Contact force-displacement relationship for geotechnical granular medium under stress wave

In order to describe the force-displacement relationship of geotechnical granular medium under stress wave, an elastoplastic contact model of low velocity impact is derived according to the theories of contact mechanics and rigid dynamics, in which the local nonlinear dynamic interaction of granulae is considered and the coefficient of restitution is introduced. Then the rationalities of the contact model are verified by several examples. The results show that the complicated incremental formula and the problem of nonlinear dynamic contact have been avoided in the contact model; and the effects of many factors such as impact velocity, physico-mechanical property, geometrical characteristic and exterior physical condition of the granulae during contact are taken into account; therefore the contact model is convenient for engineering application.