To see the other types of publications on this topic, follow the link: Size of deformations.
Journal articles on the topic 'Size of deformations'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Size of deformations.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Rojas, Eduardo, Jaime Horta, and María de la Luz Pérez-Rea. "Modeling the soil-water retention curves for highly deforming soils." MATEC Web of Conferences 337 (2021): 02003. http://dx.doi.org/10.1051/matecconf/202133702003.
Full textAbstract:
A porous-solid model based on the grain and pore size distributions of the soil is coupled with a mechanical model to simulate the soil-water retention curves while the material is deforming. During the determination of the main drying curve, the soil is subjected to high suctions which induce important volumetric deformations. These volumetric deformations modify the pore size distribution of the sample affecting both the drying and the wetting retention curves. Although, most deformation occurs at drying, the drying curve is only slightly affected by soil deformation. In contrast, the wetting curve shows important shifting when volume change is considered.
2
Ma, Dan, Yan Dong Qu, and Xiang Qing Kong. "Error Analysis in Calculating the Internal Force of Plane Statically Determinate Truss by the Original Size Principle." Applied Mechanics and Materials 268-270 (December 2012): 1168–71. http://dx.doi.org/10.4028/www.scientific.net/amm.268-270.1168.
Full textAbstract:
Ignoring the deformation effect, the original size principle is normally used to calculate the internal force and deformations of the bars in Mechanics of Materials, the calculation error is not discussed in the textbooks, however. In order to show the adaptability of the original size principle to calculate the internal force of plane statically determinate truss, a case of the two-bar statically determinate truss was also given. The calculation error of the internal force and the angle deformations are quantitatively studied to make a comparison between the actual internal force and that calculated by the original size principle. The research showed that the relative error of angle deformations and the internal forces of the two rods are nonlinear dependent on the external forces (the given force), tensile stiffness and the initial angle of the plane truss. If the strength and tensile stiffness of the bars can meet the requirements of engineering, the original size principle can be used to calculate the internal force of metallic bar truss under the conditions of small deformations.
3
Vershina, G. A., and L. E. Reut. "Influence of Elastic Core on Size of Ring Product under Bending of Fluoroplastic Band." Science & Technique 18, no. 1 (February 12, 2019): 21–31. http://dx.doi.org/10.21122/2227-1031-2019-18-1-21-31.
Full textAbstract:
The paper is devoted to study of a possibility to manufacture fluoroplastic products while using method of cold deformation of pressed blanks and research of peculiar features in mechanical behavior of fluoroplastic which are revealed during deformation that affects quality and accuracy of the manufactured parts. Manufacturing technique of fluoroplastic sealing rings which are obtained while using method of coiling a band blank on a cylindrical mandrel with further endurance in a wound state and subsequent cutting of a spiral on rings has been considered in the paper. An important stage in the development of the technological process is a calculation and a design of a tool (mandrel caliber) that ensure obtaining of ring products with the required size and shape. Deformation behavior of fluoroplastic under conditions of force action is significantly different from the behavior of the known classical materials and it has a number of specific features and manifestations. Therefore the problem for creation of a calculation methodology for tool development looks as a complicated one and it requires a justified approach while selecting a mechanical model of polymer. Considering the fact that fluoroplastic has a structure with a high degree of crystallinity, a mechanism and sequence of deformations in it due to load are largely similar to the behavior of metals and other low-molecular materials. It allows to use methods and approaches adopted in the mechanics of solids for a calculation of fluoroplastic products however it is necessary to take into account the fact that deformation processes in polymers proceed in time and have a different nature of elastic and residual deformations. When bending the fluoroplastic band in case of winding it on the mandrel residual deformations which provide the required size and shape play the most significant role. However elastic deformations which cause springing and change of size in a finished product after removal of loading are also important. It has been proved that an elastic zone of finite width which has a certain influence on accuracy of manufactured products with due account of all accumulated elastic deformations will be present in the field of a neutral layer even at high degrees of deformation. In this case, fluoroplastic is a multi-modulus material having elasticity which at stretching is significantly higher than in compression, and therefore elastic recovery is more associated with the area of stretched fibers. The authors have developed a methodology for calculation of the tool for obtaining rings of the required size on the basis of the analysis pertaining to deformation behavior of the fluoroplastic while taking into account specificity of its mechanical properties. The proposed methodology with a sufficient degree of accuracy is consistent with the results of experimental studies.
4
Ivanova, Tatiana N., Witold Biały, Jiři Fries, and Victor Nordin. "Technological Forecasting of Deformations in Flat Parts." Multidisciplinary Aspects of Production Engineering 3, no. 1 (September 1, 2020): 1–12. http://dx.doi.org/10.2478/mape-2020-0001.
Full textAbstract:
AbstractThe deformation of a part occurring in the process of grinding directly influences its exploitation and quality parameters. The instability of shape and size, which occurs due to an imbalance of residual stress, can be the one of the major causes of deformation of a part. The decrease in stress slows down the deformation process. Considering the regularities of heat source intensity dependence on the grinding modes, it can be asserted that with increasing grinding depth and grinding wheel hardness, the value increases and it decreases with a growth in a speed of the part and the use of cooling. The higher the heat removal is and the better lubricant properties of the liquid are, the more significant the decrease in is. Changing these values allows regulation of the residual stresses. As a result of the research on determination of deformations, it is recommended to reduce thermal deformations by considering the geometric size of a plate to be machined, linear expansion coefficient of plate material and an allowance for nonflatness from thermal deformations. The value of nonflatness from thermal deformations is directly proportional to linear expansion coefficient of plate material and its square overall dimensions. At the same time, the value of nonflatness is inversely proportional to the plate thickness.
5
Piekarska, Wiesława, Zbigniew Saternus, Milan Sapieta, and Peter Kopas. "The influence of joining technique on the deformation of laser welded T-joints." MATEC Web of Conferences 254 (2019): 02011. http://dx.doi.org/10.1051/matecconf/201925402011.
Full textAbstract:
T-joints are often used in large-scale welded constructions. The use of a laser beam for welding allows to create joints using various techniques. Used welding method affects the shape and size of heat affected zone, deformation of welded elements and consequently the quality of the joint. This work concerns the numerical modeling of the size of heat affected zone and welding deformations in T-joint obtained with two different welding techniques: single-side fillet T-joint and butt welded T-joint, called I-core welded joint. Numerical simulations are carried out in the commercial Abaqus FEA software, supplemented by an additional numerical subroutines which enabled the analysis of thermomechanical phenomena occurring in welding process. Mathematical model of a moveable welding source and the description of heat source positioning relative to the edges of the connected elements are described in numerical subroutines. The material parameters of austenitic steel are taken into account. The size of deformations of welded joints are determined as well as the influence of two different joininig techniques of T-joint on the amount of generated welding deformations are analyzed and compared.
6
Markiewicz, Włodzimierz. "Remarks on the Automatic Cylinder Oil Mixing System for Two Stroke Dual Fuel Crosshead Marine Engines." Multidisciplinary Aspects of Production Engineering 3, no. 1 (September 1, 2020): 13–27. http://dx.doi.org/10.2478/mape-2020-0002.
Full textAbstract:
AbstractThe deformation of a part occurring in the process of grinding directly influences its exploitation and quality parameters. The instability of shape and size, which occurs due to an imbalance of residual stress, can be the one of the major causes of deformation of a part. The decrease in stress slows down the deformation process. Considering the regularities of heat source intensity dependence on the grinding modes, it can be asserted that with increasing grinding depth and grinding wheel hardness, the value increases and it decreases with a growth in a speed of the part and the use of cooling. The higher the heat removal is and the better lubricant properties of the liquid are, the more significant the decrease in is. Changing these values allows regulation of the residual stresses. As a result of the research on determination of deformations, it is recommended to reduce thermal deformations by considering the geometric size of a plate to be machined, linear expansion coefficient of plate material and an allowance for nonflatness from thermal deformations. The value of nonflatness from thermal deformations is directly proportional to linear expansion coefficient of plate material and its square overall dimensions. At the same time, the value of nonflatness is inversely proportional to the plate thickness.
7
Niu, Xing Hua, Li Qiang Cui, Bao Chuan Hao, Si Yu Liu, Zhen Tao Zhang, and Xian Li Meng. "Analysis of Plunge Milling Force and Tool Deformation on Cr12." Advanced Materials Research 652-654 (January 2013): 2173–77. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.2173.
Full textAbstract:
The paper takes the cold working die steel Cr12 for specimen material,carries out the plunge milling test on Cr12 and the plunge milling force has been measured by YDX - Ⅲ 9702 piezoelectric milling dynamometer. The tool deformations are analyzed both in plunge milling and side milling on the same size milling force. Test and analysis show that the axial milling force significantly greater than the other two directions and the tool deformation in plunge milling less than the tool deformation in the side milling.
8
Yurkov, A. S. "On the flexoelectric deformations of finite size bodies." JETP Letters 99, no. 4 (April 2014): 214–18. http://dx.doi.org/10.1134/s0021364014040158.
Full text
9
Yurkov, A. S. "Calculation of flexoelectric deformations of finite-size bodies." Physics of the Solid State 57, no. 3 (March 2015): 460–66. http://dx.doi.org/10.1134/s1063783415030373.
Full text
10
Pesin, Alexander, Ernst Drigun, D. O. Pustovoytov, and Ilya Pesin. "Technology Development of Large-Size Bodies Manufacturing from Thick Plate Materials Based on Combined Methods of Deformation." Key Engineering Materials 685 (February 2016): 375–79. http://dx.doi.org/10.4028/www.scientific.net/kem.685.375.
Full textAbstract:
The main goal of the investigation is to determine key technological parameters, necessary for producing required curvature of sheets up to 4000 mm in width with the required mechanical properties. Investigation into dynamics of the process' main technological parameters allowed it to define its three characteristic stages: asymmetric rolling, asymmetric rolling in combination with initial unsettled plastic bending, and asymmetric rolling combined with settled plastic bending. It was found out that the intensity of the deformations changes unevenly, depending on the height of the deformation zone, on all three stages, with its highest value being in the lower part of the sheet, and with the lowest value being in its center. In the second stage, the intensity of the deformation abruptly increases, and a significant asymmetry on the sheet thickness occurs. In the third stage, the non-uniformity of the intensity deformations fields decreases. Similar results can be also observed for stress intensities. Casings on two converters were produced and installed in the oxygen-converter plant.
11
Kvačkaj, Tibor, and Jana Bidulská. "From Micro to Nano Scale Structure by Plastic Deformations." Materials Science Forum 783-786 (May 2014): 842–47. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.842.
Full textAbstract:
Nowadays, the strategy for improving of mechanical properties in metals is not oriented to alloying followed by heat treatment. An effective way how to improve the mechanical properties of metals is focused on the research looking for some additional structural abilities of steels. Structural refinement is one of the ways. Refinement of the austenitic grain size (AGS) carried out through plastic deformation in a spontaneous recrystallization region of austenite, formation of AGS by plastic deformations in a non-recrystallized region of austenite will be considered as potential ways for AGS refinement. After classic methods of plastic deformations, next structure refinement can be obtained by an application of severe plastic deformation (SPD) methods.
12
Pertseva, Olga N., Gleb V. Martynov, Daria E. Monastyreva, Ekaterina I. Pereladova, Zaur S. Daurov, and Roman S. Tikhonov. "The sustainability of micropolar concrete plasticity model to the finite element size." Vestnik MGSU, no. 5 (May 2019): 559–69. http://dx.doi.org/10.22227/1997-0935.2019.5.559-569.
Full textAbstract:
Introduction. As it is known, deformation of concrete can be divided into several stages. The first stage is characterized by a linear dependence of deformations and stresses, elastic deformations and small loads that, as they increase, lead to the second stage. At the second stage, the dependence becomes curvilinear, while deformations are irreversible, since micro-cracks are formed. Further consolidation of the micro-cracks into meso- and main cracks refers to the third stage and is accompanied by a redistribution of energy to the area of the main crack mouth. However, reaching the ultimate strength is not accompanied by an instant loss of bearing capacity due to the effect of decompression. This phenomenon should be taken into account in the numerical simulation of concrete and reinforced concrete structures, because it significantly affects their strength characteristics. The introduction of such a refinement in the design models will allow reducing cross-sections of the construction components and accordingly getting rid of material overruns.
Materials and methods. A digital sample is created for the study using the ANSYS software. A beam model is simulated as a single-span beam with longitudinal reinforcement in the bending zone. The load is applied as a 70 mm offset to the nodes in the line along the application point. Reinforcement is simulated as bilinear isotropic strengthening elements (LINK180). For uniform load distribution, load plates with linear elastic properties are specified at the points where boundary conditions and load are applied.
Results. According to the obtained data, stress-deformation curves are constructed identically to the concrete deformation diagram. The values of loads when the first cracking occurs (end of the linear-elastic state), peak loads when the main crack is formed (maximum load for the unreinforced case and the beginning of the steel softening for the reinforced case) as well as ultimate loads and maximum deflections at the mid-span are compared.
Conclusions. The results give insignificant (up to 5 %) discrepancies when changing the finite element size. Therefore, when working with calculation software, developers will be able to create correct models with any spacing of the finite element mesh depending on the available computational capabilities. Micropolar theory for simulating the concrete decompression can be considered sustainable to the size of the finite elements.
13
Dybowski, K., J. Sawicki, P. Kula, B. Januszewicz, R. Atraszkiewicz, and S. Lipa. "The Effect of the Quenching Method on the Deformations Size of Gear Wheels after Vacuum Carburizing." Archives of Metallurgy and Materials 61, no. 2 (June 1, 2016): 1057–62. http://dx.doi.org/10.1515/amm-2016-0178.
Full textAbstract:
Abstract This paper presents a comparison of the deformations and residual stresses in gear wheels after vacuum carburizing process with quenching in high-pressure nitrogen and oil. The comparison was made on a medium-sized gear wheels, made of AMS6265 (AISI 9310) steel. This steel is applied in the aerospace industry for gears. The study has provided grounds for an assessment of the effect of the method of quenching on the size of deformations. Compared to oil quenching, high-pressure gas quenching following vacuum carburizing resulted in more uniform and smaller deformations.
14
Man, Jin, Li Li Yang, Chao Feng Xia, Guang Jie Shao, and Man Jin. "The Influence of Thermomechanical Treatment on the Microstructure and Properties of a Wrought Al-Mg-Si Alloy." Advanced Materials Research 194-196 (February 2011): 1342–46. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.1342.
Full textAbstract:
. To investigate the effects of thermomechanical treatments (TMT) on the microstructure and properties of Al-Mg-Si alloy, the cold deformation on the ageing precipitation of a solution-treated Al-Mg-Si alloy was studied. The results shows that the time of reaching the peak hardness is shortened with the increasing deformation and an obvious increasing in the peak hardness and tensile strength are occured with higher amount of deformations. The microstructures of peak hardness reveals that the average size of the precipitates becomes smaller in size and greater in number in the alloy with 50% deformations. The study is also carried out to investigate the changes in resistivity of alloys during the ageing time in the alloy with and without 50% deformation. It was found that there are rapidly increasing in resistivity followed by decreasing with the onset of ageing time in both cases. However, the extent of increasing and decreasing in resistivity is much stronger in the alloy with 50% deformation. These results were discussed according to the effects of cold deformation on the dislocations and precipitates in the Al-Mg-Si alloy.
15
Paudyal, Kalyan. "Analysis of support system for a conveyance tunnel in the higher Himalayan zone: A case study on Upper Tamakoshi HEP, Nepal." Journal of Innovations in Engineering Education 4, no. 1 (March 5, 2021): 90–97. http://dx.doi.org/10.3126/jiee.v4i1.35393.
Full textAbstract:
After excavation, insitu stress conditions are changed which lead deformation due to the stress concentration. For the stability in the excavated tunnel profile, appropriate support system is essential. To recommend the support system, site specific data are used from Higher Himalayan Region of Nepal. Study is focused on 3 m and 6 m size inverted D Shaped tunnel with three different overburden thickness. For the analysis of support system: Empirical method, Analytical method and Numerical Modeling are performed. Result obtained from the different approaches for three different overburden heights as well as for both size tunnels are compared and finally required support system is recommended. It was found significant change in deformations while increase in size of tunnel. Overburden thickness is also playing the vital role in this parameter but size effect is more prominent.
16
Arefi, Mohammad, and Ashraf M. Zenkour. "Size-dependent thermoelastic analysis of a functionally graded nanoshell." Modern Physics Letters B 32, no. 03 (January 29, 2018): 1850033. http://dx.doi.org/10.1142/s0217984918500331.
Full textAbstract:
In this paper, two-dimensional thermoelastic analysis of a functionally graded nanoshell is presented based on nonlocal elasticity theory. To formulate this problem, first-order shear deformation theory (FSDT) is used for axial and radial deformations simultaneously. Material properties are assumed to be mixture of ceramic and metal based on a power law distribution. Principle of virtual work is used for derivation of the governing equations. The analytical approach is presented based on eigenvalue and eigenvector method to derive four unknown functions including radial and axial displacements and rotations along the longitudinal direction. In addition, the influence of nonlocal and in-homogeneous index parameter is studied on the responses of the system. Two-dimensional results are presented along the radial and longitudinal directions.
17
Narayana Murty, S. V. S., and Shiro Torizuka. "Process Design Concepts for the Production of Ultrafine Grained Steels through Multi-Pass Warm Rolling: Bridging Science and Technology." Materials Science Forum 683 (May 2011): 225–31. http://dx.doi.org/10.4028/www.scientific.net/msf.683.225.
Full textAbstract:
Steel bars having a cross section of 18mm square with uniform distribution of ultrafine ferrite grains were produced through a multi-pass warm caliber rolling process in a 0.15%C-0.3%Si-1.5%Mn steel. The average ferrite grain sizes of 0.43μ m, 0.70μ m and 1.2 μ m were obtained in the isothermal warm caliber rolling processes at 773K, 823K and 873K respectively. Even though caliber rolling results in inhomogeneous strain distribution, multi-pass caliber rolling to large cumulated strains of 2 or 3 can be uniformly introduced in to the bar samples. Strain accumulation due to the multi-pass warm deformations was confirmed by comparing microstructural evolution through the multi-pass deformations with that of single pass deformation. The size of ultrafine grains formed through warm deformation was found to depend on the Zener-Hollomon parameter. The similarity of the microstructural evolution with single pass deformation reveals that the multi-pass warm deformation is an effective method to obtain ultrafine grained ferrite structure in bulk materials. It is proposed that compressive strain-Z parameter plots along with grain size-Z parameter plots help in establishing the processing conditions for obtaining products with a desired microstructure and grain size. Finally, such “processing maps” developed for a variety of materials serve useful purpose in bridging the science and technology of developing bulk ultrafine grained materials in semi-finished / finished products.
18
Velsink, Hiddo. "Testing deformation hypotheses by constraints on a time series of geodetic observations." Journal of Applied Geodesy 12, no. 1 (January 26, 2018): 77–93. http://dx.doi.org/10.1515/jag-2017-0028.
Full textAbstract:
AbstractIn geodetic deformation analysis observations are used to identify form and size changes of a geodetic network, representing objects on the earth’s surface. The network points are monitored, often continuously, because of suspected deformations. A deformation may affect many points during many epochs. The problem is that the best description of the deformation is, in general, unknown. To find it, different hypothesised deformation models have to be tested systematically for agreement with the observations. The tests have to be capable of stating with a certain probability the size of detectable deformations, and to be datum invariant. A statistical criterion is needed to find the best deformation model. Existing methods do not fulfil these requirements. Here we propose a method that formulates the different hypotheses as sets of constraints on the parameters of a least-squares adjustment model. The constraints can relate to subsets of epochs and to subsets of points, thus combining time series analysis and congruence model analysis. The constraints are formulated as nonstochastic observations in an adjustment model of observation equations. This gives an easy way to test the constraints and to get a quality description. The proposed method aims at providing a good discriminating method to find the best description of a deformation. The method is expected to improve the quality of geodetic deformation analysis. We demonstrate the method with an elaborate example.
19
Sugita, Kazuki, Yasumasa Mutou, and Yasuharu Shirai. "Strain-Rate Dependence of Vacancy Cluster Size in Hydrogen-Charged Martensitic Steel AISI410 under Tensile Deformation." Defect and Diffusion Forum 373 (March 2017): 171–75. http://dx.doi.org/10.4028/www.scientific.net/ddf.373.171.
Full textAbstract:
The strain-rate dependence of vacancy cluster sizes in hydrogen-charged martensitic steel AISI410 under tensile deformation was investigated using positron lifetime spectroscopy. The vacancy-cluster sizes in hydrogen-charged samples tended to increase with decreasing strain rates during the tensile deformations. The vacancy-cluster sizes significantly correlated to the tensile elongations to fracture. It was revealed that the presence of large-sized vacancy-clusters can cause the degradation of mechanical properties and followed by brittle fracture.
20
Luri, R., C. J. Luis, J. León, and M. A. Sebastian. "A New Configuration for Equal Channel Angular Extrusion Dies." Journal of Manufacturing Science and Engineering 128, no. 4 (February 22, 2006): 860–65. http://dx.doi.org/10.1115/1.2194555.
Full textAbstract:
Equal channel angular extrusion or pressing (ECAE or ECAP) is a process used in order to impart severe plastic deformations to processed materials with the aim of improving their mechanical properties by reducing the grain size. The grain size reduction leads to mechanical properties improvement. In the present study, a new die configuration is proposed for the ECAE process. The advantage of this die geometry is that it allows us to obtain higher plastic strain in each ECAE passage than traditional ECAE dies. It is important to optimize the die geometry, as the main aim of the ECAE process is to impart severe plastic deformations to the processed materials. Consequently, the higher the deformation, the better the improvement on the mechanical properties of the processed materials. In order to determine how variations on geometry affect the plastic strain of the processed materials finite element modeling (FEM) is used. Both analytical and FEM methods will allow us to affirm that by using this new die configuration it is possible to achieve higher deformation values per ECAE passage.
21
Yang, Wenqing, Jianlin Xuan, and Bifeng Song. "Experimental Study on Flexible Deformation of a Flapping Wing with a Rectangular Planform." International Journal of Aerospace Engineering 2020 (September 24, 2020): 1–13. http://dx.doi.org/10.1155/2020/8857078.
Full textAbstract:
A flexible flapping wing with a rectangular planform was designed to investigate the influence of flexible deformation. This planform is more convenient and easier to define and analyzed its deforming properties in the direction of spanwise and chordwise. The flapping wings were created from carbon fiber skeleton and polyester membrane with similar size to medium birds. Their flexibility of deformations was tested using a pair of high-speed cameras, and the 3D deformations were reconstructed using the digital image correlation technology. To obtain the relationship between the flexible deformation and aerodynamic forces, a force/torque sensor with 6 components was used to test the corresponding aerodynamic forces. Experimental results indicated that the flexible deformations demonstrate apparent cyclic features, in accordance with the flapping cyclic movements. The deformations in spanwise and chordwise are coupled together; a change of chordwise rib stiffness can cause more change in spanwise deformation. A certain lag in phase was observed between the deformation and the flapping movements. This was because the deformation was caused by both the aerodynamic force and the inertial force. The stiffness had a significant effect on the deformation, which in turn, affected the aerodynamic and power characteristics. In the scope of this study, the wing with medium stiffness consumed the least power. The purpose of this research is to explore some fundamental characteristics, as well as the experimental setup is described in detail, which is helpful to understand the basic aerodynamic characteristics of flapping wings. The results of this study can provide an inspiration to further understand and design flapping-wing micro air vehicles with better performance.
22
Guillou, Lionel, Avin Babataheri, Michael Saitakis, Armelle Bohineust, Stéphanie Dogniaux, Claire Hivroz, Abdul I. Barakat, and Julien Husson. "T-lymphocyte passive deformation is controlled by unfolding of membrane surface reservoirs." Molecular Biology of the Cell 27, no. 22 (November 7, 2016): 3574–82. http://dx.doi.org/10.1091/mbc.e16-06-0414.
Full textAbstract:
T-lymphocytes in the human body routinely undergo large deformations, both passively, when going through narrow capillaries, and actively, when transmigrating across endothelial cells or squeezing through tissue. We investigate physical factors that enable and limit such deformations and explore how passive and active deformations may differ. Employing micropipette aspiration to mimic squeezing through narrow capillaries, we find that T-lymphocytes maintain a constant volume while they increase their apparent membrane surface area upon aspiration. Human resting T-lymphocytes, T-lymphoblasts, and the leukemic Jurkat T-cells all exhibit membrane rupture above a critical membrane area expansion that is independent of either micropipette size or aspiration pressure. The unfolded membrane matches the excess membrane contained in microvilli and membrane folds, as determined using scanning electron microscopy. In contrast, during transendothelial migration, a form of active deformation, we find that the membrane surface exceeds by a factor of two the amount of membrane stored in microvilli and folds. These results suggest that internal membrane reservoirs need to be recruited, possibly through exocytosis, for large active deformations to occur.
23
Maji, Kuntal. "Parametric Study and Optimization of Pulsed Laser Thermal Micro-Forming of Thin Sheets." International Journal of Manufacturing, Materials, and Mechanical Engineering 9, no. 2 (April 2019): 47–61. http://dx.doi.org/10.4018/ijmmme.2019040103.
Full textAbstract:
This article presents the investigations on deformation behavior in precision forming of thin sheet metal by laser pulses using finite element analysis. The temperature and deformation fields were estimated and analyzed in pulsed laser micro-forming of AISI 304 stainless steel sheet of rectangular and circular shape considering the effects of different process parameters such as laser power, spot diameter and pulse on time. Response surface models based on finite element simulation results were developed to study the effects of the process parameters on deformations for the rectangular and circular workpieces. The amount of deformation was increased with the increase in laser power and pulse on time, and it was decreased with the increase in spot diameter. The effects of pulse frequency and sample size on deformations were also explained. Experiments were conducted on pulsed laser micro-forming of stainless-steel sheet to validate the finite element results. The results of finite element simulations were in good agreement with the experimental results.
24
Kumar, G. V. Preetham, Ganesh G. Niranjan, and Chakkingal Uday. "Grain Refinement in Commercial Purity Titanium Sheets by Constrained Groove Pressing." Materials Science Forum 683 (May 2011): 233–42. http://dx.doi.org/10.4028/www.scientific.net/msf.683.233.
Full textAbstract:
Grain refinement studies in titanium have gained significant interest owing to its importance as a biomaterial. Severe plastic deformation techniques have been widely applied for grain refinement in metals and are capable of producing ultra fine and nano sized microstructures. In this study, repetitive shear deformations by constrained groove pressing have been applied to commercial purity titanium sheets of 2 mm thickness at a warm working temperature of 300oC. Microstructure studies reveal the formation of elongated grains with widths of the order of 0.5μm from an initial grain size of 40μm in the annealed condition. An increase in strength is also observed.
25
Edens, Michael Q., and Robert L. Brown. "Changes in microstructure of snow under large deformations." Journal of Glaciology 37, no. 126 (1991): 193–202. http://dx.doi.org/10.1017/s0022143000007206.
Full textAbstract:
AbstractA set of microstructural variables is selected to characterize the behavior of snow. Corresponding mathematical relations from quantitative stereology theory are presented along with relations and techniques required for numerical evaluation. An experimental investigation is carried out to determine changes in these variables for snow subjected to large compressive deformations. The micro-structural variables studied included coordination number, grain-size, bond radius, neck length, pore-size, free surface area and grains/unit volume. Measurements at several stages of deformation are used to evaluate the changes in the microstructure as functions of deformation. Microstructure measurements of six snow samples subjected to confined compression tests are presented for pre-compressed and compressed states, corresponding to final stresses of 0.387, 0.77 and 1.55 MPa. Grain-size and bond radius were found to go through finite changes during compression, although the variation of bond radius was more complicated in nature. The coordination number and number of bonds/unit volume were found to go through large changes during compression, while specific free surface area was found to increase by 100% due to grain- and bond-fracture processes. No discernible patterns of change in neck length could be found in the experiments. A close relationship between some of the microstructural variables and the stress response of the material was observed. These results serve to contribute to the presently available data and understanding of the microstructural behavior of snow.
26
Edens, Michael Q., and Robert L. Brown. "Changes in microstructure of snow under large deformations." Journal of Glaciology 37, no. 126 (1991): 193–202. http://dx.doi.org/10.3189/s0022143000007206.
Full textAbstract:
AbstractA set of microstructural variables is selected to characterize the behavior of snow. Corresponding mathematical relations from quantitative stereology theory are presented along with relations and techniques required for numerical evaluation. An experimental investigation is carried out to determine changes in these variables for snow subjected to large compressive deformations. The micro-structural variables studied included coordination number, grain-size, bond radius, neck length, pore-size, free surface area and grains/unit volume. Measurements at several stages of deformation are used to evaluate the changes in the microstructure as functions of deformation. Microstructure measurements of six snow samples subjected to confined compression tests are presented for pre-compressed and compressed states, corresponding to final stresses of 0.387, 0.77 and 1.55 MPa. Grain-size and bond radius were found to go through finite changes during compression, although the variation of bond radius was more complicated in nature. The coordination number and number of bonds/unit volume were found to go through large changes during compression, while specific free surface area was found to increase by 100% due to grain- and bond-fracture processes. No discernible patterns of change in neck length could be found in the experiments. A close relationship between some of the microstructural variables and the stress response of the material was observed. These results serve to contribute to the presently available data and understanding of the microstructural behavior of snow.
27
Benamirouche, Samir, Mebarek Chouial, and Wiam Guechi. "Radicle length and container size effects on root deformities in the Mediterranean oak Quercus suber L." BOIS & FORETS DES TROPIQUES 343 (January 14, 2020): 17–26. http://dx.doi.org/10.19182/bft2020.343.a31669.
Full textAbstract:
The aim of this study was to assess the effects on root deformations in Mediterranean cork oaks Quercus suber L. of container size and radicle length at the time of sowing. Acorns at five sowing methods – intact acorns, acorns that had germinated during storage, acorns that had germinated after moist stratification and acorns with radicles (R) less than 5 mm in length, 7 mm to 12 mm in length and more than 15 mm length – were planted individually in WM type containers of 400 cm3, 800 cm3 and 1,200 cm3. At the end of the nursery growth period, the roots of the 1,080 sampled seedlings were examined for root deformities. The experiment results showed that root deformation affected almost half (49%) of the container-grown cork oak seedlings and that the germination status of acorns at the time of planting had a significant effect on root deformations, whereas container volume had no clear effect. The largest number of deformed roots (91%) was observed in seedlings grown from germinated acorns, as compared to 9% of seedlings grown from intact acorns. Planting germinated acorns with radicles 15 < R < 20 mm and 7 < R < 12 mm in length produced the highest percentages of detrimental deformations. Irrespective of size, the bottomless WM container type was shown to be highly effective against the root spiralling frequently observed in closed cylindrical polyethylene bags. The results of this study could help to improve cork oak seedling quality for more successful reforestation programs.
28
Chkadua, Tamara Zurabovna, A. G. Nadtochiy, V. G. Asirova, M. M. Chernen’kiy, S. S. Frolov, and P. I. Davydenko. "Reconstructive otoplasty: precision virtual simulation autoreverse cartilaginous skeleton of the auricle." Russian Journal of Dentistry 21, no. 1 (February 15, 2017): 36–38. http://dx.doi.org/10.18821/1728-28022017;21(1):36-38.
Full textAbstract:
In the article the objectives are to develop a methodology for determining the size and configuration of the ear cartilage according to CT and to optimize surgical treatment ofpatients with defects and deformations of auricles of a various aetiology on the basis of development of a technique of virtual simulation precision Auto Reverse cartilaginous skeleton of the auricle. On the basis of CT studied anthropometric parameters of the cartilaginous part of the ribs - the donor area to obtain the cartilaginous skeleton of the auricle of the required size and configuration. Intraoperative data confirmed the parameters obtained in precision of virtual modeling, which helped to significantly optimize the operation, reducing her time due to the stage of obtaining cartilage grafts and allowing the donor to reduce the damage and severity ofsubsequent deformation of the chest. Suggested activities can be used as precision planning to improve the efficiency of surgical treatment to eliminate defects and deformations of auricles.
29
Wiggs, B. R., D. English, W. M. Quinlan, N. A. Doyle, J. C. Hogg, and C. M. Doerschuk. "Contributions of capillary pathway size and neutrophil deformability to neutrophil transit through rabbit lungs." Journal of Applied Physiology 77, no. 1 (July 1, 1994): 463–70. http://dx.doi.org/10.1152/jappl.1994.77.1.463.
Full textAbstract:
Neutrophil margination within the pulmonary capillary is due to a delay in their transit compared with that of red blood cells (RBC). This delay has been attributed to the large fraction of capillary segments that are narrower than spherical neutrophils and differences between the time required for deformation of neutrophils and that required for deformation of RBC. This study investigated the characteristics of neutrophil deformation in vivo and the perfusion patterns of segments within capillary pathways. Studies comparing the extraction of neutrophils with that of nondeformable microspheres in one transit through the pulmonary circulation suggest that neutrophils can undergo a rapid deformation from 6.4 to 5.0–5.1 microns, whereas larger deformations require a delay. Effective diameters of the perfused capillary pathways were larger than expected for a random distribution of capillary segment diameters within these pathways. The longer transit times of neutrophils in the upper regions of the lung were associated with a greater fraction of pathways containing narrow segments. These studies suggest that neutrophil deformability and capillary pathway diameters are important in determining the size of the marginated pool of neutrophils within the pulmonary capillaries.
30
Small, Scott R., John B. Meding, Jordan W. Oja, Katherine S. Lakstins, Danielle J. Gehron, Renee D. Rogge, and Christine A. Buckley. "Shell design and reaming technique affect deformation in mobile-bearing total hip arthroplasty acetabular components." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 231, no. 8 (April 8, 2017): 691–98. http://dx.doi.org/10.1177/0954411917701952.
Full textAbstract:
Press-fit acetabular components are susceptible to rim deformation. The inherent variability within acetabular reaming techniques may generate increased press-fit and, subsequently, additional component deformation. The purpose of this study was to analyze the insertion and deformation characteristics of acetabular components designed for dual-mobility systems based on component design, size, and reaming technique. Shell deformation was quantified in a validated worst-case scenario foam pinch model. Thin-walled, one-piece, and modular dual-mobility shells of varying size were implanted in under- and over-reamed cavities with insertion force measured and shell deformation assessed using digital image correlation. Increased shell size resulted in larger rim deformation in one-piece components, with a reduction in press-fit by 1 mm resulting in up to 48% reduction in insertion forces and between 23% and 51% reduction in shell deformation. Lower insertion forces and deformations were observed in modular components. Variability in acetabular reaming plays a significant role in the ease of implantation and component deformation in total hip arthroplasty. Modular components are less susceptible to deformation than thin-walled monoblock shells. Care should be taken to avoid excessive under-reaming, particularly in the scenario of large shell size and high-density patient bone stock.
31
Chu, Bin-Lin, Yeun-Wen Jou, and Meng-Chia Weng. "A constitutive model for gravelly soils considering shear-induced volumetric deformation." Canadian Geotechnical Journal 47, no. 6 (June 2010): 662–73. http://dx.doi.org/10.1139/t09-135.
Full textAbstract:
This study elucidates the deformational behavior of gravelly soils by analyzing how hydrostatic pressure and pure shearing affect deformational behavior. A series of drained, triaxial compression tests have been performed using large specimens made of gravelly soils, where the grain-size distribution curve was based on the field condition. The volumetric and shear deformations of gravelly soils have been determined by performing experiments with controlled stress paths — hydrostatic pressure was applied first followed by pure shearing. A simple and innovative constitutive model is also proposed. The proposed model is characterized by the following features of gravelly soils: (i) significant shear-induced volumetric deformation prior to failure, (ii) modulus stiffening under hydrostatic loading and degradation under shearing, and (iii) stress-induced anisotropy. In the proposed model, deformational moduli K and G vary according to the stress state. The stiffening and degradation of these moduli result in diverse deformational behavior of gravelly soils. In addition, an anisotropic factor, β, is introduced to represent stress-induced anisotropy. Moreover, the proposed model only requires eight material parameters; each of which can be obtained easily from experiments.
32
S, Yershov, Levchenko G, Kaiming Wu, Wen Zhou, and Ke Rui. "The development of a new deformation regime for microstructure refinement in solid railway axles by hot deformation optimization." Theory and practice of metallurgy 1,2020, no. 1,2020 (124) (January 21, 2020): 5–17. http://dx.doi.org/10.34185/tpm.1.2020.01.
Full textAbstract:
Goal. During the production of railway axles, the main target is to obtain a uniform metal structure with a grain size not larger than number 5 across the entire section of the produced axle. Moreover, in accordance with the demands of railway axle consumers, the differences in grain size numbers should not exceed 2. However, due to multi-stage processing and repeated heating of axle material, the fulfillment of aforesaid requirements is very difficult and the differences in grain size numbers are usually found as 4. Therefore, it is necessary to develop a special deformation regime for controlling the sizes and the uniformities of metal grains in the finished product. Methods. We employed experimental and theoretical investigations to reveal the microstructure refinement in the deformation zone of the produced railway axle. The experimental investigation was carried out under the production conditions, whereas the theoretical investigation was performed based on the theory of plasticity and finite element method. Results. Furthermore, the regularities of process parameters in the deformation zone were revealed; hence, a new deformation regime was developed, and consequently, the quality of the finished railway axle was improved. Scientific novelty. Rolling of solid railway axle required special de-formation regimes that differed from the deformation regimes for rolling of other types of products. Deformations in vertical and edging directions with edging reduction were less penetrative to the central zone of the billet as compared to surface layers, thus resulting in an increase in energy consumption and equipment load of the rolling mill. Rolling with edging reduction caused a worse de-formation at the central zone of the billet in the box caliber.Rolling without edging reduction caused large deformations in central layers of the billet and led to a significant improvement in the metal structure of the axle.
33
Zheng, Yonggang, Hongfei Ye, and Hongwu Zhang. "Twin-induced template effect on the inelastic deformation of hierarchically nanotwinned copper under indentation and scratch." International Journal of Damage Mechanics 25, no. 1 (March 2, 2015): 56–68. http://dx.doi.org/10.1177/1056789515574123.
Full textAbstract:
The inelastic deformation of hierarchically nanotwinned copper that is composed of primary and secondary twins under indentation and scratch has been investigated by using large-scale molecular dynamics simulations. Simulation results show that the partial dislocation activities are the main factor that dominates the inelastic deformation. Both the indentation and scratch processes show arrest and burst behaviors of partial dislocations, which indicates that the twin boundaries have a template effect on the inelastic deformations. Moreover, it is found that the characteristic size of the inelastic deformation zone increases, respectively, with the increase of the primary and secondary twin spacings.
34
Mojahedi, M., and M. Rahaeifard. "A size-dependent model for coupled 3D deformations of nonlinear microbridges." International Journal of Engineering Science 100 (March 2016): 171–82. http://dx.doi.org/10.1016/j.ijengsci.2015.12.010.
Full text
35
Liang, W., and M. Zhou. "Response of copper nanowires in dynamic tensile deformation." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 218, no. 6 (June 2004): 599–606. http://dx.doi.org/10.1243/095440604774202231.
Full textAbstract:
Molecular dynamics (MD) simulations with an embedded atom method (EAM) potential are carried out to analyse the size and strain rate effects in the tensile deformation of single-crystal copper nanowires. The cross-sections of the wires are squares with dimensions of between 5 and 20 lattice constants (or 1.8-7.2nm). Deformations under constant strain rates between 1.67 × 107 and 1.67 × 1010s−1 are analysed. It is found that the yield stress decreases with specimen size and increases with loading rate. On the other hand, ductility increases with specimen size and strain rate. The influence of specimen size is due to enhanced opportunities for dislocation motion at larger sizes. The influence of strain rate is due to the dynamic wave effect or phonon drag which impedes the motion of dislocations. The analysis also focuses on the variation in deformation mechanisms with specimen size and strain rate. Slip along alternating (111) planes is observed in small wires, while multiple cross-slips are primarily responsible for the progression of plastic deformation in larger wires. As strain rate is increased, a transition of the deformation mechanism from sequential propagation of slip along well-defined and favourably oriented slip planes to cross-slip, and then to amorphization, is observed.
36
Zhu, Mao, Xiaoli Wan, Bigang Fei, Zhuping Qiao, Chunqing Ge, Federico Minati, Francesco Vecchioli, Jiping Li, and Mario Costantini. "Detection of Building and Infrastructure Instabilities by Automatic Spatiotemporal Analysis of Satellite SAR Interferometry Measurements." Remote Sensing 10, no. 11 (November 16, 2018): 1816. http://dx.doi.org/10.3390/rs10111816.
Full textAbstract:
Satellite synthetic aperture radar (SAR) interferometry (InSAR) is a powerful technology to monitor slow ground surface movements. However, the extraction and interpretation of information from big sets of InSAR measurements is a complex and demanding task. In this paper, a new method is presented for automatically detecting potential instability risks affecting buildings and infrastructures, by searching for anomalies in the persistent scatterer (PS) deformations, either in the spatial or in the temporal dimensions. In the spatial dimension, in order to reduce the dataset size and improve data reliability, we utilize a hierarchical clustering method to obtain convergence points that are more trustworthy. Then, we detect deformations characterized by large values and spatial inhomogeneity. In the temporal dimension, we use a signal processing method to decompose the input into two main components: regular periodic deformations and piecewise linear deformations. After removing the periodic component, the velocity variation in each identified temporal partition is analyzed to detect anomalous velocity trends and accelerations. The method has been tested on different sites in China, based on InSAR measurements from COSMO-SkyMed data. The results, verified with in-field surveys, confirm the potential of the method for the automatic detection of deformation anomalies that could cause building or infrastructure stability problems.
37
Wesołowski, Marek. "Numerical Modeling of Exploitation Relics and Faults Influence on Rock Mass Deformations." Archives of Mining Sciences 61, no. 4 (December 1, 2016): 893–906. http://dx.doi.org/10.1515/amsc-2016-0059.
Full textAbstract:
Abstract This article presents numerical modeling results of fault planes and exploitation relics influenced by the size and distribution of rock mass and surface area deformations. Numerical calculations were performed using the finite difference program FLAC. To assess the changes taking place in a rock mass, an anisotropic elasto-plastic ubiquitous joint model was used, into which the Coulomb-Mohr strength (plasticity) condition was implemented. The article takes as an example the actual exploitation of the longwall 225 area in the seam 502wg of the “Pokój” coal mine. Computer simulations have shown that it is possible to determine the influence of fault planes and exploitation relics on the size and distribution of rock mass and its surface deformation. The main factor causing additional deformations of the area surface are the abandoned workings in the seam 502wd. These abandoned workings are the activation factor that caused additional subsidences and also, due to the significant dip, they are a layer on which the rock mass slides down in the direction of the extracted space. These factors are not taken into account by the geometrical and integral theories.
38
Saveliev, D. V., L. Yu Fetisov, D. V. Chashin, P. A. Shabin, D. A. Vyunik, F. A. Fedulov, W. Kettl, and M. Shamonin. "Method of Measuring Deformations of Magnetoactive Elastomers under the Action of Magnetic Fields." Russian Technological Journal 7, no. 4 (August 11, 2019): 81–91. http://dx.doi.org/10.32362/2500-316x-2019-7-4-81-91.
Full textAbstract:
Magnetic deformation is a change in the size and shape of a sample under the action of a uniform external magnetic field. The study of this effect in various materials provides deep understanding of the nature of magnetic and mechanical interactions. Moreover, magnetic deformation is of great interest from an engineering point of view for designing new devices. In magnetoactive elastomers containing magnetic microparticles in the polymer matrix, a giant deformation is detected under the action of an external magnetic field. The generally accepted methods for measuring magnetic deformation in magnetoactive soft materials are now practically absent. The article describes the installation for the study of the magnetomechanical characteristics of magnetoactive elastomers and demonstrates its experimental capabilities. The installation allows to measure deformations in the range from 0 to 12.5 mm with a resolution of 1 micron. The deformation curves obtained using these installations are required for developing actuators and sensors based on magnetoactive elastomers, and also for improving their manufacturing technologies.
39
Zhou, Min. "Thermomechanical continuum representation of atomistic deformation at arbitrary size scales." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 461, no. 2063 (September 5, 2005): 3437–72. http://dx.doi.org/10.1098/rspa.2005.1468.
Full textAbstract:
A thermomechanical equivalent continuum (TMEC) theory is developed for the deformation of atomistic particle systems at arbitrary size scales and under fully dynamic conditions. This theory allows continuum interpretation of molecular dynamics (MD) model results and derivation of thermomechanical continuum constitutive properties from MD results under conditions of general macroscopically transient thermomechanical deformations, which are not analysed by statistical mechanics. When specialized to the more specific conditions of non-deforming systems in macroscopic equilibrium, this theory yields certain results that are identical to, or consistent with, the results of statistical mechanics. Coupled thermomechanical continuum equations and constitutive behaviour are derived using MD concepts in a time-resolved manner. This theory is a further advancement from the purely mechanical equivalent continuum (EC) theory developed recently. Within the meaning of classical mechanics, the TMEC theory establishes the ultimate atomic origin of coupled thermomechanical deformation phenomena at the continuum level. The analysis is based on the decomposition of atomic particle velocity into a structural deformation part and a thermal oscillation part. On one hand, balance of momentum at the structural level yields fields of stress, body force, traction, mass density and deformation as they appear to a macroscopic observer. On the other hand, balance of momentum for the thermal motions relative to the macroscopically measured structure yields the fields of heat flux and temperature. These quantities are cast in a manner as to conform to the continuum phenomenological equation for heat conduction and generation, yielding scale-sensitive characterizations of specific heat, thermal conductivity and thermal relaxation time. The structural deformation and the thermal conduction processes are coupled because the equations for structural deformation and for heat conduction are two different forms of the same balance of momentum equation at the fully time-resolved atomic level. This coupling occurs through an inertial force term in each equation induced by the other process. For the structural deformation equation, the inertial force term induced by thermal oscillations of atoms gives rise to the phenomenological dependence of deformation on temperature. For the heat equation, the inertial force term induced by structural deformation takes the phenomenological form of a heat source.
40
Besimbayeva, Olga, Georgy Ustavitch, and Elena Oleynikova. "MONITORING OF DEFORMATIONS OF THE LAND SURFACE IN THE EARNED ADDITIONALLY TERRITORIES." Interexpo GEO-Siberia 1, no. 1 (2019): 82–91. http://dx.doi.org/10.33764/2618-981x-2019-1-1-82-91.
Full textAbstract:
In article issues of monitoring of a condition of the land surface in the earned additionally ter-ritory at the expense of a mine side work are considered. The Karaganda and Sherubaynurinsky dis-tricts were chosen for observations. In the chosen territory observing stations are put, on nine sites of the Karaganda coal basin within four years’ systematic tool observations of the earned addition-ally sites of the land surface for the purpose of identification of change of size of displacement were made eventually. Analyzing results of measurements, calculations of displacement and deformations of a surface where the direct dependence of intensity of subsidence of the land surface was found were made. Process of formation and development of a trough of displacement in dynamics is con-sidered. For a research of deformation of the land surface on earned additionally territories carried out also satellite monitoring.
41
Nukhov, Danis Sh, and Andrey O. Tolkushkin. "Development of Advanced Technologies for the Production of Innovative Materials with a Submicrocrystalline Structure by Methods of Severe Plastic Deformation." Defect and Diffusion Forum 410 (August 17, 2021): 191–96. http://dx.doi.org/10.4028/www.scientific.net/ddf.410.191.
Full textAbstract:
A promising direction for the development of steel and alloy processing processes is the intensification of plastic deformation by creating zones of localization of shear strains not only in the longitudinal but also in the transverse directions of the deformed metal flow. Intensification of alternating deformations along the entire cross-section and, especially, in the axial zone of the billet by creating new deformation schemes is an effective way to increase the physical, mechanical and functional properties of the metal with the maximum approximation of the finished product size to the original billet size. The paper shows that a promising idea is the development of new technological schemes that implement severe alternating deformation in existing metal forming processes. A continuous rolling method of wide strips is proposed, which provides severe alternating deformation with minor changes in the size of the billet. Based on this method, a scheme of continuous rolling of the strip with the intensification of plastic deformation of the metal is designed. The results of computer simulation showed that the new rolling method increases the strain uniformity in height and the value of the strain degree in the plane of symmetry of the billet.
42
PONOMARENKO, Mariya Ruslanovna, and Yuriy Ivanovich KUTEPOV. "Using the typification of mining-engineering facilities to substantiate deformation monitoring of opencast mining." NEWS of the Ural State Mining University, no. 4 (December 20, 2020): 115–22. http://dx.doi.org/10.21440/2307-2091-2020-4-115-122.
Full textAbstract:
To date, in the field of monitoring deformations of the earth’s surface in the area of opencast mining, there is almost no current regulatory and methodological documentation that regulates the conduct of observations and at the same time takes into account the features of existing mining facilities of opencast mining and the possibilities of modern survey technologies. The paper gives an approach to determining a set of methods for deformation monitoring within the territory of mining enterprises engaged in open-pit mining, based on the results of the typification of mining facilities. The developed typification makes it possible to estimate the degree of complexity of mining-engineering facilities, taking into account their size, features of engineering-geological, hydrogeological and orographic conditions, geodynamic processes. To increase the information content of mine surveying, as well as the quality and accuracy of deformation monitoring as a whole, it is proposed to include technologies for Earth remote sensing from space, namely, satellite-based synthetic aperture radar (SAR) interferometry, used within the proposed concept for areal monitoring of deformations and detection potentially hazardous areas at complex and particularly complex opencast mining facilities. The proposed approach to the organization of deformation monitoring was tested within the territory of the Khibiny apatite-nepheline deposit of the Rasvumchorr Plateau: the complexity of conditions for the development of the Tsentralny open pit was evaluated and recommendations were formulated for conducting mine surveying of deformations of the earth’s surface in its territory using satellite-based SAR interferometry. This method was used to analyze deformations of the earth’s surface for the periods from 2007 to 2011 and from 2015 to 2016 according to data from the ALOS PALSAR, TerraSAR-X and Sentinel-1 satellites.
43
Julien, Jean-Daniel, and Karen Alim. "Oscillatory fluid flow drives scaling of contraction wave with system size." Proceedings of the National Academy of Sciences 115, no. 42 (October 3, 2018): 10612–17. http://dx.doi.org/10.1073/pnas.1805981115.
Full textAbstract:
Flows over remarkably long distances are crucial to the functioning of many organisms, across all kingdoms of life. Coordinated flows are fundamental to power deformations, required for migration or development, or to spread resources and signals. A ubiquitous mechanism to generate flows, particularly prominent in animals and amoebas, is actomyosin cortex-driven mechanical deformations that pump the fluid enclosed by the cortex. However, it is unclear how cortex dynamics can self-organize to give rise to coordinated flows across the largely varying scales of biological systems. Here, we develop a mechanochemical model of actomyosin cortex mechanics coupled to a contraction-triggering, soluble chemical. The chemical itself is advected with the flows generated by the cortex-driven deformations of the tubular-shaped cell. The theoretical model predicts a dynamic instability giving rise to stable patterns of cortex contraction waves and oscillatory flows. Surprisingly, simulated patterns extend beyond the intrinsic length scale of the dynamic instability—scaling with system size instead. Patterns appear randomly but can be robustly generated in a growing system or by flow-generating boundary conditions. We identify oscillatory flows as the key for the scaling of contraction waves with system size. Our work shows the importance of active flows in biophysical models of patterning, not only as a regulating input or an emergent output, but also as a full part of a self-organized machinery. Contractions and fluid flows are observed in all kinds of organisms, so this concept is likely to be relevant for a broad class of systems.
44
Shakhov, Sergey, and Nikita Nikolaev. "Management of structural and mechanical properties of moulding compound using mineral additives." MATEC Web of Conferences 239 (2018): 04022. http://dx.doi.org/10.1051/matecconf/201823904022.
Full textAbstract:
The purpose of work: the choice of the rational composition of the batch mixture, which improves the molding properties of the silt loams in the production of wall ceramics by the method of plastic molding. In the course of the study, the fraction-size distribution and morphological features of the fractions were analyzed on a photometric sedimentometer FSX-6K and by optical microscopy. Determination of the plastic strength of elasto-visco-plastic systems was carried out by Rehbinder’s conical plastometer. The values of fast and slow elastic and plastic deformations were determined on an installation operating on the principle of a parallel- shifting plate. For molding compounds with various corrective mineral additives, optimum values of molding moisture in which the compound is not adversely affected by shortage and excess moisture have been experimentally established; moduli of fast and slow elastic deformation and other structural and mechanical characteristics are determined. The percent values of the reduced deformations were obtained on the basis of rheological curves of disperse systems in the axes “deformation - shear time”. It is established that the additions of components of different genesis and with different fraction morphology affect the deformation behavior of the molding compounds.
45
Szojda, Leszek, and Grzegorz Wandzik. "Discontinuous terrain deformation - forecasting and consequences of their occurrence for building structures." MATEC Web of Conferences 284 (2019): 03010. http://dx.doi.org/10.1051/matecconf/201928403010.
Full textAbstract:
The paper is devoted to the influence of mining origin discontinuous deformations of on buildings. In the first part the forms of deformations, their classification, examples and reasons of their formation is discussed. It is supplemented with other classification (cited from literature) related to risk for buildings with regard to the type and intensity of deformation. In the next part, examples of damages of three various buildings located in zones of faults and sinkholes. They were: simple detached house, multi-storey and hall buildings. All of them were the subject of expertizes prepared by the authors. The type of influences and the nature of damages are illustrated with photographs and discussed. In the last part the threats due to the nature of the buildings – their height and size – are discussed. The influence of the location of deformation edge (fault, sinkhole, terrain step) in relation to the object is shortly analyzed. Examples of normal stress distribution in subsoil obtained in numerical calculations have been briefly presented. Some attention have been also paid on protection methods and their effectiveness.
46
Jeng, Yeau-Ren, and Chung-Ming Tan. "Static Atomistic Simulations of Nanoindentation and Determination of Nanohardness." Journal of Applied Mechanics 72, no. 5 (January 19, 2005): 738–43. http://dx.doi.org/10.1115/1.1988349.
Full textAbstract:
This paper develops a nonlinear finite element formulation to analyze nanoindentation using an atomistic approach, which is conducive to observing the deformation mechanisms associated with the nanoindentation cycle. The simulation results of the current modified finite element formulation indicate that the microscopic plastic deformations of the thin film are caused by instabilities of the crystalline structure, and that the commonly used procedure for estimating the contact area in nanoindentation testing is invalid when the indentation size falls in the nanometer regime.
47
Lipian, Michal, Pawel Czapski, and Damian Obidowski. "Fluid–Structure Interaction Numerical Analysis of a Small, Urban Wind Turbine Blade." Energies 13, no. 7 (April 10, 2020): 1832. http://dx.doi.org/10.3390/en13071832.
Full textAbstract:
While the vast majority of the wind energy market is dominated by megawatt-size wind turbines, the increasing importance of distributed electricity generation gives way to small, personal-size installations. Due to their situation at relatively low heights and above-ground levels, they are forced to operate in a low energy-density environment, hence the important role of rotor optimization and flow studies. In addition, the small wind turbine operation close to human habitats emphasizes the need to ensure the maximum reliability of the system. The present article summarizes a case study of a small wind turbine (rated power 350 W @ 8.4 m/s) from the point of view of aerodynamic performance (efficiency, flow around blades). The structural strength analysis of the blades milled for the prototype was performed in the form of a one-way Fluid–Structure Interaction (FSI). Blade deformations and stresses were examined, showing that only minor deformations may be expected, with no significant influence on rotor aerodynamics. The study of an unorthodox material (PA66 MO polyamide) and application of FSI to examine both structural strength and blade deformation under different operating conditions are an approach rarely employed in small wind turbine design.
48
Takeda, Yu. "Prediction of Butt Welding Deformation of Curved Shell Plates by Inherent Strain Method." Journal of Ship Production 18, no. 02 (May 1, 2002): 99–104. http://dx.doi.org/10.5957/jsp.2002.18.2.99.
Full textAbstract:
In order to achieve high productivity of assembly blocks of hull structure, it is important to predict welding deformations accurately and to apply these data to the production planning. For this purpose the transient thermal-elastic-plastic analysis by FEM (finite-element method) may be utilized. However, this method is not a practical approach to analyze the deformation of large and complex structures, such as ship hull structures, in view of time and cost. Whereas the inherent strain method deals the residual strain near the weld line as the inherent strain, therefore the residual deformation can be simply calculated by elastic analysis. This method is much more practical and efficient than the transient thermal-elastic-plastic analysis. Thus, in this paper, the inherent strain method is used to predict the welding deformation of hull structures. Past research activities of the inherent strain method have been focused on the prediction of the welding deformation of small size specimens and simple shape specimens; however, very few of them treat the problem of large and complex structures. Hence, in this paper, prediction of welding deformation of curved shell plate, of which size is approximately full scale, is conducted by the inherent strain method. In applying elastic analysis to predict the welding deformation of actual hull blocks, contact condition between the plate and the positioning jig should be adequately realized in the analysis. Therefore, a practical solution is proposed to con- sider the contact condition between the plate and the jig by judging reaction forces of the jig at calculation steps. Furthermore, since the welded plates may slip on the positioning jig due to the welding deformation, rigid body motion of plates is caused. Hence this motion should be taken into account of the estimation of calculated results of FEM. In addition to the rigid body motion, coordinate system of the measured data is usually different from the calculated data, therefore, the deviation of the coordinate system must be involved. These calibrations to assess the calculated deformation by FEM are also discussed. The above prediction method is confirmed to be successful by comparing the calculated deformations and the measured ones of large size specimen of curved shell plates due to butt welding.
49
LYASHENKO, P. A., V. V. DENISENKO, and M. B. MARINICHEV. "DESCRIPTION OF THE BORED PILES WORK IN A GROUP WITH USING AN EXTENDED RESISTANCE CIRCUIT OF SOIL BASE." Building and reconstruction 94, no. 2 (2021): 46–55. http://dx.doi.org/10.33979/2073-7416-2021-94-2-46-55.
Full textAbstract:
The calculation of the resistance of piles in the foundation is proposed according to an extended scheme, which includes the surrounding soil, which is inextricably connected with the pile through the side surface. The implementation of the extended scheme is possible with the application of the method of testing a model pile with a constantly increasing load with continuous measurement of precipitation (CRL method), supplemented by measurements of soil deformations relative to the pile surface and displacements of deep marks near the pile. Increasing the amount of information about the state of the soil allows us to obtain the values of additional forces elastically transmitted to neighboring piles, depending on the size of the areas of plastic deformation of the soil. The assessment of the mutual influence of piles during the increase in load on the foundation makes it possible to choose the best option of its parameters, including the size of piles, their placement in the foundation, changes in resistance and settlement over time.
50
de Loubens, C., J. Deschamps, F. Edwards-Levy, and M. Leonetti. "Tank-treading of microcapsules in shear flow." Journal of Fluid Mechanics 789 (January 26, 2016): 750–67. http://dx.doi.org/10.1017/jfm.2015.758.
Full textAbstract:
We investigated experimentally the deformation of soft microcapsules and the dynamics of their membrane in simple shear flows. Firstly, the tank-treading motion, i.e. the rotation of the membrane, was visualized and quantified by tracking particles included in the membrane by a new protocol. The period of membrane rotation increased quadratically with the extension of the long axis. The tracking of the distance between two close microparticles showed membrane contraction at the tips and stretching on the sides, a specific property of soft particles such as capsules. The present experimental results are discussed in regard to previous numerical simulations. This analysis showed that the variation of the tank-treading period with the Taylor parameter (deformation) cannot be explained by purely elastic membrane models. It suggests a strong effect of membrane viscosity whose order of magnitude is determined. Secondly, two distinct shapes of sheared microcapsules were observed. For moderate deformations, the shape was a steady ellipsoid in the shear plane. For larger deformations, the capsule became asymmetric and presented an S-like shape. When the viscous shear stress increased by three orders of magnitude, the short axis decreased by 70 % whereas the long axis increased by 100 % before any break-up. The inclination angle decreased from 40° to 8°, almost aligned with the flow direction as expected by theory and numerics on capsules and from experiments, theory and numerics on drops and vesicles. Whatever the microcapsule size and the concentration of proteins, the characteristic lengths of the shape, the Taylor parameter and the inclination angle satisfy master curves versus the long axis or the normalized shear stress or the capillary number in agreement with theory for non-negligible membrane viscosity in the regime of moderate deformations. Finally, we observed that very small deviation from sphericity gave rise to swinging motion, i.e. shape oscillations, in the small-deformation regime. In conclusion, this study of tank-treading motion supports the role of membrane viscosity on the dynamics of microcapsules in shear flow by independent methods that compare experimental data both with numerical results in the regime of large deformations and with theory in the regime of moderate deformations.