Dynamic stiffness for lateral buckling

Abstract

The dynamic stiffness method can predict an infinite number of natural modes of a structural system by means of a finite number of coordinates. It has been successful for dynamic structural analysis under the influence of constant axial force. The influence of constant moment is considered here and the instability of the plane form of the cross-section of a thin beam member is of particular interest. It is found that the constant moment softens the flexural modes and hardens the torsional modes. As a result, the characteristic curve can be concave or convex.