On the lateral collapse of an identical pair of cylinders

Superplastic tin±lead alloy, which has a sensitivity to strain rate in the range of (10 ÿ5/s±10 ÿ3/s), serves as a representative material to simulate the dynamic lateral collapse of an identical pair of hollow cylinders made from a classical engineering material as an energy dissipative system. Actual superplastic cylinders of various inside/outside diameter ratios (R ˆ di=do) ranging from 0±0.473 are tested under di€erent strain rates (_e ) varying from 10 ÿ5/s± 10 ÿ3/s. The capacity of this system to absorb energy is governed by certain parameters. These parameters are the amount of the plastic strain and its rate, and the geometry of the employed cylinders. To understand the mechanism of deformation of this system at di€erent strain rates, a successful trail is developed using di€erent plasticine colored layers in the form of cylinders. A simple mathematical model is proposed to describe the mechanical behavior of these structures, simulating the dynamic lateral compression of rate-sensitive metallic cylinders as related to their use in an energy absorbing device. Predicted responses are in good agreement with experimental results