Experimental and analytical investigations on short GFRP composite compression members

Comprehensive experimental and analytical evaluations of 12 full-scale glass fiber-reinforced plastic composite columns are presented herewith. The pultruded columns had commonly utilized "Universal" and "Box" cross-sections with E-glass fibers in various forms as reinforcement and polyester and vinylester as binding matrices. The slenderness ratios (Ur) of the investigated columns were 5.69 and 32.7 for the "Universal" section and 9.38 and 53.9 for the "Box" section. The column lengths were 18 in. (0.46 m) and 8 ft. (2.44 m). All columns were tested in a vertical position and under compressive axial static loading and fixed-pinned and pinned-pinned end-conditions. The columns' compressive strains, buckling and crippling loads, lateral displacements, initial curvatures, and modes of failure were documented during the course of this investigation. The orthotropic mechanical properties of the composites were experimentally obtained utilizing 44 coupon specimens. Results from linear Finite Element buckling analyses conducted on full column models of the "Universal" section were compared to the behavior observed in the laboratory during the testing of specimens. In addition, the unstiffened flanges of the columns were analyzed with various boundary conditions using the classical orthotropic plate theory and the finite element method in order to establish the upper and lower bounds of the members' local flange and web buckling capacities. Based on experimental evaluations and analytical analyses results, conclusions were drawn and recommendations were made. (C) 2000 Elsevier Science Ltd. All rights reserved.