LAUSR

Abstract In this work, the rotational stiffness of flange-web junctions of pultruded GFRP I-sections is investigated through an experimental program. Flange-web junctions of GFRP profiles are found to be non-rigid, contradicting typical design assumptions. Accounting for flange-web rotational stiffness reduces the rotational restraint of the flange/web junction; often by 15% or more, although more modest reductions were observed in this study. A discussion of different test methods for assessing flange/web junction stiffness is provided. A simple method that mitigates unfavorable effects is recommended. The effectiveness of the selected test method is demonstrated through 25 experimental tests which also serve to augment the limited data available in this area. Finite element modeling is conducted to simulate the experimental test and investigate parameters impacting the experimentally-determined rotational stiffness. Recommendations are made to standardize test parameters. Findings from this study directly support the developments of evaluation criterion for flange-web junctions and design equations; particularly those intended to capture the local buckling behavior of pultruded GFRP beams.