The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
George A. Costello - One of the best experts on this subject based on the ideXlab platform.
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Theory of Wire rope
2012Co-Authors: George A. Costello, C. W. BertAbstract:1 Introduction.- 1.1 Basic Components.- 1.2 Identification and Construction.- 2 Equilibrium of a Thin Wire.- 2.1 Kinematics of a Thin Wire.- 2.2 Equations of Equilibrium.- 2.3 Relations Between Loads and Deformations.- 3 Static Response of a Strand.- 3.1 Geometry of a Strand.- 3.2 Axial Response of a Simple Straight Strand.- 3.3 Stress Determination of a Simple Straight Strand.- 3.4 Load Deformation Relation for a Simple Straight Strand.- 3.5 Pure Bending of a simple Straight Strand.- 3.6 Stress Determination of a Strand Subjected to Bending.- 3.7 Stress Determination of a Strand Passing over a Sheave.- 3.8 Multilayered Strands.- 3.9 Electric Conductor Strand.- 3.10 Contact Stresses.- 3.11 Outside Wires Contacting Each Other.- 3.12 Other Types of Strand Cross Sections.- 4 Static Response of a Wire Rope.- 4.1 Axial Response of an Independent Wire Rope Core.- 4.2 Axial Response of a Wire Rope.- 4.3 Stresses in a Wire Rope Due to Axial Loading.- 4.4 Stresses in a Wire Rope Due to Axial Loading and Bending.- 5 Friction in Wire Rope.- 5.1 Friction in an Axially Loaded Strand.- 5.2 Frictional Effects in the Bending and Axial Loading of a Strand.- 5.3 Frictional Effects in Wire Rope.- 5.4 Effective Length of a Broken Center Wire in a Simple Strand.- 5.5 Effective Length of a Broken Outer Wire in a Rope.- 6 Testing of a Wire Rope.- 6.1 Axial Testing of a Wire Rope.- 6.2 Effect of Rope Size on Rope Strength.- 6.3 Effect of Rope Size on Fatigue Life.- 7 Birdcaging in Wire Rope.- 7.1 Equations of Motion.- 7.2 Solution of Equations.- 7.3 Numerical Results.- 8 Rope Rotation.- 8.1 Rotation of a Wire Rope.- 8.2 Hand-Spliced Ropes.- 9 Tension and Compression of a Cord.- 9.1 Tension (contact between adjacent Wires).- 9.2 Compression (no contact between adjacent Wires).- 10 A Theory of Fatigue.- 10.1 Introduction.- 10.2 Theory.- 11 Remarks on Assumptions and Approximations.- 11.1 Introduction.- 11.2 Assumptions and Approximations for a Straight Strand.- 11.3 Assumptions and Approximations for a Wire Rope.- References.
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Response of a strand with elliptical Outer Wires
International Journal of Solids and Structures, 1991Co-Authors: Ted A. Conway, George A. CostelloAbstract:Abstract The linearized form of the equilibrium equations for Wire rope is used to develop a theory which describes the axial response of a strand, with elliptical Outer Wire cross-sections, to a static load for two strand configurations. The strand geometries are the same except for a small flat surface on each of the Outer Wires for the second configuration. The forces, moments, stresses and strains are calculated using the same loading conditions for each strand configuration and varying the ellipticity of the Outer Wires. The results for both cases are then evaluated and an application of the theory is briefly discussed.
Daniel Sinars - One of the best experts on this subject based on the ideXlab platform.
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Nested X Pinches on the COBRA Generator
AIP Conference Proceedings, 2009Co-Authors: T. A. Shelkovenko, S. A. Pikuz, Ryan D Mcbride, Patrick Knapp, H. Wilhelm, D. A. Hammer, Daniel SinarsAbstract:Recent results of X pinch studies on the COBRA generator at Cornell University (peak current up to 1.2 MA and rise time of 100 ns) are presented. Using an initial configuration of Wires before their twisting, similar to nested cylindrical Wire arrays enables the assembly of a symmetric configuration at the X pinch crossing region. It also enables an investigation of multilayered X pinches. X pinches with different configurations, including with different materials in the inner and Outer Wire layers, were tested.
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Nested multilayered X pinches for generators with mega-ampere current level
Physics of Plasmas, 2009Co-Authors: T. A. Shelkovenko, S. A. Pikuz, Ryan D Mcbride, Patrick Knapp, H. Wilhelm, David Hammer, Daniel SinarsAbstract:A symmetric X pinch configuration that is conducive to using large numbers of Wires on ≥1 MA pulsed power generators has been tested at 1 MA. Using an initial configuration of Wires before their twisting, similar to nested cylindrical Wire arrays, enables a geometrically simple, compact, multilayer Wire configuration at the X pinch crossing region. Multilayer X pinches with the same or different materials in the inner and Outer Wire layers were tested. Optimization resulted in X pinch radiation sources with peak power comparable to the most successful single layer X pinch, but with a compact, single bright X radiation source more reliably obtained using the nested configuration.
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Investigation of nested type X pinches with ∼ 1 MA current
2008 IEEE 35th International Conference on Plasma Science, 2008Co-Authors: S. A. Pikuz, T. A. Shelkovenko, Ryan D Mcbride, H. Wilhelm, D. A. Hammer, J.d. Douglass, Daniel SinarsAbstract:Recent results of X pinch studies on the COBRA generator from Cornell University (peak current up to 1.2 MA and rise time of 100 ns) are presented. Preliminary experiments on COBRA generated a bright burst of soft X-ray radiation with an intensity that was much higher than the intensity of X pinch radiation obtained on generators with smaller current. Theoretical estimates show that energy yield of X-ray radiation could be proportional to the generator current to the power 34/9, i.e. grows with increasing current very quickly. A determination of the real scaling experiments on generators with a range of currents, but higher current requires the use of loads with higher mass per unit length. Such loads can be made by increasing the number of Wires or the Wire diameters. It is reasonable to expect that the configuration of the Wire crossing point will influence X pinch neck formation processes. Using an initial configuration of Wires (before their twisting), similar to nested arrays, enables the assembly of a symmetric configuration for the X pinch crossing region. It also enables an investigation of multilayered X pinches. X pinches of different configurations, including X pinches with different materials in the inner and Outer Wire layers, were tested. All diagnostics developed for the COBRA generator were used in the experiments. The results of the experiments were compared with results obtained in experiments with regular multi-Wire X pinches.
Alla S. Safronova - One of the best experts on this subject based on the ideXlab platform.
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Larger Sized Wire Arrays on 1.5MA Z-pinch Generator.
2014Co-Authors: Alla S. Safronova, Viktor L. Kantsyrev, Michael E. Weller, V. V. Shlyaptseva, I. Shreshta, A. A. Esaulov, A. Stafford, Alexandre S. Chuvatin, C. A. Coverdale, B. JonesAbstract:Experiments on the UNR Zebra generator with Load Current Multiplier (LCM) allow for implosions of larger sized Wire array loads than at standard current of 1 MA. Advantages of larger sized planar Wire array implosions include enhanced energy coupling to plasmas, better diagnostic access to observable plasma regions, and more complex geometries of the Wire loads. The experiments with larger sized Wire arrays were performed on 1.5 MA Zebra with LCM (the anode-cathode gap was 1 cm, which is half the gap used in the standard mode). In particular, larger sized multi-planar Wire arrays had two Outer Wire planes from mid-atomic-number Wires to create a global magnetic field (gmf) and plasma flow between them. A modified central plane with a few Al Wires at the edges was put in the middle between Outer planes to influence gmf and to create Al plasma flow in the perpendicular direction (to the Outer arrays plasma flow). Such modified plane has different number of empty slots: it was increased from 6 up to 10, hence increasing the gap inside the middle plane from 4.9 to 7.7 mm, respectively. Such load configuration allows for more independent study of the flows of L-shell mid-atomic-number plasma (between the Outer planes) and K-shell Al plasma (which first fills the gap between the edge Wires along the middle plane) and their radiation in space and time. We demonstrate that such configuration produces higher linear radiation yield and electron temperatures as well as advantages of better diagnostics access to observable plasma regions and how the load geometry (size of the gap in the middle plane) influences K-shell Al radiation. In particular, K-shell Al radiation was delayed compared to L-shell mid-atomic-number radiation when the gap in the middle plane was large enough (when the number of empty slots was increased up to ten).
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Larger sized Wire arrays on 1.5 MA Z-pinch generator
2014Co-Authors: Alla S. Safronova, Viktor L. Kantsyrev, V. V. Shlyaptseva, A. A. Esaulov, A. Stafford, Alexandre S. Chuvatin, C. A. Coverdale, Mathias Weller, Ishor Shrestha, B. JonesAbstract:Experiments on the UNR Zebra generator with Load Current Multiplier (LCM) allow for implosions of larger sized Wire array loads than at standard current of 1 MA. Advantages of larger sized planar Wire array implosions include enhanced energy coupling to plasmas, better diagnostic access to observable plasma regions, and more complex geometries of the Wire loads. The experiments with larger sized Wire arrays were performed on 1.5 MA Zebra with LCM (the anode-cathode gap was 1 cm, which is half the gap used in the standard mode). In particular, larger sized multi-planar Wire arrays had two Outer Wire planes from mid-atomic-number Wires to create a global magnetic field (gmf) and plasma flow between them. A modified central plane with a few Al Wires at the edges was put in the middle between Outer planes to influence gmf and to create Al plasma flow in the perpendicular direction (to the Outer arrays plasma flow). Such modified plane has different number of empty slots: it was increased from 6 up to 10, henc...
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New Regimes of Implosions of Larger Sized Wire Arrays With and Without Modified Central Plane at 1.5 - 1.7 MA Zebra.
2013Co-Authors: Alla S. Safronova, Viktor L. Kantsyrev, Michael E. Weller, V. V. Shlyaptseva, I. Shreshta, A. A. Esaulov, A. Stafford, S. F. Keim, E. E. Petkov, M. Y. LoranceAbstract:The recent experiments at 1.5-1.7 MA on Zebra at UNR with larger sized planar Wires arrays (compared to the Wire loads at 1 MA current) have demonstrated higher linear radiation yield and electron temperatures as well as advantages of better diagnostics access to observable plasma regions. Such multi-planar Wire arrays had two Outer Wire planes from mid-Z material to create a global magnetic field (gmf) and mid-Z plasma ow between them. Also, they included a modified central plane with a few Al Wires at the edges to in uence gmf and to create Al plasma ow in the perpendicular direction. The stationary shock waves which existed over tens of ns on shadow images and the early x-ray emissions before the PCD peak on time-gated spectra were observed. The most recent experiments with similar loads but without the central Wires demonstrated a very different regime of implosion with asymmetrical jets and no precursor formation. This work was supported by NNSA under DOE Cooperative Agreement DE-NA0001984 and in part by DE-FC52-06NA27616. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000. −- TO4.00006 http://meetings.aps.org/link/BAPS.2013.DPP.TO4.6
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Radiation signatures of large sized multi-planar Wire arrays
2013 Abstracts IEEE International Conference on Plasma Science (ICOPS), 2013Co-Authors: Alla S. Safronova, Viktor L. Kantsyrev, Michael E. Weller, V. V. Shlyaptseva, A. A. Esaulov, A. Stafford, Ishor Shrestha, S. F. Keim, G. C. Osborne, E. E. PetkovAbstract:Summary form only given. Experiments on the Zebra generator with LCM (Load Current Multiplier, provides 1.5-1.7 MA) allow for implosions of larger sized Wire array loads (including planar Wire arrays) than at standard current of 1 MA. Advantages of larger sized planar Wire array implosions include enhanced energy coupling to plasmas and better diagnostic access to observable plasma regions. A full set of diagnostics was implemented to study radiation in a broad spectral range from few Å to few hundred Å using PCD, XRD, and EUV detectors, X-ray/EUV spectrometers and X-ray pinhole cameras. In addition, laser shadowgraphy was utilized. In multi-planar Wire arrays, two Outer Wire planes were each 4.9 mm width and made of eight mid-atomic-number (Alumel with 95% of Ni) Wires with the inter-row gap increased from 3 or 6 mm (usually used at 1 MA current) up to 9 mm. A central plane located in the middle between the Outer planes had empty slots and a few Al Wires at the edges. Recently, we have shown that such configuration produces higher linear radiation yield. In the new experiments, the number of empty slots was further increased from 6 up to 10, increasing the gap inside the middle plane from 4.9 to 7.7 mm, respectively. This allows for more independent study of the flows of L-shell Ni plasma (between the Outer planes) and K-shell Al plasma (which first fills the gap between the edge Wires along the middle plane) and their radiation in space and time. When studying the combined Wire arrays before, the time-gated X-ray spectra have always included radiation from both materials, even at early time. In the present work, for the first time we have observed that the K-shell Al radiation was delayed compared to L-shell Ni radiation when the number of empty slots was increased. In addition, the results of another new experiment are presented when a few Al Wires on each edge were replaced by a thicker Cu Wire to understand their influence on radiation from Outer planes.
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Implosions of larger size Wire arrays at enhanced current of 1.5–1.7 MA on zebra with LCM
2012 Abstracts IEEE International Conference on Plasma Science, 2012Co-Authors: Alla S. Safronova, Viktor L. Kantsyrev, Michael E. Weller, V. V. Shlyaptseva, A. A. Esaulov, A. Stafford, Ishor Shrestha, H.a. Zunino, G. C. Osborne, S. F. KeimAbstract:Summary form only given. Experiments on Zebra with a Load Current Multiplier (LCM, which provides an enhanced current of 1.5–1.7 MA) allow the implosion of larger Wire array loads than possible with the standard current of 1 MA. Advantages of the larger Wire arrays include enhanced energy coupling to plasmas and better diagnostic access to observable plasma regions. Diagnostics, fielded on 10 beam lines, included PCD, XRD, and EUV detectors, X-ray/EUV spectrometers and X-ray pinhole cameras, and laser shadowgraphy. For this work, we collected and analyzed the experimental results from standard and modified triple planar Wire arrays (TPWA), as well as cylindrical Wire arrays (CWA). The anode-cathode gap in these experiments with LCM was 1 cm, which is half the gap used in the standard mode. For TPWAs, two Outer Wire planes were made out of mid-atomic-number Wire material (Ni or Cu) with the inter-row gap increased from 1.5 or 3 mm (usually used at 1 MA current) up to 4.5 mm. The different designs of a central Wire plane from Al were implemented to investigate its role as a magnetic field extruder to prevent the formation of closed magnetic configurations around each Wire plane. Previous work has shown that larger double planar Wire arrays (at a standard current) can block the inward motion of ablated plasma jets. Therefore, multi-planar Wire arrays provide a new test bed to study jet formations in larger Wire arrays for laboratory astrophysics. In addition, we measured higher linear radiation yield and the high-temperature precursor Al plasmas, not previously observable in experiments on Zebra at 1 Ma current. However, the observation of high-temperature precursor plasmas from Cu CWAs at enhanced current was consistent with previous findings at a standard current of 1 MA.
T. A. Shelkovenko - One of the best experts on this subject based on the ideXlab platform.
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Nested X Pinches on the COBRA Generator
AIP Conference Proceedings, 2009Co-Authors: T. A. Shelkovenko, S. A. Pikuz, Ryan D Mcbride, Patrick Knapp, H. Wilhelm, D. A. Hammer, Daniel SinarsAbstract:Recent results of X pinch studies on the COBRA generator at Cornell University (peak current up to 1.2 MA and rise time of 100 ns) are presented. Using an initial configuration of Wires before their twisting, similar to nested cylindrical Wire arrays enables the assembly of a symmetric configuration at the X pinch crossing region. It also enables an investigation of multilayered X pinches. X pinches with different configurations, including with different materials in the inner and Outer Wire layers, were tested.
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Nested multilayered X pinches for generators with mega-ampere current level
Physics of Plasmas, 2009Co-Authors: T. A. Shelkovenko, S. A. Pikuz, Ryan D Mcbride, Patrick Knapp, H. Wilhelm, David Hammer, Daniel SinarsAbstract:A symmetric X pinch configuration that is conducive to using large numbers of Wires on ≥1 MA pulsed power generators has been tested at 1 MA. Using an initial configuration of Wires before their twisting, similar to nested cylindrical Wire arrays, enables a geometrically simple, compact, multilayer Wire configuration at the X pinch crossing region. Multilayer X pinches with the same or different materials in the inner and Outer Wire layers were tested. Optimization resulted in X pinch radiation sources with peak power comparable to the most successful single layer X pinch, but with a compact, single bright X radiation source more reliably obtained using the nested configuration.
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Investigation of nested type X pinches with ∼ 1 MA current
2008 IEEE 35th International Conference on Plasma Science, 2008Co-Authors: S. A. Pikuz, T. A. Shelkovenko, Ryan D Mcbride, H. Wilhelm, D. A. Hammer, J.d. Douglass, Daniel SinarsAbstract:Recent results of X pinch studies on the COBRA generator from Cornell University (peak current up to 1.2 MA and rise time of 100 ns) are presented. Preliminary experiments on COBRA generated a bright burst of soft X-ray radiation with an intensity that was much higher than the intensity of X pinch radiation obtained on generators with smaller current. Theoretical estimates show that energy yield of X-ray radiation could be proportional to the generator current to the power 34/9, i.e. grows with increasing current very quickly. A determination of the real scaling experiments on generators with a range of currents, but higher current requires the use of loads with higher mass per unit length. Such loads can be made by increasing the number of Wires or the Wire diameters. It is reasonable to expect that the configuration of the Wire crossing point will influence X pinch neck formation processes. Using an initial configuration of Wires (before their twisting), similar to nested arrays, enables the assembly of a symmetric configuration for the X pinch crossing region. It also enables an investigation of multilayered X pinches. X pinches of different configurations, including X pinches with different materials in the inner and Outer Wire layers, were tested. All diagnostics developed for the COBRA generator were used in the experiments. The results of the experiments were compared with results obtained in experiments with regular multi-Wire X pinches.
Ted A. Conway - One of the best experts on this subject based on the ideXlab platform.
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Response of a strand with elliptical Outer Wires
International Journal of Solids and Structures, 1991Co-Authors: Ted A. Conway, George A. CostelloAbstract:Abstract The linearized form of the equilibrium equations for Wire rope is used to develop a theory which describes the axial response of a strand, with elliptical Outer Wire cross-sections, to a static load for two strand configurations. The strand geometries are the same except for a small flat surface on each of the Outer Wires for the second configuration. The forces, moments, stresses and strains are calculated using the same loading conditions for each strand configuration and varying the ellipticity of the Outer Wires. The results for both cases are then evaluated and an application of the theory is briefly discussed.
