SPECIAL CASES IN STUDY OF ANOMALOUS DYNAMIC ELASTIC-PLASTIC RESPONSE OF BEAMS BY A SIMPLE MODEL

Special simplified forms of a single degree of freedom model are used to study anomalous clastic-plastic behavior of fixed-ended beams subjected to short pulse loading. Here the "anomalies" referred to are unexpected sensitivites and counter-intuitive predictions computed for the permanent deflection. The special cases treated are: (1) wholly clastic behavior in the recovery motion, following clastic-plastic deformation in the swing to the first Peak deflection: and (2) momentless behavior of the "beam" model, corresponding to vanishing thickness. Used with diagrams of energy changes. these help to clarify the general response and to show the links with some related analyses in the recent literature.