DYNAMIC ELASTIC-PLASTIC BUCKLING PHENOMENA IN A ROD DUE TO AXIAL IMPACT

Dynamic elastic-plastic buckling phenomena which might develop in a ro d from an axial impact loading are studied in order to identify the co nditions for quasi-static behaviour. A discrete model for dynamic elas tic plastic buckling, which retains the axial and the lateral inertia forces, is proposed, and the relationship between the model parameters and the characteristics of an actual structure is given. Examples of different external loadings and boundary conditions are considered in order to clarify the influence of elastic-plastic axial wave propagati on on the buckling process. The critical time for the initiation of bu ckling is obtained and the post-buckling behaviour of the model is ana lysed. Particular attention is paid to the role of the striking mass o n the characteristics of the buckling process and on the development o f the buckling shape. The numerical study reveals that the inertia of the striking mass affects considerably the development of the buckling shape causing different patterns of axial strain distributions at the initiation of buckling. The comparisons which are made between the mo del predictions and some previously published experimental data show t hat the buckling process is governed by the impact velocity as well as by the external loading history provided by the experimental techniqu e. Copyright (C) 1996 Elsevier Science Ltd.