Dynamic Economical Large Testing Apparatus--a Blast Pressure Loading Technique

摘要

A reduced scale experimental program was conducted to study a prototype air blast simulation concept referred to as Dynamic Economical Large Testing Apparatus (DELTA). Test structures as large as 13 ft in diameter could be tested in the prototype facility. The reduced scale test facility had a test area 54 in. in diameter. This program demonstrated the feasibility of the DELTA technique for a pressure range of 700 to 9,600 psi and a positive phase duration range of 1 to 30 msec. Various explosive configurations were examined and their pressure-time characteristics were determined. It was determined that, for a 1,000 psi magnitude pressure pulse with a duration greater than 10 msec, a distributed Primacord charge is desirable. If high-pressure (greater than 5,000 psi) short-duration (1 msec or less) dynamic pulses are desirable, then a concentrated or plane sheet explosive should be used. The reduced scale test facility was economically fabricated using conventional reinforced concrete construction techniques. The instrumentation work performed during the reduced scale tests indicated that, for pressures up to approximately 4,000 psi, currently available pressure gages could be used. For higher pressures, development of a piezoresistive bar gage is recommended. Near-surface stress measurements in concrete were made with concrete stress gages. Displacement of the test facility was measured by mutual inductance coil gages. All measurement techniques used in this research program proved feasible and further development is recommended. (Author)