The effect of eccentricity of load on the behavior of compressed composite columns in critical state

Abstract

The study concerns a short thin‐walled channel section column made of carbon‐epoxy laminate. The tested column was subjected to compression, including an eccentric compression force relative to the gravity center of the cross‐section of the column toward its higher rigidity. The boundary conditions applied in the study reflected articulated, simple support of the column's ends. The scope of the study included determination of the effect of eccentric load on the structure's buckling mode and critical load. The critical load of the real structure was determined using approximation methods based on the post‐critical equilibrium paths of the structure obtained in experimental tests. At the same time, a numerical analysis by the finite element method was performed using the commercial simulation software Abaqus®. The numerical analysis involved solving an eigenproblem to determine the buckling mode of the structure and to determine the critical load of this structure under axial and eccentric load. The experimental results were used to verify the developed numerical models. The analysis enabled determination of the effect of eccentric load on the structure's buckling mode and critical load, which is of vital importance for the design of thin‐walled real structures that are coated with reinforcing thin‐walled stiffeners. Examples of such constructions include thin‐walled stressed‐skin structures such as an aircraft's main body section and wings, where the thin skin or outer covering is reinforced by a series of longitudinal profiles with open and closed sections. POLYM. COMPOS., 40:70–77, 2019. © 2017 Society of Plastics Engineers