BIAXIAL INTERFACE STRESS TRANSDUCER FOR HIGH OVERPRESSURES - DEVELOPMENT

DEFINITION OF THE STRUCTURE-MEDIA INTERACTION (SMI) LOADS ON A BURIED STRUCTURE IS ONE OF THE LARGEST SOURCES OF UNCERTAINTY IN ANALYZING THE SURVIVABILITY OF STRATEGIC STRUCTURES. ADVANCEMENT OF THE STATEOF-THE-ART IN THE MODELING OF SMI BEHAVIOR IS HAMPERED BY A LIMITED DATA BASE WHICH IS CONFINED TO OVERPRESSURES MUCH SMALLER THAN THOSE CURRENTLY OF INTEREST. THIS EFFORT PROPOSES TO DEVELOP AND TEST A BIAXIAL INTERFACE STRESS TRANSDUCER (BIST) CAPABLE OF MEASURING INTER-FACE NORMAL AND SHEAR STRESSES AT VERY HIGH PRESSURES. THE PROPOSED GAGE WOULD BE A MODIFICATION OF THE TRIAXIAL INTERFACE STRESS GAGE (TIST) THAT IS CURRENTLY USED FOR LOW OVERPRESSURE ENVIRONMENTS. AS PART OF THE PROPOSED EFFORT, TECHNICAL ISSUES THAT HAVE ARISEN FROM APPLICATION OF THE TIST WILL BE INVESTIGATED. THESE ISSUES INCLUDE: (1) CROSS-AXIS ACCELERATION, (2) SUSCEPTIBILITY TO MOISTURE PENETRATION, (3) GAGE CALIBRATION, (4) GAGE OFFSETS, (5) DOWNSIZING THE GAGE, AND (6) DATA ANALYSIS AND INTERPRETATION. THE EFFORT WILL ALSO INVESTIGATE THE FEASIBILITY OF DEVELOPING A TEST FIXTURE TO MEASURE INTERFACE SHEAR IN SIMULATION DEVELOPMENT AND MATERIAL PROPERTY TESTS.