Abstract: In order to provide an accurate mechanical environment of exterior ballistics for fuze safety design, a mathematical model of the motion of unrotating projectile around the center of mess in exterior ballistics is established based on the rigid body dynamics. The formulas of the radial and axial components of the inertial force acting on fuze parts, which is caused by the motion of non-rotating projectile around the center of mess, are derived. The results show that the ratio of the maximum radial component of the inertial force to its maximum axial one is the largest nutation angle. And the radial component closes to zero when the axial component reaches to the maximum, and vice versa. So the frictional force caused by this inertial force can be ignored during the analysis for motion of fuze parts caused by the same inertial force.

Key words: ordnance science and technology, fuze design, rigid body dynamics, exterior ballistics