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Blast and Ballistic Testing Techniques
Published in Paul J. Hazell, Armour, 2023
A very simple form of blast simulator involves the use of a shock tube. In simple terms, a shock tube consists of a cylindrical section of the tube part which contains a high-pressure region separated from an ambient-pressure region with a diaphragm. Once the diaphragm is burst by the operator, the high-pressure gas expands rapidly thereby compressing the air in the ambient-pressure region. Thus, a blast wave is simulated. However, it is somewhat more complex than is outlined here, and careful attention needs to be applied to the ambient-pressure tube so that reflections of surfaces do not provide a false pressure–time profile.
Ohio State Gas Turbine Lab
Published in Maurice L. Adams, Rotating Machinery Research and Development Test Rigs, 2017
A shock tube short-duration test starts with the high-pressure driver gas rapidly expanding as a result of a controlled rupturing of the primary diaphragm, creating a shock wave, Figure 7.2. The test gas is instantly compressed and thus heated to a high temperature by incident and reflected shock waves. Clearly, this is a sudden energy conversion phenomenon that transfers initially stored driver gas pressure energy to the test gas, yielding the high-temperature/high-pressure conditions in the test chamber where data is acquired by sensors. A wide range of temperatures and pressures are achievable, that is, 600–4000 K and 0.1–1000 atm.
Wind Tunnels
Published in Ethirajan Rathakrishnan, Instrumentation, Measurements, and Experiments in Fluids, 2020
A shock tube is a device to produce a high-speed flow with high temperatures, by traversing a normal shock wave which is generated by the rupture of a diaphragm separating a high-pressure gas from a low-pressure gas.
A Shock Tube Study of Ethylene/Air Ignition Characteristics over a Wide Temperature Range
Published in Combustion Science and Technology, 2020
Zhongjun Wan, Zujun Zheng, Yijun Wang, Dexiang Zhang, Ping Li, Changhua Zhang
The experiments were carried out in a stainless steel shock tube with a constant internal diameter of 10.0 cm. The shock tube is comprised of a 6.0 m driver and a 5.0 m driven sections separated by a polycarbonate diaphragm section. For high-temperature measurements whose ignition delay times are shorter than 2 ms, the pure helium (>99.99% purity) was used as the driver gas. Whereas the tailored technique using helium/argon (>99.99% purity) mixtures as the driver gas was used for low-temperature measurements, the work times can be extended up to 15 ms. Before each experiment, the remained gas of shock tube was evacuated down to 10 Pa through the vacuum pump. Ethylene/air (21% O2 and 79% N2) mixtures were prepared in a 40 L stainless steel tank and mixed at least 3 h prior to experiments.
An experimentally validated numerical method for investigating the air blast response of basalt composite plates
Published in Mechanics of Advanced Materials and Structures, 2020
Sedat Süsler, Hasan Kurtaran, Halit S. Türkmen, Zafer Kazancı, Valentina Lopresto
There are also several studies on laminated composite plates subjected to blast load. To name a few, Kazancı [32] reviewed many papers on blast loaded laminated composite plates including solution theories, numerical methods, and various types of time-dependent external blast pulse models. Kazancı and Mecitoğlu investigated damped vibrations of a clamped laminated plate [33] and undamped vibrations of simply supported laminated plates [34] under blast loading. Upadhyay et al. [35] analysed nonlinear dynamic response of laminated composite plates subjected to different pulse loadings by using third-order shear deformation plate theory. Kazancı [36] summarized computational methods to predict the nonlinear dynamic response of laminated flat and tapered composite plates subjected to blast load. Türkmen and Mecitoğlu [37] investigated the structural response of a stiffened laminated composite plate subjected to blast load experimentally. Baştürk et al. [3] studied an analytical model for predicting the deflection of laminated basalt composite plates under several dynamic loads using FDM. Baştürk et al. [4] also investigated the damping effects for a hybrid laminated composite plate subjected to blast load. Susler et al. [38] focused on nonlinear dynamic behaviour of laminated plates with linear variable thickness subjected to blast load using classical lamination theory (CLT) and FDM. Duc et al. [39] analysed nonlinear dynamic response and free vibration of functionally graded thick plates subjected to blast load and temperature increment using higher-order shear deformation theory. In studies about blast loaded laminated plates above, only theoretical results are obtained. Rajamani and Prabhakaran [40] studied the transient response of E-glass reinforced composite plates with and without central circular holes to blast loading theoretically and experimentally and obtained peak dynamic strains. Besides, shock tube setups are generally used in air blast experimental studies instead of blasting explosive chemical materials like TNT to test composite structures like plates and shells. Some of these studies investigated the nonlinear dynamic behaviour of laminated and sandwich composite plates in elastic range [37], [40], [41]. The others focused on damage analysis and blast resistance of different types of composite plates [42], [43]. There have been no studies that investigated experimentally validated dynamic behaviour of laminated basalt/epoxy plates under the effects of air blast loading.