Confined Compressive Strength of Horizontal First-Year Sea Ice Samples

1991 ◽  
Vol 113 (4) ◽  
pp. 344-351 ◽  
Author(s):  
J. A. Richter-Menge
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Axial Stress ◽  
Testing Machine ◽  
Constant Strain Rate ◽  
First Year ◽  
Strain Rates ◽  
Triaxial Cell ◽  
Testing Techniques ◽  
Prudhoe Bay

A total of 110 first-year sea ice samples from Prudhoe Bay, Alaska, were tested in unconfined and confined constant strain rate compression. All of the tests were performed in the laboratory on a closed-loop electrohydraulic testing machine at −10°C. The confined tests were performed in a conventional triaxial cell (σ1>σ2=σ3) that maintained a constant ratio between the radial and axial stress (σ2/(σ1)=constant) to simulate true loading conditions. Three strain rates (10−2, 10−3, and 10−5/s) and three σ2/σ1 ratios (0.25, 0.50, and 0.75) were investigated. This paper summarizes the field sampling and testing techniques and presents data on the effect of confinement on the compressive strength, initial tangent modulus, and failure strain of the ice.

Confined Compressive Strength of Multi-Year Pressure Ridge Sea Ice Samples

1988 ◽  
Vol 110 (3) ◽  
pp. 295-301 ◽  
Author(s):  
G. F. N. Cox ◽  
J. A. Richter-Menge
Keyword(s):  
Compressive Strength ◽  
Axial Stress ◽  
Testing Machine ◽  
Constant Strain Rate ◽  
Confining Pressure ◽  
Triaxial Tests ◽  
Strain Rates ◽  
Pressure Ridge ◽  
Two Temperatures ◽  
Testing Techniques

Fifty-five constant-strain-rate triaxial tests were performed on verticaly oriented multi-year pressure ridge samples from the Beaufort Sea. The tests were performed on a closed-loop electrohydraulic testing machine at two nominal strain rates (10−5 and 10−3 s−1) and two temperatures (−20° and −5°C). In all of the tests the confining pressure was ramped in constant proportion to the applied axial stress (σ1 > σ2 = σ3, σ3/σ1 = constant). Two σ3/σ1 ratios were investigated: 0.25 and 0.50. This paper summarizes the sample preparation and testing techniques used in this investigation and presents data on the confined compressive strength and failure strain of the ice. Uniaxial data are also included for comparison.

Tensile Strength of Multi-Year Pressure Ridge Sea Ice Samples

1985 ◽  
Vol 107 (3) ◽  
pp. 375-380 ◽  
Author(s):  
G. F. N. Cox ◽  
J. A. Richter-Menge
Keyword(s):  
Tensile Strength ◽  
Failure Strain ◽  
Testing Machine ◽  
Constant Strain Rate ◽  
Hydraulic Testing ◽  
Strain Rates ◽  
Tension Tests ◽  
Pressure Ridge ◽  
Two Temperatures ◽  
Testing Techniques

Thirty-six constant strain-rate uniaxial tension tests were performed on vertically oriented multi-year pressure ridge samples from the Beaufort Sea. The tests were performed on a closed-loop electro-hydraulic testing machine at two strain rates (10−5 and 10−3 s−1) and two temperatures (−20° and −5°C). This paper summarizes the sample preparation and testing techniques used in the investigation and presents data on the tensile strength, initial tangent modulus, and failure strain of the ice.

A Summary of the Strength and Modulus of Ice Samples From Multi-Year Pressure Ridges

1985 ◽  
Vol 107 (1) ◽  
pp. 93-98 ◽  
Author(s):  
G. F. N. Cox ◽  
J. A. Richter ◽  
W. F. Weeks ◽  
M. Mellor
Keyword(s):  
Compressive Strength ◽  
Sample Preparation ◽  
Closed Loop ◽  
Testing Machine ◽  
Tangent Modulus ◽  
Strain Rates ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Two Temperatures ◽  
Testing Techniques

Over two hundred unconfined compression tests were performed on vertical ice samples obtained from 10 multi-yr pressure ridges in the Beaufort Sea. The tests were performed on a closed-loop electrohydraulic testing machine at two strain rates (10−5 and 10−3 s−1) and two temperatures (−20° and −5°C). This paper summarizes the sample preparation and testing techniques used in the investigation and presents data on the compressive strength and initial tangent modulus of the ice.

Dynamic and Quasi-Static Compressive Deformation Behaviour of Polyimide Foam at Various Elevated Temperature

2014 ◽  
Vol 566 ◽  
pp. 158-163 ◽  
Author(s):  
A. Yosimoto ◽  
Hidetoshi Kobayashi ◽  
Keitaro Horikawa ◽  
Keiko Watanabe ◽  
Kinya Ogawa
Keyword(s):  
Compressive Strength ◽  
Room Temperature ◽  
Deformation Behaviour ◽  
Testing Machine ◽  
Negative Temperature ◽  
Strain Rates ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Universal Testing ◽  
Pressure Bar

In order to clarify the effect of strain rate and test temperature on the compressive strength and energy absorption of polyimide foam, a series of compression tests for the polyimide foam with two different densities were carried out. By using three testing devices, i.e. universal testing machine, dropping weight machine and sprit Hopkinson pressure bar apparatus, we performed a series of compression tests at various strain rates (10-3~103s-1) and at several test temperatures in the range of room temperature to 280 ̊C. At over 100 s-1, the remarkable increase of flow stress was observed. The negative temperature dependence of strength was also observed.

scholarly journals Mechanical Properties of First Year Sea Ice in Saroma Lagoon

1985 ◽  
Vol 6 ◽  
pp. 278-280
Author(s):  
Hisao Matsushita ◽  
Nobuyoshi Yashima
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Test Specimen ◽  
Bending Strength ◽  
Growth Direction ◽  
Cross Sectional Area ◽  
First Year ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross

This paper deals with compressive strength vs temperature characteristics (-40 ºC to -2ºC), size effect (cross-sectional area of test specimen) and probability distribution of compressive strength and fracture toughness KIC (corresponding to notch effect in bending strength), of first year sea ice sampled from Saroma Lagoon. The main experimental results are as follows. (1) Temperature dependent compressive fracture modes: at temperatures of -20 ºC to 0ºC, crush fracture is dominant, and at temperatures of -40 ºC to -20 C, brittle fracture is dominant. (2) The larger the cross-sectional area of a test specimen, the lower the compressive strength becomes. It is inferred that the number of weak spots increases with increase in the cross-sectional area of the test piece, which thus becomes more susceptible to fracture. (3) The scatter of compressive strength can be approximated by a normal distribution curve. (4) The KIC values of sea ice are below 10 kg/cm2cm, though they change slightly depending on the dimensions of test pieces, the relative angle between crystal growth direction and load direction, environmental condition (air or water), and testing method.

scholarly journals Field Test 1 of Compressive Strength of First-Year Sea Ice

1983 ◽  
Vol 4 ◽  
pp. 253-259 ◽  
Author(s):  
N. K. Sinha
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Failure Time ◽  
Rate Sensitivity ◽  
Test System ◽  
First Year ◽  
Test Machine ◽  
Baffin Island ◽  
Test Results ◽  
Average Strain Rate

A test program undertaken in April 1981 on the uniaxial compressive strength of freshly recovered first-year columnar-grained sea ice at a portable field laboratory floating on top of the ice cover in Eclipse Sound, Baffin Island, Canadian Arctic, is reported. Using a small battery-operated test machine, both vertical and horizontal samples were tested so that the load could be applied either parallel or perpendicular to the axis of the columns. Rate sensitivity of the observed strength is discussed in terms of measured average strain-rate and average stress-rate to upper yield or failure. Strain and time aspects of the test results are considered as well. Although vertical samples showed considerably greater strength than horizontal samples, no significant differences were detected in the failure strains. Examination of the interdependence of failure stress and failure time revealed certain anomalies in the results for vertical samples that could be linked to the performance characteristics of the test machine. As such problems could be common to any test system, methods of analysis are proposed for rational examination of the results.

Uniaxial Constant Compressive Stress Creep Tests on Sea Ice

1995 ◽  
Vol 117 (4) ◽  
pp. 283-289 ◽  
Author(s):  
N. K. Sinha ◽  
C. Zhan ◽  
E. Evgin
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Strain Rate ◽  
Compressive Stress ◽  
Axial Strain ◽  
Acoustic Emissions ◽  
Constant Strain Rate ◽  
Rate Sensitivity ◽  
Load Test ◽  
Creep Tests

First-year columnar-grained sea ice from Resolute Passage (74° 42′ N, 94° 50′ W), off Barrow Strait in the Canadian High Arctic, was tested under constant uniaxial compressive stress applied normal to the length of the columns. Creep tests were performed at 263 K, 253 K, and 243 K in the stress range of 0.7 to 2.5 MPa, using prismatic samples with dimensions of 50 mm × 100 mm × 250 mm. Because three-dimensional creep data are extremely useful for developing constitutive equations, axial strain was measured in conjunction with the measurements of two lateral strains and acoustic emissions. The deformations were measured using displacement gages mounted on the samples. A description of the experimental procedures and the observations are presented here. One-to-one correspondence has been obtained between the present results on the dependence of minimum creep rate on stress and previous data on the dependence of uniaxial compressive strength on strain rate under constant strain rate. The strain-rate sensitivity of compressive strength can, therefore, be obtained from creep tests which can be performed by using simple dead-load test systems.

A Preliminary Examination of the Effect of Structure on the Compressive Strength of Ice Samples From Multi-Year Pressure Ridges

1985 ◽  
Vol 107 (1) ◽  
pp. 99-102 ◽  
Author(s):  
J. A. Richter ◽  
G. F. N. Cox
Keyword(s):  
Compressive Strength ◽  
Constant Strain Rate ◽  
Strain Rates ◽  
Compression Tests ◽  
Preliminary Examination ◽  
Pressure Ridge ◽  
Test Parameters ◽  
C 23 ◽  
Strain Rate Compression ◽  
Effect Of Structure

A series of 222 uniaxial constant-strain-rate compression tests was performed on vertical multi-year pressure ridge sea ice samples. A preliminary analysis of the effect of structure on the compressive strength of the ice was performed on 78 of these tests. Test parameters included a temperature of −5°C (23°F) and strain rates of 10−5 and 10−3 s−1. Columnar ice loaded parallel to the elongated crystal axes and perpendicular to the crystal c-axis was consistently the strongest type of ice. The strength of the columnar samples decreased significantly as the orientation of the elongated crystals approached the plane of maximum shear. Samples containing granular ice or a mixture of granular and columnar ice resulted in intermediate and low strength values. No clear relationship could be established between structure and strength for these ice types. However, in general, their strength decreased with an increase in porosity.

scholarly journals Influence of the loading direction on the uniaxial compressive strength of sea ice based on field measurements

2020 ◽  
Vol 61 (82) ◽  
pp. 86-96 ◽  
Author(s):  
Shunying Ji ◽  
Xiaodong Chen ◽  
Anliang Wang
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Failure Mode ◽  
Brittle Failure ◽  
Ductile Failure ◽  
Strain Rates ◽  
Vertical Loading ◽  
Loading Direction ◽  
Horizontal Loading ◽  
Nominal Strain

AbstractSea ice is composed of columnar-shaped grains. To investigate the influence of the loading direction on the uniaxial compressive strength and failure processes of sea ice, field experiments were performed with first-year level ice. Loads were applied both horizontally (parallel to the grain columns) and vertically (across the grain columns) with various nominal strain rates. Two failure modes have been observed: a ductile failure mode at low nominal strain rates, and a brittle failure mode at high nominal strain rates. However, the failure pattern of sea ice was clearly dependent on the loading direction. At low nominal strain rates (ductile failure mode), the sea-ice samples yielded due to the development of wing cracks under horizontal loading and due to splaying out at one end under vertical loading. When sea ice fails in the ductile mode, the deformation is driven by grain boundary sliding under horizontal loading and by grain decohesion and crystal deflection under vertical loading. At high nominal strain rates (brittle failure mode), the sea-ice samples failed in shear faulting under horizontal loading and in cross-column buckling under vertical loading. The nominal strain rate at the brittle–ductile transition zone is about ten times higher under vertical loading.

scholarly journals Mechanical Properties of First Year Sea Ice in Saroma Lagoon

1985 ◽  
Vol 6 ◽  
pp. 278-280
Author(s):  
Hisao Matsushita ◽  
Nobuyoshi Yashima
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Test Specimen ◽  
Bending Strength ◽  
Growth Direction ◽  
Cross Sectional Area ◽  
First Year ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross

This paper deals with compressive strength vs temperature characteristics (-40 ºC to -2ºC), size effect (cross-sectional area of test specimen) and probability distribution of compressive strength and fracture toughness KIC (corresponding to notch effect in bending strength), of first year sea ice sampled from Saroma Lagoon. The main experimental results are as follows. (1) Temperature dependent compressive fracture modes: at temperatures of -20 ºC to 0ºC, crush fracture is dominant, and at temperatures of -40 ºC to -20 C, brittle fracture is dominant. (2) The larger the cross-sectional area of a test specimen, the lower the compressive strength becomes. It is inferred that the number of weak spots increases with increase in the cross-sectional area of the test piece, which thus becomes more susceptible to fracture. (3) The scatter of compressive strength can be approximated by a normal distribution curve. (4) The KIC values of sea ice are below 10 kg/cm2 cm, though they change slightly depending on the dimensions of test pieces, the relative angle between crystal growth direction and load direction, environmental condition (air or water), and testing method.

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