Papers by Keyword: Creep Buckling

Abstract: This paper analyses the creep buckling of viscoelastic rectangular plates under axial compression with initial deflections. A standard linear viscoelastic solid model is used and the von Karman nonlinear geometry equations are introduced in the governing equations. In order to obtain an accurate solution, the deflection function is expressed as a sinusoidal series with four terms rather than only one term in the computation. For the sake of discussing the effect of higher order modes on creep buckling of viscoelastic plate, we introduce the relative error of deflection function. By computational analyses, we get the relative error of deflection function under three different loads respectively. Through computational result, we know that the relative error of deflection function is not very small, especially near the four corners of the plate. So, the effect of high order modes on creep buckling of viscoelastic plate can not be ignored.

Abstract: One of the critical factors affecting the strength of steel columns at elevated temperatures is the influence of material creep. Under fire conditions, steel columns can exhibit creep buckling, a phenomenon in which the critical buckling load for a column depends not only on slenderness and temperature, but also on the duration of the applied load. This paper will propose a preliminary methodology to study the phenomenon of creep buckling in steel columns subjected to fire. Analytical solutions using the concept of time-dependent tangent modulus are developed to model time-dependent buckling behavior of steel columns at elevated temperatures. Results from computational creep buckling studies using ABAQUS^® are also presented, and compared with analytical predictions. Both analytical and computational methods utilize material creep models for structural steel developed by Harmathy, and by Fields and Fields. The analytical and computational results clearly indicate that accurate knowledge of material creep is essential in studying creep buckling phenomenon at elevated temperatures, and that neglecting creep effects can lead to potentially unsafe predictions of the strength of steel columns subjected to fire.