Search

Shearing of fractures and faults is important because it can result in permeability change or even induce seismicity—both are keys for efficient and safe energy recovery and storage in Earth systems. Quantitative analysis of shearing of intersecting fractures and faults is challenging because it can involve dynamic frictional contacts that are complicated by deformation of the rock matrix. To predict the shearing of intersecting fractures/faults, we attempt to answer the question of how intersections impact the shearing of a fracture network and whether we can simplify the description as compared to classical discrete fracture network (DFN) models. To answer these questions, we conducted a series of numerical simulations on scenarios for variable numbers of intersecting fractures. All these examples yield consistent results: the results of using DFNs are consistent with those of using hypothetical major paths. This leads to a new model, which we name simplified discrete fracture network model, to analyze shearing of intersecting fractures/faults using major path(s). We found that the intersections of fractures do not fundamentally change the shearing of two intersecting fractures if the intersecting angles are small. Furthermore, increasing the number of fractures/faults may relax the stress as more fractures/faults become available for shearing and distributing the stress. The simplified DFN model, which can capture efficiently the shearing behavior of each major paths from a large number of intersecting fractures/faults, will be a promising conceptual model that is complementary to existing equivalent continuum and discrete fracture models to analyze shearing of intersecting fractures/faults.

We study cohomology of morphisms of Lie-Yamaguti algebras. As an application, we establish that this cohomology 'controls' the formal deformations. Additionally, we demonstrate its connection to the abelian extensions of morphisms of Lie-Yamaguti algebras. [ABSTRACT FROM AUTHOR]

The aim of this work was to develop an experimental protocol that takes into account the influence of experimental conditions on these perineal tissues, before determining their mechanical properties. Samples of each perineal tissue layer were obtained from the skin, the vagina, the external anal sphincter (EAS), the internal anal sphincter (IAS) and anal mucosa of freshly dead sows. They were tested in quasi-static uniaxial tension using the Mach-1 testing machine. Stress-strain curves of each perineal tissue layer before the first damage for each sow were obtained and modeled by hyperelastic laws described by three coefficients: C1, C2, and C3 (Yeoh model). The influence of sample preparation conditions such as tissue freezing, hygrometry and sample orientation were evaluated, and the conditions under which the tests were performed such as the displacement velocity during testing were also evaluated by analysing C1-coefficient. This study suggested that sample preparation conditions such as tissue freezing for 24 h, storage in cellophane paper for two hours and the strain rate did not statistically affect the C1-hyperelastic coefficient for each perineal layer (p > 0.05). Samples should not be stored in saline for 2 h (p < 0.05). Sample orientation did not influence C1-hyperelastic coefficient (p > 0.05). This experimental protocol could be used to study in vitro biomechanical properties of perineal tissues in order to better understand perineal tears during delivery. [ABSTRACT FROM AUTHOR]

This study presents the electrochemical reduction of graphene oxide (GO) to reduced graphene oxide (rGO) directly onto flexible interdigitated gold electrodes and its application as a strain sensor. GO reduction is achieved using cyclic voltammetry (CV). Remarkably, only a single CV cycle transformed GO into rGO to obtain low‐resistance (≈100 Ω) devices. The reduction of GO is confirmed using Raman spectroscopy and electrical measurements. rGO on flexible interdigitated gold electrodes exhibits graphene‐like characteristics when used as electrolyte‐gated field‐effect transistors. The fabricated devices display a gauge factor (GF) of ≈3.7 in the 0–794 με range. This value represents a substantial improvement, ≈60% higher than traditional metallic strain sensors, which have a GF of ≈2.1. Most importantly, the rGO strain sensor exhibits fast response (1.1 s) and recovery (0.92 s) times. The rGO sensor is mounted on a clamp with an adjustable diameter, which reveals exceptional flexibility and bendability without damage or degradation. These results highlight the potential of rGO for advancing strain‐sensing applications, offering promising opportunities for the future of this technology. [ABSTRACT FROM AUTHOR]

Highlights Sandwich structures have garnered interest as versatile structures for applications in advanced engineering structures. To fabricate sandwich structures, plastics have replaced conventional materials; however, most of these plastics remain in the environment beyond their functional lifespan. This study describes the fabrication of sustainable hybrid sandwich structures with 3D printed poly‐lactic acid (PLA) cores and self‐reinforced polyethylene terephthalate (srPET) face sheets. The mechanical responses of the hybrid sandwich structures with three types of lattice cores, S‐90, S‐45, and S‐V, were compared with those of the parent material sandwich structures after performing bending and impact tests. The face sheet in the hybrid sandwich structure transferred the load to the core without failure. The hybrid sandwich structure containing the S‐90 core exhibited a higher fracture strength (52.4 MPa) and tangent modulus of elasticity (2860 MPa) than those of the other structures. S‐V exhibited the highest fracture strains of 3.3% and 5% for parent material and hybrid sandwich structures, respectively. This study highlights the sandwich structures with excellent mechanical properties for structural applications. Novel sandwich structures with 3D printed PLA cores are fabricated. Three‐point bending and low‐velocity impact tests are performed. Failure occurred in the core, but the Sr‐PET face sheets did not deform. Hybrid sandwich structures significantly improve mechanical performance. [ABSTRACT FROM AUTHOR]

This study verifies the practicality of using finite element analysis for strain and deformation analysis in regions with sparse GNSS stations. A digital 3D terrain model is constructed using DEM data, and regional rock mass properties are integrated to simulate geological structures, resulting in the development of a 3D geological finite element model (FEM) using the ANSYS Workbench module. Gravity load and thermal constraints are applied to derive directional strain and deformation solutions, and the model results are compared to actual strain and tilt measurements from the Jiujiang Seismic Station (JSS). The results show that temperature variations significantly affect strain and deformation, particularly due to the elevation difference between the mountain base and summit. Higher temperatures increase thermal strain, causing tensile effects, while lower temperatures reduce thermal strain, leading to compressive effects. Strain and deformation patterns are strongly influenced by geological structures, gravity, and topography, with valleys experiencing tensile strain and ridges undergoing compression. The deformation trend indicates a southwestward movement across the study area. A comparison of FEM results with ten years of strain and tiltmeter data from JSS reveals a strong correlation between the model predictions and actual measurements, with correlation coefficients of 0.6 and 0.75 for strain in the NS and EW directions, and 0.8 and 0.9 for deformation in the NS and EW directions, respectively. These findings confirm that the 3D geological FEM is applicable for regional strain and deformation analysis, providing a feasible alternative in areas with limited GNSS monitoring. This method provides valuable insights into crustal deformation in regions with sparse strain and deformation measurement data. [ABSTRACT FROM AUTHOR]

Background: Although the specific relationship between the stress changes in the external fixator during tibial fracture treatment and the bone healing process remains unclear, it is believed that stress variations in the external fixator scaffold can, to a certain extent, reflect the progress of tibial healing. Objective: This study aims to propose a non‐invasive method for assessing the degree of fracture healing by monitoring the changes in stress transmission, the locations of stress‐sensitive points, and displacement in the external fixator‐tibia system during the healing process of tibial fractures. Methods: In this study, finite element models of tibial fractures at various healing stages were developed. Physiological conditions, including axial, torsional, and bending loads on the tibia, were simulated to evaluate stress and strain within the external scaffold‐tibia system under normal physiological loading conditions. Results: The results indicate variations in the stress distribution between the external fixator and the tibia during different stages of healing. In the early phase of fracture healing, the external fixator plays a crucial role as the primary load‐bearing unit under all three loading conditions. As the fracture healing progresses, the stress on the tibia gradually increases, concentrating on the medial part of the tibia under axial and torsional loading, and at the upper and lower ends, as well as the central part of the anterior and posterior tibia during bending loading. The stress at the callus gradually increases, while micro‐movements decrease. The stress within the external bracket gradually decreases, with a tendency for the connecting rod to transfer stress towards the screws. Throughout the fracture healing process, the location of maximum stress in the external fixator remains unchanged. Under axial and torsional loading, the maximum stress is located at the intersection of the lowest screw and the bone cortex, while under bending loading, it is at the intersection of the second screw and the connecting rod. Conclusion: During the bone healing process, stress is transferred between the external fixation frame and the bone. As bone healing advances, the stress on the connecting rods and screws of the external fixation frame decreases, and the amplitude of stress changes diminishes. When complete and robust fusion is achieved, stress variations stabilize, and the location of maximum stress on the external fixation frame remains unchanged. The intersections of the lowest screw and the bone cortex, as well as the second screw and the connecting rod, can serve as sensitive points for monitoring the degree of bone healing. [ABSTRACT FROM AUTHOR]

The right bank plant of Baihetan Hydropower Station has exposed C4, C5, and other fault fracture zones (FFZs), thereby increasing rock mass instability. In this paper, the effects of the number and location of FFZ on rock mass deformation were analyzed using field monitoring data. In addition, a validated numerical simulation method was employed to discuss the influence of excavation methods and FFZ properties on rock mass deformation. Results show that as the width of the middle pilot tunnel increases, the top arch deformation initially rises and then falls. Excavating the sidewalls first will significantly aggravate the deformation. As the width or dip-angle of FFZ increases or its height from the top arch decreases, the top arch deformation becomes more significant. The first layer excavation of the plant significantly influences the rock mass deformation. The rock mass located more than twice the width of the tunnel is almost unaffected by FFZ. This study is significant for the stability analysis of deep-buried caverns across FFZ. [ABSTRACT FROM AUTHOR]

Bristles in the first few rows float up from the rotor surface due to the radial airflow in the gap between the front plate and bristle pack, which directly affects seal performance and the service life of a brush seal. In this paper, firstly, two three-dimensional transient calculation models for a traditional brush seal (TBS) and a brush seal with disturbance-suppressing holes (DSBS) are established, respectively, based on the arbitrary Lagrange–Eulerian (ALE) method to study bristle deformation characteristics and leakage flow characteristics of the seals. Furthermore, effects of disturbance-suppressing (DS) hole structural parameters (i.e., height, diameter, and number of hole rows) were investigated to reveal the suppression mechanism of the DS holes on the buoyancy effect of bristles. The results showed that as soon as free ends of bristles at the first few rows moved along direction of the front plate in response to the radial airflow from the gap between front plate and bristle pack, a buoyancy effect of bristles occurred. The DSBS with DS holes set in the front plate of the TBS had a lower deformation of the bristles and a lower leakage amount of seal compared with that of TBS, indicating a good suppression to the buoyancy effect. With decreasing hole height and increasing hole diameter and number of hole rows, the suppression of bristle disturbance gradually increased due to decreases of the radial airflow and increases of torque acting on the bristles. [ABSTRACT FROM AUTHOR]

The researches of the spatial redistribution of defects of interstitial Cd in the CdSe quantum dot with a shell and the quantum dot – human serum albumin bionanocomplexes were carried out. On the basis of the developed deformation-diffusion model, the method of "deformation-diffusion retraction" is proposed, which will limit the migration of cadmium beyond the QD boundaries and significantly reduce their toxicity for living organisms. It was established that the introduction of a neutral impurity into the quantum dot, which creates stretching deformation, leads to a decrease in the concentration of interstitial Cdi on the QD surface. [ABSTRACT FROM AUTHOR]

During actual operation, a steel wire rope is deformed due to stress interaction between its internal steel wires. In this article a finite element approach is employed to simulate the interaction of steel wire under practical working conditions. In addition, according to the amount of fatigue broken wire under experimental conditions, corresponding parameters are put forward to estimate the service life of steel rope. In this article, the effect of various conditions on service life of steel wire rope is analyzed, and approaches are put forward to improve its service life. The results show that the total stress in straight strand is larger than side strand stress, while the stress increases from inside to outside while increasing from inside to outside. The bigger the pulley diameter, the more steel wire breaks inside the wire rope. [ABSTRACT FROM AUTHOR]

Current industrial production is characterized by requirements for improving the physical and mechanical properties of the used material. This causes a workload creating a rather complex load on all types of machines and mechanisms during operation. The design of such objects is currently based on a wide range of computational and experimental methods that allow modelling their state and behaviour even in the case of complicated nonstationary loading conditions. In this paper, the authors focus on the statistical evaluation of selected manufacturing operations related to mechanical and thermomechanical processing of products [Kuric 2011]. For example, in the case of long pipe billets with a thickness coefficient of 2-4, practically the only way of their production in the metallurgical cycle is cross-roll piercing followed by reduction. This process has high productivity but at the same time certain disadvantages. These disadvantages limit the efficiency and the range of use of the pipe blanks obtained by piercing, which leads to a consequent shortening of the machine production cycle. The presented approaches allow changing the structure of technological processes of production of axisymmetric metal products, by modifying the thermomechanical processing at the beginning of the production cycle. [ABSTRACT FROM AUTHOR]

Background: One of the primary concerns in the paediatric emergencies is traumatic dental injuries. Objective: This study aimed to create trauma in primary teeth and reveal its effects finite element analysis. Design: Three‐dimensional models were created using cone‐beam computed tomography images, representing a maxillary primary central incisor. An impact force moving at a speed of 10 m/s was simulated on the labial tooth surface in two directions: buccal and incisal. Results: The stress and deformation experienced in the adjacent tooth due to the primary tooth were higher than those generated in the permanent tooth. Forces applied in the incisal direction resulted in higher levels of stress and deformation in the permanent tooth germ. The difference between the stress and deformation values in primary teeth in the forces applied in the buccal and incisal directions is 21% and 75%, respectively; in the permanent tooth germ, this difference was 233% and 100%, respectively. Conclusions: Based on the findings of this study, it is crucial to thoroughly evaluate not only the affected primary tooth but also the adjacent teeth and the permanent tooth germ in traumatic dental injuries. This comprehensive examination allows for the anticipation and management of potential long‐term problems. [ABSTRACT FROM AUTHOR]

This study reports on the design optimisation of the swinging jaw crusher plate. Jaw crusher machines are used in the mining and construction industry for crushing rocks and mineral ores to the appropriate sizes for direct application or further processing. During the crushing process, large and non-evenly distributed impact forces occur, resulting from uneven feed patterns and nonhomogeneous material composition (varying hardness). Hence, the jaw plate experiences inhomogeneous stress distributions causing warping and fracture failure of the crusher plates. The plate warping reduces the crusher performance, resulting in low crusher efficiency, high cost of replacing the crushing plates, and higher energy consumption. In this study, the design parameters: plate profile, thickness, and the height of the jaw plate were optimised using ANSYS software. These design parameters were varied to analyse deformation and stress distribution during crushing. Design of experiment techniques was used to determine the optimal design parameters. Optimisation results showed that the optimal design parameters were: 40.06 mm thickness, 4.94 mm plate profile, and 996.21 mm height. An analysis using the optimal parameters produced the optimal outputs as 1.41 MPa for the maximum equivalent stress and 2.7 × 10–8 m for the average total deformation. This study shows that the jaw crusher plate geometry influences the flow stress and deformation behaviour during the crushing process. The findings from this study provide the basis for future designs of swing jaw crushers for industrial applications. [ABSTRACT FROM AUTHOR]

ABSTRACT The southern margin of the Junggar Basin (SMJB) represents the typical intra‐continental basin–orogen coupling structure of the Central Asian Orogenic Belt and is a key area to study the deformation mechanisms and the geodynamic evolution processes of the North Tianshan Orogen. Herein, we compiled data from boreholes, gravity and magnetism, seismicity‐ and magnetotellurics‐derived geological profiles and field data to recover the sedimentary history of the SMJB and discuss the intra‐continental deformation driven by the basin–orogen coupling mechanism. The results show that the sedimentary and tectonic evolution of the SMJB were both profoundly controlled by the intra‐continental orogeny of the North Tianshan Orogen and its coupling with the Junggar Basin during the Meso‐Cenozoic period. Consequently, the SMJB is dominated by thick‐skinned thrust nappes accompanied with strike‐slip faulting and thrusting. The foreland thrust belt of the SMJB is characterised by three structural belts, from south to north, including the basement‐involved thrust belt, the cover‐detached foreland thrust‐fold belt and the thrusted foreland basement uplifts, respectively. Meanwhile, as indicated by the geometry of the basement thrusts, the thickness of décollements and the structure of the foreland basement, the stress field in the SMJB is obviously stronger in the west and weaker in the east. The sedimentation and deformation migrated northwards into the basin area in a stepwise process, that corresponded to the pace of the overthrusting of the North Tianshan Orogen onto the Junggar Block. Intense regional compression induced the rapid uplifting of the North Tianshan and the significant crustal shortening of the Junggar Block, driving the three structural belts to form accordingly during the Late Jurassic to the Neogene. There are at least one or two décollements within the SMJB, representing one of the main features of basin–orogen coupling structure in most cases. The décollement of some layers represents the decoupling of the sedimentary cover with the basement, which helps to accommodate the lateral crustal shortening of the SMJB by a translation into vertical uplift. As a result, the detached foreland thrust‐fold belts in the shallow level of the upper crust overthrusted upon the basement‐involved nappes of the mountain's side, forming the opposite thrust system. Coevally, the basement of the basin, in the deep level of the upper crust keeps underthrusting beneath the North Tianshan Orogen, forming a typical crocodile mouth‐like structure. In general, both the shallow and deep deformation in the SMJB have been formed by the intense intra‐continental compression during the Meso‐Cenozoic, which were driven by the basin–orogen coupling mechanism. [ABSTRACT FROM AUTHOR]

The effects of tensile and compressive deformation on the structural stability, electronic structure and optical properties of the Zn atom-adsorbed borophene system, which are exhibited by reflectivity, absorption coefficient, bandgap and adsorption energy, were studied using the first-principles calculations based on density functional theory (DFT). The borophene planes were found to be distorted following Zn atom adsorption. The adsorption energy calculations show that the stability decreases both under tensile and compressive strains. When tensile and compressive loading increase to 5%, respectively, the system loses the stability and the ability of adsorbing Zn atoms on borophene. The band structure and density of states analysis show that the band structure of borophene is changed by the Zn atom adsorption, with a band overlap near the Fermi level and more impurity energy levels in the conduction band. The hybridization is formed between Zn atom and borophene in the range of –12 eV to 6 eV, with the s and p orbitals both contributing to the conduction and valence bands, but p orbitals make a larger contribution to the total density of states than s orbitals. Studies of optical properties have shown that tensile and compressive strains both increase the dielectric constant of the adsorbed system, with compressive strains causing a redshift in the major peaks of the real and imaginary parts of the spectrum. The tensile strain has little effect on the absorption coefficient and reflectance of the borophene. As the compressive strain increases, the peak absorption coefficient of the adsorbed system is shifted to the blue and the peak reflectance is redshifted. [ABSTRACT FROM AUTHOR]

The coupling effects of clamping pressure and catalyst distribution are comprehensively considered to improve proton exchange membrane fuel cell (PEMFC) performance. Numerical models were constructed to study the performance changes and the corresponding internal states of PEMFC under different clamping pressures. Since the increased clamping pressure reduces the uniformity of current density, non-uniform designs with decreased catalyst loading under channel and increased catalyst loading under rib are proposed for performance improvement. A weighted objective function considering current density magnitude and uniformity was constructed, and the performances of different catalyst loading distributions were analyzed. Compared to the uniform distribution, the optimized distribution with a variation of −15% and 15% under channel and rib had the maximum objective function value of 17.24%. The deformation analysis of the gas diffusion layer and optimization of catalyst loading distribution based on deformation analysis provided a reference for the assembly of PEMFC and the production of MEA. [ABSTRACT FROM AUTHOR]

Structural composite materials have gained significant appeal because of their ability to be customized for specific mechanical qualities for various applications, including avionics, wind turbines, transportation, and medical equipment. Therefore, there is a growing demand for effective and non-invasive structural health monitoring (SHM) devices to supervise the integrity of materials. This work introduces a novel sensor design, consisting of three spiral resonators optimized to operate at distinct frequencies and excited by a feeding strip line, capable of performing non-destructive structural strain monitoring via frequency coding. The initial discussion focuses on the analytical modeling of the sensor, which is based on a circuital approach. A numerical test case is developed to operate across the frequency range of 100 to 400 MHz, selected to achieve a balance between penetration depth and the sensitivity of the system. The encouraging findings from electromagnetic full-wave simulations have been confirmed by experimental measurements conducted on printed circuit board (PCB) prototypes embedded in a fiberglass-based composite sample. The sensor shows exceptional sensitivity and cost-effectiveness, and may be easily integrated into composite layers due to its minimal cabling requirements and extremely small profile. The particular frequency-coded configuration enables the suggested sensor to accurately detect and distinguish various structural deformations based on their severity and location. [ABSTRACT FROM AUTHOR]

This article presents wheel wear in light rail traffic and the friction behavior of wheel material under both dry and lubricated conditions. The main purpose of this research is to study the wheel-rail tribology for the Addis Ababa Light Rail Transit and to evaluate the friction and wear behavior of the wheel material under both dry and lubricated conditions. Composition, hardness, and ring compression tests were conducted to characterize the existing and the developed material. The percentage composition of carbon, manganese, and silicon gained 0.5%, 0.7%, and 0.25%, respectively, for existing and 0.8%, 1.15%, and 0.38% for alloyed wheel steel. It is also shown that the hardness value of the wheel material increased from 98.88 to 99.7 HRC when the existing material is compared with the developed material. The samples with dimensions outer diameter of 42 mm, inner diameter of 21 mm, and height of 14 mm were used for this study, and the dimensional change occurring under ring compression is different depending on the dry and lubricant conditions. Based on experimental analysis, 0.15, 0.13, and 0.09 were the evaluated coefficients of friction for dry, grease, and oil conditions, respectively. It is concluded that 0.09 is a coefficient of friction and oil is a suitable lubricant. To minimize wheel wear in the wheel-rail, proper lubrication and better application, improved wheel material, and revised track alignment for easier cornering and improvement are required. [ABSTRACT FROM AUTHOR]

Carburizing and quenching can endow the gear with a hardening depth, improving the part's hardness and contact fatigue strength while distorting the part, resulting in increased or uneven subsequent grinding allowances and reduced part precision. Therefore, cooperative control of hardening depth and distortion is critical. Here, the temperature, phase transition, hardness of carburizing and quenching, and the numerical strain model after die unloading were analyzed to predict the hardening depth and deformation of die quenching. Numerical model is the mathematical essence of finite element model (FEM), based on numerical model, a face gear die-quenching FEM was established to predict the hardening depth and deformation of die quenching, which was verified through carburizing and die-quenching experiments. Based on the FEM, the simulation results under multiple process parameters can be obtained. Further, using the results can built a neural network surrogate model to describe the relationship between carburizing and quenching process parameters and hardening depth and deformation. Additionally, the non-dominated sorting genetic algorithm (NSGA-II) was used to optimize the parameters of the heat treatment process, which are able to control the deformation under the condition of satisfying hardening depth. Finally, a "simulation-surrogation-optimization" model was proposed to simulate the process of carburizing and die quenching of parts, predict the deformation and hardening depth of parts, and give the optimal process parameters under certain process requirements. The results revealed that the martensite content and the deformation of the face gear increased as the carbon content increased from the surface to the center of the face gear. As the die pressure increased, the overall deformation of the face gear using die quenching decreased gradually. However, the excessive pressure caused severe distortion to the tooth height. Using appropriate pressure for die quenching not only controlled the face gear's warping but also reduced its diameter shrinkage. [ABSTRACT FROM AUTHOR]

Purpose: To demonstrate the viability of a coordinate-measuring machine (CMM) for the geometric analysis of 3D printed surgical templates. Methods: The template was designed and modified by adding 18 cylindrical landmarks for CMM test and then classified into five groups according to the slicing software and resins (opaque and transparent): Streamflow-O, Streamflow-T, Shapeware-T, Rayware-T and Polydevs-T (N = 3). Three standing times (0 w, 1 w, and 2 w) were included to observe possible deformation. All the measurements were performed automatically by the CMM through a preset program. The Euclidian distance (dxyz) was regarded as the representation of global dimension accuracy, and displacements in the x-, y-, and z-axes were also calculated. Results: The average dxyz values of Streamflow-O, Streamflow-T, Shapeware-T, Rayware-T and Polydev-T are 32.6 μm, 31.3 μm, 56.4 μm, 96.4 μm, and 55.3 μm, respectively. Deviations were mainly induced by the upward bending of the free end region (positive direction of the z-axis). Different resins did not have a significant influence on the dimensional accuracy. Moreover, deformation appeared to be negligible after 2 weeks of storage, and the z-axis displacements were only approximately 30 μm at week 1 and 10 μm at week 2. Conclusions: The deviations of the DLP-printed template are induced mainly by z-axis displacements and are determined by the processing accuracy. After 2 weeks, the dimensional stabilities of these templates are reliable, which is encouraging for clinicians. Moreover, the CMM is preliminarily demonstrated to be a feasible tool for achieving automated geometric analysis of surgical templates. [ABSTRACT FROM AUTHOR]

Today, there is a high demand and increasing trend for multifunctional composite materials and components due to the combination of a wide range of favorable properties. However, undesired deformation leading to delamination, curvature, cracks, or even complete fracture frequently occurs during the co‐sintering process of metal–ceramic laminates (MCLs). To solve these issues, experimental work highly relies on the time‐consuming trial‐and‐error principle. This work aims to develop a thermo‐mechanical‐metallurgical model capable of predicting the densification, deformation, and delamination of MCLs during the co‐sintering process. It is found that the developed model successfully considers the inhomogeneous relative density distribution and phase transformation of the steel tape. In addition, a thin interlayer formed by a mixed slurry in the MCLs is modeled as cohesive elements to simulate the delamination process. The developed model is systematically validated by the experimental measurements and observations in terms of densification, deformation, and delamination during the co‐sintering process of the investigated laminate variants. [ABSTRACT FROM AUTHOR]

This work uses finite elements to build and examine composite laminates constructed of carbon fiber reinforced polymer (CFRP). The great strength compared to weight of composite materials is an important characteristic. Using the finite element method and the ANSYS program, the optimal resistance model for tensile testing and compressive testing was chosen. This article will present hybrid 3D simulation models of woven materials reinforced with fibers, with the goal of optimizing the model by adjustment of the reinforcement angle. The Math-Cad and ANSYS software will be used to compare these reinforced models from different angles in addition to testing them under compressive and tensile loads. The results of the tensile testing of the models were illustrated using von Mises stress theory of failure. Of all the models, the tenth is the one that is least susceptible to failure. The resistance to breakdown is weaker (51.5%) when compared to the resistance to the fifth model's breakdown. The von Mises stress theory of failure was used to illustrate the findings of the compressive testing of the models. The third model is the one that has the lowest failure probability. The resistance to collapse is significantly lower (48%) than the resistance to the fifth model's disintegration. Additionally, the results show that the sixth model had the lowest shear stress (1.5686 MPa), whereas the tenth model had the highest shear stress (22.734 MPa). For resistance to stresses, strains, and deformations caused by the tensile test and compression test, the third model is the best selection. [ABSTRACT FROM AUTHOR]

This paper proposes a dual-parameter strain/displacement safety monitoring technology for railway tunnel lining structures. An integrated monitoring system with FBG (Fiber Bragg grating) and VDM (video displacement meter) components was used to monitor both the strain and deformation of the tunnel cross-section. Initially, a comprehensive experimental study was carried out using FBG strain sensors with temperature-compensated grating. The temperature-compensated grating was used to further improve the monitoring accuracy. The data show that the stability and accuracy were better than the traditional electronic strain sensor. Secondly, high-precision and multipoint monitoring of railway tunnel lining deformation was achieved by using VDM technology. Three months of case study results taken from the Gansu Railway Tunnel in China demonstrated a tunnel cross-section strain accuracy for microstrain and crown deformation at the submillimeter level, respectively. The technology provides a new high-precision way to monitor the condition of tunnel lining structures. [ABSTRACT FROM AUTHOR]

The work is devoted to the consideration of methods for determining the strain of objects using fiber Bragg gratings under a high-frequency vibration or pulsed mechanical action, which is difficult to perform using widespread methods and devices. The methods are based on numerical processing of the time dependence of the radiation power reflected from the fiber Bragg grating at various wavelengths, which makes it possible to measure strain parameters in a wide range of magnitude and frequencies. The efficiency of the proposed methods is demonstrated by numerical simulation. It is shown that it is possible to restore the strain dependence on time in the range ± 1000   μ ϵ or more from simultaneously measured power dependencies reflected by the fiber Bragg grating using common fiber-optic components. The case of sequential registration of reflected radiation power at different wavelengths to determine the probability density of the distribution of the strain values is also considered. The results of signal processing obtained both by numerical simulation and experimentally for the case of a linear vibration are presented. The technical problems of using the proposed methods are discussed. [ABSTRACT FROM AUTHOR]

The sintering process of Cu nanoparticle (Cu NP)/graphene nanoplatelet (GNP) composite solder paste was thoroughly investigated in this work through molecular dynamics simulations. The tensile properties of the sintered Cu NP/GNP composite solder paste were considered by using the uniaxial quasi-static tensile simulation method. The impact of sintering temperature, strain rate, and GNP addition on the tensile properties of Cu NP/GNP sintered structures was thoroughly investigated. The lattice structure, dislocation evolution, and atomic diffusion of the molecular dynamics results were analyzed using the common neighbor analysis (CNA), dislocation extraction algorithm (DXA), and mean square displacement (MSD) methods. The results of the post-processing analysis showed that the addition of GNP and the sintering temperature have an important influence on the mechanical properties of Cu NP/GNP sintered structures. In addition, the incorporation of GNP can significantly improve the mechanical properties of sintered Cu NP/GNP composite solder paste. More specifically, the tensile strength and fracture strain of the sintered composite solder paste will be increased by increasing the tensile strain rate. The strengthening mechanism of the sintered Cu NP/GNP composite solder paste can be attributed to the dislocation strengthening mechanism. Our study provides valuable insight for the development of high-performance composite solder paste with enhanced mechanical properties. [ABSTRACT FROM AUTHOR]

The investigation of the shear fracture mechanism under cyclic loading holds significant implications for controlling instability in the surrounding rock of roadways. Both uniaxial constant amplitude and stepwise linear loading and unloading tests were carried out to reveal the fatigue damage and shear fracture mechanisms of the coal–rock mass under cyclic stress disturbance. The rock samples for the tests were taken from the lane side of the coal mine's haulage trough, and the evolution of microcrack extension and shear damage were analyzed from the perspective of deformation modulus and energy evolution using the CT scanning technique and excavating the hidden stress–strain information. The results indicate that the microcracks undergo intermittent expansion under constant amplitude cyclic loading and unloading, while they exhibit progressive expansion under stepwise linear cyclic loading and unloading. In both cases, the cumulative damage caused to the rock samples is irreversible. The test discovered a rarely reported phenomenon of shear fracture oscillation, showing a process of "hysteresis–reciprocation–hysteresis–reciprocation," and the corresponding fracture zone formed by shear fracture exhibited a pronounced domino structure. The results also show that the shear oscillation phenomenon is a unique stress–strain state of domino structural evolution. During the failure process of the rock sample, the trends of deformation modulus, energy, stress–strain rate, and rebound strain rate show a high spatial and temporal correlation and spatial synergy. The process of shear fracture oscillation can be subdivided into six stages: initial crack micro-extension, initial crack extension, main shear fracture extension, metastable fracture extension, rapid fracture extension, and accelerated failure. The rotation–gyration motion of the domino structure can slowly release and dissipate excessive energy, providing a potential coping strategy for optimizing the supporting system and controlling the stability of surrounding rock in coal mines by fully utilizing the structure. Highlights: A shear oscillation phenomenon has been discovered in which the typical stress–strain curve evolves in a twice hysteresis–reciprocal shape during the failure stage in stepwise linear cyclic loading and unloading test. This shear oscillation phenomenon is closely related to the motion of rotational–gyration of the unique domino structure in the shear fracture zone. The rotational–gyration motion of the domino structure slowly releases the overload energy, temporarily preserving the integrity of the rock sample and significantly prolonging the duration of the damage. The unloading condition is the main stress environment that generates and triggers the process of shear fracture oscillation, which is closely related to actual underground engineering. [ABSTRACT FROM AUTHOR]

Alloying nanocrystalline Cu (nc–Cu) with immiscible elements (i.e. Zr) is a promising approach for reducing microstructural instability and inhibiting grain growth. Understanding the relationship between the grain size, Zr concentration, deformation, and mechanical properties of the nc–Cu–Zr system is essential for practical applications. Molecular dynamics simulations based on the many-body embedded-atom potential were used for the related analysis from an atomistic point of view. The grain size of nc–Cu was varied from 3 to 9 nm and the Zr concentration was varied from 0% to 7%. The simulation results show that doping Zr atoms into an nc–Cu system enhances tensile strength and ductility, but weakens compressive and shear strengths. Doping 1% Zr into nc–Cu greatly increases both ultimate tensile strength and ultimate tensile strain; the increase is insignificant for higher Zr concentrations (2% to 7%). For a given Zr concentration, the relationship between ultimate tensile strength and grain size is unclear. Grain boundary sliding dominates the elastic deformation mechanism of the nc–Cu–Zr system under tensile, compressive, and shear tests. Tensile fracture occurs faster for an nc–Cu–Zr system with a larger grain size. [ABSTRACT FROM AUTHOR]

We present an approach that supports the analysis of flow dynamics in the neighborhood of curved line-type features, such as vortex core lines, attachment lines, and trajectories. We achieve this with continuous deformation to the flow field to straighten such features. This provides "deformed frames of reference", within which qualitative flow dynamics are better observable with respect to the feature. Our approach operates at interactive rates on graphics hardware, and supports exploration of large and complex datasets by continuously navigating the additional degree of freedom of deformation. We demonstrate the properties and the utility of our approach using synthetic and simulated flow fields, with a focus on the application to vortex core lines. [ABSTRACT FROM AUTHOR]

Anchors embedded in soil are used to restrain horizontal movement of structures, especially pipelines. Block anchors are not thoroughly studied in the literature as compared to plate anchors. This research paper intended to address this gap and contribute to the field by studying various parameters influencing the behavior of block anchors embedded in sand when subjected to a horizontal load. The behavior focuses on the pullout capacity and displacements/rotation of the block anchor, and the failure mode of the soil. The parameters studied include width, depth, and thickness of the block; depth of embedment below the ground surface; location of the pulling load; and the degree of saturation of the soil. The rigorous research methodology consists of numerical, analytical, and experimental approaches. First, the analytical calculations were based on Rankine, Coulomb, and log spiral theories to obtain values for the pullout capacity, for the 3-D magnification factor, and for the mobilized friction angle. Second, the experimental work included pullout tests, made in the laboratory, on concrete block anchors of various dimensions and on steel plate anchors, embedded in sand at two different depths. The sand was deposited in a box by pluviation to ensure a uniform and reproducible density. Materials properties were determined, and instruments were calibrated. The load and the corresponding horizontal and vertical displacements were recorded, and visual observations of the failed soil surface were captured. Finally, the numerical computations used PLAXIS program for the 2-D cases to obtain the pullout capacity and the deformation for long anchors. The main findings of this study show that the block anchor has a higher pullout capacity than a plate anchor; and the depth of embedment and the moisture condition of the sand significantly affect the pullout capacity, while the thickness of the block and the exact location of the load do not significantly affect the capacity. The capacity of a short block anchor per unit width decreases with increasing width, as the 3-D effect reduces. With reference to dry sand, the capacity of the anchor is doubled if the sand is unsaturated/wet, but it is reduced to only one half if the sand is saturated. The experimental results were compared with the analytical calculations and also with the numerical computations. The analytical results were also utilized for the experimental design. The results of numerical computations were used to validate the experimental design and to explain experimental findings, especially failure mode and deformation. The findings of this research are also compared with other studies reported in the literature. These findings have very significant implications to the analysis and design of the block anchor. They also contribute to the hazard risk assessment of block anchors embedded in sand subjected to variations in the environmental condition of wetting and drying cycles. [ABSTRACT FROM AUTHOR]

Studying the patterns and characteristics of seismic activity and crustal deformation in Africa is vital for understanding the geodynamics and predicting seismic hazards in the region. By understanding the deformation characteristics, scientists can help mitigate the risk of earthquake-related disasters in Africa. However, assessing deformations has been difficult because of scarce historical and instrumental seismic records and geodetic data. In this study, the finite element analysis was used to determine the crustal deformations in the form of strains in the EARS from the tectonic model gravitational potential as a stress driver. The strain patterns in various regions were then assessed where reliable, independent studies could be validated. Finally, the inferences of crustal strains to crustal deformations in various parts of the continent were drawn. The simulation results showed us that the strain of the 2 × 10 - 8 / yr was observed in the Main Ethiopian rift, and it decreased in the EARS toward Mozambique. The strain in the convergent margins of North Africa was also in the order of ~ 2 × 10 - 8 / yr . However, the principal strains in the stable central and West African countries could reach ~ 4 × 10 - 9 / yr . Thus, the results were consistent with those from geodetic strains. In addition, a high degree of relationship existed between the seismic studies and model strains. [ABSTRACT FROM AUTHOR]

TEM studies were performed to examine the effect of holding of dispersion-strengthened heat-resistant reduced activation 12% chromium ferritic-martensitic steel EK-181 in static liquid lead for 3000 h at 600°C on the steel microstructure in comparison with the steel after conventional heat treatment by quenching and tempering at 720°C. It was found that the steel microstructure has good thermal stability under the specified experimental conditions. Microstructural deformation of EK-181 steel was studied in the neck region of tensile specimens tested at the temperatures 20, 680, 700, and 720°C with and without holding in liquid lead, and their fracture mechanisms were investigated. As a result of plastic deformation during tensile testing at room temperature, martensite plates and laths near the fracture surface are distorted and fragmented with the formation of new low-angle boundaries, and the dislocation density increases. At the deformation temperatures 680–720°C, nearly equiaxed ferrite grains are formed, the density and size of second-phase particles (M23C6 and MX) increases due to dynamic strain aging, and the dislocation density decreases locally. As the test temperature rises, the degree of martensite tempering increases. At T ≥ 700°C, some dynamic polygonization and dynamic recrystallization are observed. At elevated tension temperatures, ferrite coarsening is more significant in the specimens held in lead as compared to the conventionally treated material. The plastic deformation and fracture behavior of the steel are largely determined by the test temperature, rather than by the treatment mode. [ABSTRACT FROM AUTHOR]

The paper briefly reviews the achievements of ISPMS SB RAS in the development of numerical computation methods and models for modeling the mechanical behavior of materials with hierarchical structure in the range of scales from nano to macro. The main stages in the development of several key areas are considered: atomistic modeling at the nanoscale level, continuum numerical methods, and particle method for studying the effect of structure on the behavior and properties of materials at larger spatial and temporal scales. The application of the multiscale approach to the structural modeling and design of metallic and ceramic materials is discussed. Prospects are outlined for transitioning to complete digital twins that link the structure formation process of the material with its final structure, mechanical properties, and mechanical behavior. [ABSTRACT FROM AUTHOR]

We present an earthquake simulator, Quake-DFN, which allows simulating sequences of earthquakes in a 3D discrete fault network governed by rate and state friction. The simulator is quasi-dynamic, with inertial effects being approximated by radiation damping and a lumped mass. The lumped mass term allows for accounting for inertial overshoot and, in addition, makes the computation more effective. Quake-DFN is compared against three publicly available simulation results: (1) the rupture of a planar fault with uniform prestress (SEAS BP5-QD), (2) the propagation of a rupture across a stepover separating two parallel planar faults (RSQSim and FaultMod), and (3) a branch fault system with a secondary fault splaying from a main fault (FaultMod). Examples of injection-induced earthquake simulations are shown for three different fault geometries: (1) a planar fault with a wide range of initial stresses, (2) a branching fault system with varying fault angles and principal stress orientations, and (3) a fault network similar to the one that was activated during the 2011 Prague, Oklahoma, earthquake sequence. The simulations produce realistic earthquake sequences. The time and magnitude of the induced earthquakes observed in these simulations depend on the difference between the initial friction and the residual friction μi -- μf, the value of which quantifies the potential for runaway ruptures (ruptures that can extend beyond the zone of stress perturbation due to the injection). The discrete fault simulations show that our simulator correctly accounts for the effect of fault geometry and regional stress tensor orientation and shape. These examples show that Quake-DFN can be used to simulate earthquake sequences and, most importantly, magnitudes, possibly induced or triggered by a fluid injection near a known fault system. [ABSTRACT FROM AUTHOR]

This research advances the understanding of deep excavation impacts by integrating a refined Finite Element Method (FEM) analysis with empirical data, specifically examining the behavior of retaining structures in urban environments. Unlike prior studies that predominantly relied on theoretical models, this paper combines FEM with statistical methods, particularly ANOVA, to identify critical factors affecting the performance of barrette walls during excavation. The primary objective of this study is to analyze the deformation and force behaviors at various depths, thereby enhancing the predictive capabilities of existing models. The findings highlight significant variations in horizontal displacements (Uy) and vertical displacements (Uz) across different excavation stages, with notable mean differences ranging from 0.000529420 m to 0.000700240 m for Uy and -0.017563652 m for Uz. Axial forces (N1) also show significant increases with depth, reaching a mean difference of 516.137991 kN/m. These results underscore the importance of adaptive design strategies in deep excavation projects. However, the study is limited by the specific geological conditions and the scope of empirical data used for model validation. Practical recommendations include enhancing real-time monitoring systems and applying refined methodologies. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A foundation pit's excavation area, which is determined by its radius in a circular foundation pit, exerts a considerable influence on the pit's behavior. Using a full-scale experiment on a circular foundation pit retained by a prefabricated recyclable supporting structure (PRSS), this study develops a series of axisymmetric numerical models to systematically investigate the influence of excavation radius on the pit's deformation, stress, and stability. Furthermore, simulation results from axisymmetric models are compared with those from plane strain models to illustrate the influence mechanism. The results show that at a given excavation depth, the deflection and bending moments of the supporting piles, the earth pressure on the non-excavation side, and ground surface settlement increase with the enlarged excavation radius, but the increase rate progressively decreases. However, the foundation pit's safety factor decreases with an increasing excavation radius and gradually stabilizes. When the excavation radius exceeds 50 m, its influence on the foundation pit's behavior significantly diminishes. The axisymmetric model results closely approximate those from the plane strain models, suggesting that the spatial arching effects of the circular foundation pit can be disregarded. [ABSTRACT FROM AUTHOR]

The application of reinforced concrete modular integrated construction (MiC) has gained popularity in Hong Kong, but challenges still exist in the temporary tying of side walls during composite wall construction. This paper presents an innovative inner tie system for composite walls, applied in a MiC project in Hong Kong. The system's components are installed on the side walls of precast modules in the factory without the need to penetrate through the walls. After transport to the site, by rotating the loop on-site to engage the hook, the tying effect is achieved during on-site concrete pouring between the interstitial space of two modules. This system eliminates the use of tie bolts that penetrate precast side walls, allowing for comprehensive interior fitting-out in the factory and minimizing disruptions to internal decoration during on-site construction. The paper presents the system's mechanism, nonlinear Finite Element Analysis (FEA) simulation, section size optimization, and validation through tensile and punching shear tests. Furthermore, an instrumented mockup module assembly was carried out, and the system was eventually applied in a real MiC project. The system can effectively control the horizontal deformation of MiC module side walls within a limit. Compared to current existing tying methods, this system offers easy installation, load-bearing reliability, adaptability to certain construction errors, savings on manpower and construction time, and also a decrease in construction waste and carbon emission. It will provide a valuable reference for future MiC projects. [ABSTRACT FROM AUTHOR]

In this paper, the types and principles of operation of fiber sensors based on fiber Bragg gratings (FBGs) are investigated. The influence of strain and temperature on the characteristics of FBGs is considered, and a method for the simultaneous measurement of these parameters is presented. Laboratory studies were carried out in the temperature range from +18 °C to +135 °C with an incremental step of 5 °C, with the actual temperature not deviating by more than ±0.5 °C. From the data obtained, the Bragg wavelength–temperature relationships were plotted, which showed a linear increase in wavelength with increasing temperature. This study shows that the use of two FBGs with a different sensitivity to temperature and strain allowed for the simultaneous measurement of both parameters. Numerical models created in the MATLAB R2022b environment confirmed the high accuracy and precision of the measurements. The FBG-based sensors demonstrated a robust performance in harsh environments, withstanding temperatures of up to 160 °C and high humidity, making them applicable in various industries and sciences. This work confirms that FBGs are a promising tool for accurate temperature and strain measurements, providing reliable results in harsh environments. [ABSTRACT FROM AUTHOR]

Fibre deformation (or shearing of yarns) can develop during the liquid moulding of composites due to injection pressures or polymerisation (cross-linking) reactions (e.g., chemical shrinkage). On that premise, this may also induce potential residual stress–strain, warpage, and design defects in the composite part. In this paper, a developed numerical framework is customised to analyse deformations and the residual stress–strain of fibre (at a micro-scale) and yarns (at a meso-scale) during a liquid composite moulding (LCM) process cycle (fill and cure stages). This is achieved by linking flow simulations (coupled filling–curing simulation) to a transient structural model using ANSYS software. This work develops advanced User-Defined Functions (UDFs) and User-Defined Scalers (UDSs) to enhance the commercial CFD code with extra models for chemorheology, cure kinetics, heat generation, and permeability. Such models will be hooked within the conservation equations in the thermo-chemo-flow model and hence reflected by the structural model. In doing so, the knowledge of permeability, polymerisation, rheology, and mechanical response can be digitally obtained for more coherent and optimised manufacturing processes of advanced composites. [ABSTRACT FROM AUTHOR]

With the advancement of semiconductor manufacturing technology, thin film structures were widely used in MEMS devices. These films played critical roles in providing support, reinforcement, and insulation in MEMS devices. However, due to their microscopic dimensions, the sensitivity of their parameters and performance to thermal stress increased significantly. In this study, a Pirani gauge sample with a multilayer thin film structure was designed and fabricated. Based on this sample, finite element modeling analysis and thermal stress experiments were conducted. The finite element modeling analysis employed a combination of steady-state and transient methods to simulate the deformation and stress distribution of the device at room temperature (25 °C), low temperature (−55 °C), and high temperature (125 °C). The thermal stress test involved placing the sample in a temperature cycling chamber for temperature cycling tests. After the tests, the resonant frequency and surface deformation of the device were measured to quantitatively evaluate the impact of thermal stress on the deformation and resonant frequency parameters of the device. After the experiments, it was found that the clamped-end beams made of Pt were a stress concentration area. Additionally, the repetitive thermal load caused the cantilever beam to move cyclically in the Z direction. This movement altered the deformation of the film and the resonant frequency. The suspended film exhibited concavity, and the overall trend of the resonant frequency was downward. Over time, this could even lead to the fracture of the clamped-end beams. The variation of mechanical parameters derived from finite element simulations and experiments provided an important reference value for device design improvement and played a crucial role in enhancing the reliability of thin film devices. [ABSTRACT FROM AUTHOR]

Copyright of Transportation Science & Technolgy is the property of Transportation Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding the failure mechanism of geosynthetic-reinforced embankments on soft foundations is crucial for ensuring safety in design. This study aimed to investigate the failure mechanism and stability of embankments reinforced with varying layers and lengths of geosynthetic reinforcements utilising centrifuge testing and numerical modelling. The results show that a foundation under construction exhibits a progressive shear failure coupled with a tensile failure of the geosynthetic reinforcement. The plastic shear strain in the soft clay layer initiates at the centreline, shoulder and embankment toe and propagates both forward and backward until a critical slip surface develops. The tensile failure of the geosynthetic was observed at the embankment centre. Comparatively, implementing two shorter layers of geosynthetics proved more advantageous for overall stability than using a single layer with the entire length. By analysing the strain distribution in the foundation, the deformation modes of the embankment reinforced by different numbers of geosynthetic layers were clarified. It was found that increasing the number of geosynthetic layers extended the active shear zone in soft clay. [ABSTRACT FROM AUTHOR]

A process of plastic deforming polymer blanks is developed involving polytetrafluoroethylene (PTFE) and carbon fibers of the UVIS-AK-P grade. The production process is explored from the standpoint of increasing the strength and resistance to creep. The relationship is found between the physics, mechanical, and tribotechnical parameters and the structural composite properties. The composites obtained using various schemes of plastic deforming polymer blanks differ in the character of deformation under tension. They develop different structures and feature various wear patterns. A multidirectional approach to plastic deforming blanks based on PTFE allows obtaining isotropic polymer materials featuring improved strength properties and better resistance to deformation under load. [ABSTRACT FROM AUTHOR]

In order to achieve a full mechanistic understanding of stress corrosion cracking (SCC), the key operating mechanisms need to be identified but also quantified. In this study, we summarize and rationalize key findings from the last 15 years of high-resolution characterization of SCC in our group. A comprehensive characterization of a set of austenitic alloys with different Ni content and constant Cr level, tested under simulated pressurized water reactor (PWR) primary water conditions at various temperatures, has revealed evidence for at least two operating mechanisms: one diffusion-related and the other deformation-related. For their relevance to the nuclear industry, two additional alloys with increased Cr content were also studied (A800 and A690). Key precursors for SCC initiation and propagation are identified and their effect on alloy degradation discussed. A list of key materials' properties that ensure low SCC susceptibility is proposed. [ABSTRACT FROM AUTHOR]

Explosive attacks are increasing day by day in the present era, and the design optimization of protective structures without increasing their weight is mainly a critical task for vehicles. Assessment of the dynamic response of the structures under explosive loading through experimentation is costly, with many restrictions, and highly harmful for both people and the environment. Hence, the present study deals with an explicit numerical investigation of the protective sandwich structures' blast performance. The influence of the number of stages of honeycomb on the sandwich structures' blast mitigation capacity was evaluated with the effective utilization of face sheets' material as their intermediate sheets while maintaining the total volumes as well as masses of the structure's constant. The explosive loads of 1 to 3 kg of trinitrotoluene were used for the stand-off distance of 100 mm. The rate-dependent Johnson-Cook plasticity model was implemented on the designed sandwich models to discover their damage behaviors. The sandwiches' face deflection, energy absorption, kinetic energy variation, and crushing behaviors were considered to characterize their blast mitigation capacity. The obtained results showed that increasing the number of stages of core in the sandwich structure by using a fraction of the back face sheet materials for intermediate sheets significantly improved their blast performance without increasing their volume occupancies and masses. For the two-stage and three-stage sandwich designs, 50% and 20%, respectively, utilization of their back face material for their intermediate sheet was found to be optimal. [ABSTRACT FROM AUTHOR]

Soft and hard contact deformation is most common issue of the refrigerator gasket and it has almost been ignored in previous studies. In this paper, the novelty is to propose a thermal-solid coupling simulation to study the effect of assembly states on the heat transfer of gaskets, improving the accuracy of heat transfer simulation analysis. The numerical results indicate that the calculated temperature based on physical model of assembly state is closer to measured temperature. The assembly distance affects the assembly state of the gasket by changing the contact positions and lengths of contact interfaces. As a result, the heat transfer path and condition at the gasket region also changes. As the deformation increases form −1.0 mm to 5.0 mm, the heat leakage load of gasket rises firstly and then falls, in the range of 1.61 ~ 3.33 W•m−1. The heat leakage at the transfer paths of internal cold air, outer shell and cold bridge accounts for over 20%. Thus, it is recommended to reduce the contact interface length of internal cold air, increase the thermal resistance of auxiliary air-bag, reduce the thermal conductivity and thickness of magnetic strip and increase the contact thermal resistance of cold bridge. [ABSTRACT FROM AUTHOR]

The deformation mechanism of SiC reinforced 6061 aluminium-based metal matrix composites (MMCs) under compression is investigated in this study. Finite element analysis was used to examine the impacts of particle size, shape, and content on the stress distribution, stiffness, and strength of MMCs. To identify potential locations of debonding or material failure, the major stress and von Mises strain distributions were displayed. It was found that at 10% reinforcement content the effects of particle size and shape were negligible, however there was an increase in material strength over the monolithic material. The greatest increase to mechanical properties occurred at 20% particle content with the smallest size particle. This was due to an increase in load transfer to the stiffer particles because of increased surface contact length. The reinforcing particles also improved the resistance to matrix material flow. Circular, triangular, square, and rectangular particles were tested. Because of its more evenly distributed strain and greater areas of minimal strain in the matrix material, the rectangular particle provided the highest increase in mechanical characteristics. [ABSTRACT FROM AUTHOR]