Abstract
Based on a rigid-viscoplastic constitutive relation and a four-hinge model, this paper analyses the large deformation process of a typical ‘velocity sensitive’ energy-absorbing structure proposed by Calladine and English [Int. J. Mech. Sci.26, 689–701 (1984)]. By neglecting elastic effects, our plastic impact model shows that the velocity sensitivity is closely related to the instantaneous energy loss at the moment of impact, and that the mass ratio plays a principal role in this dynamic process. To examine this model, computing results are given and compared with the experimental ones reported by Calladine and English, while the significant effect of the ‘initial geometrical imperfection’ on the ‘velocity sensitivity’ is emphasized.