Pressure Amplification Due to Clothing
Abstract
Initial tests of shock wave impact on a surface covered with a layer of textile and positioned a short distance in front of it have shown that the pressure on the surface could be significantly higher than what would be experienced with no covering. The amplification of pressure is a function of textile type. It is suggested that the two mechanisms responsible for this effect are as follows: Firstly, on shock impact with the textile layer, part of the wave is reflected and part is transmitted. The transmitted wave then reflects off the underlying surface and part of this reflected wave is re-reflected back from the textile onto the surface raising the pressure further. A number of such reflections between the textile and the surface can raise the pressure further. Secondly, the textile layer is initially accelerated towards the wall, acting as a piston and pressurizing the gas in the gap through a compression wave. A comprehensive study of these effects is reported on, using a wide variety of textiles, both for single and multiple layers, and for head-on and inclined shock impact. Amplifications of up to 400 per cent have been recorded, and amplification variations with permeability, specific mass, and number of layers determined. Some tests with a 10 mm backing layer of gelatin have also been conducted in order to obtain information on pressure propagation into this simulated body tissue. Loads due to physical impact of the textile with the surface are not examined.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2002
- Accession Number
- ADA408205
Entities
People
- B. W. Skews
- S. Bugarin
Organizations
- University of the Witwatersrand