Influence of the Initial Imperfection on the Buckling of Steel Member Wrapped by Carbon Fibre

Abstract

Based on Ježek method of computing the elastic-plastic buckling of the member under the axial compressive load and the bending moment, considering the initial geometric imperfection, the analytical expressions of calculating the ultimate load of buckling about the neutral axis with the maximum moment of inertia for an H-shaped member with flange outsides wrapped by carbon fibre are derived. Using the elastic-plastic finite element method and the theory of nonlinear buckling, the impact of the initial geometric imperfection on the H-shaped steel member wrapped by carbon fibre under the axial compressive load and the bending moment are analyzed and the numerical solutions of ultimate bearing capacity are obtained. By compared with the values of the finite element method (FEM), it shows that the analytical method in this paper is valid. Compared the reinforced effect of the carbon fibrer to the perfection member with the defect member, we find that the former is higher than the latter. The results of the example also show that the presence of initial geometric imperfection reduces the ultimate bearing capacity of the steel member to a great extent. The influence of defect member gradually decreases when the given moment rises.

Hybrid Artificial Intelligence Approaches for Predicting Critical Buckling Load of Structural Members under Compression Considering the Influence of Initial Geometric Imperfections

“…These defects have a great influence on mechanical behaviors, causing a decrease in the buckling capacity of tubes under axial loading [3,7]. In addition, many experimental studies have shown that buckling appeared earlier than estimated because of initial imperfections, such as in the case of I-sections [6,8], box sections [3,9,10], equal angle columns [11][12][13], T-sections [14], circular sections [15,16], and C-sections [17][18][19] for steel structures or concrete structures [20][21][22], composite structures [23][24][25], and alloy structures [26][27][28][29].…”

“…Nevertheless, analytical solutions often demonstrate a limitation as the structures are simplified with regular geometry. In the case of more complex structures, the numerical finite element technique has been widely applied to investigate the influence of initial imperfections on the buckling behavior of compression members, such as sigma section members [17], I-section steel columns wrapped by carbon fibers [24], cylindrical pipes made by carbon fiber-reinforced plastic material [23], braced columns [33], and multi-layer beams [25]. However, finite element analysis of buckling problems is mainly based on commercial software, for instance, ANSYS [7,19], ABAQUS [23,27], and NASTRAN [17].…”