Compressive transverse fracture behaviour of pultruded GFRP materials: Experimental study and numerical calibration

Abstract

This paper presents a study on the transverse fracture behaviour of pultruded glass fibre reinforced polymer (GFRP) materials in compression, namely the assessment of transverse compressive fracture toughness (G2−) and transverse compressive residual strength (σr). These properties were assessed through experimental Compact Compression (CC) tests of six different GFRP materials, which were coupled with a data reduction method to determine experimental predictions of G2− and numerically calibrated as a function of the experimental load vs. displacement curves. Through this process, the expected experimental overestimation of G2−, attributed to contact stresses behind the notch tip, was evaluated and accurate numerical estimates of G2− were determined. The numerical calibration considered both G2− and σr, by considering a bi-linear cohesive law. Through the numerical calibration, the G2− results ranged between 36 and 67 N/mm and σr values varied from 9% to 16% of transverse compressive strength (7.6 and 16.9 MPa, in absolute values). Finally, the G2− results were analysed as a function of transverse fibre reinforcement percentage and compared to transverse tensile fracture toughness results (G2+) determined in a previous work. This study showed that G2− is generally higher than G2+ and that the compressive-to-tensile ratio is inversely proportional to the transverse reinforcement percentage.