SUPERVOLTAGE NDE TECHNIQUES FOR LARGE AEROSPACE STRUCTURES

INNOVATIVE TECHNICAL APPROACHES FOR DETECTING AND CHARACTERIZING BULK DEFECTS IN LARGE AEROSPACE STRUCTURES ARE URGENTLY NEEDED. THE INTEGRITY OF BONDED SURFACES IN THE Y-JOINT AND RESTRICTER REGIONS OF LARGE SOLID BOOSTERS, SUCH AS TITAN 34D MOTORS, IS A GOOD EXAMPLE OF A CRITICAL APPLICATION WITHOUT A DEPENDABLE INSPECTION METHOD. IN FULLY ASSEMBLED T34D MOTORS, THESE ZONES, WHICH ARE THE MOST CRITICAL TO SYSTEM RELIABILITY, ARE ALSO THE MOST INACCESSIBLE TO STANDARD EXAMINATION TECHNIQUES. A COMPUTER TOMOGRAPHY (CT) SYSTEM WOULD IN THEORY BE ABLE TO PROVIDE AN INSPECTION CAPABILITY WHICH COULD ADDRESS THIS CRUCIAL QA PROBLEM, BUT THE SIZE AND OPACITY OF SOLID BOOSTERS PRECLUDES THE USE OF EVEN THE MOST ENERGETIC RADIATION SOURCES USED TO DATE. AN INNOVATIVE CT CONCEPT EMPLOYING BREMSSTRAHLUNG RADIATION WITH PEAK ENERGIES TWO TO FOUR TIMES AS GREAT AS THE HIGHEST EVER USED FOR CT IS PROPOSED. DESIGNATED SUPERVOLTAGE CT, THE NOVEL INSPECTION TECHNIQUE WOULD PROVIDE A UNIQUE CAPABILITY FOR DETERMINING THE IN-SITU INTEGRITY OF BONDED STRUCTURES IN LARGE AEROSPACE COMPONENTS. A SERIES OF MEASUREMENTS TO EVALUATE THE KEY TECHNICAL UNCERTAINTIES IN THE APPROACH AND TO THUS MAKE THE FIRST DEFINITIVE DETERMINATION OF EFFICACY OF THE CONCEPT IS PROPOSED.