NONLINEAR DYNAMIC BUCKLING OF MULTI-DOF STRUCTURAL DISSIPATIVE SYSTEMS UNDER IMPACT LOADING

The nonlinear dynamic buckling characteristics of multi-degree-of-free dom (MDOF), dissipative systems under impact loading are investigated. A fully plastic impact due to a striking body falling freely from a g iven height is postulated. The initial velocities of the system immedi ately after impact are determined analytically by applying the law of impulse momentum. The resulting response is governed by autonomous hig hly nonlinear ordinary differential equations (O.D.E.) which can be in tegrated only numerically. Instead, a qualitative analysis based on en ergy criteria is performed which allows to readily establish approxima te dynamic buckling loads, very good for structural design purposes, a s well as lower and upper bound dynamic buckling estimates for step lo ading and impact loading with given initial momentum. The efficiency a nd reliability of the proposed method is comprehensively demonstrated through numerous examples of two- and three-degree-of-freedom models. Copyright (C) 1996 Elsevier Science Ltd.