Axial Compressive Strength Experimental and Numerical Studies of Full-Scale Specimens Simulating GFRP Composite Bushing Column

Abstract

To study the axial compressive performance of glass fiber-reinforced plastic (GFRP) composite structure, a full-scale axial compression experiment was conducted on GFRP composite bushing (GFRP-CB) column specimens. The axial compressive mechanical properties, failure mode, and load–displacement curves were obtained and analyzed. It is found that brittle fracture occurs in the GFRP-CB column specimens. Diagonal cracks as the main failure mode appear in the upper part of the GFRP pipe. Moreover, the maximum stress in specimens is less than the compressive strength of the GFRP composite material. The steel casing remains in the elastic state during the entire loading process. Based on the strength theory of transversely orthotropic material, the finite element method was used to scrutinize the influence of eccentricity and diameter–thickness ratios on strength of specimens. Numerical results prove that the ultimate bearing capacity of the eccentric compression specimens decreases with the eccentricity ratio. Reduction in diameter–thickness ratio can improve the ultimate bearing capacity of the specimens. As the diameter–thickness ratio decreases by 20%, the ultimate bearing capacity increases by 20%. Finally, an equation for calculating the ultimate bearing capacity of the GFRP-CB column is proposed according to test results. The calculated and test results are fairly consistent, which indicates the effectiveness and accuracy of the proposed equation.