Virginia Tech Shock Tube Research Facility
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Table of Contents
Overview
The Virginia Tech Shock Tube Research Facility is a unique academic resource equipped with a large-scale gas-detonation blast simulator and state-of-the-art high-speed data acquisition and camera systems. Located at the Thomas M. Murray Structures Laboratory in Blacksburg, Virginia, the blast simulator is designed to produce high pressure blast waves that accurately simulate those generated by accidental explosions and terrorist bombings. It us used to evaluate the resilience of structural and non-structural building components subjected to extreme blast loads, including loadbearing elements, walls, windows, and exterior cladding. Other applications include fundamental study of material behavior under high strain rate loading and development and validation of new structural systems for enhanced energy dissipation.
Description
The blast simulator is designed to generate high pressure, short-duration shock waves similar to those produced by the detonation of high explosives. The equpoment consists of three main components:
- Detonation chamber:
- Transition sections, for maintaining shock wave planarity.
- Reaction frame for mounting test specimens.
(i) a detonation chamber responsible for generating blast energy through the detonation of an oxy-fuel mixture; (ii) a transition section for maintaining shock wave planarity; and, (iii) a reaction frame for mounting test specimens. Planar and non-planar test specimens up to 10’ × 10’ square may be mounted to the reaction frame for simulated blast testing. A photograph of the shock tube is shown in Figure A.2. The shock tube is capable of generating reflected blast pressures in excess of 28 psi with positive phase durations between 15 and 40 ms. For reference purposes, this represents an equivalent hemispherical detonation of 46,000 lbs of TNT located 330’ from the target based on Kinnery-Bulmash scaled distance relationships (Jacques 2013)
Operating Characteristics
The Virginia Tech Shock Tube is designed to generate high pressure, short-duration shock waves similar to those produced by the detonation of high explosives. The operating range is defined in terms of peak reflected pressure, reflected impulse, and positive phase duration. The magnitude of
The gas-detonation driven shock tube has been demonstrated to produce planar shock waves and generate repeatable pressure-impulse combinations at the location of the test frame.
Specifications
The construciton and performance specifications of the blast facility are as follows:
- 30 psi (200 kPa) applied reflected pressure
- 5-20+ millisecond positive phase duration
- Far-field explosive pressure waveform
- Oxy-fuel gas-detonation drive
- Versatile specimen mounting frame, 10 ft x 10 ft (3.0 m x 3.0 m)
- Blast pressure flow area, 8 ft x 8 ft (2.4 m x 2.4 m)
- Footprint: 67 ft x 12 ft x 14 ft (20 m x 3.6 m x 4.2 m)
- Mass: 75,000+ lbs (34,000+ kg)
- Remote filling, firing, and operating station
- Computer controlled gas filling & metering
Instrumentation
A eighteen-channel high-speed digital data acquisition system recording at 800,000 samples per second per channel is available to measure the blast pressure profile and monitor the displacements, strains, reactions and accelerations of the test specimens. The system is triggered when one of the pressure sensors records a pressure in excess of a predetermined threshold. High-speed HD video cameras capturing 2,000 frames per second are employed to record the response of the test specimens from various vantage points, depending on the research needs the project. A wide array of contact and non-contact displacement transducers, piezeoresistive pressure gauges, accelerometers, load cells, and other instruments are available for measurement sensing.