EFFECT OF MULTIPLE COLLAPSE MODES ON DYNAMIC FAILURE OF STRUCTURES WITH STRUCTURAL INSTABILITY

In this paper, in order to establish the dynamic failure criteria of multi-degree structures with structural instability, the true dynamic ultimate strength of two-degree flexural systems with structural instability as well as the response parameters which determine these ultimate strength are investigated numerically. In particular, effects of the collapse mode shape on the dynamic ultimate strength and the amount of energy are examined.As a result, it is revealed that the effective input energy governs the dynamic ultimate state of two-degree systems with structural instability and that the input energy depends on the collapse mode shape.Furthermore, the method of estimating the effective input energy of two-degree systems is proposed from the results of the single-degree systems.