Shock Induced Stress Wave Propagation in Sand

Experiments were conducted to investigate air shock-induced stress waves in bars of dry sand confined under constant lateral pressure. Stresses were measured at a number of cross sections by means of embedded gages. Information was obtained on wave velocity, peak stress attenuation, and reflected stresses. The observed change in wave shape was bending over of the front and a lengthening of the period. It was demonstrated that the nonlinear, inelastic theory based on the static stress-strain characteristics of the sand could be used to predict all of the significant features of the observed wave, but to provide correct quantitative prediction of change in shape and wave velocity it was necessary to hypothesize some time-dependent stress-strain behavior.