Buckling Behavior of Glass-Fiber Reinforced Polyester Pultruded Columns

Fiber-reinforced plastic materials are used for lightweight structural applications in engineering. This paper is intended to contribute to knowledge of the buckling behavior of glass-fiber reinforced polyester (GFRP) composite I-section pultruded columns. Columns of two different lengths: 5.5 ft and 8.33 ft were axisymmetrically or eccentrically loaded in compression, until failure and the mid-point lateral deflections were measured during loading. Euler’s theory was used to determine theoretical deflection for comparison with the experimentally determined ultimate loads in the axisymmetrically loaded columns. An equation derived from the differential equation of the deflection curve was used for comparison with the experimental load-deflection curves for the eccentrically loaded columns. Limited scanning electron microscopy was done to differentiate between the microscopic failures in I-section columns.