Accession Number:

ADA270467

Title:

Gas Gun Experiments to Determine Shock Wave Behavior in Snow: Methods and Data

Descriptive Note:

Corporate Author:

COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH

Report Date:

1993-07-01

Pagination or Media Count:

149.0

Abstract:

A laboratory study of the behavior of snow under shock wave loading and unloading conditions was conducted using a 200-mm-diameter gas gun to generate loading waves in snow samples with initial densities of 100 to 520 kg m-3 at temperatures of -2 to -23 deg C. Stress levels were 2 to 40 MPa. The response of snow to shock wave loading was measured as a function of distance from the impact plane using embedded stress gauges. Large impedance differences between snow and the stress gauges produced complex stress histories. A finite element model, along with a simple analytical model of the experiment, was used to interpret the stress histories. Snow deformation was not affected by initial temperature, but was found to be rate dependent. The initial density of the snow determined its pressure-deformation path. The pressure needed to compact snow to a specific final density increases with decreasing initial density. The release moduli increased nonlinearly from 50 MPa at a snow pressure of about 15 MPa to 2700 MPa at a snow pressure of about 40 MPa.... Attenuation, Porous ice, Shock wave propagation in snow, Experimental methods, Shock waves, Snow

Subject Categories:

  • Snow, Ice and Permafrost
  • Guns

Distribution Statement:

APPROVED FOR PUBLIC RELEASE