Design and Testing of a Piezoelectrically Driven Airspike System on a .40 Cal Supersonic Projectile

This paper investigates the feasibility of using a piezoelectrically driven airspike system as a method of flight control on .40 caliber supersonic projectiles. The paper begins with a description of airspikes and a summary of their history in missiles and munitions. The paper then describes the piezoelectric actuation system and models its unloaded characteristics using bending beam theory. When the airspike is deflected, the axial force acting upon the airspike is shifted so that it no longer goes through the center of gravity and creates a pitching moment. This allows the bullet to create a pitching moment which can control the projectile. A basic aerodynamic analysis was done on the projectile, and subsequent wind tunnel tests through Mach 2.5 were done to prove this data. Bench top tests were also done on the system to determine the relationship of voltage to deflection of the airspike. The paper also includes considerations for setback, setforward and balloting. The paper includes a finite element analysis for the setback acceleration. The paper concludes with a system design of a beam rider projectile and simulates the trajectory of the projectile.