Simple dynamic models of elastic–plastic structures under impact

✍ Scribed by K.Q. Wu; T.X. Yu

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 291 KB
• Volume: 25
• Category: Article
• ISSN: 0734-743X
• DOI: 10.1016/s0734-743x(01)00017-3

✦ Synopsis

The dynamic behaviour of elastic-plastic structures is much more difficult to predict in comparison with the corresponding quasi-static one because of complicated loading conditions and the effect of inertia. If the quasi-static structural and interface behaviour of a structure is specified, by assuming that its dynamic deformation mode is broadly similar to the quasi-static one and the material is strain-rate insensitive, two simple mechanical models, namely the stick model and non-stick model, are proposed in this paper to predict the dynamic response of the structure under a rigid-projectile impact. Each model contains two lumped masses and two inelastic springs. While spring represents the highly non-linear and inelastic mechanical property of the interface between the target structure and the striker, spring represents the elastic-plastic behaviour of the structure itself, with hardening, perfectly plastic or softening in the plastic range. With the complicated deformation history involving loading, unloading and reversed loading being taken into account, the dynamic response can be predicted by these models. A number of numerical examples are given to demonstrate the effects of the mass ratio, energy ratio, structural stiffness/local rigidity and the hardening/softening factor on the maximum and final deformations of the simple models. Finally, the validity of the models proposed for real structures is verified by the impact tests on simply supported beams.