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In this study, we present a microstructural and mechanical analysis of Ti–6Al–4V alloys processed by low-temperature multi-directional forging at 900 °C, achieving near-theoretical density (99.9%), with a tensile strength of 1070 MPa and elongation of 14.9%. The microstructure is defined by both continuous and discontinuous dynamic recrystallization occurring simultaneously, related to an increase in dislocation density. Significantly, this study reveals the interaction between crystallographic orientation and spheroidization during the forging process. Specifically, changes in crystallographic orientation include the asynchronous formation of new subgrains/grains, the disruption of the Burgers orientation relationship, and rotation around the axis, which not only increases the orientation differences between α lamellae but also enhances the spheroidization process. Moreover, our findings demonstrate that during deformation, the activation of basal and pyramidal slip systems is favored over prismatic slip, indicating that the forging process has enhanced slip activity. The average misorientation angle and the fraction of high-angle grain boundaries are quantified, providing a detailed characterization of the evolved microstructure. This study adopts a new perspective to examine the microstructural evolution during the multidirectional forging process in powder metallurgy, presenting findings that elucidate how multidirectional forging effectively controls.

Composite materials find increasing applications in modern industry and transport. However, they may lose desirable mechanical properties due to external mechanical excitations, ultraviolet radiation, moisture penetration, or other factors. Therefore, an effective way to assess the condition of materials is necessary. In this article, a nondestructive evaluation of glass fiber-reinforced composite subjected to five-stage static bending is presented. For this reason, pulsed excitation terahertz imaging was utilized, and a data processing/exploration scheme was proposed. The proposed, novel approach consists of an efficient data registration algorithm based on surface approximation (for surface roughness and unevenness elimination) and a parametrization scheme applied for the signals gained from the time response of the glass fiber-reinforced polymer layer. Obtained parameters enable the global description of the evaluated material state and prediction of failure effectively, even in the early stages of destruction.

Precision research and technological equipment, as a rule, is not able to provide its specification characteristics without a high-quality vibration protection system. Active vibration control of an object is provided with the help of an additional source of movement, an actuator. The most promising high accuracy actuators are based on smart materials, such as materials with shape memory, piezoelectric and magnetostrictive materials, electro- and magnetic active fluids and elastomers. Dielectric elastomer is one of the types of electroactive polymers. Actuators based on a dielectric elastomer show high performance in terms of accuracy and speed and operate due to the controllable deformation of the elastomer under the action of a high voltage electric field. The paper provides a comparison of actuators based on sheet and thin film control electrodes. The influence of the quality of the polymer surface and the type of electrodes on the travel range of the actuator and maximum amplitude of vibrations the system can suppress on the basis of a dielectric elastomer is estimated. The formation of the electrode by magnetron sputtering in vacuum makes it possible to create a thin-film layer of copper that covers the elastomer, despite the developed surface. The effect of ion treatment of an elastomer before coating on the quality of the formed electrode is considered. After the ion treatment, the surface of the elastomer acquires a more uniform regular structure. A thin-film electrode layer is formed according to the topology of the elastomer to an accomplished standard.

Abstract The contact finger electrical connection structure is a crucial component of high voltage bushings, and its safety and reliability directly impact the operational stability of the bushing. To investigate electrical contact performance of the contact finger under eccentric conditions, a three‐dimensional electrical, thermal, and force multi‐physics coupling calculation model was established. Additionally, a test platform was constructed to measure electrical contact characteristics of the contact finger. The contact characteristics of the contact finger when the male head was axially deflected and radially offset compared to the female head were obtained. The research findings indicate when the male head deflects axially, the contact force changes of the contact finger blades on both sides are opposite. Moreover, as the axial deflection angle of the male head increases, the resistance of the electrical connection structure shows a rising‐slow decreasing‐fluctuating trend. The resistance is highest at 3°, with a resistance increase rate of 7.35%. Furthermore, the resistance of the electrical connection structure varies with the radial offset of the male head, following a power function. Contact failure occurs when the radial offset is 1.31 mm, and the resistance increase rate reaches 24.9% at a radial offset of 1.58 mm.

Introduction. When studying composite materials for construction purposes, it is needed to consider the mechanisms of formation of the structure and properties of modern concretes in the process of strength development. In studies of modern composite materials based on cement binder, there is no information about the development of structural defects and destruction of the material at the initial stages of strength development. This information can be obtained using X-ray computed tomography, a promising method of nondestructive testing of the state of the material. Therefore, the objective of this work was to study the formation and propagation of cracks in samples of fine-grained concrete with different fractional composition of sand due to natural processes of cement shrinkage, as well as the mechanics of destruction of samples of modified fine-grained concrete when applying a compressive load at the early stages of strength development. Materials and Methods. The study used fine-grained concrete mixtures of three compositions with different sand gradation. The tomography samples were made by placing fresh mixtures in polymer cylindrical containers. Tomography of the samples immediately after manufacture, as well as after 8 and 51 days, was performed in a YXLON Cheetah microfocus X-ray machine. The composition with two-fraction sand was modified by mechanical activation of the components, 20×20×20 mm cube samples were made. Further, compression tests were performed at the Instron installation after 3 and 7.5 hours, and then — tomography of the destroyed samples.Results. It was established that the destruction of contact zones depended on the ratio of the size of the fractions. In the presence of a bulk of coarse sand grains in concrete, the destruction of contact zones was more pronounced and had a main mode. When using fine or polyfraction sand, contact zones were destroyed locally and had a visually smaller area. The images of the destroyed modified sample, tested 3 hours after manufacturing, showed clear cracks and indents on the edges, which indicated the elastic-plastic nature of the destruction. In 7.5 hours, the edges of the sample upon destruction were covered with a network of small cracks; inside the sample there were also numerous cracks and microcracks, which indicated brittle fracture. Based on the obtained images of the deformed structure of modified concrete, the mechanism of transition from elastic-plastic destruction of the material to brittle one was clearly visible.Discussion and Conclusion. The studied dependences of the influence of the size of fine aggregate on the mechanisms of formation and propagation of structural defects contribute to the theory of the processes of destruction of fine-grained concretes. The results obtained prove the prospects of using X-ray computed tomography as a method of nondestructive testing of the internal structure of fine-grained concrete, including at the early stages of strength development.

Abstract To investigate the response of post-installed rebar connectors in steel frame retrofitted concrete structures under combined shear and tension, seven shear-and-tensile tests were conducted. The bearing capacity, stiffness, and hysteresis behavior of the connectors were investigated during the tests. Both Monotonic and cyclic load regimes were applied in the loading process. The results show that with the increase of the loading angle, the deformation capacity, the yield force, ultimate tensile force, and tensile stiffness of the specimen decrease, while the maximum shear force and shear stiffness of the specimen increase. The bearing capacity, stiffness, and energy dissipation performance of the specimen under a monotonic load is greater than that under the coupled shear-and-pull load. The bearing capacity, stiffness, hysteresis curve, and failure status of the specimens are not affected by different loading regimes. At the end, the design formula of anchor bolt for this type of connectors from the design code of China, United States, and Japan were compared. Formulas to calculate the shear strength under combined shear and tension is developed.

Slope failures in hilly terrain impact the social and economic balance of the community. The major reasons for these slope failures are steeper slopes, climate factors, seismic activity, nearby excavations, and construction. Natural slopes show significant heterogeneity due to the inherent randomness in material properties and geometric nonlinearities. Effective slope stability analysis solutions can be achieved by incorporating probabilistic approaches. We present a comprehensive method to develop and analyze a heterogeneous two-dimensional slope model, utilizing a non-linear-spatial-probabilistic-finite element method under a plane strain condition. The developed slope model encompasses geometrical and material nonlinearity with a uniform random distribution over the space. Also, the present slope model integrates the Mohr-Coulomb's constitutive model for elastoplastic analysis to capture more realistic and complex behavior. A benchmark soil slope problem was modeled using the spatial probabilistic finite element method, comprising all six material properties with uniform spatial uncertainties. These material properties are elastic modulus, unit weight, cohesion, friction angle, and dilation angle. During the numerical simulation, the detailed deformations, stress patterns, strain patterns, potential pre-failure zone, and failure characteristics of heterogeneous slopes were achieved under self-weight and step loading sequences. Nodal failure and probability of nodal failure were introduced as two novel quantitative parameters for more insights into failure investigations. The testbench slope model was subjected to self-weight load and external 100-step loading sequences with a loading increment of -0.1 kN/m. The percentage probability of nodal failure was obtained at 40.46% considering uniformly distributed material uncertainties with a 10% coefficient of variation. The developed testbench slope model was also simulated for different values of the coefficient of variation (ranging from 0% to 50%) and comparatively investigated. The detailed deformation patterns, thorough profiles of stresses-strains, failure zones, and failure characteristics provided valuable insights into geotechnical engineering practices.

The theory of cohomologies on multiplicative Hom-$ \delta $-Jordan Lie color triple systems is given. As an application, deformations and extensions on the multiplicative Hom-$ \delta $-Jordan Lie color triple system are characterized in view of relevant cohomology.

This article analyses the effects of deformation on the structure of CMnSi steel at various deformation levels. After hot forging, the structure of CMnSi steel comprises coarse-sized alpha and pearlite particles. The average grain size of steel after forging was 100 μm. After hot rolling, the grain size gradually decreases, with the average size of the ferrite and pearlite grains measured as 60 μm. After that, CMnSi steel was subjected to cold deformation at levels of 40%, 60%, and 80%. The grain size of the CMnSi steel sample after 80% cold deformation reached level 7, corresponding to about 25 μm. For a deformation level of 40%, the grain size was level 5, corresponding to 40 μm, while a deformation level of 60% produced a grain size of 35 μm, corresponding to level 6. In addition, scanning electron microscopy showed that after 80% deformation, smaller particles with a size of about 5 μm appear inside the parent particles. Moreover, energy-dispersive X-ray spectroscopy analysis revealed the carbide appearance in the form M23C6, with M being a mixture of Fe and Mn. These carbides have a fine size of about 1–2 μm and contribute to the prevention of particle growth during subsequent heat treatments.

GH4169 thin-walled parts are widely used in aerospace due to their high-temperature, corrosion resistance, and fatigue strength. However, they often deform from machining-induced residual stress, which is a significant unresolved manufacturing challenge. Additionally, initial residual stress from previous steps critically impacts subsequent processes. This study found that the residual stress of side milling of thin-walled parts under smaller cutting parameters is mainly caused by mechanical effects, and the influence of milling heat can be ignored. In this study, an analytical prediction model for residual stress of multi-step side milling thin-walled parts based on the deformation of thin-walled parts is proposed for the first time, which is suitable for smaller cutting parameters. Then, the proposed model is examined the mechanisms through which residual stresses develop during side milling and defined the applicability of model based on specific assumptions. To validate these assumptions, an experimental setup was devloped to simulate the movement of the heat source during milling. Subsequent two-step side milling experiments on GH4169 confirmed the accuracy of the analytical prediction model in predicting the residual stresses of multi-step side milling in thin-walled parts. It was observed that higher equivalent bending stiffness in thin-walled parts correlates with reduced machining deformation. The analytical model also provides a strategic approach to control machining deformation by managing the equivalent bending stiffness of the parts.

Shield tail grouting is an important measure to control tunnelling-induced ground deformation by injecting prepared grouting materials to fill the tail gap. The working performance of grout is usually invisible and hard to obtain in construction. This paper carries out an experimental study to investigate the tail grout behavior in ground. In the current research, a testing device is developed to explore the grout behavior in varying soils. The grout working performance is evaluated not only by the liquid grout properties such as fluidity, consistency, bleeding rate, stone rate and compressed deformation but also solid grout properties such as unconfined compressive strength and permeability. Three typical grouts are chosen and their behaviors in the various soils are observed. To take an insight on the behaviors, scanning electron microscopy and mercury intrusion porosimetry analysis are employed. The microstructure of solid grout is a sign of its working performance. The observation shows that the solid grout micro-structure is influenced by grout proportions, pressure, and ground permeabilities. The experimental results are applied in the case of Beijing Metro Line 12 for validation and as a result, the ground movement is inhibited due to high performance of tail grout.

Introduction. The development of Kazakhstan's megacities has led the construction sites to the territories with weak, macroporous soils. Construction on such soils requires a set of measures to strengthen and improve their mechanical properties. Methods and Materials. The article discusses the development of a method of surface hardening by replacing weak soil. This development is associated with the use of different types geosynthetics. The principles of operation of a soil foundation reinforced with various geosynthetic materials are considered. The mechanical properties of geotextiles, geogrids and geogrids used to harden embankment soils have been studied. A new test procedure for geosynthetic materials has been developed. This procedure differs from the traditional method specified in GOST 32491 with a constant deformation rate. Results and Discussion. Tests of geosynthetic materials in kinematic mode have shown that a decrease in tensile strength is observed for all materials. The reduction ranges from 28% to 42% for different types of geogrids. The elongation at break decreased for the hexagonal and biaxial geogrid by 8.6% and 30%, respectively. An increase in relative elongation was noted for a uniaxial geogrid. According to geotextile, the tensile strength decreased by 15.7%, and the elongation increased by 26.5%. Conclusion. Research results have shown the effectiveness of the recommended reinforcement methods to increase the bearing capacity of the bases and the possibility of their application in various regions of Kazakhstan.

A quarter of a century ago, during cartographic works using then-known field methods for measuring structural features, on the boundary of the Sudetic and Fore-Sudetic blocks, new phenomena were recognised; these were interpreted to be tectonic in nature and the result of left-lateral strike-slip movement in the subsurface. Grabens, half-grabens, shear zones and seismites in the gold-bearing sands and gravels that form the slopes of the valley of the River Kaczawa, are estimated to be of Pliocene and early Pleistocene age, having been interpreted as deposits of the pre-Kaczawa alluvial fan system. The natural exposures documented 25 years age have now all disappeared. In 2022, these levels became exposed again as a result of renewed gravel exploitation and phenomena described in the past reappeared. Field measurements were made again, this time using modern data-recording techniques, such as photogrammetry and terrestrial laser scanning. This work has enabled a comparison of field measurement methods with those obtained from the point clouds data. The results were found to be highly consistent. At the same time, precise reconstructions of the structures and their connection to the geodetic reference system make it possible to supplement previous geokinematic interpretations for this segment of the Sudetic Marginal Fault Zone (SMFZ). A formerly postulated left-lateral strike-slip regime in this zone was confirmed during the period of formation of the pre-Kaczawa alluvial fan deposits, but also probable is a kinematic inversion that must have occurred during, or just after, the early Pleistocene.

Objective Excavation of deep and big foundation pit destroys the equilibrium state of the original stress field in the soil, leading to ground deformation. Foundation pit deformation can be controlled by adopting GRF (green prefabricated ) surface protection structure with the premises of green environmental protection and high construction efficiency. An in-depth research on stress performance and deformation properties of GRF surface protection structure for deep and large foundation pit is required. Method Relying on the deep and large foundation pit project of Nanning International Airport Comprehensive Transportation Hub, a combination of finite element numerical simulation and on-site measurements is employed to study the stress and deformation law of the GRF surface protection structure for foundation pit top slope and the GRF surface protection structure between retaining piles in foundation pit. Result & Conclusion With the increase in foundation pit excavation depth, the location of the maximum lateral displacement of foundation pit top slope gradually shifts towards slope toe, with a maximum lateral displacement of 8.67 mm. The use of GRF surface protection structure effectively enhances the stability of foundation pit top slope. Anchor rods help transfer part of the load borne by GRE surface layer to the soil layer, thereby reducing deformation and stress GRF surface layer. The spacing between retaining piles has a great influence on soil arching effect. In this project, retaining pile spacing can be increased to around 2.5 m, and soil arching effect is most obvious at 7-8 meters below the pile top.

Earthquakes are a serious threat in the construction of multi-storey buildings in Indonesia, which are divided into several seismic design categories. The design of seismic-resistant buildings requires the management of plastic hinges to reduce seismic loads. The aspects of seismic-resistant structural design in Indonesia are regulated by SNI 1726:2019, SNI 1727:2020, and SNI 2847:2019. Intermediate Moment Resisting Frame System (IMRFS) and Special Moment Resisting Frame System (SMRFS) are used based on seismic category and earthquake intensity. Pushover analysis is used to analyze the structures behavior when exposed to seismic loads. This research designs seismic resistant structures with IMRFS and SMRFS at different locations with the aim of assessing structural performance and gaining reinforcement to the concrete ratio, which is relevant for the design and construction of multi-storey buildings in Indonesia. The results of this research are the structural performance levels, reinforcement volume, concrete volume, and the reinforcement to concrete volume ratio. Both IMRFS and SMRFS reached Immediate Occupancy to Life Safe performance levels after the earthquake because their monitored displacement was not significantly different. The structural failure modes of both systems meet the Strong Column–Weak Beam requirements. The distribution of plastic hinges also remains in the Immediate Occupancy category.

The unique continuous extrusion-based severe plastic deformation approaches were proposed recently to process high-performance magnesium (Mg) alloys, while the in-depth deformation mechanisms under such complicated thermomechanical conditions were not well understood. In the present work, the fundamental deformation behaviors of AZ61 Mg alloy from 25 to 400 °C were firstly examined under uniaxial compression deformation. Then the deformation mechanisms and microstructural characteristics of AZ61 Mg alloy during continuous expansion extrusion forming (CEEF) were systematically investigated by microstructural observations, finite element and cellular automata simulations. The results showed that the continuous evolutions of temperature, larger strain level and complex stress state with strain rate range of 0 ∼ 5.98 s−1 during CEEF brought the distinctive dynamic recrystallization behaviors and texture development in AZ61 Mg alloy, which were different to that of uniaxial compression deformation. In details, a remarkable grain refinement was achieved via CEEF processing due to the simultaneous actions of continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX). Gradually enhanced CDRX were observed from center to edge region, which had significant effects on the texture distribution and texture strength. The c-axis of most grains rotated under distinctive shear strain following parabolic metal flow, resulting in stable fiber texture. In addition, the evolution of the internal texture of the alloy led to an obvious increase in the Schmid factor for the activation of basal 〈c + a〉 slip system.

Introduction. Cable structures belong to perspective roof systems. Specialized software packages for structural analysis, however, do not provide optimization tools for obtaining efficient design solutions of the cable structures. Thus, development of improved methods for design and analysis of cable systems is an important task to be solved. An advanced technique for flexible cable analysis is proposed. It includes ordinary operations of summing the coefficients and their products. The technique is applicable for non-commercial mathematical software packages with numerical simulation tools included, thus providing structural optimization capabilities.Materials and methods. The technique proposed is based on the sine-series expansion of the external load and the shape function of the flexible cable. The differential equation of cable equilibrium is thus transformed into the set of algebraic equations. The cable length is expressed in algebraic form by means of the power expressions for the sum of the series.Results. The equation for the flexible cable is derived. It includes cable ordinate, axial stiffness, relative elongation and the external load parameters. The technique for determination of the axial stiffness of the cable is proposed under the operability conditions. The techniques for finding load-induced vertical displacements, as well as the initial cable sag and the undeformed length are given. The length of the cable under load and the ordinate given the cable length are proposed.Conclusions. The technique for flexible cable analysis allows taking into account distributed transverse external loads. For a combined load the coefficients of the series are the sum of the particular load coefficients. The technique is intended for automated structural solution. It allows facilitating the preliminary design stage, thus providing optimal parameters determination and in-depth design study implementation. Further development of the proposed technique encompasses the fields of non-shallow cable analysis, multy-chord cable systems, cable structures with stiffening girders, strutted cable systems and spatial roof structures.

Abstract This work presents experimental tests based on coal collected from a coal mine based underground water reservoir (CMUWR). The mechanical responses of dry and water-soaked coal samples under the complex normal and shear stresses under multi-amplitude and variable frequency is investigated. The experimental results reveal the effects of stress path, water soaking and frequency on deformation, energy dissipation, secant modulus and shear failure surface roughness. The experimental results show that when normal and shear stresses are applied simultaneously, there is a significant competitive relationship between them. On the dominant side, the strain rate will be significantly increased. The sample under a loading frequency of 0.2 Hz exhibits a longer fatigue life. During the cyclic shear test, the shear strain of the water-soaked sample is higher than that of the dry samples. The average roughness coefficient of failure surface exhibits an increasing pattern with increase in shear strength, the elevated roughness of a shear surface is advantageous in constraining shear displacements of specimens, thereby lowering the energy dissipation. This study can provide theoretical and practical implications for a long-term safety evaluation of CMUWR.

The paper presents the design of a damper based on a multilayer magnetorheological elastomer that has high load capacity, up to 500 N. The damper is able to operate in all vibration control modes, depending on its control signal. The damper cooling system is presented. Vibration tests were carried out and the damper amplitude-frequency characteristics were obtained. The transition process of damper displacement with a control step signal was analyzed.

The response of landforms to tectonic deformative processes can be effectively understood by using geomorphic indices. The objective of this study is to evaluate the extent of neotectonic activities in the fourth-order sub-basins of a tropical river basin (Kallada River basin) in the Southern Granulite TerrainIndia. The extend of neotectonism was analyzed using geomorphic indices such as asymmetry factor, transverse topographic symmetry factor, hypsometric integral, stream-length gradient index, drainage basin shape index, ratio of valley floor to valley height, and mountain front sinuosity, with values varying from 0.3 to 41.20, 0.12 to 0.54, 0.13 to 0.69, 12.76 to 1036.49, 0.63 to 3.81, 0.05 to 6.04, and from 1.02 to 3.08, respectively. Further, the relative active tectonics index (IRAT) was derived from the geomorphic indices using GIS and the values vary from 1.67 to 3.0. Based on the degree of relative tectonic activity, Kallada River basin was classified into class 1, 2, 3 and 4 corresponding to very high (1.0-1.5), high (1.5-2), moderate (2.0-2.5), and low (IRAT>2.5) values. The spatial distribution of different “IRAT” classes shows a gradational pattern from east to west, suggesting a gradual decrease in the neotectonic activity in the basin.

Background: Maintaining the functional integrity of primary teeth is important, as these teeth are integral in vital functions such as mastication, speech development, and space maintenance for permanent teeth; hence, premature loss of primary teeth can affect a child's quality of life. Various restorative materials are available to restore the function of grossly decayed teeth. Stainless steel crowns and zirconia crowns are widely used in pediatric dentistry; however, there are certain disadvantages associated with these materials. Recently introduced BioFlx crowns provide acceptable esthetics with a conservative approach. Nevertheless, there is a lack of evidence regarding their strength and clinical acceptability. Finite element analysis measures the physical response of teeth and assesses the stress generation, which is important to estimate the integrity of the restorations and crowns. Purpose: The aim of this in vitro study was to evaluate and compare stress generation in primary teeth restored with zirconia and BioFlx crowns using finite element analysis. Methods: Models of extracted teeth restored with zirconia and BioFlx crowns were used for the study. The finite element analysis of these models was carried out through Analysis of Systems (ANSYS) software. The models were subjected to a simulated occlusal loading force of 245 N. Results: Von Mises stress generated in BioFlx crowns along with underlying dentin was much less compared to that which was generated in zirconia crowns. Conclusion: Restoring the functional integrity of carious teeth is essential. BioFlx crowns can be used as full coverage restorations and can be a suitable alternative to zirconia crowns and traditional stainless steel crowns.

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.

Abstract When it comes to the geosynthetic-reinforced soil structures’ structural design, the analysis of deformation is of the highest relevance. In spite of this, the academic literature lays a substantial amount of attention on the potential of artificial intelligence approaches in efficiently addressing the many challenges that are faced in geotechnical engineering. The investigation of the possible use of approaches based on machine learning for the purpose of forecasting the geogrid-reinforced soil structures’ deformation ( $${\text{Dis}}$$ Dis ) was the major focus of this study. These efforts are made to reduce the time and cost of numerical modeling. This study aimed to enable computers to learn patterns and insights from data to make accurate predictions or decisions about unseen data. This paper introduces novel systems that coupled the Beluga whale optimizer ( $${\text{BWH}}$$ BWH ), Henry gas solubility optimization ( $${\text{HGSO}}$$ HGSO ), gannet optimization algorithm ( $${\text{GOA}}$$ GOA ), and Harris hawks optimizer ( $${\text{HHO}}$$ HHO ) with adaptive neuro-fuzzy inference system ( $${\text{ANFIS}}$$ ANFIS ). A dataset was created by gathering 166 finite element analyses accomplished in the literature. Between four $${\text{ANFIS}}$$ ANFIS systems, the integrated one with $${\text{GOA}}$$ GOA got the largest accuracy value, accounting for 0.9841 and 0.9895 in the train and test stages, better than $${\text{ANF}}_{{{\text{BWH}}}}$$ ANF BWH , followed by $${\text{ANF}}_{{{\text{HH}}}}$$ ANF HH . It was seen from $${\text{U}}_{{{95}}} { }$$ U 95 that the $${\text{ANF}}_{{{\text{GOA}}}} { }$$ ANF GOA scenario exhibits the least level of uncertainty in comparison to other models, hence demonstrating its greater capacity for generalization. Between four $${\text{ANFIS}}$$ ANFIS systems, the most accurate system with the lowest $${\text{OBJ}}$$ OBJ value is $${\text{ANF}}_{{{\text{GOA}}}}$$ ANF GOA at 2.6098, followed by $${\text{ANF}}_{{{\text{BWH}}}}$$ ANF BWH at 2.8002. Sensitivity analysis depicts that removing the surcharge $$\left( q \right)$$ q parameter from the input group has a considerable negative impact on output accuracy.

The paper analyzes the issue of calculating the endurance of the body of lowflying orbital objects from cyclic temperature alternating deformation beyond the limits of Hooke's law. The practical absence of direct calculation methods is stated. An indirect calculation is proposed on the basis of available experimental data on mechanical tests of samples with the «stress» parameter and an algorithm for transition from actual deformations to equivalent stresses. The calculation method is based on the use of the existing experimental fatigue curve under a symmetrical bending cycle, the results of static tensile tests at extreme cycle temperatures, and a generalization of known information about the patterns of changes in the endurance parameters of the material under consideration in relation to the conditions of cyclic temperature alternating deformation. The adequacy of the methodology is verified using the example of depressurization of the housing of the Zarya orbital module of the international space station, made of AMg6 alloy after ≈120,000 cycles of alternating temperature loading. The difference between the calculated and actual endurance of the AMg6 alloy is within the natural range of 20 % during fatigue testing.

Spur gear, helical gear, worm gear, and bevel gear are all important components in industrial applications such as vehicles, pushes, conveyors, elevators, bowl mill, rolling mills, ribbon blender, machine tools, aeroplanes, and windmills. When various types of defects, such as wear, tooth breakage, corrosion, and scratches on bearings, appear in gearboxes, normal machine function may be abruptly terminated. As a result, output and dependability suffer. As a result, several quality tracking and evaluation approaches have been adopted by companies. Finite element analysis (FEA) is one of the approaches. This research paper presents the FEA of a ribbon blender worm gear pair by using Ansys 18.0 to identify the weak gear of the worm gear pair, natural frequency, and deformation. Proe-5 utilized for creation of three-dimensional geometry of threaded worm and toothed worm wheels, as well as other related elements such as shafts and bearings. Steel is used for the worm, shaft, and bearing, whereas bronze is used for the worm wheel. Ansys 18.0 is implemented to carry out worm gear pair model analysis. The results demonstrate that the worm wheel had the most deformation when compared to the worm, and that the natural frequency is greater than the operational frequency of the worm gear pair. The findings of the research study, worm wheel deteriorate early than worm, model analysis plays a significant role in vibration monitoring of worm gear pair, and this work is valuable for further fault analysis of ribbon blender worm gearbox utilising vibration response.

Background. Measuring the degree of deformation of solids is a necessary measure in many fields of science. Such measurements can be performed using sensor equipment containing resistance strain gauges. This type of sensor uses a special type of resistor called a resistance strain gauge. Various methods for incorporating these electronic components into a strain gauge circuit are given. Materials and methods. Using linear equations, numerical characteristics were calculated for different switching options, for example, the sensitivity of the sensor. Results and conclusions. The schemes for including different numbers of active and compensating strain gauges in a measuring bridge are considered. For different types of deformation it is necessary to use suitable switching methods, this must be taken into account when designing information-measuring and control systems.

In various parts of the globe, there have been several earthquakes of a modest size. Monitoring the change of the points over time is a key component of typical techniques for extracting dynamic responses. This technique was unable to completely extract all of the earthquake’s dynamic properties. The GNSS precise point positioning (PPP) may be a useful tool for obtaining values of the point’s displacement that are more exact up to millimeters, which can help to overcome these flaws and evaluate the seismic wave of such earthquakes. Ultimately, PPP is a crucial tool for getting the precise observations. In this study, Canadian Spatial Reference System Precise Point Positioning (CSRS-PPP) approach to analyze the station’s displacement components and the station’s heights in periods from the two Kahramanmaraş earthquakes. The earthquake sequences that occurred in Turkey’s Kahramanmaraş in 2023 is an example of complicated faulting brought on by interactions between three plates close to the Hatay Triple Junction (HTJ). While the relative plate movements in this area are minimal (usually less than 10 mm/year), even sluggish plate motion zones may nevertheless see earthquakes that are quite destructive. Due to the three-plate system’s unusual geometry, a number of large earthquakes with very varied fault orientations were active throughout this series. A 7.8-magnitude earthquake happened on February 6, 2023 in southern Turkey, close to Syria’s northern border. A magnitude 7.5 earthquake, situated about 95 kilometers to the southwest, was occurred nine hours after the first one. The first earthquake was as big as the most powerful one ever recorded there in 1939 and was the most catastrophic to strike earthquake-prone Turkey in more than 20 years. In this study, the effects of two earthquakes in Kahramanmaraş were investigated on the Cyprus Arc, the Dead Sea fault, Hatay and the points close to two earthquakes zone. In the obtained results, it was computed that the greatest horizontal displacement occurred at the HAT2 station with 68.97 cm.

This study introduces an alternate spatial-temporal modeling-assisted InSAR time-series analysis method for mine subsidence mapping, aiming to address the large deformation gradients and decorrelation issues. The approach employs the iterative Modeling-Assisted Phase Unwrapping (MA-PU) algorithm for spatial phase unwrapping, and integrates it with temporal models to derive the deformation time-series. Four different inversion procedures are implemented to derive the time-series based on pixel types. The MA-PU method’s effectiveness in handling phase gradients is validated with simulations and real data analysis, showing superiority over non-model-based methods. The incorporation with temporal modeling and time-series inversion demonstrates advantages over time-series inversion alone in dealing with rank-deficiency issues within subsidence zones. The approach is applied to the West Cliff Colliery, Australia, using 23 ALOS-1 data. Results have been compared with GNSS data for validation. Obtained accuracy is approximately 16 mm, with a correlation of 0.99 between the two measurements, showing generally better performances compared to other methods. The comparison result suggest that this approach provides a more robust solution for monitoring mine subsidence in complex scenarios.

To explore the influence of the working face excavation rate on the rock deformation mechanism and seepage characteristics, deformation and seepage tests of sandstone under different loading and unloading stress paths, such as constant axial pressure unloading confining pressure and loading axial pressure unloading confining pressure, were carried out. Particle Flow Code in 3 Dimensions (PFC3D) and Python were used to realize fluid-solid coupling, and numerical simulation calculations were performed along the test path to analyze the influence of the unloading rate on the fine-scale deformation mechanism and permeability characteristics of sandstone, and the relationship between crack type and permeability was obtained. A sandstone fracture mechanics model is established to analyze the stress concentration degree at the end of the branch crack of the test path. The results show that the rate of confining pressure unloading is inversely proportional to the strain. Additionally, permeability correlates with the principal stress difference in an exponential manner. Interestingly, the sensitivity of permeability to stress shows an inverse trend with the unloading rate of confining pressure. Furthermore, there exists a linear relationship between permeability and the number of cracks. During the unloading process, tensile cracks predominate, and the propagation of shear cracks lags behind that of tensile cracks. The proportion of tensile cracks decreases with the increase of the unloading rate when the axial pressure is unchanged but increases when axial pressure is added, resulting in axial compression deformation and expansion deformation along the unloading direction. These research outcomes offer theoretical insights for the prudent selection of mining rates, and they hold significant implications for mitigating water inrush disasters in deep mining operations.

The article presents factors influencing the germination and development of plants after seeding with disk seeders. Schemes of improved two-disk seeders are proposed, forces acting on the improved seeder during operation, determination of the maximum distance between the seeder disks at the field surface level, and calculation schemes for determining the draft resistance of the serial and improved seeders, the area of the flat disk segment of the seeder, determination of the deformer, and tailstock area of the pressing plate. During the theoretical study of the seeding process, the following parameters and observations were obtained: analytical dependencies of soil density created by the pressing plate; geometric parameters of the pressing plate with a curvature radius r = 52…57 mm, plate section thickness of 2.5 mm; installation of the pressing plate insignificantly increases the draft resistance of the seeder; and the depth of the seeder’s travel has the greatest influence on spring deformation. Experimental studies reveal that the stiffness of the pressing plate is 7500…7600 N/m, ensuring an optimal furrow bottom density of 1.1–1.3 g/cm3; in the range of seed embedding depth of 0.05…0.07 m, 89% of the total number of seeds are placed compared to 76% of seeds embedded by the serial seeder.

High-purity tantalum is used as the sputtering target material for integrated circuits, requiring fine grains and random texture. Understanding different orientation deformation mechanisms, especially the metastable orientation (here {112} crystallographic orientations), is beneficial for controlling the structure of tantalum target materials. This paper employs EBSD and crystallographic calculations to regulate the grain deformation behavior by introducing a reverse strain at 135° clock rolling. The deformation behavior and dislocation density distribution of the metastable oriented grains under different strain paths are quantitatively analyzed. Results show that unidirectional rolling (UR) generates stress concentration, causing an uneven distribution of geometrically necessary dislocation density. The splitting behavior of {112} and {111} grains is promoted, and they have similar deformation behavior in UR process, while the deformation of {100} oriented grains is significantly suppressed. Furthermore, changing the strain path promotes the splitting of {100} grains, and makes the {112} change from the soft orientation to the hard orientation. This change makes it easier to start multi-slipping, resulting in a more uniform deformation. Additionally, crystallographic calculations show that Schmid factor is ineffective in explaining the strain localization problem in BCC metals. However, Schmid factor difference ratio makes it possible to analyze the distribution of dislocation density in local regions through the quantitative calculation of multi-slipping.

In this work, the nucleation and growth kinetics of pearlitic transformation are quantitatively investigated to unveil the distinctive microstructural evolution behavior under a high undercooling degree. Both intra-granular and inter-granular nucleation increasingly occur with 1-2 orders of magnitude increase in nucleation rate N˙. However, a moderate increase in the growth rate GV, namely a larger N˙/GV ratio, leads to a 30%–40% size reduction in pearlitic colonies. The avalanche-type increase in nucleation events induces a more random distribution of ferrite orientation among colonies that possess a slight increase in relative misorientation but a pronounced increase in accumulative misorientation, and an arbitrary alignment of Fe3C lamellas in colony interior. Such improved microstructural homogeneity ensures more uniform and localized deformability, which allows compatible deformation between colonies or within colonies and prevents the expansion of newly-formed cracks. These results provide guidance for industrial manufacture of high-carbon pearlitic products with high safety and reliability, resulting from the improvement in localized deformability, and for low-cost wires via reducing the drawing passes, stemming from the significant increase in uniform deformability.

The three-dimensional grain-averaged response of solid bar samples under non-proportional (NP) elastoplastic axial-torsional loading was investigated using in situ high energy diffraction microscopy (HEDM) and companion crystal plasticity finite element (CPFE) modeling. Important stress metrics including applied shear (σθZ) and axial (σZZ) stress tensor components, stress and stress deviator tensor invariants (I1, J2, and J3), von Mises equivalent stress (σVMgrain), maximum resolved shear stress (mRSS), stress triaxiality (η), and lode angle parameter (θ‾) values were tracked for ∼ 300 grains under two different loading conditions: (1) Torsion-dominated loading (low NP) and (2) Tension-torsion loading (high NP) in equiatomic NiCoCr, a representative multicomponent face-centered cubic (FCC) superalloy. Overall, significant stress localizations existed within both samples as evidenced by the radial dependence of grain-resolved σθZ, σVMgrain , and J2; by comparison, I1, J3, η, and θ‾ metrics did not show discernible trends within the volume. These stress localizations reveal a complex interplay between axial and shear stress components (e.g., stress coupling) resulting in grain yielding near the sample surface largely driven by shear stress, whereas internal grain yielding was largely accommodated by axial stress. Grain-resolved stress localization trends were described well by the CPFE model, although some discrepancies in magnitude occurred, particularly for volumetric stress metrics (I1 and η) due to initial type II residual stress distributions. The superposition of initial residual stress states onto CPFE grain-resolved data significantly improved model accuracy for η. This suggests that residual stresses more strongly influence the simulation of volumetric rather than deviatoric (yield) stress metrics.

The development of the construction industry in terms of the design and manufacture of shell structures of non-standard architectural forms made of materials with complex mechanical properties requires using modern integrated computer-aided design systems with step-by-step modeling of deformation of structural elements under operating conditions, as well as taking into account their subsequent behavior after accumulation of residual strains during plastic deformation. The purpose of the study is to simulate the process of plastic deformation of a thin-walled cylindrical shell made of 9X2 GOST 5950-2000 (Interstate Standard) steel under compression and torsion with theoretical calculations based on the general theory of elastoplastic processes by A.A. Ilyushin. The constitutive equations of the theory of elastoplastic processes by A.A. Ilyushin for complex loading path and deformation of materials in the deviatoric strain space are presented. Based on the presented solutions, according to the strain path of the 9X2 steel shell implemented in the model, the graphs showing the relation of the vector and scalar properties of the material to the arc length of the strain path are constructed. A conclusion is made about the degree of hardening of the material in question and its dependence on the magnitude of the angle of convergence at the kink point of the complex path. The graphs of changes in the constitutive plasticity functions with respect to the increments of the arc length of the strain path are presented.

Abstract The use of different types of shear panels as a large group of yielding dampers has been investigated. Acceptable seismic behavior such as stiffness and high deformation capacity, appropriate lateral resistance, ease of construction, and use in the structure are among the most important. Different types of these dampers have been developed, and yield shear panel device (YSPD) dampers are one of them. This research investigates the effects of changes in the geometric dimensions of this type of damper on their seismic behavior. For this purpose, nonlinear finite element models of dampers under cyclic loading were analyzed. The obtained results showed that the simultaneous use of side plates and stiffeners can create suitable conditions for directly controlling the dimensions of the damper. Local buckling in the side plates may concentrate deformations in this part of the damper element, affecting the hysteresis behavior with pinching. In addition, increasing the thickness of the side plate linearly has increased the yield strength and ultimate strength of these dampers. Finally, it was found that the increase in shear plate stiffness can directly increase the energy absorbed by this type of damper, effectively improving the seismic capacity of YSPD dampers.

Deposition pattern and path-planning deposition strategy have significant impacts on the deformation and residual stress of components during a wire-arc additive manufacturing (WAAM) process. This work comparatively addressed the influence of weaving and non-weaving deposition patterns on the distributions of residual stress and warping deformation during a single-bead-on-plate WAAM process. Further, four path strategies with different deposition sequences (in-out and out-in) and deposition directions (alternate and consistent) were designed for a weaving WAAM process of disc part, and their impacts on temperature history, warping deformation, and residual stress were comparatively analyzed through thermal-mechanical coupling finite element (FE) method. Simulation and experiment results manifest that, compared to the non-weaving pattern, the weaving deposition pattern results in more uniform deformation and lower residual stress on the deposited plate due to wider and shallower molten pool. Comparison results for the four deposition path strategies in the weaving WAAM process of disc part suggest that the out-in deposition sequence exhibits faster heat dissipation and uniform temperature field during the cooling stage, resulting in reduced warping deformation and residual stress on the workpiece. Moreover, uniform deformation is observed across path strategies employing alternate deposition direction. The out-in alternate deposition path strategy was identified as the optimal choice for the weaving WAAM process of disc part. Finally, physical experiments validated the simulated warping deformation of disc parts under different deposition path strategies. This work contributes to the design and optimization of weaving WAAM process for disc-shaped components.

This study explores the plastic deformation mechanism and microstructural evolution of as-homogenized and as-forging Inconel 718 alloy through low temperature and slow strain rate hot compression deformation. The stress-strain curves of Inconel 718 alloy were analyzed by modulating the deformation temperature, strain rate, and strain, and the extreme grain refinement process from cast billets (with abnormally coarse grains) to the final compression sample was revealed. The results show that the true stress levels are lower during both low temperature and slow strain rate hot compression, relative to high temperature and fast strain rate deformation. For the as-homogenized Inconel 718 sample, the same grain refinement as the high temperature and fast strain rate (i.e. forging deformation) was achieved by the low temperature and slow strain rate compression deformation. For Inconel 718 samples after forging, uniform, equiaxed, fine grains with an average size of 2.9 μm are obtained at lower deformation temperatures and slower strain rates. Based on these results this low temperature and slow strain rate metallic forming process demonstrates the potential for the application of plastic deformation in controlling grain size, morphology, and distribution, providing a direct, economical, and efficient approach to achieving fine equiaxed grain structures in as-forging metallic materials.

Purpose – Explore the development trend of chemically-improved soil in railway engineering. Design/methodology/approach – In this paper, the technical standards home and abroad were analyzed. Laboratory test, field test and monitoring were carried out. Findings – The performance design system of the chemically-improved soil should be established. Originality/value – On the basis of the performance design, the test methods and standards for various properties of chemically-improved soil should be established to evaluate the improvement effect and control the engineering quality.

Abstract As a solid energy source, CH4 hydrate will inevitably break down physically as the result of geological movement or exploitation. Here, the molecular dynamics method was employed to simulate the uniaxial-deformation behavior of structure I (sI type) CH4 hydrate under stress. The stress increases regardless of whether the hydrate is stretched or squeezed, and other physical parameters also changed, such as hydrate cage numbers, order parameters, and the number of water molecules. A noticeable difference is observed between the two systems. Upon stretching, the stress immediately recovers to 0 GPa once the hydrate is completely stretched apart. During the squeeze process, the stress is ultimately not zero since solid and liquid are always in contact. When the hydrate is stretched apart, about 5% of water molecules change from solid to liquid, about 7.8% of CH4 molecules lose their shelter and become free due to the disintegration of water cages. While in the squeezing process, large cages (51262) are crushed more easily than small cages (512); in the end, about 93.5% of large cages and 73% of small cages are crushed, and approximately 87.5% CH4 is released from the cages. In mining CH4 hydrates, caution must be exercised, as if the hydrates break as a result of stress, a large release of CH4 may pose a security risk.

Abstract Undertakings in underground mining are often complicated, particularly in situations where geotechnical conditions are not favorable. This study investigates the collapse of tunnels at the Lega-Dembi gold mine in Southern Ethiopia, an area characterized by weak talc formations. The persistent deformation of tunnels poses a threat to the safety of workers and mining operations. In this study, a numerical method that combines continuum and discontinuum approaches is employed to analyze tunnel failures. Additionally, the study evaluates the effect of geotechnical parameters on tunnel deformation, considering various support systems. The results indicate that a combination of rock bolts and shotcrete is effective in mitigating tunnel deformation. Furthermore, the study identifies the geological strength index and unconfined compressive strength as the most influential parameters on tunnel deformation. The findings also suggest appropriate support systems for managing underground instability and enhancing safety measures in weak geological formations.

Fiber-reinforced plastic (FRP) is utilized in the fabrication of the primary structures of FRP boats. A majority of these structures are produced using molds. Subsequently, these products often experience deformation upon being released from the mold, as well as when they are exposed to high temperatures. Hence, it is crucial to carry out experimental investigations and evaluations related to the deformation of laminated composite structures. The specimens, which are in the form of L-shapes and curve-shapes, are constructed using unsaturated polyester resin and fiberglass material. The study focuses on two independent variables, namely the percentage of hardeners and the temperature during the manufacturing process. The output factor under examination is deformation, which is measured on these specimens. Subsequently, all of the specimens are subjected to varying levels of temperature using an oven as the working condition. The deformation is further assessed based on the experimental findings and regression equation. The results indicate that as the rate of hardener and temperature increase, the level of deformation decreases. Additionally, it was observed that when the temperature rises from 500 to 800°C, the specimens with initial deformation values that are either too high or too low undergo rapid changes. Moreover, the experimental equations can be utilized to predict the values of deformation or input factors.

By conducting a two-dimensional experimental study, this paper aims to enhance the understanding of the mechanism of sand convective motions in the vicinity of a wall subjected to long-term cyclic lateral loadings. The experimental tests were conducted in a rectangular sandbox with a transparent front-wall, through which the process of sand particle motions could be recorded by using a high-resolution digital camera. The images were processed with a high time-resolved PIV (Particle Image Velocimetry) system. Based on the experimental data, this work (1) presents the sand flow field in the convective zones; (2) provides means to describe the convection mechanism; (3) proposes the relationships between the loading conditions and dimensions of the region with intense sand movement; and (4) elaborates the similarity of the sand flow velocity structure within the sand convective zones.

Abstract Metal alloys designated for cold metal working exhibit much higher strength properties than pure materials due to solid-solution hardening. However, with the increase of mechanical properties its plasticity and workability decreases. Constant development and demand in this area has led to research on many copper alloys, such as copper alloys with high content of magnesium which were never tested before. The limitations regarding cold metal working of CuMg alloys is the main objective of this paper. Here we show that the tested materials exhibit much higher mechanical properties than currently used as electric conductors and carrying-conducting equipment materials such as pure copper, aluminum, M63 brass or CuNiSi alloy. The results were obtained using Hollomon relation, Considére criterion, Gubkin method and hardness measurements. It lead to assessing the prospective cold metal working of CuMg alloys with 2 wt% of magnesium up to 4 wt% of magnesium. The test range included upsetting with 10–50% of cold deformation. It provided the results on evolution of mechanical properties and deformability of tested alloys. Additional information was provided based on the alloys subjected to 50% of strain. The results have proven that as the amount of magnesium increased so did the assessed values, however, it was also linked with increasing friction coefficient. Measured hardness was 2 times higher and calculated Ultimate Tensile Strength (UTS) was even 2.5 times higher in reference to pure copper in the as-cast state. However, with magnesium content at 3.6 wt% or higher, the elevated amount of α + β phase causes brittleness making it impossible to subject these materials to cold metal working processes. We anticipate our assay to be a starting point for more sophisticated models and experimental research concerning cold metal working processes of CuMg alloys of high-strength, which may lead to developing novel and promising set of alloys.

Abstract Background The intricate textural patterns commonly observed in metamorphosed and recrystallized zircon (ZrSiO4) underscore the crucial necessity of understanding the underlying mechanisms governing their formation to ensure accurate interpretation of the chemical and isotope data they contain. This study employed a combination of microanalytical techniques, including electron backscattered diffraction (EBSD) analysis, electron microprobe (EMP) mapping, and scanning electron microscope (SEM) imaging, to investigate the processes of formation and modification of zircon in a late Pleistocene (~ 35 ka) syenite enclosed within the Nari Tephra Formation on Ulleung Island in South Korea. Findings Under cathodoluminescence (CL), zircons within the syenite reveal dark, featureless, or oscillatory-zoned cores containing numerous inclusions of britholite. These cores are partially or entirely replaced by inward-penetrating bright-CL domains that exhibit minimal inclusion presence. Despite these changes, the external morphologies of the zircons remain largely unchanged, and the faded oscillatory zoning is preserved in the replaced regions. EMP mapping discloses amoebiform micro-domains with high Y, U, and Th concentrations within the dark-CL cores, while the bright-CL domains are relatively deficient in these trace elements. Microstructural analysis of the zircons using EBSD mapping indicates no significant misorientation between the dark-CL cores and the bright-CL rims. Deformation-related low-angle boundaries by lattice distortion are clearly observed in certain grains, cutting across the discrete SEM and EMP domains, and often aligned along submicron pore trails. Conclusions Microstructural and microchemical analyses carried out in this study establish that the zircons within the Ulleung syenite have undergone subsolidus recrystallization, a process likely influenced by the presence of fresh melts or fluids. This recrystallization process could be attributed to either coupled dissolution and reprecipitation or thermoactivated particle and defect volume diffusion due to inherent lattice strain. The subsequent deformation observed in the zircons might be a result of increased stress within the magma system after the recrystallization.

In Egypt, there were many earthquakes activities in seismo-tectonic regions. In the last century most of earthquakes concentrated at Gulf of Suez and Gulf of Aqqaba. Also, Egypt affected by large earthquakes in the northern Mediterranean Sea. In this study, we are trying to evaluate the crustal displacement associated with the large earthquakes activities by using of GNSS measurements. GNSS observations can measure the horizontal and vertical displacement within mm of accuracy. Earthquakes with magnitude more than 4 have been chosen. The crustal displacements have been computed using GNSS data from Egyptian Permanent Geodetic Network (EPGN). The results show that before and during and after earthquakes activities, the displacement of GNSS stations gives different behavior depending on its distance from earthquakes epicenter. In some studied GNSS station, there was a signal of deformation before the earthquake found. This displacement can used in establishment of early warning system for earthquakes using GNSS observations.

Abstract This article describes the application of the A-priori algorithm for defining the rule-based relationships between individual defects caused during the lamination process, affecting the deformation defect of the yacht shell. The data from 542 yachts were collected and evaluated. For the proper development of the algorithm, a technological process of the yacht lamination supported by expert decisions was described. The laminating technology is a complex process of a sequential application of individual laminates according to a special strategy. The A-priori algorithm allowed for obtaining the set of association rules defining the relationships between the defects resulting from the lamination process and influencing the deformation defect of the yacht shell, which is one of the most common errors in yacht production. The obtained aggregated rules were compared with the expert knowledge of the employees of the production, quality control, mould regeneration, and technology departments of the yacht yard. The use of the proposed A-priori algorithm allowed for the generation of relationship rules consistent with the general opinion of experts. Associative rules additionally took into account detailed causes of a specific error, which were not always noticed by employees of specific departments. The assessment of the lamination process using an artificial intelligence algorithm turned out to be more objective, which made it possible to gradually reduce the total number of errors occurring in the yacht shell lamination process, and thus shorten the time needed to repair errors and the total time of producing the yacht.

Tomohiro Ueno, Hideaki Fujita, Aya Ikeda, Kazuhiro Harada, Tomoko Tsukahara-Kawamura, Hiroaki Ozaki, Eiichi Uchio Department of Ophthalmology, Fukuoka University School of Medicine, Fukuoka, JapanCorrespondence: Eiichi Uchio, Department of Ophthalmology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan, Tel +81 92 801 1011, Fax +81 92 865 4445, Email euchio@fukuoka-u.ac.jpBackground: We studied the kinetic phenomenon of an airbag impact on eyes with different axial lengths using finite element analysis (FEA) to sequentially determine the physical and mechanical responses of intraocular segments at various airbag deployment velocities.Methods: The human eye model we created was used in simulations with the FEA program PAM-GENERISTM. The airbag was set to impact eyes with axial lengths of 21.85 mm (hyperopia), 23.85 mm (emmetropia) and 25.85 mm (myopia), at initial velocities of 20, 30, 40, 50 and 60 m/s. The deformation rate was calculated as the ratio of the length of three segments, anterior chamber, lens and vitreous, to that at the baseline from 0.2 ms to 2.0 ms after the airbag impact.Results: Deformation rate of the anterior chamber was greater than that of other segments, especially in the early phase, 0.2– 0.4 ms after the impact (P < 0.001), and it reached its peak, 80%, at 0.8 ms. A higher deformation rate in the anterior chamber was found in hyperopia compared with other axial length eyes in the first half period, 0.2– 0.8 ms, followed by the rate in emmetropia (P < 0.001). The lens deformation rate was low, its peak ranging from 40% to 75%, and exceeded that of the anterior chamber at 1.4 ms and 1.6 ms after the impact (P < 0.01). The vitreous deformation rate was lower throughout the simulation period than that of the other segments and ranged from a negative value (elongation) in the later phase.Conclusion: Airbag impact on the eyeball causes evident deformation, especially in the anterior chamber. The results obtained in this study, such as the time lag of the peak deformation between the anterior chamber and lens, suggest a clue to the pathophysiological mechanism of airbag ocular injury.Keywords: airbag, ocular trauma, computer simulation, lens, anterior chamber, vitreous body, finite element analysis, deformation

Indentation tests create complex stress–strain states in the region beneath the indentation tip. However, it is difficult to observe the indentation responses of bulk materials. Therefore, this study presents a wedge-indentation test technology that can investigate the subsurface deformation behavior during loading and unloading inside a scanning electron microscope. In situ observations based on multiple techniques, including a secondary electron detector, electron backscatter diffraction, and digital image correlation, are realized and used to investigate the texture evolution and stress–strain behavior of monocrystalline copper in the microregion beneath the indentation tip. Indentation induces kinked slip bands along the [01‾1‾] and [011‾] directions. The maximum shear strain of 0.324 occurs at the sides of the area in direct contact with the indentation tip. The lattice rotations in three dimensions are calculated and obtained quantitatively, and the geometrically necessary dislocation density beside the contact region reaches 0.70 × 1014/m2. The proposed method has considerable potential for explaining the deformation mechanisms of materials at microscale.

To understand the microstructural factors controlling deformability during the forming process, a comprehensive analysis using in-situ scanning electron microscopy (SEM) with digital image correlation (DIC) for hot-dip Zn–6 %Al–3 %Mg alloy coatings on steel sheets in bending deformation was performed. The Zn–Al–Mg alloy coating exhibited two major microstructural constituents: the primary solidified Al (fcc) phase with dendritic morphologies and a fine ternary eutectic (TE) microstructure of the Zn (hcp), Al, and Zn2Mg phases. Major cracks were initiated on the tensile-strained coating surface, where the strain was localized in the TE regions, whereas the softer dendritic Al phases prevented the crack propagation. Microcracks were initiated in the binary eutectic (BE) Zn/Zn2Mg phases (Al-poor region) localized around the dendritic Al phases, whereas they were arrested in the TE region containing fine granular Al phases. The dendritic Al and fine granular Al phases embedded in the TE microstructure contributed to the high crack resistance.

Large- and small-scale subsidence coexist in the world's coastal cities due to extensive land reclamation and fast urbanization. Synthetic aperture radar (SAR) images are typically limited by either low resolution or small coverage, making them ineffective for fully monitoring displacement in coastal areas. In this research, a machine learning-based method is developed to investigate the reclaimed land subsidence based on multi-satellite SAR data integration. The proposed method requires at least a pair of SAR images from complementary tracks. First, the line-of-sight (LOS) displacements are recovered in connection to a series of extremely coherent points based on the differential interferometry synthetic aperture radar (DInSAR). These LOS displacements are then converted into their vertical component, geocoded to a common grid, and simultaneously integrated (i.e., pixel-by-pixel) based on Support Vector Regression (SVR). The proposed methodology does not necessitate the simultaneous processing of huge DInSAR interferogram sequences. The experiments include high-resolution COSMO-SkyMed (CSK) and TerraSAR-X (TSX) images, as well as a small monitoring cycle Sentinel-1 (S1) images of reclaimed territories near Hong Kong Kowloon City. The overall average annual displacement (AAD) ranges from -12.86 to 11.63 mm/year derived from 2008 to 2019. The evaluation metrics including RMSE, MAE, correlation coefficient, and R-squared are used to investigate the impact of SVR in the integration of SAR datasets. Based on these evaluation metrics, SVR is superior in terms of integration performance, accuracy, and generalization ability. Thus, the proposed method has potentially performed multi-satellite SAR data integration.