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Relocation of molten corium during severe accidents of a nuclear reactor is a complex phenomenon. One of the phenomena is a spreading process of molten fuel in the core catcher. In some core catcher design, molten fuel will be directed to different room through channel. Thus, molten fuel relocation, including spreading through the channel, is the key factor in accident mitigation that has to be understood well. MPS (moving particle semi-implicit) method has been used to simulate severe accident cases due to its advantage in dealing with surface deformation. The wave propagation of fluid flow over a wet channel case was used to validate the MPS simulation. In this investigation, a 2D simulation was conducted to simulate the case. The height comparison was made for two points between the experiment and the simulation. It shows good agreement in the parameter of water level. However, MPS simulation underestimate the height of the water level that may relates to particle size. [ABSTRACT FROM AUTHOR]

Interferometric Synthetic Aperture Radar (InSAR) use two SAR data acquired in the same path but at different time. InSAR exploits the phase difference between two data acquisitions time. The phase difference contains unique information due to the occurring phenomenon in between those times, for instance; surface deformation due to earthquake, a dense ionospheric or tropospheric turbulence. In this study, we apply InSAR to C-band Sentinel-1 data during Chiba's heavy rain. As a preliminary result, we identify the turbulent troposphere that includes heavy rain SAR data. [ABSTRACT FROM AUTHOR]

In the past years, many attempts have been made to combine GNSS with InSAR techniques to measure surface deformations resulting from mining area activities. The use of GNSS data with spaceborne radar interferometry can determine sites' deformation and sudden subsidence on the Earth's surface, which depends on the permanent scatter (PS). Deformation of the earth's surface in urban areas may cause a great danger to human lives, structures, and infrastructure in that area. The recent exploitation of mineral resources without the supervision of government institutions and a large number of excavations in mining areas may lead to sudden subsidence of the soil surface. Therefore, the use of InSAR techniques and their combination with GNSS data contributes to discovering sudden landing sites and identifying deformation areas at standard intervals after providing data for six CORS reference stations through GPS / GNSS, to create a network of points with coordinates known by ARC GIS program for the purpose of continuous monitoring of deformation sites in mining areas. The aim of the research is to continuously determine and monitor surface deformations, in addition to isolating local mining impacts from general impacts in mining areas. so, this study is considered one of the most important practical principles in the application of the Incorporation of GNSS data and InSAR technologies and their usefulness in identifying and monitoring sites of surface deformation and subsidence in mining areas. [ABSTRACT FROM AUTHOR]

Reverse engineering (RE) is a sophisticated science that involves building numerous tools to assist with various jobs. Modern technologies, the most significant of which is the scanner, have contributed to introducing another notion in this field of study. We must decide whether the object is related to engineering, medicine, or archaeology, as well as whether it has surface deformations or is disposable. This research will demonstrate how to utilize software programs, and Arduino UNO approaches to display digital data produced by a device intended to measure product dimensions on a computer without using sophisticated algorithms. The improvement in the dimensions of the data processed by CloudCompare and MATLAB programs reached 96.07%. [ABSTRACT FROM AUTHOR]

This article aims to investigate theoretically the performance of a transversely rough Electrohydrodynamics lubrication by considering bearing deformation. The Stochastic modeling of Christensen and Tonder has been adopted for calculating the effect of transverse surface roughness. The pressure distribution is obtained by deciphering the associated stochastically average Reynolds equation. All results, customized in a graphical way established that the transverse roughness in conjunction with the deformation has a robust adverse effect on the performance of the bearing system. This article may also have triumphed some measures for extending the life span of the bearing system, [ABSTRACT FROM AUTHOR]

In the nature, almost all the leaves were overlapping with other leaves. Separating a leaf from another is a step in deeply analyzing each leaf, for example leaf health analysis. Therefore, the image segmentation algorithm on overlapping leaves is needed to separate the target leaf from other leaves automatically. For this reason, this research proposes the overlapping leaves segmentation method by using the Chan-Vese model and the morphological operations. First, Chan-Vese model is applied for image segmentation by minimizing an energy functional for controlling the curve deformation movement and the evolution of the contour curve. Therefore, several morphological operators are used to improve the performance of the Chan-Vase method. This proposed method uses 3 operators which are the opening, dilation and erosion operators. The morphological operators are used for removing the small object and adjusting the result images size to the original image. Four images of natural leaves are used to evaluate the performance of the proposed method. The experimental results show that the proposed method is more accurate than Distance Regularized Level Set Evolution (DRLSE) method especially for the overlapping leaves. [ABSTRACT FROM AUTHOR]

Reverse engineering (RE) is an advanced science that entails the creation of many devices that help perform various tasks. Another concept of this science was introduced by modern technologies, the most important of which is the scanner. However, we are faced with several issues, including whether the piece has surface deformations or is expendable and whether it is related to engineering, medicine, or archaeology. This study will show how to use digital data generated by a device designed to measure product dimensions and display it on a computer using Arduino UNO techniques and several software programs without using complex algorithms. It was found that the data efficiency results through processing by MeshLab and MATLAB programs reached 89.15%. [ABSTRACT FROM AUTHOR]

This paper deals with an unfavorable phenomenon called the ponding effect. This phenomenon can cause an increase in local deformations on a tensile surface and therefore endanger the integrity of the structure in case of overcoming the tensile strength of the membrane material. A searching algorithm has been developed in order to analyze and prevent occurrence of this phenomenon. An improvement of the algorithm was made so that only an expected amount of precipitation would be considered during the calculation. [ABSTRACT FROM AUTHOR]

A reinforcement of concrete structures is needed because of the low tensile strength of concrete. Corrosion of the usually used steel reinforcments cause issues during time. Therfore, alternative reinforcements produced from non-corosive materials - like polymer fibers - become more interesting. A polymer fiber has to reach high mechanical properties and a good bonding ability to concrete. Both properties can be influenced by the selection of polymer and the used production process. Two polymers, polypropylene and aliphatic polyketone are tested within this study. First mono-material fibers of each material are produced and tested, later the materials are combined in a core-shell fiber. All fibers are produced by standard extrusion or coextrusion and a later drawing process. The mechanical properties are determined by tensile tests. The calculation of interfacial shear strength from single fiber pull-out tests allows an evaluation of the bonding ability. Additionally, fiber surface before and after pull-out is examined using reflected light microscopy. Contact angle measurements are done to evaluate possible influences of the surface energy and polarity. Density measurements are used to compare weight potential of the different mono-material and core-shell fibers. The results show good mechanical properties for all fiber materials. The interfacial shear strength is ≈ 2-3 times higher for fibers with polyketone compared to the ones with polypropylene at the fibers surface, which can be explained by higher surface energy and polarity of the polyketone compared to polypropylene and different surface deformation during pull-out. Lower densities are reached by fibers containing polypropylene. [ABSTRACT FROM AUTHOR]

Based on a performed analysis, an analytical method is proposed in the paper, for determining the accuracy during processing, taking into account the mutual influence of the components of the total inaccuracy. This is of particular importance in the processes of finishing treatment, such as surface plastic deformation (SPD), where technological heredity and the formative technological environment play an important role in forming the quality of the finished part. The matrix approach is applied, describing most fully the mechanism of formation of the constituent inaccuracies, taking into account the phenomenon of "technological heredity". The sequence for determining the transformation coefficients is given, by which the degree of mutual influence of the constituent inaccuracies in the interaction of the workpiece with the technological environment at the level of an operation is shown. [ABSTRACT FROM AUTHOR]

The possibility of using the microhardness method to determine the deformation of surface layers during cavitation wear of cast metal alloys is analyzed. The studies were carried out on two casting alloys: titanium alloy and AK12pch silumin. The experiments consisted of two stages. At the first stage, cylindrical samples were made from the listed alloys, which were compressed on a press to a different degree of plastic deformation, then cut in the middle along or across the axis of the sample. The obtained section was ground and polished, and then the microhardness of the obtained sections was measured and calibration graphs of the dependence of microhardness on the intensity of plastic deformation were built. The second stage included tests of alloys for cavitation wear on an ultrasonic magnetostrictive vibrator in fresh water at a frequency and amplitude of oscillations of the end of the concentrator of the device equal to 22 kHz and 28 µm, respectively. During the tests, the microhardness of the worn surface was periodically measured and the dependence of the microhardness on the duration of the cavitation effect was plotted. The maximum achievable value of microhardness during the incubation period of cavitation wear was determined from the maximum point on this dependence. According to the obtained maximum value of microhardness, the corresponding value of the intensity of plastic deformation of the worn surface was "removed" from the calibration curve. The causes of possible errors in determining the deformation of the surface of cast alloys worn during cavitation, when using the microhardness method, are established. [ABSTRACT FROM AUTHOR]

3D evaluation of machined surface texture parameters is required. Modern machining technologies make it possible to obtain developed surfaces and commonly used microgeometry parameters do not allow accurate assessment of surface data. The durability and performance properties of machine parts largely depend on the surface layer quality which is currently defined by a group of parameters referred to in the new ISO standards and GOST R ISO based on them as the "surface texture". The concept of "roughness" is included in the term "surface texture". Finishing processes that form a complex surface texture and are used in mass production are surface plastic deformation (for example, burnishing) and honing (plateau honing). Method for surface texture estimation previously developed by author was tested on 2D elementary figures. This publication discusses the elements formed by 3D figures, such as conical type irregularities. The significance of the considered parameter is shown. Subsequently this parameter can be used to evaluate surfaces obtained by such processes as honing and burnishing. [ABSTRACT FROM AUTHOR]

The article conducts an experimental study to investigate the opening effect on the capacity and behavior of built-up steel beams with corrugated webs. Five specimens were fabricated and tested under a two-point load, one of them without openings in its web (control specimens), while the other four specimens had openings at their maximum bending moment zone with various shapes of the same equivalent area (circular, rectangular, square, and rhombus). The results of load-deflection curves for all tested specimens were recorded; also, the distributed of deformation in control beam and around of openings was plotted using Digital Image Technique (DIC). The results show that the presence of an opening in the pure flexural zone of a beam negligible affect the beam's final carrying capacity compared with the control specimen and the difference between them is only in the form of mode failure in the beam. The specimen that contains one opening has more toughness because the load capacity is greater and shows less ductility. From this test, the circular opening is the best type of opening, while the failure shape of rhombus opening is the more dangerous. [ABSTRACT FROM AUTHOR]

In this paper, the equations of contact curves of rolls of rolls of roll machines are developed, where the rolls have coatings with different stiffness. The influence of the deformation and geometrical parameters of the roll pair and the material on the shape of the roll contact line is analyzed. It was revealed that the roll contact line are described by equations of the same type in cases where the deformation of the material being processed occurs along the vertical and along the radii of the rolls. [ABSTRACT FROM AUTHOR]

Hydrodynamic journal bearing is one of the most cost-effective and efficient machine elements, without any external means to maintain lubricant pressure along the periphery of the shaft, used to support the rotating shaft. When the journal begins to rotate it drags the lubricant to the zone where sliding contact exists between the shaft and bearing surfaces. The pressure underneath the journal gets raised, and when the journal rotates faster and a wedge action takes place, and the bearing which lifts the journal and separates it from the bearing surfaces. If the lubricant viscosity is too low, then the wedge won't be formed at all and if the viscosity is too high, then the friction will quickly overheat the bearing. In this work we have added nanoparticles of several sizes and also used several volume fractions with the fluid and perform an analysis to see its result. Empirical formulas are taken into the account for the calculation of density and viscosity of nanofluids by using their diameter and the volume fraction. Computational fluid dynamics analysis is performed to analyze the effect of density and viscosity of nanofluid on the lubricant pressure during operation and FSI analysis is performed to investigate the effect of deformation on the bearing surfaces. Temperature can reduce the viscosity of the lubricant and due to this the film thickness reduces and thus higher pressure is generated resulting in a higher eccentricity ratio and better load-carrying capacity of the journal bearing. [ABSTRACT FROM AUTHOR]

Burnishing is a surface treatment process that involves cold working. The process entails exerting pressure through a hard and smooth roller or ball onto a surface, resulting in plastic deformation of surface irregularities and the creation of a uniform, work-hardened surface. This study investigated the impact of burnishing force, burnishing feed, number of passes, and step-over on surface roughness and hardness. To facilitate burnishing on an NC lathe, we proposed a new method that employs a flank face positioned a few millimeters below the nose cutting edge of a tool. This research paper focused on fixed burnishing depth, speed, feed, and number of passes to study surface quality parameters. We presented our findings on surface roughness, surface micro hardness, and circularity. Ultimately, our results demonstrated the efficacy of the proposed method for achieving desired surface properties through burnishing. [ABSTRACT FROM AUTHOR]

Anak Krakatoa Volcano is a young volcano that appeared in the caldera after the proximal eruption in 1883 from the Krakatoa volcanic complex. currently, Anak Krakatoa Volcano is in the construction phase. Based on measurements by the Center for Volcanology and Geological Hazard Mitigation (PVMBG) conducted in September 2018, it was found that the elevation of the Anak Krakatoa volcano is above 338 m from sea level. From June 25, 2018, until the end of 2019 Anak Krakatoa Volcano experienced a strombolian eruption, this eruption caused deformation on the surface of the Volcano. The research used the Differential Interferometry Synthetic Aperture Radar (DInSAR) method with Sentinel-1A image data from April 2018 to December 2019 which was further validated using volcanic activity released by PVMBG. The results were obtained in the form of deformation value based on Line of Sight (LOS) displacement, and the result of deflation is 0,01 cm to 17,1 cm using cross-section in the area around the crater is deflation in June 2018 to February 2019. [ABSTRACT FROM AUTHOR]

Thermoforming process has now become the most suitable and conventional method for manufacturing 3D circuits with complex geometries. The mold of commercially available automobile lighting LED is developed using CNC machine. The stretchable circuit is printed on a thermoplastic substrate through screen printing technique before undergoing thermoforming process. The factors that affect a thermoformed product are the stretch level and thickness reductions of the substrate. This paper aims to study the effect of the variation in dimensions of the thermoformed product without the printed stretchable circuit on the substrate. Finite element methods (FEM) analysis is also carried out in order to visualize the behavior of the substrate in terms of area stretch ratios (ASR) and thickness reductions of different wall surfaces after deformation according to the geometry of the mold. The ASR and thickness values obtained by experiment and simulation are compared. As a result, the simulated values are bit higher than the experimental ones but they are acceptable, therefore, the behavior of thermoforming product like large stretch areas and less thickness, can be determined prior to the actual thermoforming process of the product with printed stretchable circuit. [ABSTRACT FROM AUTHOR]

The paper discusses the use of Interferometric Synthetic Aperture Radar (InSAR) technology to detect and monitor surface deformation caused by natural hazards such as earthquakes, volcanoes, and land subsidence. The article reviews various studies that have used InSAR to monitor deformation caused by earthquakes. The studies demonstrate the utility of InSAR in detecting and monitoring ground deformation caused by earthquakes. The paper provides details on two earthquake events at Iraq-Iran border, including their magnitudes, locations, and focal mechanism parameters, and includes a displacement map that illustrates the surface deformation caused by the events. The paper concludes by emphasizing the broad range of applications of InSAR technology, from natural hazard monitoring to topographic mapping and infrastructure projects. [ABSTRACT FROM AUTHOR]

Interferometric Synthetic Aperture Radar (InSAR) is a powerful technique used for measuring and monitoring surface deformation due to natural hazards. It combines Synthetic Aperture Radar (SAR) with interferometry and is used to detect small changes in surface deformation over time, regardless of weather or time of day. InSAR is extensively used to monitor and measure earthquakes, volcanoes, and land subsidence. This paper reviews the application of InSAR in earthquake monitoring and deformation analysis. The reviewed studies demonstrate the effectiveness of InSAR in detecting and monitoring ground deformation caused by earthquakes. The use of advanced remote sensing technology and data processing techniques have enabled the detection of deformation at increasingly high spatial and temporal resolutions. Additionally, the paper provides a case study of a 6.3 Mw earthquake event in 2018, discussing the fault type and displacement map generated through InSAR technology. In conclusion, InSAR is a valuable tool in natural hazard monitoring and has wide-ranging applications from structural engineering. [ABSTRACT FROM AUTHOR]

The effects of underground mining on road surfaces are a serious problem. Deformed road surfaces significantly affect the comfort and safety of use. For example, discontinuous deformations characterized by discontinuity of the medium affect the condition of the road structure. Loosening the layers that make up the pavement structure reduces its stiffness and thus reduces the fatigue life of the pavement. Frequent repairs are the result. Therefore, it is important in mining areas to constantly monitor the condition of the facilities, determine the need and scope of surface repair. Various measurement methods can help, mainly geodetic measurement of displacements. Additionally, in order to monitor the condition of the road infrastructure, their operational features are determined, such as the condition of cracks and surfaces, longitudinal evenness or the depth of ruts. Subsoil surveys performed with geophysical methods are often required. In the research, both classical and modern measurement techniques were used to measure the deformation of the road surface in the mining area. The observations were made for a group of points constituting the observation line along the right-of-way. The changes that were observed were linear, discontinuous deformations and pavement undulations. In addition to identifying the geometric changes of the road, the method of assessing changes in pavement stiffness was also used. [ABSTRACT FROM AUTHOR]

This research has studied the features of the surface relief and the change in the microstructure of ARMCO iron after propagation the deformation front at room and elevated temperatures. The fronts of the Chernov–Luders bands move monotonously at room temperature. This corresponds to the typical stress-strain curve of low-carbon steel. After deformation, shear bands are observed in the material, both in individual grains and conglomerates of grains. At elevated temperatures, the fronts of the Chernov–Luders bands move discretely with stops. In this setting, a serrated deformation is observed on the stress-strain curve. A periodic relief with a spatial period of∼6 mm is observed after passage the deformation front at the mesoscopic level. [ABSTRACT FROM AUTHOR]

The development of non-linear deformations in slabs supported along the contour and weakened by holes is evaluated. The data and main features of full-scale testing of slabs, the results of measurements of deflections, settlements of supports, surface deformations on the lower surface of the slab, and crack opening widths are presented. The patterns of cracks at each stage of loading structures with an external load are described. Large holes affect the distribution of forces. The interruption of the longitudinal working reinforcement along the short side leads to a delay in the growth of forces in the ratio of 1:3 in the zones of the slab without holes, 1:2 in the zones with holes. The bearing capacity of the slabs was determined based on the test results. The deflection of 1.25 mm achieved with a control load of 0.51 tf/m2 is lower than the calculated 4.3 mm. Data on the possibility of constructing a picture of cracks, yield lines as a result of computer calculation have been obtained. [ABSTRACT FROM AUTHOR]

To obtain the required data on the deformation modes for manufacturing and on the quality parameters of the surface of the manufactured sheet metal parts with complex configuration, the issues of simulation of magnetic pulse forming of sheet parts and the formation of complex transition surfaces by deformation on die with various forms of profile geometry are considered. [ABSTRACT FROM AUTHOR]

The processes of local surface plastic deformation of machine parts are considered. It has been established that the real surface of machine parts after blade processing has a predominantly wedge-shaped (triangular) profile in the longitudinal direction. It is shown that the mechanism of microprofile shaping, due to its irregular nature, etc., has not been sufficiently studied. The mechanism of the shape change of the microroughness model at the degrees of deformation comparable to the height of the initial micro-profile has been established. The influence of the degree of micro-profile settlement on the angle at the base of the deformed micro-profile, the relative width of the contact surface, as well as on the behavior of the point of the micro-profile depression depending on the loading conditions is presented. A significant effect of loading conditions on the nature of deformation of the microprofile has been established. [ABSTRACT FROM AUTHOR]

The article identifies the effect of the speed of heavy trucks on the strength of the pavement. The effect of road pavement temperature on its strength is high, and the load falling from heavy trucks during the high temperature causes various deformations on the pavement surface. The study observed a decrease in pavement strength as a result of the increase in air temperature. The pavement strength decreased to 3330 MPA at 30°C and the pavement temperature to 423 MPA at 70°C. With this in mind, to ensure the normal service life of the highway, a minimum speed has been developed according to the number of axles of heavy trucks during the hot summer months. As the number of axles of heavy trucks increases, so does the minimum moving speed. According to the type of truck axles, it has been determined that the strength of the pavement also increases as the speed of the truck increases. [ABSTRACT FROM AUTHOR]

New anisotropic silicone magnetoactive composites were synthesized and studied. The surface structure and filler microdimensions in these elastomers were determined by electron microscopy. The atomic force microscopy use made it possible to determine significant surface deformations and magnetostrictive effects when small external magnetic fields are applied to the composites. Mössbauer spectroscopy on iron isotope nuclei made it possible to identify the fillers hyperfine parameters. [ABSTRACT FROM AUTHOR]

New anisotropic silicone magnetically active elastomers were synthesized and studied. Significant surface deformations and magnetostrictive effects in the obtained composites under the application of small external magnetic fields were visualized by the atomic force microscopy methods. This opens up the controlled wrinkling possibility for micro- and nanostructured surfaces. The use of nuclear gamma resonance made it possible to identify the iron filler electronic configuration in these anisotropic composites. [ABSTRACT FROM AUTHOR]

It is known that the fatigue process begins with the plastic deformation of the surface layers of the metal fittings. Moreover, the displacement of dislocations under conditions of re-alternating loads is observed at loads below the elastic limit of the metal. The rate of local plastic deformation during cyclic deformation is several orders of magnitude higher than the rate of deformation under static loading. Dislocation slip begins in grains with a favorable orientation near stress concentrators. As the number of cycles in the surface layers increases, the density of dislocations and the number of vacancies increases. When the base number of NR cycles is reached, a surface reinforced layer of metal with a large number of germinal cracks is formed, the size of which does not reach a critical value. Increasing the number of cycles cannot cause further development of fracture in such a layer. Only when the stresses exceed the endurance limit of the crack reach a critical length, after which the process of their discharge into the main crack begins with the spread of the latter. The results of experimental studies indicate a strong effect of diffusion hydrogen on static and cyclic parameters of crack resistance. It was found that with increasing flooding, especially when the hydrogen content exceeds 5 cm 3100g, both static strength and long-term strength (fatigue) decrease sharply. Moreover, for these areas of hydrogen solution in reinforcing steel is characterized by a viscous nature of fracture, while for heavily flooded reinforcement (from 5 to 12 cm3100g is characterized by brittle fracture by the mechanism of microfission in the hardened (martensite or troostite structure). allowed to determine the optimal hydrogen content in reinforcing steel (3-5 cm3 100g), the excess of which will reduce the crack resistance of reinforcement during long-term operation, especially in corrosive environments. The results of the research confirm the above data. bainite structure y sharply reduces the crack resistance of reinforcing steel, which makes it impossible to use in the manufacture of reinforcement involved in reinforced concrete structures designed for long-term operation (more than 50-60 years). Thus, the obtained diagram can be recommended to designers of reinforced concrete structures for hydraulic purposes, as it greatly facilitates the reasonable choice of reinforcement in the development of reinforced concrete structures for responsible and long-term use. [ABSTRACT FROM AUTHOR]

Microstructure, hardness and corrosion behaviour of SUS304 subjected by dry ice shot peening have been investigated in phase transformation and surface evolution. The shot peening process is a deformation technique applied on the surface of metallic material, especially for nuclear, aerospace and automotive applications. The surface of austenitic stainless-steel SUS 304 was treated by dry ice shot-peened for 30 minutes to observe and analyze the preliminary deformation on its surface. The annealing process followed after the shot peening process. The microstructure observation was carried out by transmission electron microstructure on a normal plane. The phase transformation was analyzed by X-ray diffraction. Nanoindentation measured the hardness behaviour to define the hardness on the sub-surface by the value of the load and displacement of the indenter. The corrosion behaviour was analyzed by anodic polarization curve by observing the shift pitting appearance on the curve. The surface deformation induced the martensite in a short time of dry ice shot peening, and the deformed structure and high angle grain boundary may appear during the process. The shifting of the anodic polarization curve to the right position is comparable to the as-annealed sample due to phase transformation on the surface and localized corrosion in both samples. [ABSTRACT FROM AUTHOR]

The evolution of the deformation relief on the surface of samples of cemented steels WC-(Fe-Mn-C) during axial compression tests was studied. It was found that during deformation of cemented steels an ordered deformation macrorelief in the form of bands of localized deformation is formed on the polished end surface. The bands are oriented in two directions and propagate regardless of the material structure. With an increase in the average distance between the bands, the compressive strength and ultimate strain to fracture decrease. It is shown that the values of the fractal dimension of the deformed surface profile increase at increased strain and depend on the average distance between the bands of localized deformation. [ABSTRACT FROM AUTHOR]

The features of evolution in space and time of distributions of deformation fields on the surface of the composite, reinforced with carbon tape, have been studied at meso- and macroscopic scale levels by method of correlation of digital images. The obtained pictures reflect in detail the evolution of distribution of isofields of relative deformations on the surface of composite, corresponding to different degrees of deformation action under uniaxial tension. Based on the results of the conducted studies of the carbon composite samples, numerical values of the strain concentration factor, expressing the ratio of the maximum value of deformations on the surface of the sample to the total average deformation over the entire working field of the sample, have been obtained to estimate the concentration of deformations. It has been established that the strain concentration factor is equal to 1.3 for the non-stressed carbon composite of carbon plastic tapes and 1.21 for the prestressed one. Modification of the carbon composite during prestress molding leads to a 22% reduction in stress concentration on the surface of the carbon composite, increases strength by 37.8%, deformation by 25% and modulus of elasticity by 10.25%. [ABSTRACT FROM AUTHOR]

The article describes the nucleation and development of plastic deformation in a titanium crystal subjected to ultrasonic impact treatment, using the molecular dynamics method. The regularities of surface roughness formation and microstructure refinement in the surface layer of commercially pure titanium are identified. It is shown that surface plastic deformations of a titanium sample proceed by the mechanism of plastic plowing, accompanied by dislocation glide and twinning. The mechanism of phase transformations associated with the formation of stacking fault is demonstrated by molecular dynamics. [ABSTRACT FROM AUTHOR]

The paper presents the analysis of the research data on the investigation of the local deformation behavior and mechanical properties of the surface layers of NiTi alloy depend on the shape of the indenter's tip (Vickers and Berkovich). Investigations of the mechanical properties (microhardness HOP, Young's modulus EOP, parameter of plasticity δh, and shape recovery ratio η) of the surface layers of NiTi alloy were held by the method of instrumented indentation test. The analysis of the experimental data shows, that at a maximum load Pmax from ∼5 up to ∼300 mN, the deformation behavior of the surface layers of the initial NiTi samples under instrumented sharp indentation with tips of different shapes are similar at a surface layer of ∼1 µm thickness. It means that, regardless of the shape of the indenter's tip, almost identical stress and strain states are created in the indentation zone and adjacent areas. [ABSTRACT FROM AUTHOR]

In this study, AISI 1018 Mild/Low Carbon Steel is used as a metal substrate for investigating the nanoindentation effects at room temperature in the dry and lubricated regimes. The Oliver-Pharr technique is employed to estimate the unloading data of nanoindentation according to the Power law and the peak load (Pmax) is increased from 0-10000 µN for all the nanoindentation experiments. The Coconut oil and different concentrations of Graphene-Coconut oil nanofluids are used to lubricate the metal substrate and their mechanical properties such as hardness, Young modulus, residual indentation depth, and contributions of elastic as well as plastic parts to total nanoindentation deformation are observed. The mechanism of the change in surface deformation rate of nanofluid lubricated metal substrate is also demonstrated through their indentation hardness AFM micrographs. The results exhibit that the lubrication of metal substrate by 0.1 wt% of Graphene-Coconut oil nanofluid significantly reduces the permanent plastic surface deformations. [ABSTRACT FROM AUTHOR]

The paper considers the development that relates to machine-tool industry, in particular, to technological processes of cutting and surface plastic deformation of low-rigid parts with automatic control of a self-centering steady rest. The installation helps to control automatically the position of the shaft-type work piece axis and eliminate self-oscillations that occur when turning low-rigid ax symmetric parts. The paper states a new issue in the turning process. The position of the work piece axis is stabilized in the cutting zone in the ZOY plane, which makes it possible to increase the machining accuracy and cutting conditions. The controlled self-centering steady rest helps to process stepped parts with surface-plastic processing. The axial force is recorded applying a sensor installed on the steady rest lever, and is corrected using information about the opposite cutting zone. The installation is mounted on the machine support from the opposite cutting zone and is equipped with a four-circuit control system with a hydraulic steady feed drive. [ABSTRACT FROM AUTHOR]

Digital filtering is an essential part of electronic speckle pattern interferometer which is been used widely to study surface deformations. Raw speckle patterns needs digital filtering before it is used for further analysis. Many times multiple use of digital filtering leads to change in the quantitative information of surface under study. This paper reports effect of multiple usages of various digital filters on the calculated surface deformation values. Multiple usages of various digital filtering leads to loss in speckleness of the pattern indicating decrease in speckle noise and marginal and in some cases significant change in surface displacement values. [ABSTRACT FROM AUTHOR]

The article proposes a model of the friction surface wear of pumping equipment involved in pumping oil and oil products at high temperatures. The applicability of the proposed dependencies is substantiated only for the period of steady-state wear. The general dependences of determining the wear of the surface nanogeometry in the stated mode and their constituent factors are presented. The analysis of the proposed provisions shows that the wear of nanogeometry depends to a greater extent on the deformation and adhesive components. The materials of the article can be used to determine the friction unit wear of oil pipeline pumping equipment, subject to elastic and plastic deformations. [ABSTRACT FROM AUTHOR]

The mechanical damages created on buried pipelines by any external activities are important consideration to assess the structural integrity of pipelines. The damages could be in the form of corrosion, dent, crack, gouge or any combination of these. A dent is a permanent inward plastic deformation in the pipe wall. The dents may not immediately cause failure of the pipe. However, it can reduce the pipe's structural capacity and cause rupture or leak in the long run. The current researches focus on studying the behavior of dented pipe with respect to burst strength and fatigue life considering initial deformed shape. However, the effects of residual stresses formed during the formation of a dent on the performance of dented pipe are not extensively studied yet. In this study, finite-element modelling is used to understand the importance of residual stresses on the integrity assessment of dented pipe. The analysis results revealed that both residual stresses and stress history have significant effects on the structural capacity of dented pipes under internal pressure and axial loads. [ABSTRACT FROM AUTHOR]

The most common method of joining ribs and edges is riveting. In modern technology riveting process is mostly used in automotive and aerospace industry. When the bulging effects of rivets occur, there will be deformation in the material's surface structure. Riveting sequence is one important approach to eliminate continues effect of the bulging and control the deformation of the surface structure. In this investigation, sequence study of riveting process was conducted using CAD Design on 3D modeling software and finite element method in ANSYS. The materials used are Aluminum (AL1050) and SS Steel (SS310). Three ways of riveting process are done, in order to get the effective way which, last for longer period of time. In two out the three-process silicon rubber is used as adhesive. The complete study gives the ability of the riveting surface when load and various forces acting impacting the surface. It will enhance the understanding of the components assembly with riveting and help systematically improving the precision control efficiency in automotive assembly. [ABSTRACT FROM AUTHOR]

The features of the process of structural change of steel in space and time by isofields of deformations, obtained by the method of correlation of digital images, have been studied at meso- and macroscopic scale levels. The plates without stress concentrator and with stress concentrator in the form of round holes were taken for uniaxial tension testing. The patterns, reflecting in details the process of structural change of steel by distribution of isofields of deformations on the plate surface in the area of stress concentrators and stress pattern, corresponding to stages on the stress-strain curve, have been analyzed. [ABSTRACT FROM AUTHOR]

Tensile deformation curves of flat samples of commercially pure aluminum 1070 have been produced. The features of the evolution of distributions of deformation fields on the surface of the samples at a macroscopic scale level under uniaxial tension deformation have been studied using the Vic-3D digital optical system. Formation of chaotically located tension and compression deformation zones has been revealed at the transitional stage of the dependence α = f(χ). Upon reaching stresses above the elastic limit, when passing to stage III, small deformation zones merge into larger ones in the distribution patterns of longitudinal εyy relative deformations on the sample surface. It has been established that individual plastic deformation zones are localized into macrobands when the plastic deformation reaches above 1.3% averaged over the entire sample. These macro bands completely intersect the entire gauge length of the sample and are directed at an angle of ∼30° to the longitudinal tension axis of the sample. [ABSTRACT FROM AUTHOR]

This paper presents numerical investigations of the texture effect on deformation-induced surface roughening in surface-modified titanium specimens subjected to uniaxial tension. Three-dimensional polycrystalline models taking an explicit account of the grain morphology and crystallographic orientations are generated by the method of step-by-step packing. A crystal plasticity-based constitutive model describing the nonlinear behavior of individual grains is implemented in a dynamic boundary-value problem that is solved by the finite-element method. Two sets of calculations for polycrystalline models with textured and non-textured surface layers are performed. The basal texture of the surface layer is shown to effectively suppress surface roughening, both at the grain and mesoscales. [ABSTRACT FROM AUTHOR]

In this work a mathematical model was formulated for calculating the natural frequencies and vibration modes of a variable geometry blade. The calculation of natural frequencies and vibration modes of a pre-loaded controlled blade for various force shell reinforcement schemes was carried out. A comparative analysis of the results obtained was carried out. It was revealed that the [0°/90°] reinforcement scheme is the most sensitive to piezoelectric deformations. The maximum change in natural frequency was observed for the second bending-torsional vibration mode and amounted to 4.3%. [ABSTRACT FROM AUTHOR]

The paper investigates the deformation behavior of a mechanical metamaterial. The metamaterial is made up of tetrachiral elements. An analytical solution is obtained for the deformation behavior of a unit cell of the metamaterial depending on its parameters. The results of the analytical solution were used for numerical modeling. The computer FEM model was built using beam elements. The numerical solution of the mechanical loading of the metamaterial was performed in the static case of the linear theory of elasticity. In the course of numerical simulation of the uniaxial loading of the mechanical metamaterial, it was found that the specimen inclines when elongated. The difference in inclination angles between the right and left sides of the specimen is probably related to the rotation of the ring in the tetrachiral structure. [ABSTRACT FROM AUTHOR]

This paper proves that regular right circular cylinder permits non-trivial infinitesimally small deformation, which preserves geodesic lines and any pieces of the given surface with an equal area. The above mentioned surface is uniquely defined by preliminary chosen non-zero function of a single variable and two meaningful constants. Under these conditions tensor fields are found in explicit way. Every deformation can be interpreted as momentless stressed state of cylindrical shell with a certain surface stress. [ABSTRACT FROM AUTHOR]

Fracture mechanical methods describe the local failure behavior very precisely and allow a simple comparison of materials and their molecular structure. One of these methods, derived from the field of post-yield mechanics, is the essential work of fracture (EWF). The investigation of the EWF in combination with the digital image correlation is so far mostly limited to an one-sided camera setup and the verification of the complete plasticization of the fracture process zone. In this work, the fracture behavior of polyethylene terephthalate (PET) and glycol modified polyethylene terephthalate (PETg) was investigated using the EWF method in combination with digital image correlation. By using a novel fourcamera setup, it is now possible to combine information from two independent two-camera systems to obtain a threedimensional evaluation of the deformation of the specimens. PET has demonstrated a higher specific essential and nonessential work of fracture compared to PETg. Furthermore, it was possible to establish a more accurate method for separating the non-essential work of fracture and the associated geometry factor by the image correlation. Thus, it could be shown that, in the case of polyethylene terephthalate, the process of crack initiation is less affected by the molecular structure than the process of crack propagation. It could further be shown that the deformed volume was significantly higher in the case of PETg compared to PET and therefore the non-essential work of fracture showed lower values. [ABSTRACT FROM AUTHOR]

Based on the actual parameters of a domestic CVT, the strength and stiffness of some key components of the CVT transmission using the finite element analysis method was analysed in this paper. The results show that the deformation of the cone surface of the pulley is mainly concentrated in the area of inclusion angle of metal belt on pulley; And the maximum deformation of the pulley occurs at the edge of the pulley, and the amount of deformation of the tapered surface of the pulley increases as the speed ratio increases; The maximum stress of the pulley appears at the connection between the pulley and the pulley shaft and at the working radius of the metal belt. When using three keys to transfer power, the stress distribution is uniform. When a single key is used, the stress concentration on the keyway is obvious, and there is a significant eccentric load. The research results can be used to theoretically predict the strength risk and deformation of key components of CVT, and provide a theoretical basis for subsequent structural optimization design. [ABSTRACT FROM AUTHOR]

Proper description of large deformation of the continuum or the shell requires dealing with curved spaces and application of tensor analysis and distinguishing of covariant and contravariant basis. Thanks to symbolic computations and visualization capabilities of the Mathematica system, this task can be carried out straightforward. It has been already discussed in [1] and [2]. This paper is a further extension of them. First it will be shown that the deformation is indeed changing of curvature of the considered space. Next, there will be shown how Cartesian basis of the flat undeformed space splits to the covariant and contravariant ones and that this basis changes in the space. It makes possible to explain why we have to introduce covariant derivatives and Christoffel symbols, for example. It is important in case of the optical analysis of large deformations of thin wall structures. Moreover it is possible to easily explain that strain tensor is defined with change of metric tensor. It also helps to show the idea of material (Lagrangian) and spatial (Eulerian) description of the deformation and the motion and avoid misunderstandings in this matter. Everything is visualised with 3D graphical capabilities and interactive maniputation of the plots provided within the Mathematica system. This paper can be also usefull inspiration both in teaching and learning of the Continuum Mechanics, the Theory of Shells and Thin-Wall Structures. The work has been presented at the conference Polish Congress of Mechanics, Computer Methods in Mechanics PCM-CMM-2019 in Krakow. [ABSTRACT FROM AUTHOR]

Mount Okmok is an active volcano, located on the northeastern end of Umnak Island in the Aleutian Islands of Alaska. It is a shield volcano with an approximately 10 km wide caldera, and has undergone several eruptions over the last decades, with the most recent one taking place in 2008. Presence of an underground magma reservoir is manifesting on the surface in form of terrain deformations, e.g. subsidence and uplift. Because of that, Okmok is one of the most thoroughly studied volcanoes in the Aleutian Islands. Its deformations have been examined in the past using field geodetic techniques, like GPS. Work has also been done to determine Okmok’s surface displacements using SAR Interferometry. The article presents an approach of calculating terrain deformations with the differential SAR interferometry method, as well as a quality assessment of obtained results by a comparison with GPS data received from various stations located over the study area. The DInSAR calculations have been conducted on a set of radar images taken by the Sentinel-1A and Sentinel-1B satellites from tracks 44, 95 and 117, covering a period of time between years 2015 and 2018. Calculated LOS deformations show that there is a significant uplift in the area of volcano’s caldera, in contrast to the rest of Mount Okmok’s surface. The comparison with GPS time series shows that both methods bring similar results, meaning that Sentinel-1 imagery processed with the DInSAR method can successfully be used to determine ground surface deformations over large areas. [ABSTRACT FROM AUTHOR]