HYPERVELOCITY COLLISION SCALING: THE THEORETICAL FOUNDATIONS

SPACE STRUCTURES REQUIRE PROTECTION FROM DISASTEROUS IMPACTS OF METEOROID AND MAN-MADE SPACE DEBRIS POPULATIONS. LIMITATIONS ON EXPERIMENTS CREATES A NEED FOR A THEORETICALLY-SOUND BASIS FOR EXTRAPOLATION TO FASTER AND LARGER IMPACTING PARTICLES. THIS RESEARCH WILL DEVELOP THE THEORETICAL FOUNDATIONS FOR THE POWER-LAW SCALING RELATIONS COMMONLY USED. THE PRIMARY BASIS FOR THOSE FORMS IS A SINGLE SCALAR MEASURE OF THE IMPACTING PARTICLE WHICH EXISTS BECAUSE THE MESAURES OF THE OUTCOME OF A COLLISION OCCUR AT TIME AND LENGTH SCALES LARGE COMPARED TO THOSE OF THE IMPACTING PARTICLE: THE EFFECTS ARE APPROXIMATELY THOSE OF A "POINT-SOURCE." POINT-SOURCE SOLUTIONS FOR REALISTIC EQUATIONS OF STATE INCLUDING DISSIPATION, PHASE CHANGE AND FINITE STRENGTH GIVE THE THEORETICAL BASIS AND THE CORRECT POWER EXPONENTS FOR SCALING LAWS. THE PHASE I EFFORT IS TO DERIVE POINT-SOURCE APPROXIMATE SOLUTIONS FOR COMMON METALS, AND TO DETERMINE THE RESULTING SCALING LAWS FOR IMPACTS INTO THICK TARGETS, IN TERMS OF THE EQUATION OF STATE PARAMETERS. THE PHASE II EFFORT WILL EXTEND THAT WORK INTO THE THIN TARGETS TYPICAL OF THE SPACE STATION AND OTHER SPACE STRUCTURES, USING THE THEORETICAL RESULTS AUGMENTED BY CODE CALCULATIONS AND RESULTS FROM LABORATORIES AND THE LDEF.