Perturbation of Initial Stability of an FSAPDS Projectile

Abstract

For a spinning projectile, the initial stability condition is 2 = 1+ (4 K 3 / K 2 2 ) > 0. In the present study, this condition has been modified for the malalignments arising due to pressure gradient and damping moment for an FSAPDS projectile. The equations of motion are established for the first phase of motion. A mathematical model for the first phase of motion has been developed. The effect of perturbation on the trajectory and stability of motion are discussed. It is proved that if 3 K (a parameter appearing due to perturbation) (-K 2 2 2 /4 ), the initial stability of motion will breakdown.

Motion Analysis during Sabot Opening Process

“…The propellant gases following the projectile, exert pressure on the projectile and affect its trajectory and stability. The effect of these forces has been discussed in the earlier work by the authors 2 .…”

“…The stability of the projectile motion in phase I has been discussed with modified stability parameter and it was observed that the motion remains stable due to perturbation caused by pressure gradient and damping moment 2 . The modified stability parameter has been discussed due to shock wave and mechanical forces exerted on the projectile body.…”

Modelling of Shockwave Force and its Effect during Sabot Discard Process

“…The equations for stability in projectile-fixed frame are the same as those in phase II 2 . The changed values of K i (i=1,2,3,4,5,6) modified the stability parameter 13 .…”