Elastic and elastic-plastic threshold stiffness of stiffened steel plate walls in compression. (September 2018) - Xu, Zhaoyu
Abstract: This paper studies the minimum stiffness required to ensure elastic buckling and elastic-plastic post-buckling strength of subpanels of vertically stiffened steel plate walls (S-SPWs) under compression. In the linear elastic analysis, the threshold stiffness at which the buckling mode of S-SPWs changes from overall to subpanel local buckling is determined. Based on the understanding that the increased elastic critical buckling strength of the S-SPW is provided by the elastic buckling resistant capacity of the stiffeners, a formula is proposed to predict the elastic threshold stiffness. The elastic-plastic threshold stiffness of vertical stiffeners, which makes the subpanels develop their full elastic-plastic post-buckling capacity, is obtained through nonlinear analysis. This paper investigated the effects of subpanel aspect ratio, subpanel width-to-thickness ratio, number of stiffeners on the elastic-plastic threshold stiffness. The effect of initial imperfection is also included. Based on the understanding that the increased capacity of the S-SPW from overall to subpanel post-buckling is provided by the elastic-plastic strength and stiffness of the stiffeners, a formula to predict the elastic-plastic threshold stiffness is proposed. The proposed formulas for both threshold stiffness are found to possess good accuracy after some minor modifications. The comparison between elastic and elastic-plastic threshold stiffness is also presented. Highlights: Behaviour of compressed vertically stiffened steel plate wall is studied, focusing on application in high-rise buildings. The threshold stiffness of stiffeners for elastic buckling is presented and the effect of torsional rigidity is included. The threshold stiffness of stiffeners to ensure the full elastic-plastic post-buckling capacity of subpanels is determined. Increased capacity of S-SPWs over unstiffened SPWs is related to the stiffness and strength of stiffeners. Based on this understanding, formulas for both types of threshold stiffness are proposed.