A Variational Approach for the Deflections and Stability Behavior of Postbuckled Elastic-plastic Slender Struts

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Department of Civil, Environmental, and Geospatial Engineering; Department of Mathematical Sciences


In this paper, we present the large deflection behavior of a postbuckled vertical slender strut made of elastic-plastic material and subjected to uniformly distributed loads, w, including their own weight. Such struts will buckle at the critical buckling load. wcr. As the load is increased beyond wcr, the deflections of the strut also increase. Eventually the strut may undergo a second instability, where a small increase in the load will cause a large jump in the deflections, and the strut will move to another position of equilibrium. The problem is formulated in terms of a variational approach, to which the Ritz method of solution is applied. In addition, we use determinants to develop an inequality for stability behavior of the strut in the postbuckled region.

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© 1987

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International Journal of Non-Linear Mechanics