Experimental investigation on the web crippling behaviour of pultruded GFRP wide-flange sections subjected to two-flange loading conditions

Abstract

In this paper, an experimental investigation on the web crippling behaviour of GFRP pultruded wide-flange sections profiles is reported. The experimental investigation mainly comprised mechanical characterization tests as well as full scale web crippling experiments, performed under two loading configurations, namely, end two flanges (ETF) and interior two flanges (ITF). To examine the effects of bearing length and thickness of the loading (or support) plates on web crippling behaviour, five bearing lengths (N): 25, 50, 70, 100 and 120 mm; and two different plate thicknesses (tplate): 8 and 10 mm were used. It was observed that increasing the bearing length from 25 mm to 120 mm (or N/tw = 5–24; tw is web thickness) with a plate thickness of 8 mm increased the ultimate load by upto +280.9% for ETF loading, whereas, in case of ITF loading, this increase was +85.5% when the bearing length was increased from 25 mm to 100 mm. However, change in plate thickness from 8 mm to 10 mm (or tplate/tw = 1.6–2.0) did not have significant effect on the ultimate load. Based on the experimental results and data obtained from literature, reliable design equations were developed using Eurocode3, and NAS design formulations.