Flexible bar buckling under short-time and long-term compressions

Abstract

PurposeThe purpose of this paper is to expand possibilities of stability computing method when performing a dynamic analysis of bar- or rod-shaped elements for actual structures.Design/methodology/approachThe methodology is based on the changes of stress–strain state of the bar-shaped elements at the moment of buckling. The proposed method is based on three assumptions. Firstly, the spatial stress–strain state is determined in the bar. Secondly, technological deviations inherent in real structures are introduced into the bar. Thirdly, mechanical behaviour of the bar is investigated in the mode of real time, which makes it possible to take into account wave deformation processes in the bar. To implement the suggested method of analysis, LS-DYNA package was selected in a dynamic formulation using solid finite elements.FindingsValidity of the proposed method is shown by an example of dynamic stability analysis of a steel flat thin bar with two types of loads: short-time and long-term axial compressions. Comparison of the results showed different nature of the mechanical behaviour of the bar: wave processes are observed under short-time loading, and continuous monotone ones are stated under long-term loads.Practical implicationsResearch results are applicable in the rocket and space industry.Originality/valueA new computer-based methodology for dynamic analysis of heterogeneous elastic-plastic bar-, rod-shaped structures under shock axial compressive loads is proposed.