scholarly journals Measurements of sea-ice flexural stiffness by pressure characteristics of flexural-gravity waves

2013 ◽  
Vol 54 (64) ◽  
pp. 51-60 ◽  
Author(s):  
Aleksey Marchenko ◽  
Eugene Morozov ◽  
Sergey Muzylev
Keyword(s):  
Elastic Modulus ◽  
Gravity Waves ◽  
Water Depth ◽  
Water Pressure ◽  
Field Measurements ◽  
Effective Elastic Modulus ◽  
Flexural Stiffness ◽  
Flexural Gravity Waves ◽  
Using Data ◽  
Relative Errors

Abstract A method to estimate the flexural stiffness and effective elastic modulus of floating ice is described and analysed. The method is based on the analysis of water pressure records at two or three locations below the bottom of floating ice when flexural-gravity waves propagate through the ice. The relative errors in the calculations of the ice flexural stiffness and the water depth are analysed. The method is tested using data from field measurements in Tempelfjorden, Svalbard, where flexural-gravity waves were excited by an icefall at the front of the outflow glacier Tunabreen in February 2011.

scholarly journals Convergence of eigenfunction expansions for flexural gravity waves in infinite water depth

2021 ◽  
Vol 2070 (1) ◽  
pp. 012006
Author(s):  
Santanu Koley ◽  
Kottala Panduranga
Keyword(s):  
Gravity Waves ◽  
Water Depth ◽  
Water Waves ◽  
Eigenfunction Expansion ◽  
Velocity Potential ◽  
Wave Theory ◽  
Delta Function ◽  
Dirac Delta Function ◽  
Dirac Delta ◽  
Flexural Gravity Waves

Abstract In the present paper, point-wise convergence of the eigenfunction expansion to the velocity potential associated with the flexural gravity waves problem in water wave theory is established for infinite water depth case. To take into account the hydroelastic boundary condition at the free surface, a flexible membrane is assumed to float in water waves. In this context, firstly the eigenfunction expansion for the velocity potentials is obtained. Thereafter, an appropriate Green’s function is constructed for the associated boundary value problem. Using suitable properties of the Green’s functions, the vertical components of the eigenfunction expansion is written in terms of the Dirac delta function. Finally, using the property of the Dirac delta function, the convergence of the eigenfunction expansion to the velocity potential is shown.

Scattering of flexural gravity waves by abrupt change in water depth

PAMM ◽  
2007 ◽  
Vol 7 (1) ◽  
pp. 2050021-2050022
Author(s):  
D. Karmakar ◽  
T. Sahoo
Keyword(s):  
Gravity Waves ◽  
Water Depth ◽  
Abrupt Change ◽  
Flexural Gravity Waves

scholarly journals Drone-Based Remote Sensing for Research on Wind Erosion in Drylands: Possible Applications

2021 ◽  
Vol 13 (2) ◽  
pp. 283
Author(s):  
Junzhe Zhang ◽  
Wei Guo ◽  
Bo Zhou ◽  
Gregory S. Okin
Keyword(s):  
Remote Sensing ◽  
Wind Erosion ◽  
Field Measurements ◽  
Spatially Explicit ◽  
Surface Model ◽  
High Resolution Imagery ◽  
Soil Elevation ◽  
3D Photogrammetry ◽  
Using Data ◽  
Sample Set

With rapid innovations in drone, camera, and 3D photogrammetry, drone-based remote sensing can accurately and efficiently provide ultra-high resolution imagery and digital surface model (DSM) at a landscape scale. Several studies have been conducted using drone-based remote sensing to quantitatively assess the impacts of wind erosion on the vegetation communities and landforms in drylands. In this study, first, five difficulties in conducting wind erosion research through data collection from fieldwork are summarized: insufficient samples, spatial displacement with auxiliary datasets, missing volumetric information, a unidirectional view, and spatially inexplicit input. Then, five possible applications—to provide a reliable and valid sample set, to mitigate the spatial offset, to monitor soil elevation change, to evaluate the directional property of land cover, and to make spatially explicit input for ecological models—of drone-based remote sensing products are suggested. To sum up, drone-based remote sensing has become a useful method to research wind erosion in drylands, and can solve the issues caused by using data collected from fieldwork. For wind erosion research in drylands, we suggest that a drone-based remote sensing product should be used as a complement to field measurements.

scholarly journals Experimental and Numerical Analysis of the Mechanical Properties of a Pretreated Shape Memory Alloy Wire in a Self-Centering Steel Brace

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 80
Author(s):  
Bo Zhang ◽  
Sizhi Zeng ◽  
Fenghua Tang ◽  
Shujun Hu ◽  
Qiang Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Loading Rate ◽  
Effective Elastic Modulus ◽  
Maximum Energy ◽  
Numerical Results ◽  
Energy Dissipation Capacity

As a stimulus-sensitive material, the difference in composition, fabrication process, and influencing factors will have a great effect on the mechanical properties of a superelastic Ni-Ti shape memory alloy (SMA) wire, so the seismic performance of the self-centering steel brace with SMA wires may not be accurately obtained. In this paper, the cyclic tensile tests of a kind of SMA wire with a 1 mm diameter and special element composition were tested under multi-working conditions, which were pretreated by first tensioning to the 0.06 strain amplitude for 40 cycles, so the mechanical properties of the pretreated SMA wires can be simulated in detail. The accuracy of the numerical results with the improved model of Graesser’s theory was verified by a comparison to the experimental results. The experimental results show that the number of cycles has no significant effect on the mechanical properties of SMA wires after a certain number of cyclic tensile training. With the loading rate increasing, the pinch effect of the hysteresis curves will be enlarged, while the effective elastic modulus and slope of the transformation stresses in the process of loading and unloading are also increased, and the maximum energy dissipation capacity of the SMA wires appears at a loading rate of 0.675 mm/s. Moreover, with the initial strain increasing, the slope of the transformation stresses in the process of loading is increased, while the effective elastic modulus and slope of the transformation stresses in the process of unloading are decreased, and the maximum energy dissipation capacity appears at the initial strain of 0.0075. In addition, a good agreement between the test and numerical results is obtained by comparing with the hysteresis curves and energy dissipation values, so the numerical model is useful to predict the stress–strain relations at different stages. The test and numerical results will also provide a basis for the design of corresponding self-centering steel dampers.

scholarly journals Flexural-gravity waves in ice channel with a lead

2021 ◽  
Vol 921 ◽  
Author(s):  
L.D. Zeng ◽  
A.A. Korobkin ◽  
B.Y. Ni ◽  
Y.Z. Xue
Keyword(s):  
Gravity Waves ◽  
Flexural Gravity Waves

Abstract

Influence of snow cover on the parameters flexural-gravity waves in ice cover

2013 ◽  
Vol 54 (3) ◽  
pp. 458-464 ◽  
Author(s):  
V. M. Kozin ◽  
V. L. Zemlyak ◽  
V. Yu. Vereshchagin
Keyword(s):  
Snow Cover ◽  
Gravity Waves ◽  
Ice Cover ◽  
Flexural Gravity Waves
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