An ANSYS-Based Approach for Nonlinear Dynamic Stability Analysis

Abstract

Study on dynamic stability of structure is a hot subject in the fields of engineering mechanics, but its basic theory and analytical method still need to be further improved. This paper improved the current method for dynamic stability analysis called “dynamic eigenvalue method”, and the method for nonlinear dynamic stability analysis based on ANSYS platform is proposed. A long column under harmonic loads is taken as the research objective, dynamic eigenvalues affected by the load frequency, load amplitude and damping ratio are studied. Results show that, the increasing of load frequency or dynamic load amplitude will lead to the increase of maximum dynamic eigenvalue and decrease of minimum dynamic eigenvalue, which is not beneficial to dynamic stability of structure. The increasing of damping ratio will lead to the decrease of maximum dynamic eigenvalue and increase of minimum dynamic eigenvalue, this make the dynamic eigenvalue more stable. Therefore, the high damping is beneficial to dynamic stability of structure.