Abstract: The contact conditions of cuboid fragments penetrating into gelatin and the pressure distribution assumptions on the contact surface are established to study the motions of the fragments. On the basis of the assumptions, a six-DOF motion model of the fragments is deduced from the mass center motion equations and Euler motion equations. The change rules of translational displacements and Euler angles with time are obtained by solving the motion equations with Runge-Kutta method. Two cuboid fragments are tested in the experiments. The attack angles, horizontal displacements and vertical displacements are captured by using a high-speed camera. The dynamic coefficient in the motion model is obtained by using try-out method. The calculated results show that the theoretical displacements agree well with the experimental data.

Key words: ordnance science and technology, pressure distribution, cuboid fragment, gelatin