Novel Criterion for Identification of Dynamic Stability of Structures

Abstract:

In this paper, the differences between static instability and dynamic instability are explored with the aid of a nonlinear spring model. It is pointed out that the dynamic instability of structures can not be identified by the pseudo static stiffness criterion. The concept of intrinsic energy of system is then put forward and it is found that the essence of dynamic instability of structures lies in that the intrinsic energy surpasses the energy imported into the structure, where a novel criterion for the identification of dynamic instability of structures is proposed accordingly. The relevant numerical computations indicate that the proposed criterion can analyze and judge the dynamic instability of structures subjected to arbitrary dynamic loadings effectively.

Key words:dynamic stability; tangent stiffness; intrinsic energy; input energy; identification criterion