A theoretical formula for predicting the folding wavelength in the rectangular columns

Abstract

In this article, a theoretical relation is derived to predict the folding wavelength in the square and rectangular columns under the axial loading. For this purpose, a new deformation model of the columns during the folding progress is introduced. Based on the energy method, final equation is obtained. The derived relation shows the folding wavelength is dependant on the wall thickness and the edge length of the columns cross section and is independent of the column material. Some static folding tests are performed on the square and rectangular columns. Finally, the predictions of the theoretical formula are compared with the experimental results for which good agreement is observed.