Deformation Characteristics Research Articles

The influence of desalinization of reservoir rocks on their mechanical and filtration properties using the example of the Chayandinskoye field

Using the Independent Triaxial Loading Test System of the Institute for Problems in Mechanics of the Russian Academy of Sciences (TILTS), rock specimens from the core material of the reservoir of the Chayandinskoye oil and gas condensate field were tested in order to experimentally study the effect of desalinization of reservoir rocks on their deformation, strength and filtration characteristics. It has been shown that desalinization sharply increases the permeability of rocks. At the same time, the deformation and strength properties of the studied rocks change towards softening (with the exception of the angle of internal friction), nevertheless remaining quite high. Experiments on physical modeling of the process of reducing pressure at the bottom of a horizontal well using TILTS showed that a slight decrease in the elastic and strength properties of the reservoir rocks of the Chayandinskoye oil and gas condensate field after their desalinization should not affect the stability of the well walls. The results obtained allow us to draw an important practical conclusion that when operating a field at the stage of salt washing out due to water filtration during operation, one should not expect a significant increase in the risks associated with reservoir destruction and increased sand production.

ON IDENTIFICATION OF PARAMETERS OF A NONLINEAR CONSOLIDATION MODEL OF SANDY SOIL

Previously, the authors of this article formulated a physically and geometrically nonlinear formulation of the problem of porous fluid-saturated medium deformation during fluid filtration (consolidation problem) in terms of the rate of solid phase displacement and the change in pore pressure in differential and variational forms. The developed consolidation model takes into account changes in the porosity and permeability of the medium during deformation. Deformation-type constitutive relations are used in the model. The developed consolidation model can be used to simulate non-stationary processes in the soil, for example, the formation of ruts and unevenness of dirt roads, as well as to calculate the uneven settlement of engineering structures. This work is devoted to the experimental determination of the deformation and strength properties of water-saturated sandy soils, which is the next stage in the consolidation process simulation. The results of the experimental determination of the bulk and shear properties of sandy soil using the ASIS automated complex (OOO NPP “Geotek”) are presented. The studies were carried out on three quartz sands of various grain sizes. To determine the volumetric moduli of dry and water-saturated sandy soils, compression tests were carried out under a continuously growing vertical load at a constant strain rate. The experiments were carried out for various strain rates in the range from 3·10–6 to 3·10–3 s–1. According to the experimental results, the bulk properties do not depend on the strain rate in the specified range. Deformation and strength shear characteristics of sandy soils were determined by the method of multiplanar shear, approximating a simple shear. The tests were carried out under a kinematically applied shear load with a given constant strain rate according to the scheme of consolidated-drained shear. The dependences of the deformation and strength properties of coarse and fine quartz sands on the shear strain rate in the range from 2·10–4 tо 4·10–3 s–1 were studied. Increasing, decreasing and nonmonotonic dependences of the internal friction angle on the shear strain rate were obtained for dry and water-saturated sands of various grain sizes. For water-saturated sands, the maximum spread in the values of the internal friction angle for different strain rates does not exceed 7 %. A technique has been developed for recalculating the obtained properties and experimental dependences into the parameters of the proposed sandy soil consolidation model.

PREDICTION OF WELD-ABILITY CHARACTERISTICS OF DUAL-PHASE STEEL HCT600X BY NUMERICAL SIMULATION

Dual-phase (DP) steel plates are characterized by very good absorption capacity, so they are used in the automotive industry for body deformation zone parts. They are attached to the frame of the car-body by welding. Laser welding of dual-phase steels is gaining increasing importance in the automotive industry. In the present paper, the possibility of predicting the strength and deformation characteristics of laser-welded HCT600X steel sheets was analyzed based on experiments and numerical simulations. Butt joints were formed by YLS-5000 laser in two variants, which differ by laser power input and welding speed. The HCT600X- HCT600X with welded joint was analyzed based on microstructure and mechanical tests. The tensile strength and hardness of the welded joints were greater than those of the base material (BM). The microstructure of the weld metal (fusion zone) consisted of martensite, austenite and bainite, in the heat-affected zone it consisted of a mixture of martensite, bainite, ferrite and residual austenite. In numerical simulation, the finite-element mesh was created by linear volume elements refined in the weld region, and the Gauss model of the surface heat source was applied when modelling laser welding. The results of numerical simulation of the microstructure and selected mechanical properties were correlated with the experimental results.

Deformable multi-level feature network applied to nucleus segmentation

IntroductionThe nucleus plays a crucial role in medical diagnosis, and accurate nucleus segmentation is essential for disease assessment. However, existing methods have limitations in handling the diversity of nuclei and differences in staining conditions, restricting their practical application.MethodsA novel deformable multi-level feature network (DMFNet) is proposed for nucleus segmentation. This network is based on convolutional neural network and divides feature processing and mask generation into two levels. At the feature level, deformable convolution is used to enhance feature extraction ability, and multi-scale features are integrated through a balanced feature pyramid. At the mask level, a one-stage framework is adopted to directly perform instance segmentation based on location.ResultsExperimental results on the MoNuSeg 2018 dataset show that the mean average precision (mAP) and mean average recall (mAR) of DMFNet reach 37.8% and 47.4% respectively, outperforming many current advanced methods. Ablation experiments verified the effectiveness of each module of the network.DiscussionDMFNet provides an effective solution for nucleus segmentation and has important application value in medical image analysis.

Систематика многоинструментных наладок на станках токарной группы

Introduction. The analysis of factory lathe-automatic operations revealed a significant variety of multi-tool setups and identified its areas of application. To develop a matrix theory of accuracy for multi-tool machining and create a unified algorithmic approach to errors modeling for all possible spatial multi-tool setups, it is necessary to consider the flexibility of the technological system in all coordinate directions. In this regard, it is required to systematize a large number of existing multi-tool setups and classify it to structure the information and improve the understanding of its application. Purpose of the work is to develop a classification of multi-tool setups on multi-carriage and multi-spindle CNC lathes, enabling the creation of both a matrix model of machining accuracy for each classification class and a unified generalized matrix model of machining accuracy for the entire classification class. The work investigates the systematics of multi-tool setups, oriented toward the development of matrix models of machining accuracy. Therefore, the classification considered in this work is aimed at identifying the characteristics of force loading and deformation of the technological system during multi-tool machining. The research methods involve identifying the parameters used for classification and the hierarchy of these parameters, which determines the levels and order of the systematics. Based on the principles of systematics of multi-tool setups used in traditional automatic lathes, an analysis of its adaptation to the capabilities of modern lathes designed for multi-tool machining is conducted. Results and discussion. As a result of the research, a formalized six-level classification of multi-tool setups is developed, which includes the following aspects: the method of workpiece mounting, the set of carriages, the types of cutting tools, the types and directions of carriage feeds, the orientation of cutting tools relative to the workpiece, and the method of tool engagement (parallel, sequential). This classification takes into account the technological capabilities for organizing multi-tool machining on modern CNC lathes. The main classes of the proposed systematics of multi-tool setups in the presented work include single-carriage single-coordinate setups, single-carriage two-coordinate setups, dual-carriage single-coordinate setups, dual-carriage two-coordinate setups, and multi-carriage setups. The proposed systematics of multi-tool setups on lathe group machines is aimed at developing machining accuracy models and can serve as a basis for developing recommendations on cutting modes for these CNC machines. The proposed classification of multi-tool setups forms the foundation of the methodological support for the CAD system of lathe-automatic operations and serves as the basis for creating next-generation CAD systems for lathe operations.

Comparative Study of Numerical Simulation on Short-Term Creep Behavior of Steam-Pretreated White Oak (Quercus alba L.) Wood

This paper investigates the effects of steam pretreatment temperature (100~120 °C), test temperature (20~80 °C), and earlywood vessel belt on parameters associated with the bending creep properties of white oak (Quercus alba L.) wood. The Burger model, Five-parameter model, and Six-parameter model are used for short-term simulation and comparative analysis of the bending creep curve of steam-pretreated white oak wood, and creep fitting curves and viscoelastic parameters are obtained. The advantages and disadvantages of different viscoelastic mathematical models for fitting the bending creep curve of white oak are analyzed. The results indicate that the Six-parameter model is more consistent with the creep behavior of wood in simulating and predicting the creep behavior of wood than that of the Burger and Five-parameter model and can reflect the short-term deformation characteristics of wood.

Effect of interstitial nitrogen on physical and mechanical properties of Al0.5CoCrNi high-entropy alloys: a first-principles study

Abstract The N-doped high entropy alloys (HEAs) have recently garnered significant interest for their outstanding mechanical properties, making them valuable structural materials within the industry, aerospace, and biomedical science. In this work, the impact of interstitial N atom on various properties of Al0.5CoCrNi HEA is investigated through first-principle calculations. Specifically, the changes in lattice constant, formation energy, elastic modulus, density of states, Vickers hardness, Debye temperature, energy factor, and charge density caused by the presence of interstitial N atom are analyzed. The results show that the interstitial N atoms lead to a decrease of the sample stability due to an increasing formation energy of the N-doped HEA. As the interstitial N content increases, the elastic module decreases, and an apparent anisotropy appears in N-doped HEA. Moreover, Vickers hardness decreases, suggesting the change of the stiffness and deformation characteristics. Compared to the N-doped tetrahedrons, the N-doped octahedrons exhibit high ductility due to an increasing Poisson’s ratio, a decreasing G/B ratio, and an increasing Cauchy pressure. The significant decreasing Debye temperature and average sound velocity reduces the thermal stability. The change of the electronic structure suggests the possibility for customizing electronic and optical properties. Additionally, the low energy factors for screw and edge dislocations promote dislocation nucleation in N-doped HEA. Charge density analysis reveals strong bonding characteristics, potentially affecting the chemical stability and reactivity. This work provides a unique perspective on the N-doped mechanical mechanism, and offers important insights for the advancement of advanced N-doped HEA.

Numerical Simulation of Backfilling Construction for Underground Reinforced Concrete Grain Silos

Food security is an important guarantee for national security and public health. Underground reinforced concrete (RC) grain silos can provide a quasi-low temperature environment for grain storage, effectively ensuring the quality of the stored grain. The stress status of the underground silo during soil backfilling construction is complex, which puts the structure at risk of failure. The present study developed a numerical simulation method to investigate the mechanical properties of underground silos during backfilling construction processes. A finite element (FE) analysis of the backfilling construction process of an underground RC grain silo was conducted, and the nonlinear contact between the underground silo and the surrounding soil, as well as the material nonlinear behavior of the soil, was considered. The deformation characteristics and stress distribution of the underground silo during the backfilling construction process were revealed. The results indicate that the underground RC grain silo exhibits good mechanical performance. The underground silo underwent overall settlement during the backfilling construction process, with a total settlement of 21 mm. The maximum radial displacement of the silo wall and the maximum deflection of the radial primary beam were 0.84 mm and 5.67 mm, respectively, both of which were smaller than the limit values. After the completion of backfilling construction, there was a high risk of concrete cracking of the silo wall. The maximum radial and circumferential tensile stresses of the concrete at the silo top were both high, which led to cracking in the top of the silo. Our research results provide important support for the design and evaluation of underground RC grain silos.

Landscape changes caused by the 2024 Noto Peninsula earthquake in Japan.

Landscapes are shaped by tectonic, climatic, and surface processes over geological timescales, but we rarely witness the events of marked landscape change. The moment magnitude 7.5 Noto Peninsula earthquake in central Japan was caused by a large thrust faulting, up to nearly 10 meters of slip, that expanded more than 150 kilometers along the fault zone. The deformation field reconstructed from satellite data and field surveys reveals up to 4.4 meters of uplift and associated coastal advance along the entire northern coast of the peninsula, meter-scale systematic movement of the mountain slopes consistent with slip on flexural faults, and activation of secondary inland faults, suggesting synchronized ruptures. The findings show excellent consistency between the coseismic deformation and geomorphic features and provide a vivid example of the role of a major earthquake in landscape formation.

Study on Soil Freeze–Thaw and Surface Deformation Patterns in the Qilian Mountains Alpine Permafrost Region Using SBAS-InSAR Technique

The Qilian Mountains, located on the northeastern edge of the Qinghai–Tibet Plateau, are characterized by unique high-altitude and cold-climate terrain, where permafrost and seasonally frozen ground are extensively distributed. In recent years, with global warming and increasing precipitation on the Qinghai–Tibet Plateau, permafrost degradation has become severe, further exacerbating the fragility of the ecological environment. Therefore, timely research on surface deformation and the freeze–thaw patterns of alpine permafrost in the Qilian Mountains is imperative. This study employs Sentinel-1A SAR data and the SBAS-InSAR technique to monitor surface deformation in the alpine permafrost regions of the Qilian Mountains from 2017 to 2023. A method for spatiotemporal interpolation of ascending and descending orbit results is proposed to calculate two-dimensional surface deformation fields further. Moreover, by constructing a dynamic periodic deformation model, the study more accurately summarizes the regular changes in permafrost freeze–thaw and the trends in seasonal deformation amplitudes. The results indicate that the surface deformation time series in both vertical and east–west directions obtained using this method show significant improvements in accuracy over the initial data, allowing for a more precise reflection of the dynamic processes of surface deformation in the study area. Subsidence is predominant in permafrost areas, while uplift mainly occurs in seasonally frozen ground areas near lakes and streams. The average vertical deformation rate is 1.56 mm/a, with seasonal amplitudes reaching 35 mm. Topographical (elevation; slope gradient; aspect) and climatic factors (temperature; soil moisture; precipitation) play key roles in deformation patterns. The deformation of permafrost follows five distinct phases: summer thawing; warm-season stability; frost heave; winter cooling; and spring thawing. This study enhances our understanding of permafrost deformation characteristics in high-latitude and high-altitude regions, providing a reference for preventing geological disasters in the Qinghai–Tibet Plateau area and offering theoretical guidance for regional ecological environmental protection and infrastructure safety.

Timed-Release Silica Microcapsules for Consistent Fragrance Release in Topical Formulations

Microcapsules are widely utilized in various applications to preserve active ingredients for prolonged durations while enabling controlled release. However, limited release of active ingredients often hampers their effectiveness in daily-use products. In this study, we demonstrated the synthesis of silica core–shell microcapsules designed for controlled fragrance release in topical formulations. The microcapsules were synthesized via the sol–gel polymerization of tetraethyl orthosilicate (TEOS) on the surface of an oil/water emulsion, leveraging the shrinkage and deformation characteristics of sol–gel-derived silica during drying. The concentrations of dipalmitoylethyl dimethylammonium chloride, a cationic emulsifier used in cosmetics, and TEOS were optimized to sustain fragrance release for up to 24 h after topical application. An additional silica coating on the microcapsules reduced the Brunauer–Emmett–Teller surface area by 76.54%, enhancing fragrance stability for long-term storage. The timed-release behavior was assessed using fragrance evaluation tests and gas chromatography–mass spectrometry. The fragrance intensity and release profiles confirmed the potential of these microcapsules in daily-use cosmetics. These findings suggest that silica microcapsules with extended-release properties have application potential in both cosmetic and pharmaceutical products.

Ground response during of EPB shield shutdown in gravel ground based on coupled CEL-FEM analysis

The shutdown of earth pressure balance (EPB) shield tunneling in gravel stratum can easily lead to significant unexpected ground deformation. In order to study the response of gravel strata during shield shutdown and the characteristic change of soil state in the chamber, this paper establishes a coupled Eulerian-Lagrangian finite element method (CEL-FEM) coupling analysis model that reflects the interaction between the spoiled soil and gravel strata. The plastic flow parameters of CEL spoiled soil are calibrated using the slump method, and a quantitative relationship between the slump value, plastic flow parameters, equivalent coefficient of loosening, and excavation face support pressure is established. The reliability and applicability of CEL method in the simulation of shield shutdown are verified by the field measurements. Results show that: (1) The chamber’s soil equivalent loose coefficient is inversely proportional to the soil slump value which is related to soil’s plastic flow parameters. (2) The shield shutdown in gravel strata has a more significant impact on the deep strata displacement than on the surface. (3) During the shield shutdown stage, the chamber pressure should be dynamically adjusted based on the soil deformation characteristics, and an increase of 16% could result in a stable rebalance.

Full-field and wideband surface deformation reconstruction from the Fourier domain by spatio-temporal heterodyne interferometry (STHI)

In this paper, we propose what we believe to be a new full-field laser vibrometer designed to detect longitudinal deformations of a scattering surface, which are either harmonic, transient, stationary, or progressive (but necessarily repeatable) with a large bandwidth (10kHz – 10 MHz) using a slow camera that has a narrow detection bandwidth (<1kHz). Based on an interferometric setup, this vibrometer combines spatial and temporal beatings to access the deformation characteristics in the frequency domain. In our setup, the exposure time of the camera is used to average a heterodyne signal, giving the amplitude and phase of the deformation at a given frequency for each camera pixel. The surface under investigation is continuously illuminated, making it ideal for the study of transient or progressive vibrations. The principle and performance of our Fourier-domain laser vibrometer will be explained and illustrated by numerical and, above all, experimental examples.

Biaxial Thermo–Mechanical Response of ABS Sheet Above Tg Using DIC–Based Bubble Inflation Technique

ABSTRACTIn this study, we examine the biaxial, large, and rapid deformation characteristics of heavy‐gauge ABS sheets within the temperature range of 120°C to 160°C, relevant to the industrial forming process. A custom‐built bubble inflation apparatus with a 300 mm diameter was designed for this purpose. Temperature uniformity across the sheet was verified using a thermal camera, while the temperature profile through the material's thickness was monitored during the heating using thermocouples near the top and bottom surfaces of the sheet. The bubble inflation test, combined with displacement, strain fields, and deformation rates at different locations, enables detailed characterization of the bubble's shape under large deformation. To address early‐stage geometric instabilities due to sagging from thermal expansion, airflow was regulated with a precise flow control valve before inflation, while 3D‐DIC monitored the real‐time displacements to correct for sag deformation. The inflation pressure profile was recorded and synchronized with 3D‐DIC strain evolution data for each test, allowing for analysis of the characteristic stress–strain curve at the pole. By evaluating the material's equi‐biaxial properties at the pole and biaxial strain measurements away from the pole, the collected data provides a strong basis for future calibration of constitutive material models through an inverse approach, enabling accurate integration into process simulations.

Effect of adjacent structures on footing settlement for different multi-building arrangements

Abstract Rapid urbanization and land scarcity lead to the construction of multiple structures in proximity, supported on common soil media. This proximity increases soil stress, influencing the deformation characteristics of nearby footings. Hence, there is a need to investigate the effect of structure–soil–structure interaction (SSSI) on the footing settlement. In the present study, the effect of SSSI on the footing settlement of a three-storey building is investigated due to the presence of similar adjacent buildings arranged in various patterns (single adjacent building, side-by-side, L-shape, and inverted T-shape). The various interaction analyses are performed using finite element software ANSYS under gravity loading. The vertical and differential settlement of footings obtained from soil–structure interaction (SSI) and SSSI analyses are compared to evaluate the effect of SSSI under various adjacent building arrangements. The results indicate that in SSI case, inner footings show greater settlement compared to peripheral footings which causes high value of differential settlement between peripheral footings and those immediately adjacent to them. However, the presence of an adjacent structure in SSSI cases provides higher settlement in adjacent footings, which in turn reduces the differential settlement in these footings. Moreover, the SSSI effect on vertical settlement in SSSI (L-shaped) and SSSI (inverted T-shaped) is found to be more in corner footing located near to the adjacent buildings due to overlapping of soil stresses from two sides. The study quantifies the extent of settlement increase in various SSSI cases compared to SSI case, contributing valuable insights to mitigating potential settlement issues in densely developed areas.

Effect of anchor shear deformation on the propagation rules of excitation stress waves

To address the shear deformation failure resulting from misalignment of rock strata in anchor support, a range of methods, including laboratory tests, numerical simulation, and others, are employed to study the deformation process of anchor rods under shear comprehensively. This approach permits an investigation of the deformation characteristics of the surrounding rock and anchoring agent under shear. Moreover, the propagation characteristics of the stress wave in the anchor rods under shear with varying degrees of deformation have been elucidated. A novel non-destructive testing method for assessing the degree of shear deformation in anchor rods is proposed based on the correlation between the energy evolution law of the stress wave and the degree of anchor deformation. Following experimental verification, it was determined that the average discrepancy between the detection outcomes of the stress wave method and the actual measurement results was minimal and consistent. The findings provide a theoretical foundation for the non-destructive testing of anchor rod shear deformation under on-site support conditions.

A study on the factors influencing the transient deformation characteristics of compressor cylinders based on thermal–mechanical coupling

The deformation of the reciprocating compressor seriously affects the efficiency and reliability of the shale gas extraction unit. In order to study the deformation characteristics and influencing factors, this paper established a coupled system model of reciprocating compressor cylinder block-piston assembly, proposed a transient calculation method applicable to the 3D compressor cylinder model, and studied and analyzed the heat transfer characteristics, deformation characteristics, and main factors influencing the deformation of each component in one cycle. The results show that the temperature of the compressor cylinder shows a “W”-type trend, with low temperature fluctuation; the stress and deformation of the cylinder block are almost unchanged, and the stress of the piston fluctuates greatly, with a maximum fluctuation of 14.37 MPa; the temperature and deformation of the compressor cylinder block-piston assembly show the distribution characteristics of ‘high out and low in’; the maximum deformation of the cylinder block at the extreme moment is 0.298 mm; the piston ring expands and deforms on the exhaust side, and shrinks on the intake side, the maximum deformation is 0.089 mm at the extreme moment; thermal load has a greater influence on the deformation of the working chamber and piston ring.

Study on the deformation mechanism of chair-like bedding rock landslides under the coupling effect of geological and hydrological factors

Chair-like bedding rock landslides are prevalent in the Three Gorges Reservoir area (TGRA), necessitating further investigation into their inducing mechanisms. This study focuses on the Muyubao and Tanjiahe landslides, conducting a comparative analysis of their deformation characteristics and mechanisms while comprehensively considering geological and hydrological factors. The findings indicate that the Muyubao landslide was primarily triggered by the combined effects of rainfall during the water storage period and the rise of the reservoir water levels (RWL), with a threshold of approximately 165 m. In contrast, the Tanjiahe landslide was influenced by a rapid drawdown in RWL, heavy rainfall, and a high RWL, with a threshold of around 175 m. Both landslides exhibited a clear response to the rise in groundwater levels in the steep sections, with significant deformation occurring when groundwater levels reached 175 m (Muyubao landslide QSK1) and 245 m (Tanjiahe landslide QSK2). Notably, variations in landslide morphology, permeability coefficients, and fluctuations in groundwater levels can facilitate the mutual conversion between different landslide types (seepage-driven and buoyancy-driven). To investigate the influence of chair-like slope morphology on landslides, eight landslide models were constructed, featuring a range of dip angles for the rock formation (15° to 30°) and varying length ratios of gentle to steep sections (2:8 to 5:5). The UDEC Code was employed to simulate and analyze the governing effects of slope morphology on landslide deformation and evolution. Through a comparative analysis of the Muyubao, Tanjiahe, Jiuxianping, and Qianjiangping landslide cases, we examined the significant influence of landslide morphology and permeability coefficients on landslide behavior. The results indicate that the length ratio of gentle to steep section is a crucial parameter. When this ratio exceeds 2:8, the landslide is characterized by pushing deformation; conversely, when the ratio is lower, it tends to exhibit overall movement. Additionally, geological factors affect groundwater seepage and water level variation under the influence of rainfall and reservoir water, resulting in distinct deformation characteristics and mechanisms across different landslide types. Factors such as slope angle and the length of the gentle section influence the extent of the submerged area, leading to varied landslide responses to rise of the RWL.

The truncation effect of soil slope acceleration responses

A dynamic centrifugal model test was conducted for a homogeneous sandy slope under an impulsive ground motion to investigate the relationship between seismic response and slope deformation. Firstly, the deformation characteristics and dynamic responses of the slope were analyzed. Then, the main features associated with the response truncation effect were expounded. Subsequently, the Sliding block theory was introduced to explain the mechanism of the acceleration response truncation effect. At last, an approximate calculation method for the sliding mass dynamic response was developed, considering the influence of the truncation effect. The results show the variation pattern of response differs inside the slope and near the slope surface, and the dynamic amplification coefficients calculated by different methods also exhibit significant variations. The truncation of horizontal response acceleration results from the relative sliding in slope, and the truncated response fluctuates around a limited value related to the yield acceleration.

Study on deformation characteristics and damage mechanisms of soil-red stratum soft rock mixture undergoing tunnel excavation unloading considering wetting

Study on deformation characteristics and damage mechanisms of soil-red stratum soft rock mixture undergoing tunnel excavation unloading considering wetting