Web-crippling of GFRP pultruded profiles. Part 1: Experimental study

There is evidence that glass fibre reinforced polymer (GFRP) pultruded profiles are particularly susceptible to transverse compressive loads, owing to the much lower mechanical properties in the direction transverse to the pultrusion axis. Although very relevant, the understanding about the web-crippling phenomenon in GFRP pultruded profiles is still very limited, as attested by the lack of information available in design codes and guidelines. This paper reports an experimental study about the web-crippling phenomenon in GFRP pultruded profiles with I-section. The experimental programme included comprehensive material characterization tests (tension, compression, flexure and shear), and full-scale web-crippling tests on four different I-profiles, with heights ranging from 100 mm to 400 mm, thus covering the vast majority of structural profiles currently available in the market. In the web-crippling experiments, two load configurations were tested: interior two flanges (ITF); and end two flanges (ETF). In addition, tests were performed with three different bearing lengths: 15 mm, 50 mm, and 100 mm. The experimental results confirmed the susceptibility of GFRP pultruded profiles to transverse compressive loads, outlining the influence of both the load configuration and the bearing length on the web-crippling phenomenon in terms of strength, stiffness, and failure modes.