The mechanical properties of sea ice — A compilation of available data

1984 ◽  
Vol 11 (4) ◽  
pp. 884-923 ◽  
Author(s):  
Luc Lainey ◽  
René Tinawi
Keyword(s):  
Mechanical Properties ◽  
Sea Ice ◽  
Elastic Moduli ◽  
Shear Tests ◽  
Short Term ◽  
Relaxation Functions ◽  
Multiaxial Compression ◽  
Tension And Compression ◽  
Ice Strength

The mechanical properties of S2- and S3-type sea ice are reviewed. Strength and, in some cases, elastic moduli are presented for short-term loadings. The loadings considered are uniaxial tension and compression and multiaxial compression; annular tests as well as flexural and shear tests were also reported. The parameters that influence the values are also described. These are the grain diameter and orientation, loading rate, temperature, salinity, and density, as well as the size of the specimens and whether these are obtained in the field or are laboratory grown. The long-term mechanical properties are also presented. Creep laws or relaxation functions are given whenever available. The results of the compilation are presented in a tabulated form for each type of loading. A short discussion is also given for each mechanical property. Key words: sea ice mechanical properties, sea ice strength, sea ice modulus, sea ice creep, sea ice behaviour.

Design properties of laterally loaded nailed or bolted wood joints

1988 ◽  
Vol 15 (4) ◽  
pp. 633-643 ◽  
Author(s):  
Ian Smith ◽  
Luke R. J. Whale ◽  
Colin Anderson ◽  
Barry O. Hilson ◽  
Peter D. Rodd
Keyword(s):  
Mechanical Properties ◽  
Key Words ◽  
Bolted Joints ◽  
Design Codes ◽  
Short Term ◽  
Limit States ◽  
Design Solutions ◽  
Reliable Knowledge ◽  
Laterally Loaded

This paper summarizes the output from a long-term project commenced in 1980 with the objective of providing reliable knowledge of the mechanical properties of nailed or bolted joints subjected to short-term lateral loadings. Motivation was the development on an international basis of probability-based partial coefficients limit states design codes for structural timberwork. Comparisons are presented between design solutions produced by applying this research and those by the use of contemporary "soft conversion" international partial coefficients limit states design codes that were calibrated from previously available data. Differences relate primarily to design of bolted joints. It is shown that there is an established acceptance in Canada of the approach adopted. Key words: wood, joints, nails, bolts, design.

The Effects of Retesting on the Mechanical Properties of Brain Tissue

2013 ◽  
Author(s):  
A. Rezaei ◽  
M. Salimi Jazi ◽  
G. Karami ◽  
M. Ziejewski
Keyword(s):  
Mechanical Properties ◽  
Brain Tissue ◽  
Relaxation Times ◽  
Human Brain Tissue ◽  
Relaxation Functions ◽  
Before And After ◽  
Short And Long Term ◽  
Tissue Characteristics ◽  
Testing Protocols

Traumatic brain injury (TBI) is one of the most important problems in biomechanical engineering, and there have been many experiments conducted in order to characterize the mechanical properties of brain tissue. However, obtaining fresh human brain tissue is difficult, if not impossible. Also, the sample preparation and testing protocols must be carried out with great delicacy because brain tissue is very soft and vulnerable to being deformed under a very small amount of load. Most importantly, according to several researchers, each sample must be tested only one time as the tissue may be damaged and its characteristics subsequently changed. This paper is intended to examine the amount of decay that can happen in material characteristics due to retesting. A stress relaxation test is conducted on the same samples of the swine brain tissue multiple times in small and large deformations. The mechanical properties of the substance are calculated before and after retesting, and the constants of the tissue, as mechanical characteristics, are determined and compared. Short- and long-term moduli, relaxation times and relaxation functions are calculated and compared to understand how much they decay after repeating the experiments. The results show that retesting does not significantly change the elastic part of the tissue characteristics, but the viscous behavior shows a relatively sizeable change. The ability to account for the material decay of the samples due to repetition of the experiments results in the need for fewer samples and less preparation time and effort.

scholarly journals Influence of Gradation on the Mechanical Properties of Aged Hot-Mix Asphalts

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 632
Author(s):  
Saieth Baudilio Chaves-Pabón ◽  
Hugo Alexander Rondón-Quintana ◽  
Carlos Alfonso Zafra-Mejía
Keyword(s):  
Mechanical Properties ◽  
Cyclic Load ◽  
Stress Condition ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Short Term ◽  
Clear Trend ◽  
Indirect Tensile ◽  
Effects Of Aging

When a hot-mix asphalt (HMA) ages, its mechanical properties, resistance, and durability change. Several studies have been conducted throughout the world to evaluate the effects of aging in HMAs. However, few studies have analyzed the influence of gradation. The main objective of this study was to evaluate the influence of gradation on the mechanical properties of aged HMA mixes. For such purposes, three HMA mixes with different gradations were manufactured (named HMA-10, HMA-19, and HMA-25), which were conditioned in STOA (short-term oven aging) and LTOA (long-term oven aging) by following the guidelines established by the AASHTO R30 specification. Marshall, Indirect Tensile Strength (ITS), resilient modulus, permanent deformation, fatigue (under controlled-stress condition), and Cantabro tests were performed. These tests were carried out to evaluate resistance under monotonic and cyclic load as well as the resistance to moisture damage and abrasion. The best performing mix in the test was HMA-19. There is no clear trend about the influence of gradation over the susceptibility of mixes for aging. This susceptibility changes depending on the test performed and the property measured. Furthermore, in resilient modulus tests, it is observed that the influence of gradation on aging susceptibility changes depending on the test temperature.

scholarly journals The Effects of Various Conditions of Short-Term Rejuvenation Heat Treatment on Room-Temperature Mechanical Properties of Thermally Aged P92 Boiler Steel

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6076
Author(s):  
Ladislav Falat ◽  
Lucia Čiripová ◽  
Viera Homolová ◽  
Miroslav Džupon ◽  
Róbert Džunda ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Toughness ◽  
Room Temperature ◽  
Laves Phase ◽  
Short Term ◽  
Boiler Steel ◽  
P92 Steel ◽  
The Impact

In this work, the effects of various conditions of short-term rejuvenation heat treatment on room-temperature mechanical properties of long-term aged P92 boiler steel were investigated. Normalized and tempered P92 steel pipe was thermally exposed at 600 °C for time durations up to 5000 h in order to simulate high-temperature material degradation, as also occurring in service conditions. Thus, thermally embrittled material states of P92 steel were prepared, showing tempered martensitic microstructures with coarsened secondary phase precipitates of Cr23C6-based carbides and Fe2W-based Laves phase. Compared with the initial normalized and tempered material condition, thermally aged materials exhibited a slight decrease in strength properties (i.e., yield stress and ultimate tensile strength) and deformation properties (i.e., total elongation and reduction of area). The hardness values were almost unaffected, whereas the impact toughness values showed a steep decrease after long-term ageing. An idea for designing the rejuvenation heat treatments for restoration of impact toughness was based on tuning the material properties by short-term annealing effects at various selected temperatures somewhat above the long-term ageing temperature of P92 material. Specifically, the proposed heat treatments were performed within the temperature range between 680 °C and 740 °C, employing variable heating up and cooling down conditions. It was revealed that short-term annealing at 740 °C for 1 h with subsequent rapid cooling into water represents the most efficient rejuvenation heat treatment procedure of thermally aged P92 steel for full restoration of impact toughness up to original values of normalized and tempered material state. Microstructural observations clearly indicated partial dissolution of the Laves phase precipitates to be the crucial phenomenon that played a key role in restoring the impact toughness.

Study of the Influence of the Chemical Resistance of Polyphenylenesulphone from Radel on Mechanical Properties

2021 ◽  
Vol 899 ◽  
pp. 245-252
Author(s):  
Elena V. Rzhevskaya ◽  
Vladlena V. Davydova ◽  
Igor V. Dolbin
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Chemical Resistance ◽  
Short Term ◽  
Chemical Reagents

The paper presents the results of a study of the chemical resistance and mechanical properties of polyphenylene sulfone manufactured by Solvay, Radel brand, obtained by injection molding. Chemical resistance was investigated in short-term tests (24 hours duration), standard (7 days) and long-term (16 weeks). The mechanics of PPSU samples after exposure to chemical reagents is presented. It was revealed in what chemical environments and how much the mechanical properties of polyphenylene sulfone are preserved.

The Effect of Ageing on the Micro-Creep Properties of Radiation Cross-Linked Materials

2016 ◽  
Vol 368 ◽  
pp. 134-137
Author(s):  
Martin Řezníček ◽  
Martin Ovsík ◽  
Adam Škrobák ◽  
David Manas
Keyword(s):  
Mechanical Properties ◽  
Polymeric Materials ◽  
Term Effect ◽  
Short Term ◽  
Creep Properties ◽  
Long Term Effect ◽  
Radiation Crosslinking ◽  
Positive Effect

Radiation crosslinking of polymeric materials have placed and nowadays in the field of long-term use of loaded products. This article aims to identify the long-term effect of radiation crosslinking on micro-creep properties. The article compares the micro-creep properties of HDPE measured two years ago with the results of tests conducted under the same conditions and on the same samples now. The effect of time on the mechanical properties of the radiation crosslinked materials was demonstrated in short-term tests. These findings demonstrate the positive effect of time on the evaluated parameters.

The Effects of Retesting on the Mechanical Properties of the Brain Tissue

2013 ◽  
Author(s):  
Asghar Rezaei ◽  
Ghodrat Karami ◽  
Fardad Azarmi ◽  
Mehdi Salimi Jazi ◽  
Mariusz Ziejewski
Keyword(s):  
Mechanical Properties ◽  
Brain Tissue ◽  
Relaxation Times ◽  
Stress Relaxation Test ◽  
Preparation Time ◽  
Relaxation Functions ◽  
Before And After ◽  
Short And Long Term ◽  
The Brain

This research is intended to examine the amount of changes that can happen in material characteristics after retesting. Stress relaxation test is conducted on the same samples of the swine brain tissue for several times in small and large deformations. The mechanical properties of the substance are calculated before and after retest and the constants of the tissue, as mechanical characteristics, are determined and compared. Short- and long-term moduli, relaxation times and relaxation functions are of those data that are calculated and compared to understand how much they decay after repeating the experiments. The results show that applying different tests on one sample slightly changes the mechanical properties of the tissue and, as a result, it is partly possible to perform more than one test on the same sample resulting in less sample preparation, time and effort.

scholarly journals The Weibull Distribution on Reliability Evaluation of Mechanical Property for Impaction Bone Grafting

2020 ◽  
Author(s):  
Mumingjiang Yishake ◽  
Lan Tang ◽  
Chenyi Ye ◽  
Rongxin He
Keyword(s):  
Mechanical Properties ◽  
Weibull Distribution ◽  
Bone Grafting ◽  
Elastic Moduli ◽  
High Reliability ◽  
Bone Grafts ◽  
Impaction Bone Grafting ◽  
Large Bone

Abstract Background: The mechanical properties of bone grafts used to reconstruct defects during revision surgery, and their long-term reliability, are important in terms of treatment outcomes. However, few relevant studies have appeared. Herein, we use a new method, the Weibull distribution, to evaluate reliability.Methods: We created impacted bone grafts of two distinct sizes (7–10 mm and small slurry) using an impacting apparatus. The elastic moduli were evaluated in vitro and the Weibull moduli (m values) were calculated.Results: The elastic moduli fitted the Weibull distribution well. Large bone grafts (7–10 mm) exhibited high elastic moduli but low Weibull moduli, suggestive of poor reliability.Conclusions: The Weibull distribution was useful to evaluate the reliability of bone graft mechanical properties. A high Weibull modulus indicated high reliability and thus low variability. Both the values and reliability of mechanical properties must be considered when contemplating bone grafting.

Effect of weld structure on fracture mode of heat-temperature HP40NbTi alloy

2021 ◽  
pp. 369-379
Author(s):  
S.Yu. Kondrat'ev ◽  
M.D. Fuks ◽  
M.A. Frolov
Keyword(s):  
Mechanical Properties ◽  
Fracture Mode ◽  
Welded Joint ◽  
Structural Heterogeneity ◽  
Term Strength ◽  
Short Term ◽  
Heat Temperature ◽  
Weld Structure

The microstructure and phase composition of pipe welded joint made of HP40NbTi alloy are studied. The short-term and long-term mechanical properties of the pipe base metal and the welded joint are determined. It is shown that the structural heterogeneity of the weld and the formation of G-phase in the heat-affected zone significantly reduce the long-term strength of the alloy. The fracture mode and the role of G-phase in the cracks formation during the operation of the welded joint are studied.

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