Effect of bearing length on web crippling behavior of pultruded GFRP channel section

Pultrude glass fiber reinforced polymer (GFRP) sections have gained increasing acceptance in building and construction industries considering their promising physical and mechanical properties. However, they are prone to premature web crippling failure due to their orthotropic nature and relatively low interlaminar shear strength and modulus when subjected to transverse bearing load. This paper presents a study on the effect of bearing length on web crippling behavior of pultruded GFRP channel sections. Four channel sections with different sectional dimensions were selected for web crippling testing. Two loading conditions including end-two-flange (ETF) and interior-two-flange (ITF) were adopted. Transverse loading was applied through bearing plates with five different lengths of 20 mm, 50 mm, 100 mm, 150 mm and 200 mm. Failure modes, load–displacement curves and web crippling capacities were reported and discussed associated with the effect of bearing length. Mechanism based design equations which were able to consider effect of bearing length were proposed, and the predicted web crippling capacities agreed well with experimental results.