Dynamic behavior of double cantilever beams subjected to impact

The dynamic plastic behavior of a double cantilever beam system subjected to impact by a rigid mass at their tips is studied. Three approaches are adopted: a rigid, perfectly plastic (r.p.p) complete solution, a mode an elastic, perfectly plastic (e.p.p) solution' based on non-linear beam theory using the Dyna3D finite element code. In the complete solution based on the r.p.p. idealization, the dynamic response of the system comprises three successive phases, which are characterized by different sets of plastic hinges in the system and expressed in closed analytical forms. The mode solution based on the r.p.p. idealization is presented in a much simpler form. Particular attention is paid to the partitioning of the dissipation of the total input energy between the two beams. Numerical examples are given to demonstrate the influence of some of the structural parameters on the energy partitioning. In particular, the results obtained from the three approaches are compored, and the validity of the r.p.p. models in predicting the energy partitioning between the two beams is examined.