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The spallation behavior of polycrystalline Al with helium (He) bubbles (poly Al–He) under unsupported shock loadings at a wide range of impact velocities was investigated via molecular dynamics simulations. We found that the microstructural features during shock compression and release processes for the poly Al–He are highly analogous to those observed in polycrystalline Al (poly Al), indicating that the bubbles studied here do not have a significant influence on the mechanical deformation before tension. During the tension process, the expansion-merging of He bubbles dominates damage accumulation and leads to the ultimate fracture of the metal, the same as that in a single crystal with He bubbles. The presence of grain boundaries (GBs) does not exhibit an apparent effect on the evolution of He bubbles, resulting in comparable expansion rates for the bubbles in different locations (i.e., near GBs or at grain interiors). Additionally, the nucleation of voids occurs subsequent to bubble expansion due to the much higher critical stress. Voids are preferentially nucleated on GBs when the material is solid and at liquid parts when the material is partially molten, demonstrating that GBs and melting can strongly facilitate void nucleation. However, He bubbles significantly impede void nucleation and growth, resulting in a much smaller quantity and volume of voids formed in the poly Al–He, compared to the poly Al. Furthermore, the critical stress for void nucleation and the spall strength of the metal matrix are reduced by He bubbles. [ABSTRACT FROM AUTHOR]

By using a tight-binding model, first-principles calculations, and ab initio molecular dynamics simulations, we theoretically demonstrate that the C76-Td-assembled two-dimensional (2D) honeycomb lattice is stable at room temperature and is resistant to mechanical deformation. We disclose that each C76-Td mimics a single carbon atom (geometrically and electronically); hence, it plays the role of one supercarbon. This inspires that the 2D material exhibits an exotic hourglass-like fermion at the Fermi level. Furthermore, we suggest that biaxial strains could modify the hourglass shape, including the electronic Fermi velocity, and induce magnetization. Hexagonal boron nitride can be employed as a protective layer without affecting the electronic structure of this material. This hourglass fermion has the potential to serve as a promising material for high-speed electronic devices and to bridge the gap between zero-dimensional spherical carbon clusters and two-dimensional graphene. [ABSTRACT FROM AUTHOR]

In this work, the effect of random substitution modes of Fe and Ni on the stability and mechanical properties of Co3Ti-based intermetallics was investigated using first principles calculations through occupancy modes, electronic structures, energies, and elastic constants. The results show that FeCo type substitution favors ductility while NiCo type substitution favors strength. Compared to the above two types of substitution, FeTi type substitution is favorable for obtaining a balance between stability and ductility, but it is not easy to achieve energetically. Synergy of three types of substitutions enables stability and equilibrium mechanical properties of Co3Ti-based multi-component intermetallics. In addition, the anti-site substitution of neighboring Co and Ti atoms interchanging their positions may be a key step in the formation of FeTi type substitutions in terms of energy. This work provides useful data and insights into the design and utilization of Co3Ti-based multi-component intermetallics. [ABSTRACT FROM AUTHOR]

The thermomechanical behavior of materials is known to be sensitive to preexisting defects in their microstructure. In this paper, non-equilibrium molecular dynamics simulations have been used to investigate the effects of the microvoid size on the plastic deformation in single-crystal iron shock-compressed along the [ 001 ] crystallographic direction. The higher the microvoid radius, the faster the kinetics of dislocations. Thus, as the microvoid radius increases, the plastic activity evolves from a regime where the deformation is dominated by twin activities to a regime where both twin and dislocation activities play an essential role and then to a regime where the deformation is dominated by dislocation slip. Furthermore, in both defect-free and defective initial crystal states, the elastic precursor wave is observed to decay with propagation distance, resulting in a constitutive functional dependence of the yielding pressure, σ E , on the plastic deformation rate, ε ˙ p. In the regime where both deformation twinning and dislocation slip play important roles, the constitutive behavior is consistent with the original Swegle–Grady model and is in overall agreement with experimental data and thermomechanical simulations. [ABSTRACT FROM AUTHOR]

Meso-scale calculations of energy localization and initiation in energetic material microstructures must capture the deformation and collapse of pores and high-temperature shear bands, which lead to hotspots. Because chemical reaction rates depend sensitively on temperature, predictive continuum models need to get the pore-collapse dynamics and resulting hotspot temperatures right; this imposes stringent demands on the fidelity of thermophysical model forms and parameters and on the numerical methods employed to perform high-resolution meso-scale calculations. Here, continuum material models for β-HMX are examined in the context of shock-induced pore collapse, treating predictions from all-atom molecular dynamics (MD) simulations as ground truth. Using atomistics-consistent material properties, we show that the currently available strength models for HMX fail to correctly capture pore collapse and hotspot temperatures. Insights from MD are then employed to advance a Modified Johnson–Cook (M-JC) strength model, which is shown to capture key aspects of the physics of shock-induced localization in HMX. The study culminates in a MD-guided strength model for β-HMX that produces continuum pore-collapse results in better alignment on several aspects with those predicted by MD, including pore-collapse mechanism and rate, shear-band formation in the collapse zone, and temperature, strain, and stress fields in the hotspot zone and the surrounding material. The resulting MD-informed/MD-determined M-JC model should improve the fidelity of meso-scale simulations to predict the detonation initiation of HMX-based energetic materials in microstructure-aware multi-scale frameworks. [ABSTRACT FROM AUTHOR]

We employed all-atom molecular dynamics simulations to explore the mechanical response of bending, twisting, and overwinding for double-stranded DNA (dsDNA). We analyzed the bending and twisting deformations, as well as their stiffnesses, using the tilt, roll, and twist modes under stretching force. Findings indicate that the roll and twist angles vary linearly with the stretching force but show opposite trends. The tilt, roll, and twist elastic moduli are considered constants, while the coupling between roll and twist modes slightly decreases under stretching force. The effect of the stretching force on the roll and twist modes, including both their deformations and elasticities, exhibits sequence-dependence, with symmetry around the base pair step. Furthermore, we examined the overwinding path and mechanism of dsDNA from the perspective of the stiffness matrix, based on the tilt, roll, and twist modes. The correlations among tilt, roll, and twist angles imply an alternative overwinding pathway via twist–roll coupling when dsDNA is stretched, wherein entropic contribution prevails. [ABSTRACT FROM AUTHOR]

The cytoskeleton, a dynamic network of structural proteins within cells, is essential for cellular deformation and responds to external mechanical cues. Here, based on the structure of the cytoskeleton, combined with the biochemical reactions of the activator RhoA and the inhibitor F-actin, we develop a novel mechanochemical cytoskeleton model to investigate the mechanical behavior of cells. Interestingly, we find that active stress fibers exhibit diverse dynamical modes at specific inhibitor concentration thresholds. The existence of concentration differences and sustained mechanochemical feedback in activators and inhibitors trigger a global oscillation of isolated cells. In addition, under uniaxial and biaxial stretches, activators and inhibitors preferentially diffuse toward the more significantly deformed cytoskeletal elements, and their dynamic interactions regulate the cell to align with the main stretching direction. Our findings, consistent with many experimental results, provide fundamental insights into cytoskeletal remodeling and cellular mechanosensing mechanisms. [ABSTRACT FROM AUTHOR]

Flexible electronic devices with skin-like properties are hailed as revolutionary for the development of next-generation electronic devices, such as electric-skin and humanoid robotics. Graphene is intrinsically flexible due to its structural thinness in nature and are considered next-generation materials for wearable electronics. These devices usually experience a large mechanical deformation in use so as to achieve intimate conformal contact with human skin and to coordinate complex human motions, while heat dissipation has been a major limitation when the device is under a large mechanical strain. Unlike the small deformation (<1%) induced by intrinsic material factors such as lattice mismatch between material components in devices, a large mechanical deformation (>1%) by an external loading condition could lead to apparent changes to global geometric shapes and significantly impact thermal transport. In this study, we investigated the thermal conductivities of graphene under several large mechanical strains: 2.9%, 4.3%, and 6.1%. We used a refined opto-thermal Raman technique to characterize the thermal transport properties and discovered the thermal conductivities to be 2092 ± 502, 972 ± 87, 348 ± 52, and 97 ± 13 W/(m K) for the relaxed state, 2.9%, 4.3%, and 6.1% tensile strain, respectively. Our results showed a significant decreasing trend in thermal conductivities with an increasing mechanical strain. The findings in this study reveal new thermal transport mechanisms in 2D materials and shed light on building novel flexible nanoelectronic devices with enhanced thermal management. [ABSTRACT FROM AUTHOR]

Surface pattern formation of Smart Cut™ silicon-on-insulator (SOI) substrates is investigated using a new process derived from this technology. The local control of SOI surface roughness is achieved by using hetero-temperature surface activated bonding to introduce locally bespoke shear stresses into bonded silicon wafers. The finite element method is used to back up experimental measurements of these large deformations to determine the amount of shear stresses introduced into the structure, and to determine its impact on the fracture mechanism. [ABSTRACT FROM AUTHOR]

Metallic glasses (MGs) are of high strength but limited plasticity at room temperature (RT) due to localized shear in the intrinsically heterogeneous structure. Here, we investigate the variation of structural heterogeneity and plasticity of a Zr-based MG after high-temperature (T) tension under different stresses (σ) at 579 K (0.9Tg, where Tg is the glass transition temperature). The correlation length (ξ) of the heterogeneous structure and the average Young's modulus ( E ¯ ) increase with σ when σ is below 160 MPa; when σ exceeds 160 MPa, both ξ and E ¯ decrease with σ, leading to the improvement of the plasticity. This research could be enlightening for improving the plasticity of MGs at RT through tuning their structural heterogeneity with high-T deformation. [ABSTRACT FROM AUTHOR]

A gradient nano-grained (GNG) structure demonstrates satisfactory surface strength. However, the underlying mechanism responsible for its strengthening lacks sufficient research. To explain how gradient nano-grained structures improve surface strength in detail, large-scale parallel molecular dynamics simulations are utilized in this study to investigate the mechanical deformation behavior of BCC tungsten with varying grain sizes during spherical nanoindentation. The findings suggest that a well-designed gradient structure can promote rational plasticity and an appropriate distribution of internal atomic stress. The critical point of maximum stress and hardness is observed when the initial grain size is 4.5 nm, with an average grain size of 7.1 nm. The interaction between grain boundary slip and migration in small grains, along with the enhanced activity of grain boundary dislocations in large grains, collectively contributes to the enhancement of the strength and hardness of the GNG structure. Compared with a homogeneous nano-grained structure, the gradient nano-grained structure exhibits a more rational distribution of dislocations and stress relaxation effects to enhance strength. The present work utilizes the molecular dynamics nanoindentation method to study GNG materials, providing a methodology for investigating the surface strengthening effects of GNG structures at the atomic scale and effectively revealing potential mechanisms for resisting surface deformation in GNG structures. [ABSTRACT FROM AUTHOR]

A Belousov–Zhabotinsky (BZ) gel is a unique biomimetic system that undergoes autonomous volume oscillations induced by the redox oscillation of the BZ reaction. In a previous study, researchers reported that the oscillations of two BZ gels coupled by compression were synchronized by a mechanical interaction. They mathematically explained the synchronization behavior using a phase oscillator model. As a different approach to the previous study, a physicochemical investigation of the phenomenon will lead to a better understanding of the functional biological rhythms essential for life. In this study, we construct a simple phenomenological model to understand the synchronization of BZ gels. The model consists of two parts. One is the dynamics of the chemical reactions in the BZ gels. We use a phenomenological model based on the Oregonator for the BZ reaction. The other is the dynamics of the mechanical deformation of the BZ gel. Using approximations, we extract the parameters essential for the synchronization of a mechanical interaction. Thus, we can derive a novel equation for the deformation dynamics of mechanically coupled BZ gels. By combining these two parts, we perform numerical calculations. This allows us to find that the synchronization of the two BZ gels is less likely to occur under stronger compression. We explain this trend through one physicochemical parameter in our model: the volume fraction of the BZ gel in the reduced state. [ABSTRACT FROM AUTHOR]

This paper utilizes a coupled chemomechanical model that integrates chemical reactions, diffusion, and mechanical deformation to describe the high-temperature interfacial reactions and stress evolution within an enamel coating/Ni-based super-alloy system. Through finite element simulation, we conduct a comprehensive analysis of multiple reactions and processes at the interface. Experimental characterization of the concentration distribution of various elements is employed to verify the accuracy of the proposed chemomechanical model. Additionally, the simulation reveals that the interface region experiences compressive circumferential stress, which can potentially lead to interfacial failure due to buckling. On the other hand, the enamel coating undergoes tensile circumferential stress, resulting in the formation of vertical surface cracks. These findings hold practical implications for the development of advanced coatings with enhanced durability and performance. Future research can further optimize coating design and enhance the reliability of high-temperature applications based on these results. [ABSTRACT FROM AUTHOR]

In the process of ring rolling, the anisotropic deformation uniformity of a ring not only has a significant influence on the accuracy of the section geometry and rolling stability, but also affects the subsequent processing deformation of the ring. Aiming at the deformation behavior of aluminum alloy profiled ring rolling process (PRRP), the finite element analysis of PRRP was carried out based on ABAQUS software. By extracting the node displacement of the single-layer mesh of a ring section, the deformation values of the section in some typical directions such as the circumferential direction of a ring are obtained. The deformation behavior of the ring section in the filling stage and the stable deformation stage is analyzed, and the deformation distribution of the profiled ring in the radial-axial rolling process is summarized. Secondly, the influence of the main rolling parameters on the deformation uniformity, stability and filling performance of a ring is analyzed. Finally, more reasonable rolling process parameters are provided for the rolling of large profiled rings, and the method's effectiveness is verified by rolling tests. [ABSTRACT FROM AUTHOR]

This work explores stretchable silver (Ag)-based conductive traces for wearable electronic devices. Various aspects of the horseshoe-shaped stretchable Ag trace were investigated, including design principles, geometric effects on electrical and mechanical properties, techniques for achieving stretchability, fabrication materials and processes, and their efficacy in circuit connection. Systematic simulations and analysis generated an optimized horseshoe design with width and inner radius of 3 mm, angle of 30°, turn number of 3, and thickness of 10–20 µm, ensuring low resistance, high stretchability, and robust configuration simultaneously. A cost-efficient method based on screen printing and blade coating was employed to fabricate the Ag traces, which were thoroughly characterized in terms of static and dynamic electrical and mechanical properties, durability, and stability under various environmental temperatures. The measured results exhibit that (i) the printed Ag traces have high conductivity of more than 6000 S/cm; (ii) by utilizing stretchable Ag paste, pre-stretched elastic substrate, optimized horseshoe-shaped pattern, and ultra-thin PDMS cover, the printed Ag trace can achieve a stretchability of 50% with relative resistance change of < 80%, maintaining its resistance in the range of tens of ohms even under diverse mechanical deformations; (iii) the stretchable Ag trace shows an extraordinarily low and stable gauge factor of 1–1.5 at stretching strain range of 5–50%; (iv) significant durability, exceeding 3000 stretching/releasing cycles at a strain of 12.5% was obtained; and (v) the printed Ag trace shows good stability with varying environmental temperatures across diverse stretching states. In summary, this work contributes significantly to the promising domain of stretchable electronics by offering a cost-effective solution for fabricating high conductivity, good stretchability, and super durability metallic traces. [ABSTRACT FROM AUTHOR]

This paper presents an analytical method to study the lateral response of offshore slender piles near sandy slopes. A slope deformation model is constructed to evaluate the slope displacement induced by the load transfer of a pile at the slope crest. A modified strain wedge (SW) model is developed by considering the slope deformation and the impact of the slope on the effective overburden pressure. A geometric transformation is employed to facilitate the analysis of the edge distance. The efficiency and accuracy of the method are demonstrated through comparisons of its results with those of six centrifuge piles and four model piles. Finally, the effects of the slope angle and edge distance on the pile response are discussed. This method introduces the slope deformation into the analysis of soil-pile interaction, allowing for comprehensive consideration of the combined effects of slope angle and edge distance. [ABSTRACT FROM AUTHOR]

Existing structures can deform and damage due to newly constructed underground structures, which induces surrounding soil deformation due to ground loss and stress relief. Compensation grouting is an active control method widely used in practice due to its advantages of using readily accessible material, a convenient construction process, and the ability to make real-time adjustments compared with passive control methods. However, in current studies, consolidation settlement is commonly considered the primary factor causing the gradual loss of the grouting effect. In this study, a numerical model exhibiting an elastic viscoplastic behavior was established using the finite-difference method to investigate the influence of creep on grout efficiency. The model parameters were first calibrated by comparing them with the measured and computed results of the grouting tests conducted in a consolidometer. Then, the model was used to perform parametric studies, to investigate the influences of initial overconsolidation ratio (OCR) and grout volume. The results show that the grout efficiency, defined as the ratio between total displacement and ideally anticipated heave displacement after grouting, is lower than that when only consolidation is considered. It can decrease up to 2.5 times over 3 years when the OCR is set to 1.00 and the grout volume is 1 mL. This implies that neglecting creep behavior may lead to a nonconservative design for compensation grouting in the long term. The creep control efficiency, defined as the ratio between the settlement induced by creep and that induced by consolidation, has been newly proposed to evaluate the influence of soil creep. It is found that the creep control efficiency of OCR = 1.00 serves as an upper limit under different OCRs because of the significant consolidation settlement in underconsolidated soil and the small creep settlement in overconsolidated soil. Therefore, the creep control efficiency value of OCR = 1.00 can be recommended for conservative design estimates when determining the final grout efficiency. [ABSTRACT FROM AUTHOR]

As per bulk-edge correspondence, the junction between two topologically distinct lattices in a topological optical fiber supports topological interface states, which enable highly stable, scattering-free, robust propagation of light. We investigate the propagation characteristics of a multi-channel topological optical fiber having co-existing multiple topological interface states in the presence of potential structural defects and deformation in shape. The tolerance analysis has been carried out by deliberately introducing structural imperfections upto ⩽4% with reference to the annular area at the topological junction of trivial and non-trivial lattices. These studies demonstrate robust properties of multiple topological interface states despite the presence of such structural deformations. Furthermore, a deliberately introduced lateral misalignment upto a maximum of 800 nm of the topological junction exhibits a low splice loss of 0.3 dB and high confinement properties of the multiple topological interface states. These results clearly indicate that the propagation characteristics and properties of the co-existing multiple topological interface states exhibit exceptional tolerance to structural defects, junction deformations, and lateral misalignments, surpassing the performance of state-of-the-art conventional optical fibers. Hence, topological optical fibers could outperform conventional optical fibers in terms of undistorted signal transmission irrespective of fabrication-related potential structural defects. [ABSTRACT FROM AUTHOR]

Shield tunnel is susceptible to nearby disturbances, resulting in excessive longitudinal differential deformation, which severely affects the structural performance of the tunnel. Reinforcing the tunnel with steel plates spanning circumferential joints was recently proposed to control the longitudinal differential deformation of the tunnel. However, the acting mechanism and strengthening effects of the steel plates need to be further investigated. Firstly, a multi-scale solid ring-spring numerical model was proposed in the ABAQUS software and validated by available field data. Next, the behaviour of shield tunnel linings reinforced with steel plates in the rings (in-ring scheme) and spanning the rings (across-ring scheme) was compared in detail. Results indicate that the stiffness of circumferential joints can be greatly improved by the across-ring scheme, thereby effectively controlling the longitudinal differential settlement and dislocation. Even when the coupling effect of longitudinal and lateral deformation is present, the across-ring scheme can control lateral deformation more effectively than the in-ring one. Overall, the across-ring scheme is more effective in controlling the deformation of shield tunnels, whether it be longitudinal differential deformation, dislocation, or lateral deformation. This research can provide helpful guidance on deformation control of shield tunnels. In addition, it could be broadly applied in engineering. [ABSTRACT FROM AUTHOR]

Here, we present a new thermomechanical geodynamic, numerical implementation that incorporates Maxwell viscoelastic rheology accounting for temperature-dependent power-law dislocation creep and pressure-sensitive, non-associated Drucker–Prager brittle failure, as well as for volumetric stresses and strains during viscoplastic flow, a departure from the traditional incompressible assumptions. In solving for energy conservation, we incorporate the heat source term resulting from irreversible mechanical deformations, which embodies viscoelastic and viscoplastic work, and by considering the total stress tensor and total inelastic strain rate tensors, including dilatant plasticity effects for lithospheric-scale applications, instead of only the shear terms as is usually assumed for incompressible materials. This form of the work term thus allows to consider, volumetric deformation and to couple the energy equation to the constitutive description, and hence the stress balance, via the evolving temperature field. Code design enables us to switch individual features of this general rheology 'on or off' and thus to benchmark this implementation with published numerical experiments of crustal-scale shortening experiments. We investigate whether 'brittle-plastic' compressibility can promote or inhibit localization of deformation and thermal evolution during compression for crustal, and upper mantle rheology. For both crustal-scale and lithospheric-scale experiments, we establish that the feedback from volumetric dissipation, while contributing to temperature increase along with shear dissipation, can potentially slow down heat production per unit time, depending on the choice of boundary conditions. Our new implementation can be used to address buckling problems and collision tectonics. [ABSTRACT FROM AUTHOR]

Many new and developed oilfields are confined to carbonate reservoirs with a complex void space structure. In this study, the behavior of carbonates as a function of decreased reservoir pressure was examined. The study was based on actual production data from wells rather than just on model data or results from computational experiments. Well-test data (170 well tests) and laboratory core samples (45 samples) results were used in the analysis. The problem of reservoir deformation has been comprehensively addressed at the micro and macro levels. The effect of reservoir permeability throughout the entire reservoir volume on reservoir pressure was determined. With a decline in reservoir pressure, the permeability of fractures and pores in carbonates decreases. The deformation coefficients, which characterize the actual rate of decrease in permeability with decreasing reservoir pressure, were also calculated. The deformation coefficients and data from core studies using μ-CT and SEM were compared. Based on micro-CT data, the effective diameters of the voids were calculated to be 93 mm, 109 mm, and 140 mm for the Vinnikovskoe, Sofinskoe, and Sukharev fields, respectively. Based on μ-CT and SEM data, the predominant geometric shapes of the voids were assessed. The deformation coefficient of voids was found to depend on their size and geometric shape. The study's findings revealed deformation coefficients of 0.172, 0.205, and 0.748 for the Vinnikovskoe, Sofinskoe, and Sukharev fields, respectively. Maximum deformation coefficients are typical for large voids with a predominant slot-like shape. However, even with the predominance of primary spherical voids in carbonates, the permeability of voids decreases with decreasing reservoir pressure. [ABSTRACT FROM AUTHOR]

In order to solve the problem of low detection accuracy in building structure safety monitoring, the author proposes a deformation monitoring and analysis during deep foundation pit construction based on Internet of Things technology. This method takes a large-scale construction project in a certain city as an example, applies neural network prediction models to deformation monitoring of foundation pits and main structures, and compares and analyzes the predicted results with actual measurement data. The experimental results show that the average MAE value of the predicted values is 0.15mm, and the average RMSE value is 0.17mm. The prediction accuracy of the neural network prediction model is high, which meets the accuracy requirements of deformation monitoring prediction. The use of Internet of Things technology can effectively ensure the safety of large buildings during construction, and has wider application value and prospects in deformation monitoring of future construction projects. [ABSTRACT FROM AUTHOR]

The present study focuses on the evolution of residual stress (RS) and internal damage of a S550MC + 100Cr6 cladded steel after pre-deformation. Deformation-induced internal porosity was hardly found. RS depth profiles point at tensile RS in the 100Cr6 clad layer. These are most pronounced when minor pre-deformation levels are considered. A higher degree of deformation leads to reduced magnitudes of RS. This can be rationalized based on reduced differences in layer strength due to local strain hardening. [ABSTRACT FROM AUTHOR]

This paper introduces a biomimetic gradient hierarchical multicellular structure consisting of two tree-like fractal variants: one based on vertex connections (HCV) and the other based on wall connections (HCW). We investigate their mechanical behavior and deformation through numerical simulations. Our findings reveal that, irrespective of whether they have the same wall thickness or mass, second-order and third-order structures exhibit superior energy absorption capacity (EA) and crushing force efficiency (CFE) compared to first-order structures, resulting in significantly enhanced crashworthiness performance. In the case of HCV structures with identical wall thickness, the third-order structure outperforms the first-order structure by 79.73% in specific energy absorption (SEA) and by 38.51% in CFE. Similarly, for HCW structures, the third-order variant surpasses the first-order one by 45.57% in SEA and 28.39% in CFE. We also conduct a parametric study, exploring the influence of inner circle diameter, fractal coefficient, and fractal angle on the crashworthiness of biomimetic gradient hierarchical multicellular structures. We identify the optimal fractal coefficient and inner diameter distribution range for HCV when the fractal angle is 60 ∘ . Lastly, we compare these structures with traditional multicellular tubes, demonstrating that biomimetic gradient hierarchical multicellular tubes achieve up to 50.34% higher SEA and 55.13% higher CFE. The results of this study offer valuable design insights for developing lightweight and efficient energy-absorbing structures. [ABSTRACT FROM AUTHOR]

Fractional derivatives have received considerable attention in modeling thermoelastic behavior due to their ability to reflect memory effects and non-local interactions. In this paper, we introduce a novel thermoelastic model designed to explore the behavior of porous materials featuring voids. This advanced framework builds upon the fractional phase lag thermoelastic model by integrating a two-parameter Mittag-Leffler kernel. An important enhancement over conventional elastic models is the inclusion of both spatial and temporal non-local effects, which are essential for accurately capturing the intricate microscopic interactions characteristic of porous structures. Furthermore, the addition of the Goufo-Caputo two-parameter fractional derivative into the heat conduction equation has improved the representation of memory effects, providing a more comprehensive understanding of how historical deformations and thermal conditions impact material behavior. By evaluating temperature, displacement, stress, and volume fraction fields, this study highlights the strengths and weaknesses of these fractional operators, shedding light on their significance in advancing thermoelastic modeling. [ABSTRACT FROM AUTHOR]

To address the challenge of rib filling in large-scale ribbed thick plate components (LSRTPCs), this study adopts a combined experimental and finite element (FE) simulation approach. The reliability of FE simulations was evaluated by comparing the rib groove filling effect of LSRTPC, from which variations in plate thickness lead to differences in the rib filling effect. The analysis based on characteristic models demonstrates that thinner billets exhibit faster material flow during the forming process, resulting in higher material filling rates under the same forming force. The velocity field analysis based on energy theory and FE simulations indicates that as billet thickness increases, shear power consumption within the effective deformation area rises, whilst the high-hydrostatic-stress area outside the effective deformation area expands. These two factors collectively result in an increase in forming force. A compatible deformation process combining local extrusion and integral extrusion was proposed, and forming experiments were conducted. Results show a significant improvement in the forming quality of the rib, achieving controllable metal flow under low-forming-force conditions. This work provides technical support for defect suppression and low-energy manufacturing of LSRTPCs in extrusion forming. [ABSTRACT FROM AUTHOR]

In this study, dynamic deformation behavior of electron beam melted Ti-6Al-4V alloy and effect of initial defects on deformation process of the alloy were investigated with high strain rate experimental and numerical studies. Dynamic compression tests at the strain rates of 350, 850, 1250, 1750, 1950, and 2500/s at room temperature and at higher temperatures of 150 and 240 °C were performed using a split-Hopkinson pressure bar. Compression simulations in three dimensions (3D) with LS-Dyna software were conducted using the determined Johnson–Cook parameters of the Ti-6Al-4V alloy specimens, to assess the strain, temperature distribution during deformation. In addition, simulation studies with initial defects in the model were performed to investigate the effect of these defects on strain formation during compression. The experimental results showed that strain rates over 1250/s caused failure at 45° to the loading direction. Adiabatic shear bands were observed for the specimens compressed at the strain rates of 1250/s and higher. As strain rate increased from 1250 to 2500/s, the type of adiabatic shear band altered from deformed to transformed type. The simulation results showed that initial defects in the specimen led to formation of higher plastic strain in the direction of 45° around initial defects. This high strain might be the cause of formation of adiabatic shear band. The simulation results also indicated that void morphology could affect strain distribution in the specimen. [ABSTRACT FROM AUTHOR]

The surrounding rocks in deep roadways frequently undergo dynamic disturbances caused by adjacent blasting or mining activities. These dynamic disturbances lead to the propagation and coalescence of cracks in the surrounding rock, inducing dynamic disasters in the roadways. However, the mechanisms of rock crack propagation and the roadway failures, induced by dynamic disturbances under different blasting positions and strengths, remain unclear. To investigate the dynamic disturbance of deep roadway surrounding rocks, large-scale physical model tests are carried out on the dynamic instability of surrounding rock under high in situ stress and dynamic disturbance. The dynamic instability failure modes under different disturbance loads and positions are analyzed. The results suggest that under conditions of high ground stress, cracks initiate in stress concentration zones in deep roadways. As disturbance intensities increase, these cracks can further extend, leading to the rapid failure of the surrounding rock. The location of dynamic disturbances influences the failure process of the surrounding rock in deep roadways. Under such stress conditions, stress concentration often occurs at the arch shoulder and arch bottom of the roadway. When the source of dynamic disturbance changes from the side wall to the arch, it is more likely to cause damage within the stress concentration zones in the arch shoulder and arch bottom, which can result in instability and failure of the roadways. [ABSTRACT FROM AUTHOR]

Gradient nano-grained (GNG) high-entropy alloys (HEAs) generally exhibit an excellent balance of plasticity and strength compared to homogeneous alloys, but their mechanical behaviors vary significantly with grain size distributions. This work has systematically investigated the mechanical behaviors and deformation mechanisms of GNG Al0.1CoCrFeNi HEAs with various grain-size gradients using molecular dynamics. The results have indicated that the grain-size gradient induces stress and strain gradients, and results in more dislocations and a unique multiaxial stress state, which contribute to the strength-plasticity synergy in the GNG structure. The deformation mechanism of GNG Al0.1CoCrFeNi HEA involves dislocation slip in low strain level, martensitic transformation, and twinning in high strain level. The GNG Al0.1CoCrFeNi HEA with a grain size gradient rate of n = 3 exhibits the best strength-plasticity synergy due to its significant strain and stress gradients, alongside notable deformation-induced twins and martensite. These simulation results are consistent with the strain gradient theory and some experimental reports. [ABSTRACT FROM AUTHOR]

AbstractCaisson composite–pile foundation (CCPF) is a major type of deep–water foundation. It is composed of gravity caissons and a pile foundation. It is widely used in bridge piers, wharf platforms, breakwaters, offshore platforms, and offshore wind–power foundations. Herein, the geotechnical characteristics and deformation of CCPFs are examined. Further, Emphasis is placed on theoretical, experimental, and numerical studies of the loading mechanism, transfer law, and deformation distribution of blended foundations under static and dynamic loading. Based on these studies, suggestions for future research and development are provided. [ABSTRACT FROM AUTHOR]

The early shrinkage-deformation and mechanical property evolution of gradient-structured composites in extreme environments are still insufficient. The paper prepared ordinary Portland cement-alkali-activated slag (OPC-AAS) and ordinary Portland cement-alkali-activated metakaolin (OPC-AAMK) gradient-structured composite by stacking cement and alkali-activated materials together. The effects of temperature difference cycling and wetdry cycling extremes on the early shrinkage strain and splitting strength of OPC-AAS and OPC-AAMK composites, as well as the structure of the bond interface and the micromorphology of the hydration products, were comparatively analyzed. The results demonstrated that the temperature difference cycling affected the early deformation and bond strength of the gradient-structured composite interfaces more significantly than the dry-wet cycling. The maximum expansion strains of OPC-AAS and OPC-AAMK were 1,130.88 μm and 1,399.25 μm, respectively, under the effect of temperature difference cycling; the splitting strengths of OPC-AAS and OPC-AAMK after three cycles of temperature difference cycling were reduced by 26.37% and 31.32%, respectively, compared with that after three cycles of wet-dry cycling. In addition, the OPC-AAS composites showed better interfacial bonding properties after extreme environmental cycling compared to the OPC-AAMK composites. The early splitting strengths under the two extreme environmental effects increased and then decreased, and the maximum splitting strengths of OPCAAS were 2.66 MPa and 3.65 MPa under the temperature difference cycling and dry-wet cycling, respectively, which were 5.14% and 35.69% higher than those of OPC-AAMK, respectively. Scanning electron microscopy (SEM) characterization analysis showed that the temperature difference cycling resulted in more severe product decomposition of the AAMK cementitious material, and obvious cracks and holes appeared at the bonding interface of OPC-AAMK. This study provides some references for the optimal design of the early shrinkage-deformation properties and mechanical properties of gradient-structured composites under extreme environments as well as the assessment of service life. [ABSTRACT FROM AUTHOR]

Global assessments of landslide impact on critical communication infrastructure have become urgent because of rising occurrences related to human activities and climate change. The landslide and glacial slide susceptibility along the Karakoram Highway poses a significant threat to the infrastructure ecosystem, local communities, and the critical China–Pakistan Economic Corridor. This research paper utilized the Small Baseline Subset InSAR technique to monitor the deformation patterns over the past 5 years, yielding high-resolution insights into the terrain instability in this geologically active region. The SBAS time series results reveal that the substantial cumulative deformation in our study area ranges from 203 mm to −486 mm, with annual deformation rates spanning from 62 mm/year to −104 mm/year. Notably, the deformation that occurred is mainly concentrated in the northern section of our study area. The slope's aspect is responsible for the maximum deformed material flow towards the Karakoram Highway via steep slopes, lost glacial formations, and the climate variations that cause the instability of the terrain. The given pattern suggests that the northern area of the Karakoram Highway is exposed to a greater risk from the combined influence of glacial slides, landslides, and climatic shifts, which call for the increased monitoring of the Karakoram Highway. The SBAS-InSAR method is first-rate in deformation monitoring, and it provides a scientific basis for developing real-time landslide monitoring systems. The line of sight limitations and the complexity and imprecision of weather-induced signal degradation should be balanced through additional data sources, such as field surveys to conduct large slide and glacial slide susceptibility evaluations. These research results support proactive hazard mitigation and infrastructure planning along the China–Pakistan Economic Corridor by incorporating SBAS-InSAR monitoring into the original planning. The country's trade policymakers and national level engineers can enhance transport resilience, efficiently manage the landslide and glacial slide risks, and guarantee safer infrastructure along this strategic trade route. [ABSTRACT FROM AUTHOR]

During the LPBF (Laser Powder Bed Fusion) process, excessive residual stress can lead to a decline in the forming quality of printed parts. Residual stress is the primary cause of part deformation; therefore, monitoring the part deformation trend can, to a certain extent, reflect the overall residual stress level of the part. Online stress or deformation monitoring presents significant challenges due to the part being covered by powder and the need for a sealed environment. This paper proposes a novel monitoring system that replaces the bolts used to fix the baseplate with bolts capable of measuring tensile force. The deformation trend of the part will be inhibited by the bolts fixing it to the base plate, and the magnitude of the bolt tensile force is indicative of the magnitude of the deformation trend. Printing experiments were conducted under different scanning strategies and preheating conditions. The experimental curves reveal the patterns of deformation trend evolution in the parts, and these patterns are well explained by existing theories, which confirms the reliability and accuracy of the monitoring system. [ABSTRACT FROM AUTHOR]

This research examines the impact of lateral constraints on the deformation and mechanical properties of compacted loess, a prevalent material for road construction foundations. Through laboratory compression tests on samples from a specific project area, it evaluates how compactness, confining pressures, and vertical loads affect compacted loess's stress–strain behavior and lateral deformation. The study demonstrates that lateral constraints significantly influence soil deformation behavior and mechanical characteristics, particularly under complete confinement. A new formula for accurately calculating soil compression deformation in engineering practices is introduced, enhancing the prediction and management of subgrade settlement in loess regions. This work contributes to improved construction methodologies and infrastructure durability in challenging terrains by offering insights into compacted loess's compressibility under various lateral constraints. [ABSTRACT FROM AUTHOR]

[Display omitted] • The bouncing dynamics of droplets on sessile soap bubbles is dependent on the deformability of the curved soap film. • The deformation of the soap bubble against impacting droplet includes two types compared to that of the flat soap film. • The variation trend of the contact time with the impact velocity for more deformable soap bubbles is non-monotonic. The curvature of the free-standing liquid film is expected to modify its surface deformability, thereby affecting droplet bouncing dynamics and possibly tuning the liquid repellency performance in practical applications. In this study, the bouncing dynamics of water droplets on sessile soap bubbles with different curvatures has been experimentally investigated using high-speed camera. To resist the impacting droplets, the soap bubbles is observed to show two types of deformation: the geometrical deformation caused by the total impacting force and the pressure distribution induced deformation from the droplet dynamics. The variation trend of the contact time of the droplet with the impact velocity is found to be highly dependent on the surface deformability of the soap bubble. This trend becomes non-monotonic when the soap bubble is large and more deformable. The decreasing contact time with increasing impact velocity can be well captured by a phenomenological model of coupled springs. The increasing contact time for the large soap bubbles at high impact velocities is due to the further compression of the soap bubble by the recoiling droplet, leading to the decoupling of the above two types of bubble deformation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rheology-guided DIW-printed MXene-based current collector with high flexibility and conductivity. • MXene facilitates uniform deposition and anti-corrosion in ZnP anode. • The printed ZnP anode achieves over 130 h cycling life at 30 % DOD. • Printed FZIB has excellent cycling performance and capacity retention. Flexible zinc (Zn) batteries have gained considerable attention as wearable energy storage devices because of their inherent safety and high theoretical capacity. However, conventional Zn anodes suffer from dendrite growth, high rigidity, and poor cycling stability issues, hindering their practical application in flexible zinc-ion batteries. Herein, a dendrite-free and flexible Zn anode is designed using direct ink writing (DIW) printed MXene as a flexible and highly conductive current collector and MXene-wrapped Zn powder (ZnP) as the active material by carefully optimising the rheological properties of MXene-based dispersion. As a result, the synergistic effects of the MXene-based current collector and the MXene protective layer promoted dendrite-free Zn deposition and prevented side reactions, achieving an outstanding cycling performance that exceeded 130 h at a high depth of discharge of 30%. When paired with a Vanadium pentoxide (V 2 O 5)-based cathode, the flexible full cell demonstrated stable electrochemical performance under mechanical deformation and can power electronic devices, presenting a promising pathway for the development of flexible zinc-ion batteries. [ABSTRACT FROM AUTHOR]

In this paper, we devote to extending structures for dendriform algebras. First, we define extending datums and unified products of dendriform algebras, and theoretically solve the extending structure problem. As an application, we consider flag datums as a special case of extending structures, and give an example of the extending structure problem. Second, we apply matched pairs and bicrossed products of dendriform algebras and theoretically solve the factorization problem for dendriform algebras. Moreover, we also introduce cocycle semidirect products and nonabelian semidirect products as special cases of unified products. Finally, we define the deformation map on a dendriform extending structure (more general case), not necessary a matched pair, which is more practical in the classifying complements problem. [ABSTRACT FROM AUTHOR]

The outcrop and microscale structural constraints on metamorphosed fragments of Carpathian-Balkan exotic north Gondwanan continental crust show sequential recurrent peripheral subduction processes which produced a series of collisional orogens: (i) Variscan suturing of 'Median Dacides' (western Danubian/Moesian realm), and (ii) post-dating polystage Alpine overprinting. The 'Median Dacides' comprise the two gneiss-bearing amphibolite-facies, Serbo-Macedonian and Getic/Kučaj basements, embedded into Southern Carpathians (Romania) and Carpathian-Balkans (Serbia, North Macedonia, Bulgaria). To unravel polyphase deformation processes, we have incorporated the data available on Neoproterozoic-Lower Palaeozoic protoliths and tectonometamorphic events, coupling these with new extensive structural field-based analysis. The deformation patterns expose polystage deformation history (D1-2), fashioned by the youngest Alpine overprinting (D3-4). The structural data and protolith analyses suggest a Lower Palaeozoic Cadomian-to-Cenerian geodynamic linkage between the two gneissic basements. Notably, the pre-Variscan anatexis, migmatitization, metamorphism (D1-1), and the formation of Cenerian (axial planar) foliation (D1-2) are precursors of the tight isocline Variscan folds (D2-1). Progressive deformation of the initial Variscan structural fabric (metre-scale folds) produced complete transposition (D2-2) with scarcely preserved metre-scale folds. The successor Alpine shortening (D3) (re)activated the existing remnants of Variscan axial plane cleavages (or overlapped foliation-to-cleavage planes), further producing schistosity and folding pattern preserved due to the partial transposition. [ABSTRACT FROM AUTHOR]

This study explores the vapochromic and vapoluminescent behaviors of [Pt(tpy)Cl]PF6 host molecules (tpy = 2,2′:6′,2′′-terpyridine) under acetonitrile (CH3CN) vapor guest, challenging the conventional view that these phenomena arise solely from direct host–guest interactions. Our findings reveal a cooperative mechanism where mechanochromic surface perturbations prime the Pt(II) host for guest incorporation, leading to initial color and luminescence changes prior to significant structural alterations. While the color transition between the yellow [Pt(tpy)Cl]PF6 form and the red/orange [Pt(tpy)Cl]PF6·CH3CN form is reversible, repeated vapor cycling induces a loss of crystallinity, as indicated by diffraction peak broadening and emission shifts. Scanning electron microscopy analyses show mechanical deformations such as bending and surface pitting, emphasizing the role of vapomechanical stress in altering optical properties. These insights highlight the need for integrated design strategies in developing robust vapochromic materials for gas sensing applications. [ABSTRACT FROM AUTHOR]

Wind turbine blade deformation affects the ability of the blade to capture wind energy, and the dynamic deformation law of the actual wind turbine blade is unclear. This study constructs a wind turbine blade dynamic deformation measurement system based on DIC, investigates the blade dynamic deformation regularity, and fits a polynomial to predict the blade dynamic wave deformation. The results show that the modulus of elasticity of the blade determines the time required to calm the fluctuation after deformation, and the length of this time is negatively correlated with the modulus of elasticity of the blade. As the wind speed increases, the change in the amount of blade dynamic deformation is significant, and the degree of change in the maximum value increases. With the increase in rotational speed, the dynamic deformation of the blade tends to increase and then decrease. The sensitivity and interaction analysis are used to screen out the instability zones of blade elastic modulus, wind speed, and rotational speed. The accuracy of the blade dynamic fluctuation deformation prediction model is verified by experiments and error analysis, and the study's conclusions provide a reference for the design and safe operation of wind turbines. [ABSTRACT FROM AUTHOR]

To more rationally and effectively handle and utilize solid wastes, this study explored the preparation of superior performance green backfill materials under alkaline activation conditions. Using waste stone limestone powder (LP), slag powder (SP), and fly ash (FA) as cementitious materials, coal gangue (CG) as fine aggregate, and incorporating polypropylene fibers (PP) of different lengths and contents, a ternary solid waste-cemented coal gangue green backfill material (LSFCLs + Ps) was developed. The mechanical properties and deformation characteristics of LSFCLs + Ps were investigated through splitting tensile strength (STS) tests, uniaxial compression strength (UCS) tests, digital image correlation (DIC), and scanning electron microscopy-energy dispersive spectroscopy (SEM–EDS). The results indicate that: (1) When the fiber length is 9 mm and the content is 0.3%, the STS and UCS reach optimal values of 1.05 MPa and 7.53 MPa, respectively, which are 56.72% and 45.93% higher than those of the control group. (2) The addition of PP enhanced the deformation resistance of LSFCLs + Ps, improved the efficiency of elastic strain energy conversion, and reduced the energy consumption ratio of the backfill. (3) The effective bonding of PP with hydration products improved the overall density of the samples, inhibiting the formation and propagation of internal cracks. The research findings provide a theoretical basis for the treatment of coal gangue and the development of new backfill materials in mining areas. [ABSTRACT FROM AUTHOR]

The in situ electron backscatter diffraction (EBSD) is used to study the microstructure and texture evolution, twinning behavior and selection of twin variants under two different loading modes at room temperature. Tension along the C-axis or compression along the basal plane is the favored loading modes for extension twin. Compared with tension along the ERD (along the C-axis), when compression along the ED (along the basal plane), twins are more likely to nucleate, grow or even be completely twinning, and the overall growth rate of the twinning region is higher, which also leads to stronger texture deflection. Extension twin has six equivalent twin variants; the selection of twin variants is related to the loading direction and the activation of the twin variant or variants in all two samples following the Schmid factor (SF) law; twin variants with relatively high SF are supposed to activate. The activation of a few low SF twins is related to the local stress field of grains or adjacent grains and is activated to coordinate the deformation. When compression along ED, the SF of six variants is quite different, and one variant with relatively high SF is mainly activated in a single grain, while tension along ERD is beneficial to the activation of multiple twin variants in a single grain. [ABSTRACT FROM AUTHOR]

Dental defects are relatively common in long-distance pipeline engineering and can lead to permanent plastic deformation of the pipeline, compromising its structural integrity. To clarify the evolution process of the dented pipelines in engineering practice, this paper puts forward the method of combining the whole and local calculation to analyze the mechanical behavior of pipeline indentations. Based on the combination of whole and local method, the influence of concentration, bending and internal pressure load on the indentation deformation of long-distance oil and gas pipelines under typical scenarios is explored. The research found that the simulated values of indentation depth largely coincided with the measured values. The Mises stress, equivalent plastic strain, and indentation depth reached their maximum values at the contact edges between the pipeline and the supports, making the contact edge between the pipeline and the support the most unfavorable position. In the significance analysis of loads, it is found that the stress change of the pipeline was significant under concentrated loads. As the internal pressure gradually increased, the pipeline stress exhibited a trend of first decreasing and then increasing. When the internal pressure load is 4 MPa, the Mises stress reached its minimum value. During the service stage of the pipeline, low-load conditions can lead to the elastic recovery of indentation deformation in the pipeline, but high-load conditions will exacerbate the indentation deformation, which is detrimental to the continued service of the pipeline. In this study, the mechanical analysis of long-distance oil and gas pipeline is carried out by combining the whole and local, which provides a new technical idea and guarantee for the development of long-distance oil and gas pipeline mechanical analysis industry. [ABSTRACT FROM AUTHOR]

Mudstone has peculiar structural properties, which have a significant impact on its strength, deformation, and other characteristics. However, there are few reports on the impact of structural properties on its yield characteristics. For the structural properties of hydrous mudstone on the yield characteristics during isotropic loading, a multifunctional triaxial apparatus was used as a research tool to conduct isotropic loading tests on four types of hydrous mudstone samples. With CT (computerized tomography) technology, the real-time dynamic scanning of mudstone samples is carried out after deformation stabilization, and the macroscopic mechanical indicators are connected with the microscopic scanning data to clarify the structural evolution law of mudstone during the loading process. The results indicate that based on the CT number (Me) reflecting the density of coal in different regions, the variation law of coal structure in resisting external loads during the loading process was explained. Before yielding, the CT number Me increases slowly, but after yielding, Me shows a linear and rapid growth trend. The change of Me values also clearly reflects the yield behavior and structural damage evolution law of mudstone loaded with different water contents. The smaller the moisture content of the mudstone sample, the greater the stress at the mudstone yields, and the structural influence of mudstone on its mechanical deformation characteristics is relatively small, but it has a strong effect on resisting external loads. The research results can provide reference for further establishing structural constitutive models of hydrous mudstone. [ABSTRACT FROM AUTHOR]

Although extensive research has been conducted in literature to investigate tunnelling effects on pipelines, the performance of existing jointed pipelines subjected to excessive tunnel movement has not been investigated. This study sets out to examine the effects of tunnel active instability on three-dimensional deformation patterns of existing pipelines using physical model tests. Tunnelling induced ground/pipeline settlement, joint rotation, and bending strain under various horizontal tunnel face movements are systematically explored. Results show that the tunnel face pressure at the active limit state is practically independent of tunnel cover to diameter ratio (C/D). Existing pipelines that fall within a range of 0.1 D–0.5 D ahead of the tunnel face experience excessive settlements, significant bending strains and joint rotations. The measured peak settlement of pipelines at 0.3 D in front of the tunnel face exceeds the allowable limit, and the maximum settlements in the jointed pipeline are up to 2.67 times those observed in the continuous pipeline. Meanwhile, the joint rotation angle and settlement induced in the jointed pipeline are greatly affected by the C/D ratio and decrease by up to 55.5% and 22.0%, respectively, with an increasing C/D ratio from 1.0 to 1.5. [ABSTRACT FROM AUTHOR]

AbstractIntroductionMethodsResultsConclusion\nIMPLICATIONS FOR REHABILITATIONThe management of hand deformities of people with neurological impairment is complex and challenging. The use of orthoses to manage hand deformity in clinical practice continues despite low level evidence. Understanding the purpose of an orthosis supported by a biomechanical framework, the Neurological Hand Deformity Classification (NHDC), to identify deforming forces and how to resolve them with appropriate orthotic intervention may reduce controversy surrounding orthosis use.Detailed case descriptions were used to demonstrate how the NHDC can be clinically applied to aid orthotic decision making. In the description of the participants presented, the use of the NHDC provided structure to: observe and classify the dynamic movement of the wrist and hand musculature; identify the dynamic forces causing deformity; and guide decision making for intervention strategies.The identification of the structures involved in the deforming forces on the hand and how orthotic intervention to resolve the deforming forces was guided by the NHDC is discussed. Context is provided regarding the reason, purpose and description of the orthoses used, and timing and dosage of wear is outlined.The NHDC can form part of a comprehensive upper limb assessment to inform intervention decisions including upper limb orthotic intervention.Managing neurologically-based hand deformity can challenge even the most experienced clinicianThe Neurological Hand Deformity Classification was developed to guide clinicians to classify hand deformity and to identify deforming forcesDescriptive case study methods are used to demonstrate how the Neurological Hand Deformity Classification can be applied clinically to aid upper limb orthotic decision making in managing deforming forcesManaging neurologically-based hand deformity can challenge even the most experienced clinicianThe Neurological Hand Deformity Classification was developed to guide clinicians to classify hand deformity and to identify deforming forcesDescriptive case study methods are used to demonstrate how the Neurological Hand Deformity Classification can be applied clinically to aid upper limb orthotic decision making in managing deforming forces [ABSTRACT FROM AUTHOR]

AbstractThe dynamic deformation characteristics of saturated sands are considerably influenced by the loading frequency (f). Nevertheless, the effect of f on the deformation behavior of saturated coral sand (CS) has not been comprehensively investigated. This study aims to investigate how frequency (0.01‒4Hz) affects the shear modulus (G) and damping ratio (λ) characteristics of CS through a series of cyclic shear tests. The experimental results demonstrate that, under consistent initial conditions, both the strain-dependent G and λ increase as f increases. Moreover, there is a linear relationship between the maximum shear modulus (G0) and small strain damping ratio (λmin) with ln(f). Specifically, the regularized G of CS remains unaffected by variations in f. To facilitate the prediction of G in CS at different f, we propose a prediction equation that integrates the revised Hardin’s model and Davidenkov skeleton curve. Besides, a power function expression is suggested for λ−λmin versus G/G0 to predict λ in CS at different f. The revised equations for G and λ are validated using experimental data from natural sands in the literature, confirming their suitability for evaluating strain-dependent G and λ values of natural sandy soils over a wide strain range. [ABSTRACT FROM AUTHOR]

Objective: This study used a dental model scanner and best-fit alignment to analyze the deformation patterns of stabilized occlusal appliances (OcAs) used to treat sleep bruxism when stored in wet or dry conditions. Methods: Eight OcAs were prepared using polymethyl methacrylate, stored in water at room temperature for 4 weeks (wet storage), and then in air for 4 weeks (dry storage). After being stored in water for one month for hydration, they were 3D-scanned and digitized on days 0, 28, and 56. 3D-deformation patterns were obtained by comparing the storage-D group data using a best-fit alignment program that aligns the nearest points of the corresponding images in a virtual space and calculates the difference between the two images. The maximum deviation and deformed area in the ± direction, and the volume of the wet (W) and the dry (D) condition groups were compared using Wilcoxon's signed rank test. Results: OcA showed no obvious deformities in the W group at 4 weeks. However, in the D Group, a typical deformation pattern was detected at 4 weeks, with the posterior margin of the molars shrinking anteriorly, the palatal side of the molars lifted, and the buccal side retracted inward. The Ⅾ group was significantly larger than the W groups in terms of maximum deviation in the ± direction, deformed area, and volume. Conclusions: After 4 weeks of storage under dry conditions, OcA showed a typical deformation pattern of shrinkage toward the center, with in-center lifting toward the palatal side. Significantly greater surface deviations, deformation areas, and deformation volumes were observed under dry conditions than in wet conditions. [ABSTRACT FROM AUTHOR]

Groundwater seepage can easily cause large deformation and fracture instability of the surrounding rock in deep roadways, and the coupling support of "yield-bolt-grouting" can effectively control the occurrence of such accidents. This paper takes the specific engineering geological conditions of deep water-enriched roadway as the research background, revealing the coupling control mechanism of yield-bolt-grouting. The mechanical characteristics of the yielding tube were determined using lab analysis, and an investigation was conducted for the support control mechanism of high-strength yielding bolts. The control mechanism of grouting reinforcement is summarized, and a comprehensive coupling control technology system of "yield-bolt-grouting" is proposed based on the rheological large deformation characteristics of the surrounding rock of deep water-enriched roadway, with high-strength yielding grouting anchor rods and high-strength yielding grouting anchor cables as the core. The on-site monitoring results indicate that this technology effectively controls the deformation of the surrounding rock. The research results provide new ideas and technical approaches for controlling the surrounding rock of deep water-enriched roadways. [ABSTRACT FROM AUTHOR]