Regularities Of Deformation Research Articles

Experimental Study of the Regularities of Deformation of the Rubber Cord Shell of a Pneumatic Spring of High-Speed Rolling Stock

Purpose. The aim of this work is to establish the regularities of deformation of the rubber cord shell in the vertical and horizontal directions in the case of changes in the internal pressure in the pneumatic spring by static experimental studies. Methodology. A static test bench was used to establish the regularities of deformation of the rubber cord shell of a pneumatic spring. Changes in the internal pressure in the pneumatic spring were achieved using a compressor, and the deformation of the rubber cord shell was measured directly by high-frequency potentiometric linear displacement sensors. The deformation of the rubber cord shell of a pneumatic spring in both the vertical and horizontal planes was studied under the condition of changing the internal pressure in the spring in the range from 0 to 5 atm. Findings. Using the designed test bench, a methodology for experimental studies of the deformation of a rubber cord shell with increasing internal pressure in a pneumatic spring was developed. The dependences of the deformation value of the rubber cord casing of a pneumatic spring when the internal pressure changes in the range of 0÷5.0 atm were obtained. It is established that the deformation of the rubber cord casing with an increase in the internal pressure in the pneumatic spring in the horizontal plane is more intense compared to the vertical plane. It is found that the maximum values of deformation of the rubber cord shell of a pneumatic spring in the vertical and horizontal directions are observed at the initial stage of air injection in the range of pressure changes from 0 to 0.5 atm. The polynomial equations describing the deformation dependences of the rubber cord shell of a pneumatic spring were obtained. Originality. The regularities of deformation of the rubber cord casing in the vertical and horizontal planes at different values of the internal pressure in the pneumatic spring were determined by experimental static studies. Practical value. The study of the regularities of deformation of the rubber cord shell will contribute to a more accurate modeling of the operation of the pneumatic spring and a reliable determination of its dynamic performance. This will make it possible to use the dynamic performance of the air spring in the spatial mathematical model of the rolling stock at the design stage, as well as to evaluate its dynamic performance and traffic safety indicators.

Deformation and Force Analysis of Utility Tunnel joint under Longitudinal Uneven Foundation

To study the regularity of force and deformation of utility tunnels under longitudinal uneven foundations, considering the traffic load, the authors established a finite element model based on pipe-soil interaction to analyze the effect of different working conditions on force and deformation of utility tunnel joints. The results indicated that different stiffness of the foundation can lead to different mechanical properties of the utility tunnel top plate, bottom plate and socket joints. The deformation of the bell joint which on the undisturbed soil and located 2 to 3 sections pipes to the replacement junction changes most obviously, meanwhile, as the longitudinal stiffness difference increases, the maximum horizontal opening on the top plate shifts closer to the replacement junction, and the maximum opening up to 3.561mm; the phenomenon of axial stress below the waterproof requirement exists in the interface of the top plate on the undisturbed soil and the interface of the bottom plate on the replacement soil at the difference in stiffness of the foundation is greater; the maximum differential settlement of joint is located the first corridor interface to the replacement junction which on the undisturbed soil, that is characterized by ‘decreasing from the replacement junction to both sides’.

Research on Tensile Test of Dissimilar Steel Body Solder Joints

With 22 mnb5 St16 and ordinary steel as the research object, under the conditions of medium frequency spot welding connection plate welding, solder joint for the electric logging under shear load test, determination of solder joints, solder joint and away from the solder joint around the base of strain, according to measurement data analysis of solder joints and the deformation regularity of parent metal. The test results show that the strain in the spot welding joint distribution is uneven, the center of the welding strain is small, large deformation mainly exist in the heat affected zone, near the solder heat affected zone is the main area prone to give in. Away from the solder joint area of the parent metal, the influence of solder joint is small, mainly tensile strain, and strain as the load increases, solder joint strain is negative, the center is linear, and basic antisymmetric location of strain values different test points.

EXPERIMENTAL TESTS OF CONCRETE MEANS OF PROTECTION FOR COAL MINES DISTRICT ROADWAYS

The current paper is devoted to experimental tests of working protection means in the construction of which concrete in liquid state is used. Such means of protection are most vulnerable to irreversible deformations during the period of their hardening, which coincides with the period of intensive growth of pressure on them from the side of the rock massif. Studies have shown that the pressure of fake rocks on the working protection means depends significantly on the depth of its location and the category of collapse of the roof of the coal seam. The maximum pressure is reached at the moment before the collapse of the roof, that is, at the maximum values of the length of the console of fake rocks, which hangs over the produced longwall space and rests on the working protection means. It was established that the pressure of the fake roof of the coal seam and the relative vertical deformation of the district roadway protection means increase according to the logarithmic dependence of the distance to the longwall outcrop and the time of concrete hardening. With heavy and medium roof collapse, these processes are divided into two stages: in the first stage (the length of which corresponds to the step of the roof collapse), as the longwall moves, the pressure increases intensively, at the moment of collapse it drops by 15-20%, and in the second stage again increases, but 6-8 times more slowly than in the first one, and, provided the relative vertical deformation of the protective device stabilises, passes into a stable mode. With an easily collapsed roof, the step of its collapse does not have a significant effect on the growth and stabilisation of the stress-deformed state of the protective device. The mechanism was revealed and the regularities of loading and deformation of district roadway protection means from a quick-setting mixture depending on the time of its hardening and the distance to the outcrop of longwall, taking into account the category of stability of the roof of the coal seam, were established. Implementation of recommendations for the parameters and technology of the construction of a guard-isolation wall in the conditions of the "Chervonogradska" and "Lisova" mines of the SE "Lvivvugilya" made it possible to reduce the costs of cement-mineral mixture by 27% and save the belt roadways No. 562 and No. 166 for reuse in the production as ventilation during the working out of the adjacent trench column.

Using the method of correlation of digital images for plotting stress–strain curves in true coordinates

This article describes the features of determining strain curves in true stress–true strain coordinates, using samples of circular cross section from Al–Cu–Mg–Zn aluminum alloy. The calculation and experimental methods of determining true stresses and strains were compared Calculation methods based on the condition of volume constancy may not reflect actual regularities of deformation at the stage of strain localization in the considered material. Nevertheless, the use of systems of digital image correlation (DIC) allows measurements of both the geometrical sizes of deformed sample and strain fields on its surface to be performed, including on the sample neck. It was demonstrated that the measurement error of the sample diameter by the coordinate field was 0.02 mm at the instance of destruction. In order to improve the measurement precision, an increase in the recording frequency in proportion to increase in strain rate was proposed, as well as measuring the surface coordinates from both sides of the sample. It is also possible to supplement the strain curves obtained by DIC optical systems with the measurements of true fracture stress, and the true fracture strain determined by calculations on the destructed sample. The presented methods of analysis of plastic flow by direct measurement of field displacements and strains allow actual regularities between true stresses and strains at the interval of irregular plastic strain to be established. This cannot be achieved by analytical conversion of conventional curve. The obtained hardening coefficients and strain curves can be used for simulation and design of machinery structures and parts.

Numerical simulation of the subgrade settlement of highway expansion based on CPTU data

ABSTRACT The differential settlement law of new and old subgrade is considered the key problem for settlement control of subgrade in highway expansion in soft soil areas. Along these lines, based on the on-site CPTU test and laboratory test results of the Huai’an-Jiangdu section of the Beijing-Shanghai high-speed expansion project, the physical and mechanical parameters of the soils were obtained in this work. In addition, by performing numerical simulations, the laws of settlement and deformation of both new and old embankments were systematically studied. From the acquired results, it was demonstrated that the deformation regularity of the whole subgrade before and after the expansion was the same, while it was observed that it only diffused outwards. However, according to the analysis of additional deformation after expansion, it was found that the load exerted on the widened part had a greater influence on the widened part of the foundation. The numerical simulation outcomes of the highway expansion foundation can provide design guidance for differential settlement control and monitoring of both the new and old highway foundation.

Deformation diagrams of amorphous polyimide (kapton H) in the state of moderate and deep cooling: Experiment and theory

A comprehensive experimental and theoretical study of the regularities of active deformation at a constant rate of an amorphous polymer at room temperature and the influence of moderate and deep cooling on them was performed. The samples of amorphous aromatic polyimide (an analogue of kapton H) that are randomly cut fragments of the industrially produced thermoplastic film with a thickness of 25 μm were the object of the experimental study. The σ–ε diagrams of the tensile test, where σ and ε=ε˙t are the tensile stress and the relative strain, respectively, were recorded for 32 samples at three rates ε˙ = 7⋅10–5, 7⋅10–4, 6⋅10–3 s–1 under three temperatures T = 293, 77, and 4.2 K. In the state of deep cooling at T = 4.2 K, several samples were deformed as brittle glassy bodies – rupture after short elastic deformation. But the majority of the samples at all values of the experimental parameters (T,ε˙) had the rheological properties of rubber-like highly elastic materials (elastomers) with traditional tensile test diagrams: initial stage I of linear elastic deformation σI=Meε with Young’s modulus Me=Me(T); stage III of linear highly elastic deformation σIII=σfe+Mheε with modulus Mhe=Mhe(T) and conditional limit of elasticity σfe=σfe(T,ε˙); intermediate stage II of the relaxation type σII(ε;T,ε˙) with a nonlinear stress-strain dependence. The σ–ɛ diagrams of the individual samples with sufficiently high accuracy coincide with the graph of the function σ(ε;T,ε˙) which is the solution of the previously derived nonlinear rheological equation (V. D. Natsik and H. V. Rusakova, Fiz. Nizk. Temp.48, 281 (2022) [Low Temp. Phys.48, 253 (2022)]; Fiz. Nyzk. Temp.49, 246 (2023) [Low Temp. Phys.49, 228 (2023)]). In its derivation, a molecular-kinetic model was used: an amorphous polymer is considered as a set of statistically independent kinetic units, namely, molecular segments, and the elementary act of deformation is caused by thermomechanical activation of nonlinear excitations of these segments called elastons. The elaston mechanism of transformation of the deformation diagrams of amorphous polyimide samples under their moderate and deep cooling is discussed in detail: the transition between deformation states of warm and frozen elastomer, low-temperature effects of structural-deformation glass transition and deformation melting. Comparing the results of experiments and theory made it possible to obtain the empirical estimates for the macromechanical characteristics of the studied samples and the microparameters of elaston excitations. A significant and unsystematic (random) scatter of the macro- and micromechanical characteristics of the samples was revealed, which indicates a significant and random heterogeneity of the macro- and microstructure of the polyimide film from which they were made.

Some aspects of the processes of obtaining and application of mineral powders as fillers for cement systems

The main theoretical prerequisites for the thermodynamic analysis of the process of grinding rocks are given. The structural-energetic relationships between the regularities of plastic deformation with energy characteristics that occur during the crushing of mineral substances are described. The evaluation of the grindability of rocks in a ball mill under different grinding modes was made. Rational operating modes of the mill have been determined to ensure the required degree of grinding, which makes it possible to significantly reduce the energy consumption of the grinding process. To assess the quantitative content of adsorption centers, a classification of the “indicator of reduced hydration activity” is proposed. (Ppga), allowing the most accurate assessment of the contribution of the surface activity of mineral fillers to the course of the processes of interactions and transformations occurring in a hydrated medium.

ВЫБОР ТИПА И ОБОСНОВАНИЕ КОНСТРУКЦИИ АНКЕРНОЙ КРЕПИ ГОРНЫХ ВЫРАБОТОК ПРИ РАЗРАБОТКЕ ГЛУБОКОЗАЛЕГАЮЩИХ МЕСТОРОЖДЕНИЙ КАЛИЙНЫХ СОЛЕЙ

The article presents the peculiarities of the Gremyachinskoe potash salt deposit development conditions, which influence the choice of type and justification of anchoring design. The practice of anchoring of mine workings in salt rocks at great depths is generalized. The factors influencing the choice of the type and parameters of anchoring of mine workings are systematized. The parameters of anchor support are substantiated on the basis of establishing the regularities of deformation of the system "anchor-rock massif" in time to ensure the operational reliability of the support and stability of mine workings with the definition of parameters of rational use of improved designs of anchor support.

ПРОГРАММА И МЕТОДИКА ЭКСПЕРИМЕНТАЛЬНЫХ ИССЛЕДОВАНИЙ ЖЕЛЕЗОБЕТОННЫХ ЭЛЕМЕНТОВ С ВНЕШНИМ АРМИРОВАНИЕМ КОМПОЗИТНЫМИ МАТЕРИАЛАМИ ПРИ ИЗГИБЕ С КРУЧЕНИЕМ

External reinforcement of reinforced concrete structures with composite materials is successfully used for strengthening of damaged elements. At the same time, torsion with bending of such reinforced concrete structures is poorly studied and requires experimental and theoretical investigation. The scientific literature presents the results of the study of strength and deformability in bending with torsion of reinforced concrete elements of different cross-sectional shapes under static and dynamic loads, elements of composite cross-section. For reinforced concrete structures strengthened with external reinforcement by composite materials, such studies were carried out only for bending elements. The authors have developed a program and methodology of experimental studies of such structures. The results of experimental investigations according to the proposed methodology will allow us to verify the assumed design model, the working assumptions put in its basis and reveal the regularities of deformation of reinforced concrete structures with external composite reinforcement under bending with torsion.

ВДОСКОНАЛЕННЯ СПОСОБІВ ЗБЕРЕЖЕННЯ СТІЙКОСТІ ПІДГОТОВЧИХ ВИРОБОК З УРАХУВАННЯМ ДЕФОРМАЦІЙНИХ ВЛАСТИВОСТЕЙ ОХОРОННИХ СПОРУД

Purpose. To evaluate the deformation properties of protective constructions of preparatory workings to maintain their stability in the excavation areas of coal mines with steep coal seams. Methodology. To achieve this goal, laboratory and field studies of the deformation properties of protective constructions have been performed. Results. It has been established that under uniaxial compression, under the action of a statistical external force, which manifests itself in the conditions of uniaxial compression and relative deformation of wood chocks within 0.1<λ<0.2, their stiffness decreases, and then it increases at 0.4<λ<0.7, which creates conditions for ensuring the bearing capacity of protective constructions. Under field conditions, when using the method of protecting the slope drifts with wood chocks made of sleepers, after their deformation of more than 40% in the zone of influence of mining works (0<l<100 m), a gradual decrease in the increase in the displacement of side rocks on the contour occurs during the compaction process, due to which the operational condition of the preparatory workings along the length of the excavation section is ensured. To study the deformation characteristics of the protective constructions, we used the function of the incremental displacement of the side rocks on the contour of the workings at the section of 0<l<100 m behind the face. Scientific novelty. The regularities of deformation of protective constructions of preparatory mine workings under uniaxial compression with regard to changes in their stiffness have been established. Practical significance. When mining steep coal seams, using the peculiarities of geomechanical phenomena manifested in the coal massif, it is advisable to use compressible protective constructions of preparatory mine workings.

Characteristics and Formation Mechanism of Surface Residual Deformation above Longwall Abandoned Goaf

With the rapid development of social economy in China, the contradiction between the wide distribution of abandoned goaf and the shortage of land for engineering construction is becoming increasingly prominent. The effective utilization of coal mining subsidence areas has become an effective measure to alleviate the poverty of construction land in mining areas and promote the green transformation of mining cities. The key to the scientific utilization of abandoned goaf is the prevention and control of surface residual deformation, which depends on the formation mechanism of surface residual deformation. Based on the regularity of mining-induced surface movement and deformation under different mining sizes, it is concluded that the full mining degree of working face is the primary condition for entering the surface recession period. The trapezoidal and periodic forward movement characteristics of mining-induced overburden destruction are analyzed. The regularity of upward transmission of mining-induced fissures with overburden destruction is clarified. The influencing factors of surface residual deformation are equivalent to the influencing factors of overburden structure and caved zone. The deformation characteristics of broken rock in the caved zone under different conditions (particle size, gradation, and water content) are analyzed. It is concluded that the surface residual subsidence near the boundary of the goaf is more significant than that in the middle of the goaf. It is revealed that the overburden structure at the boundary of the goaf and the re-compaction of the caved zone is the mechanism of surface residual deformation. The characteristics of surface residual deformation in abandoned goaf have been verified by field measurement, and it is pointed out that the surface residual deformation in abandoned goaf has long-term characteristics, which provides a theoretical basis for accurate prediction of surface residual deformation and rational utilization of abandoned goaf.

Seq2Morph: A deep learning deformable image registration algorithm for longitudinal imaging studies and adaptive radiotherapy.

To simultaneously register all the longitudinal images acquired in a radiotherapy course for analyzing patients' anatomy changes for adaptive radiotherapy (ART). To address the unique needs of ART, we designed Seq2Morph, a novel deep learning-based deformable image registration (DIR) network. Seq2Morph was built upon VoxelMorph which is a general-purpose framework for learning-based image registration. The major upgrades are (1) expansion of inputs to all weekly cone-beam computed tomography (CBCTs) acquired for monitoring treatment responses throughout a radiotherapy course, for registration to their planning CT; (2) incorporation of 3D convolutional long short-term memory between the encoder and decoder of VoxelMorph, to parse the temporal patterns of anatomical changes; and (3) addition of bidirectional pathways to calculate and minimize inverse consistency errors (ICEs). Longitudinal image sets from 50 patients, including a planning CT and 6 weekly CBCTs per patient, were utilized for network training and cross-validation. The outputs were deformation vector fields for all the registration pairs. The loss function was composed of a normalized cross-correlation for image intensity similarity, a DICE for contour similarity, an ICE, and a deformation regularization term. For performance evaluation, DICE and Hausdorff distance (HD) for the manual versus predicted contours of tumor and esophagus on weekly basis were quantified and further compared with other state-of-the-art algorithms, including conventional VoxelMorph and large deformation diffeomorphic metric mapping (LDDMM). Visualization of the hidden states of Seq2Morph revealed distinct spatiotemporal anatomy change patterns. Quantitatively, Seq2Morph performed similarly to LDDMM, but significantly outperformed VoxelMorph as measured by GTV DICE: (0.799±0.078, 0.798±0.081, and 0.773±0.078), and 50% HD (mm): (0.80±0.57, 0.88±0.66, and 0.95±0.60). The per-patient inference of Seq2Morph took 22 s, much less than LDDMM (∼30 min). Seq2Morph can provide accurate and fast DIR for longitudinal image studies by exploiting spatial-temporal patterns. It closely matches the clinical workflow and has the potential to serve both online and offline ART.

Stability of Postcritical Deformation of CFRP under Static ±45° Tension with Vibrations.

The paper presents an experimental study on regularities of postcritical deformation of carbon-fiber-reinforced plastic (CFRP) under static ±45° tension. The employed test method is based on ASTM D3518. Displacement and strain fields were identified by a digital image correlation method (DIC) using a VIC-3D contactless optical video system. Acoustic emission signals were obtained using an AMSY-6 system. The surface analysis of samples was carried out using a CarlZeiss SteREO Discovery. V12 optical stereomicroscope and a DinoLite microscope. Three experimental test types were considered: active loading, deformation with unloadings, and tension under additional torsion vibrations with various amplitudes. Loading diagrams were constructed; they showed a number of stages in the damage accumulation process. It was analyzed how heterogeneous strain fields develop; a neck development during softening process was observed. It was noted that the loading system rigidity influences the failure moment. The research considered various shear strain calculation methods using a "virtual extensometer" instrument. Composite mechanical properties were obtained. A shear modulus reduction during a plastic strain increase was revealed. The acoustic emission signals were analyzed; three characteristic frequency bands were observed. Most of the contribution to cumulative energy was made by matrix cracking. A reduction of the number of AE signals associated with the violation of adhesion between the fibers and the matrix during postcritical deformation was observed. The research identified basic surface defects. An appearance of the defects corresponds with their identification by the AE system. It was revealed that the presence of additional torsion vibration leads to an increase in the softening stage length. It was concluded that due regard for the postcritical deformation stage and the loading system rigidity is reasonable during the structure strength analysis.

Deformation monitoring and influence factor analysis of expressway over strong saline soil based on an advanced multi-temporal InSAR technique

Saline soil harbors crystallized salt in the solid phase and salt solution in the liquid phase. By the natural environmental and human activity factors, migration and accumulation of the salt and crystallization process alternated with dissolving, which makes saline soil with significant seasonal differences appear in the deformation and regional scattering characteristic. These phenomena raise the limitation of conventional multi-temporal interferometric synthetic aperture radar (MT-InSAR) technique and consequently high-precision deformation monitoring of strong saline soil subgrade and pavement. To overcome the limitations, this study aimed to propose an advanced MT-InSAR method, which considers the seasonal interferometric coherences caused by precipitation and the temporal physical deformation evolution of the subgrade and pavement over strong saline soil. To present the better performance of the advanced method, a segment of the Qarhan–Golmud Expressway (QGE), which is the first expressway built in the strong saline soil area in China, was selected for this study. Two sets of SAR images acquired from January 2018 to January 2022 from Sentinel-1A ascending and descending orbits over the QGE were utilized, 774 and 928 seasonal filtered interferograms are optimized for deformation monitoring based on the deformation Poisson curve (PC) model. Compared with the method in the previous studies, the accuracy, efficiency, and reliability of the monitoring results increased dramatically. Subsequently, further discussions are conducted in detail on the regularity of expressway deformation over strong saline soil, especially from physical and chemical perspectives. Findings show that the ratio between Cl− and SO42- determines the deformation distribution and morphology. Also, the precipitation and temperature affect the seasonal characteristics. The contributions of this investigation might provide technical references for related expressway management and policy-making departments to ensure the long-term safe operation and stability of the QGE.

Research on deformation coordination of composite metal gears in the process of cold extrusion

In order to realize lightweight manufacturing of gear parts, the cold extrusion forming process of steel-aluminum composite metal gears was studied. Using numerical simulation software Deform, the effects of five steel rings with different thicknesses on forming pressure and shapes of formed forgings were compared. The simulation results showed that final forming force of the gear was smaller and the radial deformation degree of steel ring was larger when using thinner steel ring. This radial deformation degree was characterized by height difference between the convex and the concave in steel-aluminum bonding position, and great deformation presented as obvious bimetal occlusion. The physical experiment verified numerical simulation results, and meanwhile found that the thickness of steel sleeve had an important effect on bonding tightness of steel-aluminum contact surface of formed part and the composite gear formed by thin steel ring had a gap at tooth tip between steel and aluminum. Comprehensive analysis suggested the ratio of outer diameter to inner diameter (R0/Ri) of steel sleeve reflected different deformation regularity. Consequently, the thick-walled axial compression model was used to analyze forming process of steel sleeve with high R0/Ri ratio, and the thin-walled cylindrical shell model was used to analyze forming process of steel sleeve with low R0/Ri ratio. The axial compression of thin cylindrical shell produced local buckling deformation, which led to the appearance of gaps in steel-aluminum bonding position. In order to avoid gaps in bimetal contact surface, the influence of steel ring thickness on deformation coordination of two metals should be fully considered in cold extrusion of steel-aluminum composite metal gear.

Regularities of the creep deformation and failure of 15Kh2NMFA-A steel within the temperature range of 900–1200 °C

This paper presents and summarizes main results of the research to define the high-temperature creep parameters and strength characteristics of the unirradiated steel 15Kh2NMFA-А tested in the temperature range of 900–1200 °C. This ferritic-pearlitic steel is one of the main types of steel used for the production of the VVER RPVs of the Russian design. The results of research of the strength properties and creep parameters for 15Kh2NMFA-А steel are meant to support, first and utmost, the estimation of the integrity and predicting the behavior of the VVER pressure vessel during the SA, when it may deform due to high-temperature creep and the overpressure in the RPV. One of the main goals of the investigation was to determine such strength properties and creep parameters of the investigated steel as, for instance, steady-state creep rate, creep tensile strength under the condition of isothermal creep at different temperatures and test stress. The creep tensile tests were conducted in vacuum and in the protective argon medium. A series of creep tests was conducted in air. The analysis and comparison of the test results demonstrated significant impact of the surficial oxidation process on the nature of their damage and the time to failure of the test samples. The absence of a protective medium during testing, as observed in the case of the test in air, causes decarburization and the damage of the surficial layer of the steel samples, so that the specimen fractures prematurely. Based on the statistic estimation the (B) and (n) parameters for the secondary creep rate equations were defined for the researched steel within the temperature range of 900–1200 °C. The agreement between the values of the steady-state creep rate of 15Kh2NMFA-A steel from the conducted creep tensile tests and similar calculation values from the obtained parameters (B) and (n) for the temperature range from 900 to 1200 °C was satisfactory. The paper also presents the definition of the LMP parametric dependence coefficients, completed on the basis of the creep test results for 15Kh2NMFA-А steel with a time span up to 100 h in the given temperature range. The comparative analysis of the defined LMP dependence demonstrated good agreement of the predicted values for the failure time with similar values defined during the experiment.The research of the steel specimens’ microstructure following the tests demonstrated a difference in the mechanisms of damage accumulation and fracture at the temperatures over 1000 °C in comparison to similar mechanisms at lower temperatures. It is important to apply more precise research methods to understand this phenomenon to a better extent; such research may take place later.

RSegNet: A Joint Learning Framework for Deformable Registration and Segmentation

Medical image segmentation and registration are two tasks to analyze the anatomical structures in clinical research. Still, deep-learning solutions utilizing the connections between segmentation and registration remain underdiscovered. This article designs a joint learning framework named RSegNet that can realize concurrent deformable registration and segmentation by minimizing an integrated loss function, including three parts: diffeomorphic registration loss, segmentation similarity loss, and dual-consistency supervision loss. The probabilistic diffeomorphic registration branch could benefit from the auxiliary segmentations available from the segmentation branch to achieve anatomical consistency and better deformation regularity by dual-consistency supervision. Simultaneously, the segmentation performance could also be improved by data augmentation based on the registration with well-behaved diffeomorphic guarantees. Experiments on the human brain 3-D magnetic resonance images have been implemented to demonstrate the effectiveness of our approach. We trained and validated RSegNet with 1000 images and tested its performances on four public datasets, which shows that our method successfully yields concurrent improvements of both segmentation and registration compared with separately trained networks. Specifically, our method can increase the accuracy of segmentation and registration by 7.0% and 1.4%, respectively, in terms of Dice scores. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —Registration and segmentation of medical images are two significant tasks in medical research and clinical application. However, most existing approaches consider these two tasks independently while neglecting the potential association between them. Therefore, we suggest a new approach that combines these two tasks into one joint deep learning framework, boosting registration, and segmentation performance by introducing dual-consistency supervision. Besides, our framework could generate outputs within 1 s by taking an affinely aligned medical image pair as input, which is suitable for time-critical requirements in a clinic. We tested it on four public datasets and achieved state-of-the-art performance to demonstrate the proposed method’s feasibility and robustness. Furthermore, our proposed RSegNet is a general learning framework suitable for various image modalities and anatomical structures. Hence, we expect our framework to serve as a practical clinical tool to speed up medical image analysis procedures and improve diagnostic accuracy.

A solution to the problem of pile settlement caused by vertical static loading with consideration to plastic properties of the foundation soil

Introduction. The article addresses the problem of nonlinear analyses of structures having pile foundations. The purpose of the study is to develop a method for determining the nonlinear behaviour of a single pile. The tasks of the study are to use the analytical method to define and solve the settlement problem of a single pile, taking into account the plastic properties of soils along the lateral surface and under the tip, as well as to verify the obtained solutions using the field data obtained by testing the pile subjected to static loading.&#x0D; Materials and methods. The analytical model of the telescopic motion of coaxial cylindrical soil layers around the pile was applied to obtain the solution. Pile settlement due to the punching of the bottom layer was calculated using the available formula dealing with a circular rigid stamp located at a given depth from the surface. To verify the solution, the authors used the materials of static loading tests conducted in respect of three reinforced concrete prismatic piles of the base of a hospital building located in the city of Tver. A static method was used to drive the piles.&#x0D; Results. A comparison between the results of the analysis obtained using the proposed solution and the field test data is presented. The analysis of this comparison shows that the solution allows describing the load-settlement curve for the static loading of a single pile. A reasonable mismatch between the calculated and field data is identified; it is associated with the inability of the derived formula to take account of soil consolidation.&#x0D; Conclusions.The solution, obtained for single pile settlement, takes into account plastic properties of soil on the lateral surface and under the pile tip. This solution describes the regularity of single pile deformation under static loading. Further research will take soil consolidation into account. The assumed values of the ultimate resistance of a pile along a lateral surface and under the pile tip have a considerable influence on the results of the calculation according to the solution obtained by the authors. A relevant task, to be solved in the course of further research, is to find alternative methods of their determination.

Elastic 3D–2D Image Registration

We propose a method to nonrigidly align a three-dimensional (3D) volumetric image with a two-dimensional (2D) planar image representing a projection of the deformed volume. The application in mind comes from biological studies in which 2D intravital microscopy videos of living tissue are recorded, after which the tissue is excised and a more detailed 3D volume microscopy is performed. Coregistration of both data sets allows to combine the temporal (but 2D) information with more detailed spatial 3D information. Our approach is variational and uses a hyperelastic deformation regularization, as is appropriate for biological material. As a particular feature, the out-of-plane deformation is estimated based on the out-of-focus blur inside the 2D microscopy image. The approach becomes computationally feasible through the use of a coarse-to-fine optimization strategy and higher-order optimization methods.