Ice Pressure Sensor Inclusion Factors

1981 ◽  
Vol 103 (1) ◽  
pp. 82-86 ◽  
Author(s):  
A. C. T. Chen
Keyword(s):  
Sea Ice ◽  
Pressure Distribution ◽  
Pressure Sensor ◽  
Pressure Measurement ◽  
Measurement Data ◽  
Ice Sheet ◽  
Field Tests ◽  
Approximate Equation ◽  
Analytical Work ◽  
Ice Pressure

The inclusion of a pressure sensor in an ice sheet will disturb the pressure distribution in the ice sheet. The ratio of undisturbed ice pressure to the pressure felt by the sensor, defined herein as the inclusion factor, is required in interpreting the ice pressure measurement data. An approximate equation which expresses the inclusion factor in terms of the geometry of sensor and the sea ice/pressure sensor stiffnesses ratio is proposed in this study. Some results of analytical work and field tests which were performed to evaluate the accuracy of this expression are also presented. These results demonstrate the validity of the proposed inclusion equation.

Field In-Ice Pressure Sensor Response Tests

1983 ◽  
Vol 105 (1) ◽  
pp. 6-11
Author(s):  
A. C. T. Chen ◽  
J. S. Templeton
Keyword(s):  
Pressure Sensor ◽  
Data Reduction ◽  
Broad Class ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Ice Sheet ◽  
Sensor Response ◽  
Sensor Output ◽  
Reduction Procedure ◽  
Ice Pressure

An ice pressure sensor has been designed and built at Exxon Production Research Company (EPR) to measure the pressure in an ice sheet. Laboratory and analytical studies were performed to establish a data reduction procedure to relate the pressure sensor output to the pressure in the ice sheet. However, because of the complex mechanical behavior of sea ice, the present experiment was conducted to validate this data reduction procedure. The validated procedure is considered applicable to a broad class of embedded ice pressure sensors. Field in-ice pressure sensor response tests were conducted near Prudhoe Bay, Alaska, between February and April of 1978. Twenty-two tests were conducted on three test blocks of ice to investigate the in-ice response of three ice pressure sensors. An ice block measuring 10 ft by 20 ft and of full thickness of the natural annual ice was cut free from the surrounding ice sheet after the pressure sensor was installed at the center of the block. This ice block was loaded by an in-situ hydraulic ice loading device capable of delivering approximately two million lb of load. The pressure sensor output and the test load were monitored continuously during each test so that the pressure sensor output could be compared directly to the corresponding applied pressure. The test results indicated ratios of applied ice pressure to measured sensor pressure within the range hindcast by theoretical analysis.

The Distribution of Ice Pressure Acting on Offshore Pile Structure and the Failure Mechanics of Ice Sheet

1987 ◽  
Vol 109 (1) ◽  
pp. 85-92 ◽  
Author(s):  
S. Tanaka ◽  
H. Saeki ◽  
T. Ono
Keyword(s):  
Aspect Ratio ◽  
Strain Rate ◽  
Local Buckling ◽  
Ice Sheet ◽  
Field Tests ◽  
Ice Thickness ◽  
Economic Factors ◽  
Failure Mechanics ◽  
Ice Pressure ◽  
Ice Force

The total ice force acting on offshore pile structures, located in cold regions, has already been investigated by many researchers. Few papers, however, have described the distribution of ice pressure on the structures and the failure mechanics of ice sheet. It is necessary to study them in order to design the pile structures, keeping in mind safety and economic factors. The results of our experiments on failure mechanics of an ice sheet are useful for dynamic analysis. For analysis of stress and, especially, local buckling of structures, it is essential to examine the distribution of ice pressure acting on the structures. This paper describes a systematic study of these aspects through field tests with three rectangular piles (20, 40, 60 cm in width) in Saroma Lagoon in Hokkaido, Japan’s northernmost island, to clarify the effect of aspect ratio. It is clear from our experiments on ice pressure that the distribution of ice pressure can be classified into two types according to the strain rate ε˙ (= V/4B, V: penetration velocity of piles, B: pile width) defined by Michel and Toussaint [1] in each aspect ratio, B/h (h: ice thickness). It is our hypothesis that the failure periods of ice sheet are determined by the aforementioned strain rate and the aspect ratio.

Laboratory Compression Tests of Sea Ice at Slow Strain Rates From a Field Test Program

1988 ◽  
Vol 110 (2) ◽  
pp. 154-158 ◽  
Author(s):  
Y. S. Wang ◽  
J. P. Poplin
Keyword(s):  
Sea Ice ◽  
Strain Rate ◽  
Field Test ◽  
Ice Sheet ◽  
Field Tests ◽  
Crystallographic Structure ◽  
Strain Rates ◽  
Full Thickness ◽  
Test Program ◽  
Thin Sections

In the winter of 1979/80, five petroleum companies participated in a field test program conducted by Exxon Production Research Company in Prudhoe Bay, Alaska, to measure the unconfined compressive strength of the sea ice sheet in its full thickness at various strain rates between 10−7 and 8 × 10−5 s−1. As part of this program, ice sample blocks at four different levels in the ice sheet were collected from seven field test sites and shipped to Exxon’s Cold Laboratory in Houston. A total of 221 cylindrical ice samples were made from the ice blocks and tested for their compressive strengths on a closed loop test machine. The sample size was 2.725 in. (6.92 cm) in diameter and 5.75 in. (14.60 cm) long. The strain rate and temperature under which each sample was tested were selected to match actual field test conditions. In addition, 76 thin sections were prepared from tested samples and were studied for the crystallographic structure. Results indicate that local variations of the crystalline structure of the ice sheet could be significant and could cause large variations in the strength of individual samples. The results of the laboratory tests were used to estimate the strength of the full-thickness ice sheet by taking the average value of the through-thickness strength profile. Comparison with field tests shows that this procedure gives very accurate strength estimation for the strain rate range used in the field tests.

scholarly journals Discrete Element Analysis of High-Pressure Zones of Sea Ice on Vertical Structures

2021 ◽  
Vol 9 (3) ◽  
pp. 348
Author(s):  
Xue Long ◽  
Lu Liu ◽  
Shewen Liu ◽  
Shunying Ji
Keyword(s):  
High Pressure ◽  
Sea Ice ◽  
Failure Mode ◽  
Contact Area ◽  
Loading Rate ◽  
Discrete Element ◽  
Offshore Platforms ◽  
Marine Structures ◽  
Element Analysis ◽  
Ice Pressure

In cold regions, ice pressure poses a serious threat to the safe operation of ship hulls and fixed offshore platforms. In this study, a discrete element method (DEM) with bonded particles was adapted to simulate the generation and distribution of local ice pressures during the interaction between level ice and vertical structures. The strength and failure mode of simulated sea ice under uniaxial compression were consistent with the experimental results, which verifies the accuracy of the discrete element parameters. The crushing process of sea ice acting on the vertical structure simulated by the DEM was compared with the field test. The distribution of ice pressure on the contact surface was calculated, and it was found that the local ice pressure was much greater than the global ice pressure. The high-pressure zones in sea ice are mainly caused by its simultaneous destruction, and these zones are primarily distributed near the midline of the contact area of sea ice and the structure. The contact area and loading rate are the two main factors affecting the high-pressure zones. The maximum local and global ice pressures decrease with an increase in the contact area. The influence of the loading rate on the local ice pressure is caused by the change in the sea ice failure mode. When the loading rate is low, ductile failure of sea ice occurs, and the ice pressure increases with the increase in the loading rate. When the loading rate is high, brittle failure of sea ice occurs, and the ice pressure decreases with an increase in the loading rate. This DEM study of sea ice can reasonably predict the distribution of high-pressure zones on marine structures and provide a reference for the anti-ice performance design of marine structures.

Subglacial sediment pathways and deglacial chronology of the northern Barents Sea Ice Sheet

Boreas ◽  
2017 ◽  
Vol 46 (4) ◽  
pp. 750-771 ◽  
Author(s):  
Kelly A. Hogan ◽  
Julian A. Dowdeswell ◽  
Claus-Dieter Hillenbrand ◽  
Werner Ehrmann ◽  
Riko Noormets ◽  
...  
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Ice Sheet

scholarly journals The North Sea Ice Sheet

Nature ◽  
1894 ◽  
Vol 50 (1282) ◽  
pp. 79-79
Author(s):  
HENRY H. HOWORTH
Keyword(s):  
Sea Ice ◽  
North Sea ◽  
Ice Sheet ◽  
The North ◽  
The North Sea

scholarly journals Morphology of sea ice pressure ridges in the northwestern Weddell Sea in winter

2012 ◽  
Vol 117 (C6) ◽  
pp. n/a-n/a ◽  
Author(s):  
Bing Tan ◽  
Zhi-jun Li ◽  
Peng Lu ◽  
Christian Haas ◽  
Marcel Nicolaus
Keyword(s):  
Sea Ice ◽  
Weddell Sea ◽  
Ice Pressure

scholarly journals Dynamic, in situ measurement of sea-ice characteristic length

2001 ◽  
Vol 33 ◽  
pp. 339-344 ◽  
Author(s):  
Colin Fox ◽  
Tim G. Haskell ◽  
Hyuck Chung
Keyword(s):  
Sea Ice ◽  
Characteristic Length ◽  
Ice Sheet ◽  
In Situ Measurement ◽  
Effective Characteristic ◽  
Mcmurdo Sound ◽  
Periodic Loading ◽  
Flexural Response ◽  
Measurement Signal

AbstractWe present a method for measuring the characteristic length of sea ice based on fitting to a recently found solution for the flexural response of a floating ice sheet subject to localized periodic loading. Unlike previous techniques, the method enables localized measurements at single frequencies of geophysical interest, and since the measurements may be synchronously demodulated, gives excellent rejection of unwanted measurement signal (e.g. from ocean swell). The loading mechanism is described and we discuss how the effective characteristic length may be determined using a range of localized measurements. The method is used to determine the characteristic length of the sea ice in McMurdo Sound, Antarctica.

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