Abstract
Abstract
The air-blast response of a sacrificial cladding consisting of a cellular material with a front face-plate is investigated. The cellular material is sandwiched between a rigid face-plate and a rigid support. The support represents the structure that is to be protected. The air blast is assumed to be an exponentially decaying pulse. The cellular material is idealised as rigid, perfectly-plastic, locking and the deformation is governed by the propagation of a compaction (shock) wave travelling through the material. A second order nonlinear ordinary differential equation is derived to predict the displacement of the face-plate and the compression of the cellular layer by coupling the reflected over-pressure with the stresses at the interface between the face-plate and the cellular material.
The cellular material may attenuate or enhance the shock transmitted to the structure. Extensive simulations are carried out to define the attenuation/enhancement boundary for a range of initial peak pressures and cladding parameters. Herein, enhancement is considered to occur if the shock front reaches the support. A new method of accounting for fluid–structure interaction (FSI) is derived. The predictions are compared to those with no FSI as well as an existing model that accounts for the FSI effect, but for a free-standing plate.
The air-blast response of a sacrificial cladding consisting of a cellular material with a front face-plate is investigated. The cellular material is sandwiched between a rigid face-plate and a rigid support. The support represents the structure that is to be protected. The air blast is assumed to be an exponentially decaying pulse. The cellular material is idealised as rigid, perfectly-plastic, locking and the deformation is governed by the propagation of a compaction (shock) wave travelling through the material. A second order nonlinear ordinary differential equation is derived to predict the displacement of the face-plate and the compression of the cellular layer by coupling the reflected over-pressure with the stresses at the interface between the face-plate and the cellular material.
The cellular material may attenuate or enhance the shock transmitted to the structure. Extensive simulations are carried out to define the attenuation/enhancement boundary for a range of initial peak pressures and cladding parameters. Herein, enhancement is considered to occur if the shock front reaches the support. A new method of accounting for fluid–structure interaction (FSI) is derived. The predictions are compared to those with no FSI as well as an existing model that accounts for the FSI effect, but for a free-standing plate.
Original language | English |
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Pages (from-to) | 64-70 |
Number of pages | 7 |
Journal | International Journal of Mechanical Sciences |
Volume | 91 |
Early online date | 20 Apr 2014 |
DOIs | |
Publication status | Published - Feb 2015 |
Bibliographical note
Acknowledgement:The second author is grateful for the support provided by Lloyd׳s Register Foundation (LRF) to The Lloyd׳s Register Foundation Centre for Safety and Reliability Engineering at the University of Aberdeen. LRF supports the advancement of engineering-related education, and funds research and development that enhances safety of life at sea, on land and in the air.
Keywords
- cellular material
- blast response
- fluid structure interaction (FSI)