Development of a Biaxial Interface Stress Transducer for High Overpressures

Period of Performance: 01/01/1987 - 12/31/1987

$344K

Phase 2 SBIR

Recipient Firm

Applied Research Assoc., Inc.
4300 San Mateo Blvd. NE, Suite A-220
Albuquerque, NM 87110
Principal Investigator

Abstract

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 IF CONFINED TO OVERPRESSURES MUCH SMALLER THAN THOSE CURRENTLY OF INTEREST. UNDER THE PHASE I EFFORT, A PROTOTYPE BIAXIAL INTERFACE STRESS TRANSDUCER (BIST) CAPABLE OF MEASURING INTERFACE NORMAL AND SHEAR STRESSES AT VERY HIGH PRESSURES WAS DEVELOPED. BIST IS A MODIFICATION OF THE TRIAXIAL INTERFACE STRESS TRANSDUCER (TIST) DEVELOPED BY NMERI FOR LOW OVERPRESSURES. TWO PROTOTYPE TRANSDUCERS WERE FABRICATED AND EVALUATED IN LABORATORY TESTS THAT INCLUDED CALIBRATION, CROSS-AXIS SENSITIVITY, ACCELERATION SENSITIVITY, AND STATIC INTERFACE SHEAR TESTS. TRANSDUCER PERFORMANCE WAS VERY GOOD UNDER THESE TESTS AND CONTINUED DEVELOPMENT OF THE GAGE IS RECOMMENDED. THE PHASE II EFFOROT PROPOSES TO CONTINUE DEVELOPMENT AND TESTING OF BIST. THE EFFORT WILL ADDRESS DESIGN MODIFICATIONS TO THE TRANSDUCER TO IMPROVE THE EASE OF ASSEMBLY AND TO CORRECT IDENTIFIED DEFICIENCIES. EVALUATION OF THE GAGE IN THE LABORATORY WILL CONTINUE AND BE EXPANDED TO INCLUDE DYNAMIC INTERFACE SHEAR TESTS. FIELD TESTING OF THE GAGE IS ALSO PROPOSED TO EVALUATE THE GAGE PERFORMANCE/SURVIVABILITY AT VERY HIGH PRESSURE.