Impulse Plug Measurements of Blast Reflected Impulse at Close Range

Nansteel, M.; Veldman, Roger L.; Chen, Charles Chih-Tsai; Lawrence, William

doi:10.1007/978-1-4614-4235-6_60

Cited by 5 publications

(5 citation statements)

References 2 publications

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“…Since the development of the KB predictive method there have been efforts to experimentally measure the blast load in extreme near-field conditions. One method involves measuring the residual momentum of -and hence inferring the impulse imparted to -small, rigid metal plugs embedded within a larger target surface [7,8], however this approach cannot be used to give a temporal description of the blast load. An alternative, developed in 1914 by Bertram Hopkinson, is the apparatus now known as the Hopkinson pressure bar (HPB) [9], consisting of a length of cylindrical bar which propagates an elastic stress pulse along its axis to be recorded by sensitive equipment situated a safe distance from the loaded end.…”

Section: Literature Reviewmentioning

confidence: 99%

Experimental Measurement of Specific Impulse Distribution and Transient Deformation of Plates Subjected to Near-Field Explosive Blasts

et al. 2018

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The shock wave generated from a high explosive detonation can cause significant damage to any objects that it encounters, particularly those objects located close to the source of the explosion. Understanding blast wave development and accurately quantifying its effect on structural systems remains a considerable challenge to the scientific community. This paper presents a comprehensive experimental study into the loading acting on, and subsequent deformation of, targets subjected to nearfield explosive detonations. Two experimental test series were conducted at the University of Sheffield (UoS), UK, and the University of Cape Town (UCT), South Africa, where blast load distributions using Hopkinson pressure bars and dynamic target deflections using digital image correlation were measured respectively. It is shown through conservation of momentum and Hopkinson-Cranz scaling that initial plate velocity profiles are directly proportional to the imparted impulse distribution, and that spatial variations in loading as a result of surface instabilities in the expanding detonation product cloud are significant enough to influence the transient displacement profile of a blast loaded plate.

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Section: Literature Reviewmentioning

confidence: 99%

Experimental Measurement of Specific Impulse Distribution and Transient Deformation of Plates Subjected to Near-Field Explosive Blasts

et al. 2018

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“…Alternatively, experimental methods can be used to directly measure near-field reflected specific impulse and specific impulse distributions, for example, impulse plugs (Huffington and Ewing 1985;Nansteel et al, 2013), Hopkinson pressure bars (Cloete and Nurick, 2016;Edwards et al, 1992;Piehler et al, 2009, Rigby et al, 2015aTyas et al, 2016), and flush-mounted pressure gauges (Aune et al, 2016). Near-field blast load measurements are onerous for a number of reasons.…”

Section: Introduction and Contextmentioning

confidence: 99%

Predicting specific impulse distributions for spherical explosives in the extreme near-field using a Gaussian function

Pannell

Panoutsos

Cooke

et al. 2021

International Journal of Protective Structures

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Accurate quantification of the blast load arising from detonation of a high explosive has applications in transport security, infrastructure assessment and defence. In order to design efficient and safe protective systems in such aggressive environments, it is of critical importance to understand the magnitude and distribution of loading on a structural component located close to an explosive charge. In particular, peak specific impulse is the primary parameter that governs structural deformation under short-duration loading. Within this so-called extreme near-field region, existing semi-empirical methods are known to be inaccurate, and high-fidelity numerical schemes are generally hampered by a lack of available experimental validation data. As such, the blast protection community is not currently equipped with a satisfactory fast-running tool for load prediction in the near-field. In this article, a validated computational model is used to develop a suite of numerical near-field blast load distributions, which are shown to follow a similar normalised shape. This forms the basis of the data-driven predictive model developed herein: a Gaussian function is fit to the normalised loading distributions, and a power law is used to calculate the magnitude of the curve according to established scaling laws. The predictive method is rigorously assessed against the existing numerical dataset, and is validated against new test models and available experimental data. High levels of agreement are demonstrated throughout, with typical variations of <5% between experiment/model and prediction. The new approach presented in this article allows the analyst to rapidly compute the distribution of specific impulse across the loaded face of a wide range of target sizes and near-field scaled distances and provides a benchmark for data-driven modelling approaches to capture blast loading phenomena in more complex scenarios.

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“…Veldman et al [6] concluded that the tourmaline transducers may be useful for measuring pressure and impulse at small charge standoff provided that a sufficiently large number of tests are performed to reduce the measurement uncertainty to an acceptable level. The impulse plug technique described herein and in Nansteel et al [7] is found to result in much lower data scatter than transducer methods for standoffs in and around the near-field blast zone. Further descriptions of the measurements done in this area up until the early 1970's can be found in Baker [8].…”

Section: Introductionmentioning

confidence: 63%

Impulse Plug Measurements of Blast Reflected Impulse at Close Range

Nansteel

Veldman

Chen

et al. 2013

Propellants Explo Pyrotec

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A series of blast tests is described in which blast impulse is measured by an impulse plug technique for spherical explosive charges. In this approach the reflected blast impulse delivered to a hardened bullet-shaped steel plug is determined from a measurement of the plug terminal momentum. Plug velocity is measured by a high-speed, high-resolution video camera operating at 20,000 frames per second. Spherical C4 charges are studied for varying charge weight and charge-to-plug standoff distance. Tested standoffs include the demanding near-field blast zone within which pressure measurement by transducer is ex-tremely difficult or impossible. Results are compared with previous studies made using transducer and impulse plug methods for both C4 and Pentolite charges. The present data for half-pound C4 charges are in good agreement with much earlier impulse plug data for spherical Pentolite in the near-field region, however, differences of up to 26 % are noted with more recent transducer measurements for C4 just beyond the near-field zone. Test results are also compared with hydro-code simulations of the plug response.

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Impulse Plug Measurements of Blast Reflected Impulse at Close Range

Cited by 5 publications

References 2 publications

Experimental Measurement of Specific Impulse Distribution and Transient Deformation of Plates Subjected to Near-Field Explosive Blasts

Experimental Measurement of Specific Impulse Distribution and Transient Deformation of Plates Subjected to Near-Field Explosive Blasts

Predicting specific impulse distributions for spherical explosives in the extreme near-field using a Gaussian function

Impulse Plug Measurements of Blast Reflected Impulse at Close Range

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