Dynamic buckling of thin-walled viscoplastic columns

The purpose of this paper is the analysis of strain-rate effect in dynamic stability of thin-walled orthotropic column of closed rectangular cross-section, subjected to in-plane pulse loading of finite duration. For the solution the first-order shear deformation theory displacement field is employed with the Green–Lagrange strain tensor application. The effect of strain rate sensitivity is included in the framework of the viscoplasticity constitutive Perzyna model for material behaviour under high strain rate loading. The numerical results are obtained with the finite element method application. In the performed analysis the strain-rate effect influence on the dynamic buckling load is examined as well as the initial imperfections of walls, pulse shape and the orthotropy ratio are considered. The results of dynamic criteria application are compared furthermore.