Form Approved
REPORT DOCUMENTATION PAGE
OMB No. 0704-0188
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1. AGENCY USE ONLY (Leave blank)
2. REPORT DATE
3. REPORT TYPE AND DATES COVERED
September 1996
4. TITLE AND SUBTITLE
5. FUNDING NUMBERS
Sea Ice: Part II. Estimating the Full-Scale Tensile, Flexural, and
Compressive Strength of First-Year Ice
6. AUTHORS
Austin Kovacs
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)
8. PERFORMING ORGANIZATION
REPORT NUMBER
U.S. Army Cold Regions Research and Engineering Laboratory
72 Lyme Road
CRREL Report 96-11
Hanover, New Hampshire 03755-1290
9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)
10. SPONSORING/MONITORING
AGENCY REPORT NUMBER
U.S. Army Cold Regions Research and Engineering Laboratory
72 Lyme Road
Hanover, New Hampshire 03755-1290
11. SUPPLEMENTARY NOTES
For conversion of SI units to non-SI units of measurement consult ASTM Standard E380-93, Standard Practice for Use of the
International System of Units, published by the American Society for Testing and Materials, 1916 Race St., Philadelphia, Pa.
19103.
12a. DISTRIBUTION/AVAILABILITY STATEMENT
12b. DISTRIBUTION CODE
Approved for public release; distribution is unlimited.
Available from NTIS, Springfield, Virginia 22161
13. ABSTRACT (Maximum 200 words)
Sea-ice salinity, density, and temperature data were used to develop new methods for determining the bulk
brine volume and porosity of sea-ice floes. Methods for estimating full-thickness ice sheet strength, based on
large-scale field tests, are presented. The relationships among bulk sea-ice properties, strain rate, and strength
are illustrated. A new constitutive equation was developed for predicting the full-thickness horizontal com-
pressive strength σc of first-year sea ice as a function of the applied strain rate and bulk porosity in the form
σc = B2 ε l/n φ B , where parameters B2, n, and m are about 2.7 103, 3, and 1, respectively, and ε and φB are
m
˙
˙
the ice strain rate and ice floe bulk porosity of sea ice, respectively. An estimate of the horizontal force that may
develop between first-year sea-ice and a 90-m-wide structure is given. Estimating sea-ice strength based on
remote ice conductivity measurements is also discussed conceptually.
14. SUBJECT TERMS
15. NUMBER OF PAGES
26
Porosity
Salinity
Sea ice
Strain rate
16. PRICE CODE
17. SECURITY CLASSIFICATION
18. SECURITY CLASSIFICATION
19. SECURITY CLASSIFICATION
20. LIMITATION OF ABSTRACT
OF REPORT
OF THIS PAGE
OF ABSTRACT
UNCLASSIFIED
UNCLASSIFIED
UNCLASSIFIED
UL
Standard Form 298 (Rev. 2-89)
NSN 7540-01-280-5500
Prescribed by ANSI Std. Z39-18
298-102
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