The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
J. Kawakami - One of the best experts on this subject based on the ideXlab platform.
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Large-scale penetration test using a Drop Hammer
Rock Mechanics and Rock Engineering, 1997Co-Authors: Seisuke Okubo, Katsunori Fukui, J. KawakamiAbstract:In the present study, large-scale penetration tests using a wedge-type Drop Hammer were performed. The primary objective was to determine the penetration curve in a large-scale test. The force-penetration curve is well known to be approximately linear in small-scale tests. The secondary objective was to investigate the effect of Hammer size on the force-penetration curve. Laboratory tests have shown that the strength of a rock sample decreases with its size. Thus, the apparent rock strength during a Drop-Hammer test likely decreases in relation to the size of the Hammer.
R. Velmurugan - One of the best experts on this subject based on the ideXlab platform.
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Experimental and numerical investigations into collapse behaviour of thin spherical shells under Drop Hammer impact
International Journal of Solids and Structures, 2007Co-Authors: Narinder Kumar Gupta, N. Mohamed Sheriff, R. VelmuruganAbstract:Abstract A study of the collapse behaviour of hemi spherical and shallow spherical shells and their modes of deformation under impact loading are presented in this paper. Aluminium spherical shells of various radii and thicknesses were made by spinning. These were subjected to impact loading under a Drop Hammer and the load histories were obtained in all the cases. Three-dimensional numerical simulations were carried out for all the tested specimen geometries using LS-DYNA®. Material, geometric and contact nonlinearities were incorporated in the analysis. The uni-axial stress–strain curve for the material was obtained experimentally and was assumed to be piecewise linear in the plastic region. The results from impact experiments are used for the validation of the numerical simulations. Three distinct modes of deformation, namely local flattening, inward dimpling and formation of multiple numbers of lobes were analysed and influence of various parameters on these modes is discussed.
Seisuke Okubo - One of the best experts on this subject based on the ideXlab platform.
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Large-scale penetration test using a Drop Hammer
Rock Mechanics and Rock Engineering, 1997Co-Authors: Seisuke Okubo, Katsunori Fukui, J. KawakamiAbstract:In the present study, large-scale penetration tests using a wedge-type Drop Hammer were performed. The primary objective was to determine the penetration curve in a large-scale test. The force-penetration curve is well known to be approximately linear in small-scale tests. The secondary objective was to investigate the effect of Hammer size on the force-penetration curve. Laboratory tests have shown that the strength of a rock sample decreases with its size. Thus, the apparent rock strength during a Drop-Hammer test likely decreases in relation to the size of the Hammer.
Arash Gonabadi - One of the best experts on this subject based on the ideXlab platform.
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Experimental Investigation of Energy Absorption in Aluminum Sandwich Panels by Drop Hammer Test
Mechanics Materials Science & Engineering Journal, 2017Co-Authors: Mohammad Damghani, Arash GonabadiAbstract:This paper is aimed to study the behavior of sandwich panels made of Aluminum face sheet and Aluminum corrugated core under impact loading. Sandwich panels with square and triangular honeycombs of two different heights are constructed and the effect of honeycomb geometry on the level of absorbed energy as well as the panel strength are investigated. Drop Hammer apparatus by a cylindrical impactor with the weight of 25 kg is applied for exerting the impact. Acceleration, velocity, and displacement of impactor as well as the absorbed energy are evaluated throughout the test. The damage mechanisms include the buckling of core walls, separation of core from surface sheets, and formation of plastic hinges in the core plate. The results show that panel height and the geometry of its core play an important role on the impact strength, as the panels with more height have higher energy absorbability and panels with square core have higher impact strength than ones with triangular core.
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Numerical and Experimental Study of Energy Absorption in Aluminum Corrugated Core Sandwich Panels by Drop Hammer Test
Mechanics Materials Science & Engineering Journal, 2017Co-Authors: Mohammad Nouri Damghani, Arash GonabadiAbstract:This paper is aimed to study the behavior of sandwich panels made of Aluminum face sheet and Aluminum corrugated core under impact loading. Sandwich panels with square and triangular corrugated cores of two different heights are constructed and the effect of corrugated geometry on the level of absorbed energy as well as the panel strength are investigated. Drop Hammer by a cylindrical impactor with the weight of 25 kg is applied for exerting the impact. Acceleration, velocity, and displacement of impactor as well as the absorbed energy are evaluated throughout the test. The damage mechanisms include the buckling of core walls, separation of core from surface sheets, and formation of plastic hinges in the core plate. The results show that panel height and the geometry of its core play an important role in the energy absorbability impact strength, as the panels with more height have higher energy absorbability and panels with square core have higher impact strength than ones with triangular core. At the end, the numerical method confirms the Experimental method.
Narinder Kumar Gupta - One of the best experts on this subject based on the ideXlab platform.
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Experimental and numerical investigations into collapse behaviour of thin spherical shells under Drop Hammer impact
International Journal of Solids and Structures, 2007Co-Authors: Narinder Kumar Gupta, N. Mohamed Sheriff, R. VelmuruganAbstract:Abstract A study of the collapse behaviour of hemi spherical and shallow spherical shells and their modes of deformation under impact loading are presented in this paper. Aluminium spherical shells of various radii and thicknesses were made by spinning. These were subjected to impact loading under a Drop Hammer and the load histories were obtained in all the cases. Three-dimensional numerical simulations were carried out for all the tested specimen geometries using LS-DYNA®. Material, geometric and contact nonlinearities were incorporated in the analysis. The uni-axial stress–strain curve for the material was obtained experimentally and was assumed to be piecewise linear in the plastic region. The results from impact experiments are used for the validation of the numerical simulations. Three distinct modes of deformation, namely local flattening, inward dimpling and formation of multiple numbers of lobes were analysed and influence of various parameters on these modes is discussed.
