate while the partial release of thermal stress associated with crack formation leads to a residual curvature on unloading. Results for crack onset and the residual properties as a function of damage are in reasonable agreement with a closed-form analytical model based on one-dimensional beam theory (with the cracked 90° ply properties degraded in accordance with a shear-lag model) in conjunction with fracture mechanics.

Keywords

bending, transverse cracks, stiffness, fracture mechanics, cross-ply laminate, residual curvature.