Post buckling analysis of imperfect nonlinear viscoelastic columns

The post buckling behavior of imperfect columns made of a nonlinear viscoelastic material is investigated. The material is modeled according to the Leaderman representation of nonlinear viscoelasticity. Solutions are developed to calculate the growth of the initial imperfection in time and within the elastica. The numerical results show that unlike the case of the post-buckling analysis of linear elastic or viscoelastic materials, here the ratio of h/I plays an important part in the structure response. It is shown that the post-buckling behavior of columns made of nonlinear viscoelastic materials is qualitatively and quantitatively better than in the linear viscoelastic case. Conclusions concerning creep buckling within the small deflection theory are also presented.