Nonlinearity parameter can be used for the estimation of the gas void fraction in gassy sand sediment. If two primary acoustic waves of different frequencies are incident on gassy sediment, nonlinear acoustic waves can be strongly generated at the difference frequency of the primary frequencies. Nonlinearity parameter of gassy sediment is related to the gas void fraction provided the primary fr...

Mechanical responses of nanoporous Cu samples under various loading conditions are investigated by molecular dynamics simulations. Effects mode, initial void size, temperature, and distribution analyzed. The simulations show that the collapse time uniaxial compression is about three times triaxial compression, rate increases as temperature rises. Dislocation nucleation found to stimulate void. ...