SHOCK FOCUSING IN SPIKE NOSE-TIPS

SPIKE NOSE-TIPS CAN GREATLY IMPROVE THE REENTRY PERFORMANCE OF ADVANCED REENTRY VEHICLES AND/OR ASSOCIATED PENETRATION AIDS. HOWEVER, EXPOSURE TO A NUCLEAR ENVIRONMENT CAN PRODUCE RADIA STRESSES WHICH CAN BE MAGNIFIED BY A FACTOR OF 10 OR MORE AS THESE STRESSES PROPAGATE TOWARD THE SPIKE AXIS. AN INNOVATIVE ANALYTIC TECHNIQUE IS PROPOSED WHICH YIELDS A CLOSED-FORMS SOLUTION FOR THE PEAK RADIAL STRESSES NEAR THE AXIS. THIS SOLUTION IS BASED ON FIRST PHYSICAL PRINCIPLES AND WILL COMPUTE THE RADIAL STRESS WITH A PRECISION DEPENDENT ONLY ON THE KNOWLEDGE OF THE MATERIAL PROPERTIES. THIS TECHNIQUE WILL PROVIDE A CLEAR PHYSICAL PICTURE OF THE SHOCK-FOCUSING PROCESS AND A DIRECT IDENTIFICATION OF KEY MATERIAL PROPERTIES AND DIMENSIONS WHICH AFFECT SURVIVABILITY.