Experimental Study and Finite Element Analysis of Initial Imperfection on 7A04-T6 Aluminum Alloy Circular Hollow Section Column

In this study, a combination of experiments and finite element analyses was conducted to investigate the effect of initial imperfections on the axial compression of the 7A04-T6 aluminum alloy columns. Prior to the loading tests, measurement of the initial geometric imperfections for the columns were performed by optical theodolite and vernier calipert. The failure modes of 10 extruded circular columns were investigated. Meanwhile, the ultimate strengths, deflections and surface strains in whole process under axial compression were recorded. The finite element (FE) models of the tested columns were developed using the non-linear finite element analysis (FEA) software ABAQUS, and the imperfections and material nonlinearities were considered in the FE models. The validation of the FE models was performed against the test results; it was observed that the proposed FE models are sufficiently accurate to predict the ultimate strengths and buckling behaviors of the tested columns.