Nonlinear Effects in Creep Buckling Analysis of Columns

Abstract

A consistent theoretical investigation of geometrically nonlinear creep buckling behavior of structures is presented. The study is based on the analysis of eccentrically compressed viscoelastic columns with the material properties described in terms of linear integral operators of the convolution type. The nonlinear solution is obtained by means of the quasi‐elastic method. Subsequently, the linear solution is derived as a special case using the assumptions of the small deformation theory. The analysis involves materials with both limited and unlimited creep behavior. It is observed that in the case of limited creep there is a safe load limit below which the creep buckling process stabilizes in time. The nonlinear and linear creep buckling characteristics are derived and compared for two viscoelastic material models and various magnitudes of the load and the eccentricity parameters. On the basis of these results applicability of the geometrically linear theory is examined and the question is raised as to the usefulness of the critical time criterion in terms of infinite deformations. The derived results are compared with those of previous studies.