scholarly journals Peridynamic Analysis of Fragmentation of Ice Plate Under Explosive Loading With Thermal Effects

2020 ◽  
Author(s):  
Yuan Zhang ◽  
Chao Wang ◽  
Chunyu Guo ◽  
Longbin Tao
Keyword(s):  
Thermal Effects ◽  
Underwater Explosion ◽  
Arctic Region ◽  
Ice Cover ◽  
Bottom Surface ◽  
Ice Jams ◽  
Load Distributions ◽  
Peridynamic Model ◽  
Ice Failure ◽  
Fully Coupled

Abstract Along with the development in arctic region, the icebreaking technologies are gradually becoming the focus. As one of the most powerful and effective way to breaking ice, especially in the ability to solve ice jams, the study of the behaviour of the sea and river ice under dynamic loads is an urgent subject of scientific research and it attracts extensive attention. In addition, the temperature change in the process of ice failure cannot be neglected since that temperature plays an important role in the mechanical properties of the ice. In this study, a fully coupled thermoelastic ordinary state-based Peridynamic model is employed to investigate fragmentation of ice cover subjected to an underwater explosion. Both the deformation effect on the thermal effects and the thermal effects on deformation are taken into consideration. The pressure shocks generated by the underwater explosion are applied to the bottom surface of the ice cover for non-uniform load distributions. Crack propagation paths are investigated, the damage is predicted and compared with existing experimental results. The corresponding temperature distributions are also examined. Furthermore, the ice failure mode in both the top surface and the bottom surface of the ice sheet is investigated.

scholarly journals Modeling of Thermal Effects in Semiconductor Structures

VLSI Design ◽  
1998 ◽  
Vol 8 (1-4) ◽  
pp. 53-58
Author(s):  
Christopher M. Snowden
Keyword(s):  
Thermal Effects ◽  
Large Scale ◽  
High Electron Mobility Transistors ◽  
Thermal Modelling ◽  
High Electron ◽  
Temperature Model ◽  
Active Devices ◽  
Electron Mobility Transistors ◽  
Fully Coupled ◽  
Scale Surface

A fully coupled electro-thermal hydrodynamic model is described which is suitable for modelling active devices. The model is applied to the non-isothermal simulation of pseudomorphic high electron mobility transistors (pHEMTs). A large-scale surface temperature model is described which allows thermal modelling of semiconductor devices and monolithic circuits. An example of the application of thermal modelling to monolithic circuit characterization is given.

Recent Variability in Sea Ice Cover, Age, and Thickness in the Pacific Arctic Region

2014 ◽  
pp. 31-63 ◽  
Author(s):  
Karen E. Frey ◽  
James A. Maslanik ◽  
Jaclyn Clement Kinney ◽  
Wieslaw Maslowski
Keyword(s):  
Sea Ice ◽  
Arctic Region ◽  
Ice Cover ◽  
The Pacific

Numerical Design of Extrusion Process Using Finite Thermo-Elastoviscoplasticity with Damage. Prediction of Chevron Shaped Cracks

2009 ◽  
Vol 424 ◽  
pp. 265-272 ◽  
Author(s):  
Carl Labergère ◽  
Khemais Saanouni ◽  
Philippe Lestriez
Keyword(s):  
Constitutive Equations ◽  
Thermal Effects ◽  
Initial Temperature ◽  
Kinematic Hardening ◽  
Extrusion Process ◽  
Main Process ◽  
Damage Prediction ◽  
User Subroutine ◽  
Micro Cracks ◽  
Fully Coupled

The influence of the initial temperature and its evolution with large plastic deformation on the formation of the fully coupled chevron shaped cracks in extrusion is numerically investigated. Fully coupled thermo-elasto-viscoplastic constitutive equations accounting for thermal effects, mixed and nonlinear isotropic and kinematic hardening, isotropic ductile damage with micro-cracks closure effects are used. These constitutive equations have been implemented in Abaqus/Explicit code thanks to the user subroutine vumat and used to perform various numerical simulations needed to investigate the problem. It has been shown that the proposed methodology is efficient to predict the chevron shaped cracks in extrusion function of the main process parameters including the temperature effect.

Analysis of freeze-up ice jams on the Peace River near Taylor, British Columbia

1982 ◽  
Vol 9 (2) ◽  
pp. 176-188 ◽  
Author(s):  
T. Keenhan ◽  
U. S. Panu ◽  
V. C. Kartha
Keyword(s):  
British Columbia ◽  
Leading Edge ◽  
Simulation Models ◽  
Ice Cover ◽  
Water Levels ◽  
Ice Jams ◽  
Peace River ◽  
Air Temperatures ◽  
Generating Capacity ◽  
Summer Flood

Since the construction of the Bennett Dam on the Peace River in British Columbia, the temperature of flow releases from G.M. Shrum Generation Station, located at the dam, has been 0.5 °C or higher during the winter months. As a result, the progression of ice cover below the dam is inhibited and a long reach of ice-free river persists throughout the winter. During February, 1979 below normal air temperatures persisted in the area and the cover progressed to a point 103 km downstream of the dam, or 19 km upstream of the Water Survey of Canada (WSC) stream gauge at Taylor. This was only the second occurrence of ice cover at the town of Taylor since 1972, when an increase in generating capacity at the G.M. Shrum Station raised maximum powerhouse releases to 1580 m3/s.A series of ice jams at the leading edge of the ice cover formed as the cover advanced, producing water levels within Taylor that approached the maximum historic summer flood levels. The ice movement, including ice cover advance and retreat, ice levels, and jam formation were monitored and documented. The data provided an opportunity to examine various river ice simulation models and assess their applicability to the Peace River.

River ice breakup processes: recent advances and future directions

2007 ◽  
Vol 34 (6) ◽  
pp. 703-716 ◽  
Author(s):  
Spyros Beltaos
Keyword(s):  
Climate Change ◽  
Effective Means ◽  
Climate Change Impacts ◽  
Ice Cover ◽  
Aquatic Life ◽  
Ice Jams ◽  
Ice Jam ◽  
Ice Breakup ◽  
Extreme Flood ◽  
Mitigation Methods

The breakup of the winter ice cover is a brief but seminal event in the regime of northern rivers, and in the life cycle of river and basin ecosystems. Breakup ice jams can cause extreme flood events, with major impacts on riverside communities, aquatic life, infrastructure, navigation, and hydropower generation. Related concerns are underscored by the issue of climate change and the faster warming that is predicted for northern parts of the globe. Advances in knowledge of breakup processes and related topics, achieved over the past 15 years or so, are outlined. They pertain to breakup initiation and ice-jam formation, ice-jam properties and numerical modelling of ice jams, waves generated by ice-jam releases, forecasting and mitigation methods, sediment transport, ecological aspects, and climate-change impacts. Major knowledge gaps are associated with the dynamic interaction of moving ice with the flow and with the stationary ice cover. Increasing computing capacity and remote sensing sophistication are expected to provide effective means for bridging these gaps. Key words: climate, ecology, forecasting, ice jam, modelling, onset, sediment, wave.

scholarly journals Impact of a warm anomaly in the Pacific Arctic region derived from time-series export fluxes

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255837
Author(s):  
Catherine Lalande ◽  
Jacqueline M. Grebmeier ◽  
Andrew M. P. McDonnell ◽  
Russell R. Hopcroft ◽  
Stephanie O’Daly ◽  
...  
Keyword(s):  
Sea Ice ◽  
Bering Sea ◽  
Chukchi Sea ◽  
Arctic Region ◽  
Ice Cover ◽  
Biological Pump ◽  
Northern Bering Sea ◽  
Pacific Waters ◽  
The Pacific ◽  
The Impact

Unusually warm conditions recently observed in the Pacific Arctic region included a dramatic loss of sea ice cover and an enhanced inflow of warmer Pacific-derived waters. Moored sediment traps deployed at three biological hotspots of the Distributed Biological Observatory (DBO) during this anomalously warm period collected sinking particles nearly continuously from June 2017 to July 2019 in the northern Bering Sea (DBO2) and in the southern Chukchi Sea (DBO3), and from August 2018 to July 2019 in the northern Chukchi Sea (DBO4). Fluxes of living algal cells, chlorophyll a (chl a), total particulate matter (TPM), particulate organic carbon (POC), and zooplankton fecal pellets, along with zooplankton and meroplankton collected in the traps, were used to evaluate spatial and temporal variations in the development and composition of the phytoplankton and zooplankton communities in relation to sea ice cover and water temperature. The unprecedented sea ice loss of 2018 in the northern Bering Sea led to the export of a large bloom dominated by the exclusively pelagic diatoms Chaetoceros spp. at DBO2. Despite this intense bloom, early sea ice breakup resulted in shorter periods of enhanced chl a and diatom fluxes at all DBO sites, suggesting a weaker biological pump under reduced ice cover in the Pacific Arctic region, while the coincident increase or decrease in TPM and POC fluxes likely reflected variations in resuspension events. Meanwhile, the highest transport of warm Pacific waters during 2017–2018 led to a dominance of the small copepods Pseudocalanus at all sites. Whereas the export of ice-associated diatoms during 2019 suggested a return to more typical conditions in the northern Bering Sea, the impact on copepods persisted under the continuously enhanced transport of warm Pacific waters. Regardless, the biological pump remained strong on the shallow Pacific Arctic shelves.

scholarly journals Formation and movement of ice accumulation waves under ice cover –an experimental study

2019 ◽  
Vol 67 (2) ◽  
pp. 171-178 ◽  
Author(s):  
Jun Wang ◽  
Yifan Wu ◽  
Jueyi Sui ◽  
Bryan Karney
Keyword(s):  
Ice Cover ◽  
Bed Load ◽  
Transport Capacity ◽  
Ice Jams ◽  
Frazil Ice ◽  
Ice Accumulation ◽  
River Bed ◽  
Ice Conditions ◽  
Formation And Evolution ◽  
Good Agreement

Abstract Ice jams in rivers often arise from the movement of frazil ice as cover-load under ice cover, a process which is conceptually similar to the movement of sediment as bed-load along a river bed. The formation and movement of an ice-accumulation wave is one facet of a larger class of cover-load movements. The movement of an ice-accumulation wave obviously plays a crucial role in the overall process of ice accumulation. In the present study, experiments under different flow and ice conditions help reveal the mechanics of formation and evolution of ice-accumulation waves. In particular, suitable criteria for formation of an ice-accumulation wave are investigated along with the resulting speed of wave propagation. The transport capacity of frazil ice under waved accumulation is modeled by comparing those of experiments collected in laboratories, and the resulting equation is shown to be in good agreement with measured experimental results.

Peridynamics simulation of the fragmentation of ice cover by blast loads of an underwater explosion

2017 ◽  
Vol 23 (1) ◽  
pp. 52-66 ◽  
Author(s):  
Qing Wang ◽  
Yi Wang ◽  
Yingfei Zan ◽  
Wei Lu ◽  
Xiaolong Bai ◽  
...  
Keyword(s):  
Underwater Explosion ◽  
Ice Cover ◽  
Blast Loads

Longitudinal floating structures – new concepts in river ice control

1991 ◽  
Vol 18 (6) ◽  
pp. 933-939 ◽  
Author(s):  
Darryl J. Calkins
Keyword(s):  
Patent Application ◽  
Ice Cover ◽  
River Ice ◽  
Army Corps ◽  
Army Corps Of Engineers ◽  
Ice Jams ◽  
Control Structures ◽  
Ice Jam ◽  
New Concepts ◽  
Ice Control

Ice control structures placed in the streamwise direction of a river were analyzed to determine the effectiveness in reducing ice jam thicknesses. The theory describing the thickness for “wide” river ice jams was modified to analyze these longitudinal types, providing the computational verification that ice jam thicknesses could be reduced where the mode of ice cover thickening is internal collapse. These longitudinal structures appear to provide a new tool for modifying the river ice regime at freeze-up and possibly at breakup. By decreasing the ice jam thicknesses, which leads to lower stages, the structures have the potential for decreasing ice jam flood levels. The structures' ability to function is independent of the flow velocity and these structures should perform in rivers with velocities greater than the usual limitation of roughly 1 m/s associated with conventional cross-channel ice booms. Other possible applications include controlling ice movement at outlets from lakes, enhancing river ice cover progression, or even restraining the ice cover at breakup. A U.S. patent application has been filed jointly by the author and the U.S. Army Corps of Engineers. Key words: river ice, ice jams, ice control, hydraulic structures, ice booms.

Ice jams in shallow rivers with floodplain flow

1983 ◽  
Vol 10 (3) ◽  
pp. 538-548 ◽  
Author(s):  
Darryl J. Calkins
Keyword(s):  
Field Measurements ◽  
Close Correlation ◽  
Ice Cover ◽  
Ice Jams ◽  
Ice Jam ◽  
Surface Gradient ◽  
Breakup Channel ◽  
Modified Equations ◽  
Cover Thickness ◽  
Ice Jam Thickness

The equilibrium ice jam thickness given by Pariset et al. is modified to yield a clearer, consistent relationship between the flow hydraulics and thickness. The modified equations are analyzed with respect to a floating ice jam in the main channel with flow also occurring in the floodplain. The final derivation allows the expected ice jam thickness to be computed, given the bed and ice cover roughness coefficients, the channel characteristics, the water surface gradient, and the pre-breakup channel ice cover thickness. The analytical computation for the ice jam thicknesses is compared with prototype data on ice jam thicknesses from four shallow rivers which had significant floodplain flow with the ice jam event. A reasonable correlation between the predicted and measured ice jam thicknesses was obtained. The data suggests that once bankfull depth is exceeded the ice jam thickness does not increase appreciably because of flow diversion to the floodplain. Field measurements of the thickness of the remaining ice jam shear wall along with actual measurements of the ice jam thickness showed a close correlation between the two sets of data.

Sign in / Sign up

Export Citation Format

Share Document