The observation of dislocation reversal in front of crack tips of polycrystalline copper after reducing maximum load

2003 ◽  
Vol 345 (1-2) ◽  
pp. 215-222 ◽  
Author(s):  
H.L. Huang ◽  
N.J. Ho
Keyword(s):  
Maximum Load ◽  
Polycrystalline Copper ◽  
Crack Tips

Dislocation structures around crack tips of fatigued polycrystalline copper

2005 ◽  
Vol 400-401 ◽  
pp. 418-421 ◽  
Author(s):  
Yoshihisa Kaneko ◽  
Masao Ishikawa ◽  
Satoshi Hashimoto
Keyword(s):  
Polycrystalline Copper ◽  
Crack Tips

Study on the Interaction of Multiple Flaws in Ductile Fracture Process

2011 ◽  
Author(s):  
Kazuhiro Suga ◽  
Katsumasa Miyazaki ◽  
Shota Kawasaki ◽  
Yohei Arai ◽  
Masanori Kikuchi
Keyword(s):  
Ductile Fracture ◽  
Maximum Load ◽  
Initial Crack ◽  
Multiple Cracks ◽  
Horizontal Distance ◽  
Initial Crack Length ◽  
Ductile Crack Growth ◽  
Crack Tips ◽  
Fracture Processes ◽  
Ductile Fracture Process

Study on the interaction of multiple cracks during ductile crack growth processes is important for the integrity evaluation of nuclear structure. The ductile fracture processes are well simulated using Gurson’s constitutive equation and taking into account of void growth during plastic deformation. In this study, two through wall cracks are assumed to exist in a plate in tension and the interaction between two cracks is studied. By changing the initial crack length, horizontal distance and vertical distance between inner crack tips, more than twenty cases are simulated. Interaction behavior between two crack tips is studied precisely. Criteria to evaluate maximum load in the ductile fracture processes are discussed.

An in vitro Comparison of Two Replacement Techniques Utilizing Fascia Lata after Cranial Cruciate Ligament Transection in the Dog

1993 ◽  
Vol 06 (02) ◽  
pp. 85-92 ◽  
Author(s):  
G. L. Coetzee
Keyword(s):  
Femoral Condyle ◽  
Cruciate Ligament ◽  
Maximum Load ◽  
Fascia Lata ◽  
Patellar Ligament ◽  
Cross Sectional ◽  
Cranial Cruciate Ligament ◽  
Replacement Technique ◽  
Over The Top

SummaryThe immediate postoperative biomechanical properties of an “underand-over” cranial cruciate ligament (CCL) replacement technique consisting of fascia lata and the lateral onethird of the patellar ligament, were compared with that of a modified intra- and extracapsular “under-and-over-the-top” (UOTT) method. The right CCL in twelve adult dogs was dissected out and replaced with an autograft. The contralateral, intact CCL served as the control. In group A, the graft was secured to the lateral femoral condyle with a spiked washer and screw. In group B the intracapsular graft was secured to the lateral femoro-fabellar ligament, and the remainder to the patellar tendon. Both CCL replacement techniques exhibited a 2.0 ± 0.5 mm anterior drawer immediately after the operation. After skeletonization of the stifles, the length and cross-sectional area of the intact CCL and CCL substitutes were determined. Each bone-ligament unit was tested in linear tension to failure at a fixed distraction rate of 15 mm/s with the stifle in 120° flexion. Data was processed to obtain the corresponding material parameters (modulus, stress and strain in the linear loading region, and energy absorption to maximum load).The immediate postoperative structural and material properties of the “under-and-over” cranial cruciate ligament replacement technique with autogenous fascia lata, were compared to that of a modified intra- and extracapsular “under-and-over-the-top” (UOTT) method. The combined UOT T technique was slightly stronger (6%), but allowed 2.8 ± 0.9 mm more cranial tibial displacement at maximum linear force.

Structural features and strength behavior of TRIP/TWIP steels

2020 ◽  
pp. 5-18
Author(s):  
D. V. Prosvirnin ◽  
◽  
M. S. Larionov ◽  
S. V. Pivovarchik ◽  
A. G. Kolmakov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Thermomechanical Processing ◽  
Maximum Load ◽  
Structural Features ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Structural And Functional Properties ◽  
Twip Steels ◽  
The Creation

A review of the literature data on the structural features of TRIP / TWIP steels, their relationship with mechanical properties and the relationship of strength parameters under static and cyclic loading was carried out. It is shown that the level of mechanical properties of such steels is determined by the chemical composition and processing technology (thermal and thermomechanical processing, hot and cold pressure treatment), aimed at achieving a favorable phase composition. At the atomic level, the most important factor is stacking fault energy, the level of which will be decisive in the formation of austenite twins and / or the formation of strain martensite. By selecting the chemical composition, it is possible to set the stacking fault energy corresponding to the necessary mechanical characteristics. In the case of cyclic loads, an important role is played by the strain rate and the maximum load during testing. So at high loading rates and a load approaching the yield strength under tension, the intensity of the twinning processes and the formation of martensite increases. It is shown that one of the relevant ways to further increase of the structural and functional properties of TRIP and TWIP steels is the creation of composite materials on their basis. At present, surface modification and coating, especially by ion-vacuum methods, can be considered the most promising direction for the creation of such composites.

The possibility of using myotonometry to assess the muscle fatigue of physical labor workers

2020 ◽  
Vol 60 (11) ◽  
pp. 892-894
Author(s):  
Evgeniya S. Shitova ◽  
Inga S. Malakhova ◽  
Vladislav I. Lemeshko
Keyword(s):  
Clinical Practice ◽  
Occupational Health ◽  
Muscle Fatigue ◽  
Soleus Muscle ◽  
Initial Level ◽  
Maximum Load ◽  
Main Area ◽  
Modern Methods ◽  
The Moment

Introduction. The use of classical methods for diagnosing muscle fatigue of physical workers, including dynamometry and electromyography, is often limited due to the complexity of the process, the inability to use them in production, and the subjectivity of the methodology. At the same time, such a method as myotonometry does not have these disadvantages, but the main area of its use at the moment is clinical practice. The aim of study was to determine the possibility of using myotonometry to assess muscle fatigue. Materials and methods. In the course of the study, the biomechanical characteristics of muscles that differ in their depth were evaluated using the "MyotonPro" device (Myoton AS, Estonia). We determined the tone and stiffness of the biceps of the shoulder, the soleus muscle, and the muscle that straightens the back at different periods of time under the influence of maximum load on them. Results. It was found that the studied parameters of these muscles immediately after performing a series of exercises "to failure" statistically significantly increased, and after 30 minutes - again decreased, but did not reach the initial level. Conclusions. The myotonometric study showed objectivity, reliability, repeatability and proved to be one of the most promising modern methods for assessing muscle fatigue, including for solving problems in the field of occupational health.

Plastic Yielding at Crack Tips.

1988 ◽  
Author(s):  
S. B. Altan ◽  
A. C. Eringen
Keyword(s):  
Plastic Yielding ◽  
Crack Tips

Wastewater Lagoons in a Cold Climate

1987 ◽  
Vol 19 (12) ◽  
pp. 47-53 ◽  
Author(s):  
J. A. Oleszkiewicz ◽  
A. B. Sparling
Keyword(s):  
Control Mechanism ◽  
Maximum Load ◽  
Domestic Sewage ◽  
Full Scale ◽  
Cold Climate ◽  
Odor Control ◽  
Intermittent Rivers ◽  
In Series ◽  
Break Up ◽  
Lagoon Systems

Severe climate, intermittent rivers and availability of land make facultative lagoon systems the method of choice in treating primarily domestic sewage from smaller municipalities. The lagoons are designed on a recommended maximum load of 55 kgBOD5/ha d to first cell, while the second cell provides storage. The discharge is twice annually and the occurrence of the spring ice break-up odor period is one of the primary criteria limiting this load. Based on full scale performance data, it is demonstrated that, from the standpoint of odor nuisance, the load to the first cell should be kept equal to or less than 35 kg/ha d. Full scale studies of an overloaded lagoon system show the futility of under-ice aeration for odor control. Mechanism of natural odor control during ice break up is elucidated. Upgrading of the overloaded systems or lagoons receiving significant industrial contribution is best achieved by construction of a 3–5 m deep aerated lagoon preceding the two or more facultative cells in series.

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