Critical Buckling Strength Prediction of Pultruded GFRP Composite Columns

Fiber-reinforced polymeric (FRP) composites offer a unique addition to common construction materials utilized in Civil Engineering. However, unlike traditional construction materials (steel, timber, concrete, etc) FRP composites lack adequate design standards and or criteria. The need for appropriate design guidelines is subsequently required in order to ease the progression of the use FRP composites in construction. The present research investigates several previously proposed prediction models\u27 ability to calculate failure of GFRP composite columns of varied length and cross section. Material properties were developed through testing specimens of the coupon and 1ft pure compression (component) levels. Furthermore, a strain-energy density failure model developed by researchers at WVU-CFC for GFRP coupons in tension and bending was manipulated to evaluate full-length samples in axial compression. Prediction of failure within the proposed models displayed a range of precision and accuracy. The strain energy density failure model commonly predicted the critical buckling load within 10% of experimental failure for each of the different column lengths tested (6ft, 8ft-6in, 9ft, 10ft). In conjunction with failure analysis, P-Delta effects enhanced by eccentricity due to loading and initial out-of-straightness were also investigated. Preliminary design guidelines have proposed a total eccentricity limit of h/220 where \u27h\u27 is the column height in inches. The current research found this limit to be acceptable, however, the component due to initial imperfections along the column length (h/700), proved to be slightly too low and was commonly found to fall within the range of h/500-h/700