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In this work, we propose a variation of Miura origami which, different from the existing out-of-plane bending Miura origami, has an in-plane bent configuration due to its graded crease pattern. By combining with the one-way shape memory alloy spring, we show that the proposed graded Miura origami can serve as a smart actuator and can be applied to drive crawling robots or grippers. First, we constructed a physical model of the graded Miura origami, from which a curvature-programmable geometric equation is proposed. Then, in addition to providing a mechanical model that can capture the mechanical behavior of the initial force–displacement relationship of the curved beam, we show that the proposed curved origami has a different mechanical behavior compared to the corresponding simple flexible arch, specifically if realized by silicon rubbers. By arranging anisotropic friction to the feet, the origami robot can crawl with an omega-elongation/compression motion like an inchworm. With a closed-loop current source control system using a high-frequency pulse width modulation-based topology, where the strain state of the arched origami is detected by a demodulator-free fiber Bragg grating sensor, the average speed of the origami crawling robot can reach 2.72 mm/s. In addition, by arranging three graded Miura origami, a gripper capable of lifting a weight of 518.5 g can be formed, where the carried load is over 4.5 times its own weight. [ABSTRACT FROM AUTHOR]

Machine learning techniques are potent tools to predict structural failures and forecast future failure patterns. They can provide insights that are not immediately recognizable to human operators, and hence, enhance the maintenance decision-making process, leading to better safety and longevity of structures. This research employed a genetic algorithm based on an identification technique to estimate the location and depth of cracks in circular arches. The arches were made of homogeneous material and had a rectangular cross-section. The study adopted two different procedures for detecting cracks in the circular arches. The first method used natural frequency contours represented in a three-dimensional plot to identify the location and depth of cracks by intersecting a set of natural frequency contours. The second procedure utilized the regression method and an optimization technique to minimize the cost function objective function and determine the crack parameters. The influences of crack location and depth on the vibrational behavior of cracked arches were presented and discussed. Similarly, the results indicate a high level of consistency between the two techniques in predicting both crack size and location. [ABSTRACT FROM AUTHOR]

Translation abstract Wind‐induced vibrations on the hangers of the ÖBB‐RheinbrückeThe ÖBB‐Rheinbrücke near Lustenau is a new type of steel‐concrete composite arch structure with a span of 102 m. The main supporting structure is a Langer's beam with twelve round steel hangers on each side of the bridge, each 100 mm in diameter, with a maximum hanger length of 18.9 m. In arch bridges of this type with steel hangers, wind‐induced hanger vibrations can cause high‐frequency, high‐amplitude stress fluctuations in the hangers and their connections. This can be problematic from a fatigue point of view. After completion of the bridge, extensive monitoring was carried out as planned with the aim of obtaining information about the hanger vibrations that occur and the resulting damage to the material in order to determine whether vibration‐reducing measures need to be taken. In the course of monitoring and evaluation, it was found that wind‐induced hanger vibrations can cause fatigue‐relevant stress ranges to occur. This article presents the effects of two different physical phenomena, such as vortex‐excited transverse vibrations and rain‐wind‐induced vibrations, on the service life of the structure, as well as vibration‐reducing measures that help to mitigate these effects. [ABSTRACT FROM AUTHOR]

This study aims to investigate the responses of shield tunnel structures subjected to disturbances caused by bilateral pit excavation, and it systematically reveals for the first time the impact mechanism of bilateral pit excavation on the distribution of perimeter pressure and deformation patterns of shield tunnels. Using a bilateral pit excavation project in Nanjing as a case study, this research establishes methods for calculating longitudinal displacement and circumferential pressure of tunnels under bilateral pit excavation conditions, employing the image source method for analysis. A refined three-ring segment model is developed, and the load structure method is used to analyze the impact of deep foundation excavation on the tunnel located between the two excavation sites. The results indicate that, compared to unilateral excavation, bilateral excavation significantly increases the perimeter pressure at the top and bottom of the tunnel, with a smaller increase in pressure at the arch waist. The deformation pattern is characterized by contraction at the top and bottom and expansion at the waist, forming a transverse elliptical deformation. The maximum vertical convergence values of the middle segment ring are 25.00 mm at the top and 25.88 mm at the bottom, with a vertical absolute convergence value of 44.5 mm and a convergence ratio (ΔDt/Dt) of 0.72%. As the foundation coefficient increases, the perimeter pressure at the top and bottom of the tunnel also increases. When the tunnel is closer to the foundation pits (Sp decreases), the perimeter pressure at the bottom of the tunnel increases. Conversely, as the distance between the two foundation pits (S) increases, the impact of excavation on the tunnel shifts from the upper part to the lower part, resulting in decreased upper perimeter pressure and increased lower perimeter pressure. The research findings provide important references for similar engineering projects. [ABSTRACT FROM AUTHOR]

In this research, we are concerned with intraday volatilities computed by functional ARCH(1) (fARCH(1), for short) model for high-frequency financial time series. A conditional-Copula multiple change point detection (CPD) for intraday volatilities is proposed using fARCH(1), bivariate Gaussian Copula and t-Copula conditional distributions. We employ current available multivariate CPD models which include energy test based control chart (ETCC) and nonparametric multivariate change point model (NPMVCP) to implement the proposed CPD method for the intraday volatilities. A simulation study is conducted to demonstrate that the functional ARCH based conditional-Copula CPD for the intraday volatilities can be a useful econometrics method to detect abnormal intraday volatilities in the financial market. We analyze intraday volatilities of the Korea composite stock price index (KOSPI) and the Hyundai-Motor (HDM) company stock data with one minute high-frequency to illustrate our proposed CPD method. [ABSTRACT FROM AUTHOR]

The long-line abalone culture system in the bottom waters outside the bay is a new type of aquaculture facility that utilizes the underwater attenuation effect of waves to achieve better wind and wave resistance. Currently, most of the research on long-line aquaculture systems is aimed at the sea surface, and the research on the seabed is still pending. Therefore, to ensure the abalone culture system’ s survival rate and structural safety, it is of great significance to study the dynamic characteristics of the long-line abalone culture system in the bottom waters. Based on the similarity criterion, a model test was carried out in the wave-current flume laboratory; a numerical simulation method of the dynamic response of the long-line abalone culture system in the bottom waters was established based on the centralized mass model, and the accuracy of the numerical simulation method was verified. In view of the actual sea conditions off Luoyuan Bay, Fujian Province, the dynamic characteristics of the long-line abalone culture system in the bottom waters were numerically simulated under the action of different waves and currents to analyze the effects of the wave heights, current velocities and flow directions on the stresses on the abalone culture system and the structural safety of the system. The effects of wave height, current speed, and flow direction on the force and trajectory of the system were analyzed. The results show that the numerical model is consistent with the model test results: the maximum relative error of the maximum cable tension measured against the waves is 8. 33%, the minimum relative error is 4. 84%, and the average relative error of the peak horizontal and vertical motions of the float A is 5. 23% and 8. 92% respectively, which proves that the numerical simulation method used in this paper is accurate and reliable; there is a significant difference in the distribution of the force of the long-line and the anchor rope, and the force curve of the long-line shows an arch of the force. The force distribution of the long-line and the anchor rope has obvious differences; the force curve of the long-line shows an arch shape and a sawtooth shape, and the maximum force section is not on the anchor rope but located in the middle region of the long-line; the wave height has a linear relationship with the maximum force of the system and the motion amplitude of the abalone cage, i. e., the higher the wave height is, the larger the transverse and vertical motion amplitude of the system is, and the larger the maximum tension in the middle part of the long-line, the supporting rope and the anchor rope is, and the peak tension curve of the supporting rope shows a sawtooth shape; the maximum tension of the anchor rope in the headward side appears nonlinearly when the velocity of the current is increasing, the maximum tension of the anchor rope in the headward side appears nonlinearly. When the flow velocity increases, the maximum tension of the anchor rope on the headwater side shows a nonlinear steep increase. The maximum tension of the long-line on the headwater side increases slowly, and the maximum tension of the anchor rope and the long-line on the backwater side decreases significantly. In contrast, the maximum tension of the branch ropes does not increase significantly with the flow velocity, and the maximum tension of each branch rope is the same; when the flow direction increases, the maximum tension of the system’s anterior part of the longline and the anchor rope decreases. The posterior part of the long-line and the anchor rope increases, and the branch ropes’ tensions remain relatively stable. The results of this study can provide a reference for the structural design of similar long-line abalone culture systems in the bottom waters. [ABSTRACT FROM AUTHOR]

The in-plane stability of internally hinged, end-fixed shallow arches is in the spotlight. The non-linear model accounts for the coupled effect of the bending moment and axial force on the membrane strain. The model itself can handle homogeneous or non-homogeneous material distributions along the thickness of the uniform arch. Analytical findings reveal how the typical geometrical data, like arch length, radius of gyration, and arch angle, affect the lowest buckling loads. The typical non-linear behaviour of arches is also assessed including the equilibrium path and the internal force system. [ABSTRACT FROM AUTHOR]

This paper presents a laboratory testing rig designed to investigate the failure mechanisms and load transfer of rock masses under rock anchor loading. The study revealed that joint patterns significantly affect the strength and capacity of the rock mass, with existing design approaches based on apex angles of 90 ∘ or 60 ∘ found to be potentially overly conservative. Joint orientation and spacing should be included in the anchor design to obtain a more precise design criterion. In all the studied patterns, increasing the horizontal and vertical stress increased the block models' capacity, and load arching did not occur in the model with an unfavourable joint orientation. This study also revealed that the failure surface followed the joints in all tests and that the block model capacity was significantly higher than estimated with the design principle based on the weight of the overlying rock. The findings of this work have important implications for designing rock anchoring systems in mining and civil engineering demonstrate that joint orientation and block size significantly affect the rock mass capacity. This study confirms the need to consider the influence of in situ stresses on rock mass capacity when designing of rock anchors. Overall, this work guides the development of more precise design criteria for rock anchors, contributing to more efficient and effective rock engineering practices. Highlights: The models exhibited increase in horizontal stress upon application of a vertical anchor load to the blocks, indicative of load arching effects. The maximum vertical displacement in the blocks was in the normal direction to one of the joint sets under the influence of a vertical anchor load. The capacity of the block models was enhanced with an increase in both horizontal and vertical in situ stress. Crater-like failures were observed, with separation surfaces aligning with the joint set surfaces. Apex angles of the block patterns ranged from 90 to 140 ∘ ; symmetrical failures were observed in models with symmetrical jointing around the anchor. [ABSTRACT FROM AUTHOR]

Much has been learned over the last half century regarding the molecular and genetic changes that take place during cardiac development. As yet, however, these advances have not been translated into knowledge regarding the marked changes that take place in the anatomical arrangements of the different cardiac components. As such, therefore, many aspects of cardiac development are still described on the basis of speculation rather than evidence. In this review, we show how controversial aspects of development can readily be arbitrated by the interested spectator by taking advantage of the material now gathered together in the Human Developmental Biology Resource; HDBR. We use the material to demonstrate the changes taking place during the formation of the ventricular loop, the expansion of the atrioventricular canal, the incorporation of the systemic venous sinus, the formation of the pulmonary vein, the process of atrial septation, the remodelling of the pharyngeal arches, the major changes occurring during formation of the outflow tract, the closure of the embryonic interventricular communication, and the formation of the ventricular walls. We suggest that access to the resource makes it possible for the interested observer to arbitrate, for themselves, the ongoing controversies that continue to plague the understanding of cardiac development. [ABSTRACT FROM AUTHOR]

In this paper, a novel arch structure—circular box arch with sinusoidal corrugated webs (CBASCW)—is presented. Through the methods of theoretical derivation and finite element simulation, we studied its in-plane elastic buckling and in-plane elastoplastic stability. Through theoretical derivation, a shear stiffness formula of the arch section is determined, and the elastic buckling load when the arch is in pure compression state is proposed considering the shear deformation. We also introduced a simplified model, which can simulate the deformation and internal forces conveniently. The failure mode and global elastoplastic instability mechanism are investigated under uniformly distributed full-span radial load, uniformly distributed full-span vertical load, and uniformly distributed half-span vertical load. Furthermore, by introducing a regular slenderness ratio and stability coefficient, the stability curve of the arch under the state of pure compression is plotted. Subsequently, based on the stability curve and the numerical simulation results of a simplified model, a design formula for the stability bearing capacity is proposed for situations where global elastoplastic instability occurs. [ABSTRACT FROM AUTHOR]

The aim of this research is to investigate the impact of a viscoelastic foundation on the vibration of a curved beam structure with clamped and simply-supported boundary conditions. The structure considered is a micro-scale laminate composite beam made up of two piezoelectric face layers and a carbon nanotube-reinforced composite core. The study employs non-classical elasticity theory and nonlocal strain gradient theory to account for both nano-scale and microscale effects. The equations of motion are derived using the energy terms of the beam and a variational principle, with boundary conditions assumed to be clamped at one end and simply supported at the other end. A semi-analytical method of general differential quadrature method is used to solve the equations due to their nonlinear terms. To capture the effects of various parameters on the in-plane vibration of sandwich arches, an artificial neural network is designed and implemented. The study analyzes the impact of nonlocal and gradient parameters, geometrical aspect ratios, and substrate constants of the structure on the natural frequency and amplitude of vibration of the laminate beam. Results show that increasing nonlocal and gradient parameters have different effects on the amplitude and frequency of vibration of the beam. [ABSTRACT FROM AUTHOR]

• The internal force analytical solution of lining structure under P-ware action was obtained by using the analytical method. • The influence of the hardness of surrounding rock and peak acceleration on the analytical solution were analyzed. • Through the engineering, the reasons for the large error between numerical solution and analytical solution was analyzed. • The most unfavorable position of lining structure under P-wave seismic load was proposed. In an earthquake, the strong interaction between the surrounding rock and the lining structure causes the lining structure susceptible to extrusion or shear damage, and predicting the internal force distribution trend of the lining structure by the analytical method was advantageous for the preliminary design of the tunnel structure. In this work, the quasi-static method was used to approximate the displacement and deformation caused by the P-wave seismic load as far-field compressive stress. The analytical solution of the internal force for the lining structure was obtained by the analytical method, and the reliability of the analytical method was further verified. The dynamic response law of the lining structure was analyzed using numerical solutions in conjunction with engineering examples. The results show that the analytical method can be used to predict the trend of internal force distribution in the lining structure under seismic action, which has important theoretical guiding significance for the preliminary design of the tunnel structure. With the decrease in the hardness of the loess surrounding, the relative deviation of the theoretical, numerical, and literature results gradually decreases. With the increase of ground motion intensity, the interaction between the loess surrounding and the lining structure becomes more intense, and the internal force of the lining structure gradually increases. The numerical results were greater than the analytical results due to the consideration of the influence of initial stress. Under the action of the P-wave earthquake, the extreme values of the internal force with the lining structure mainly occurred at the location of the vault, arch waist, and inverted, and the most unfavorable positions of circular loess tunnel lining structures under P-wave seismic load was proposed. [ABSTRACT FROM AUTHOR]

• A dynamic theory of the HMS curved rod under 3D large deformation is presented. • The "tension-bending" and "shear-torsion" coupling effects of curved rod emerge in our model. • The finite element formulation and exact linearization of the dynamical problem are obtained. • An implementation based on Newmark algorithm and some numerical examples are presented. • Several experiments about a quarter arc HMS robotic arm are presented. Magnetorheological elastomers are active materials which can be actuated by the applied magnetic field. Hard magnetic soft (HMS) materials, a type of magnetorheological elastomers, show great potential in the fields of biomedical engineering and soft robotics, due to their short response time, remote operation, and shape programmability. To exploit its potential, a series of theoretical frameworks of HMS rods have been developed, but they are mainly limited to the static rod models or classical curved rod models that fail to consider the effect of the "initial curvature" on the distribution of the stress. In this work, we develop a curved rod theory to predict the 3D dynamic motion of the rod-like HMS robotics under large deformation. Based on the geometrically exact rod theory, we include the heterogeneous initial length of the longitudinal fiber caused by "initial curvature" into our model and obtain the reduced balance equations of the HMS robotics. As a result, the "tension-bending" and "shear-torsion" coupling effects of curved rods emerge in the present model. A numerical implementation of our model based on the classical Newmark algorithm is presented. To validate our model, three numerical examples, including the dynamic snap-through behavior of a bistable arch, are performed and compared with the simulation or experiment results reported in literatures, which show a good agreement. Finally, we experimentally study the 2D and 3D static and dynamic motion of a quarter arc HMS robotic arm under an applied magnetic field of 10 mT, and our model gives a satisfactory prediction, especially for static deformation. [ABSTRACT FROM AUTHOR]

The limit support pressure significantly influences the stability of the shield tunnel face and deformation control during tunneling. Current research predominantly focuses on soils under dried or saturated conditions. However, unsaturated soils, which are more commonly encountered in engineering practice and widely distributed, have not been as extensively studied. Based on limit equilibrium theory, a modified analytical wedge-prism model is proposed in this paper to predict the limit support pressure acting on the shallow shield tunnel face in unsaturated sandy soil where the soil arching effect is considered. Taking advantage of finite-element software ABAQUS (version 2021), a series of numerical trapdoor tests are conducted first to study the failure behavior of unsaturated sandy soil. Then, by combining the rotation trajectory of major principal stress with the shear strength theory of unsaturated soil, the loosening earth pressure solution above the shallow trapdoor can be derived analytically. The limit support pressure can be finally obtained through a force equilibrium analysis of the wedge body. The accuracy of the proposed model is validated by comparing the calculated results with current model tests and numerical simulations. Parameter analysis results reveal that both the loosening earth pressure and limit support pressure initially decrease and then increase with the rising degree of soil saturation. A critical saturation point is identified where the loosening earth pressure and the limit support pressure reach their minimum values, attributed to the full development of the soil arching effect. [ABSTRACT FROM AUTHOR]

This paper presents an arch structure called the circular box arch with sinusoidal corrugated webs (CBASCW). This study investigates the out-of-plane elastic buckling behavior and elastoplastic stability capacity of the arch through a combined approach of theoretical derivation and finite element simulation. The section stiffness of the arch, including flexural stiffness, shear stiffness, and torsional stiffness, is achieved through theoretical derivation. Additionally, the elastic buckling load in both pure compression and pure bending states is derived. A simplified model is also introduced, which can conveniently simulate the internal force and deformation of the arch. The elastoplastic instability mechanism and failure mode are studied under various loading conditions, including uniform radial load, end bending moment, vertical load uniformly distributed in full-span, and vertical load uniformly distributed in half-span. Furthermore, the stability curves of the arch under conditions of pure compression and pure bending are graphed by incorporating stability coefficient and regularized slenderness ratio. According to the simulation results obtained from the simplified model and the analysis of stability curves, a design formula for stability capacity is proposed. [ABSTRACT FROM AUTHOR]

Drawing from the engineering context of a shallow-buried, biased-load, permeable ribbed double-arch tunnel, the strength reduction method was employed to determine the failure pattern of the surrounding rock at the tunnel's ultimate excavation state. According to the failure characteristics of surrounding rock and the basis of basic assumptions, a fractured sliding surface was hypothesized, and a structural load calculation model for the surrounding rock pressure in the permeable ribbed double-arch tunnel was derived. This model was compared and validated against the results obtained from the stratum structure model. An analysis of the sensitivity of the surrounding rock pressure was conducted. The findings indicated that the tunnel was subjected to asymmetric biased loads, with the vertical load on the side with large buried depth chamber being significantly greater than that on the side with small buried depth chamber. The horizontal load on the right sidewall of the side with large buried depth chamber was significantly greater than the horizontal load on the surface of the left and right lining segments above the central partition wall. The horizontal lateral pressure coefficient was influenced by the slope's biased angle and the internal friction angle of the surrounding rock's sliding surface, with the latter having a more substantial effect. The surrounding rock pressure was closely related to the horizontal lateral pressure coefficient and was influenced by the rock density, the slope's biased angle, and the internal friction angle of the sliding surface. The sensitivity of surrounding rock pressure was significantly impacted by the slope's biased angle and the internal friction angle. [ABSTRACT FROM AUTHOR]

The deformation and failure of the surrounding rock mass is a key issue during the construction of large‐scale underground powerhouse, and large discontinuities are likely to cause this problem in the presence of complex geological structures. This article takes the right bank underground powerhouse of the Baihetan Hydropower Station as a case study. In this case, deformation mutation of the surrounding rock mass occurred in the south section of the main powerhouse, with the maximum deformation reaching 178 mm, and the deformation and failure of different parts showed differences. A comprehensive study integrating field survey, site monitoring, laboratory test and numerical simulation was carried out. By field survey and monitoring, characteristics of deformation and failure are described, and the spatiotemporal difference in deformation is analysed. The stress evolution during excavation is studied based on numerical simulations, the mechanical response of rock is derived through laboratory tests, and the mechanism of spatiotemporal difference is revealed. The results indicate that the main reason for the spatiotemporal difference is the presence of slightly inclining interlayer shear zone C4. In the south section, the excavation‐induced stress concentration at the arch was enhanced due to C4, with the maximum principal stress exceeding 70 MPa, and the high compressive stress here triggered the deformation mutation of surrounding rock mass. After undergoing a stress path from concentration to unloading, the surrounding rock mass at the downstream sidewall was seriously damaged, and its deformation also mutated under approximately vertical stress. The mutation resulted in the uneven spatial distribution, large increment and time‐dependent feature of deformation. [ABSTRACT FROM AUTHOR]

Motivated by a curiosity to explore the behavior of innovative arch structures enabled by the use of fiber-reinforced polymer (FRP) composites, this paper proposes a theoretical model built upon an enhanced formulation of the deflection method, broadening its scope to large-curvature problems. Traditionally, the deflection method approximates curvature as the second-order derivative of deflection, a simplification valid only for small curvatures. This limitation poses a challenge when applying the deflection method to problems involving large curvatures, a characteristic inherent in FRP-enabled arches where significant curvatures arise either initially or due to deformation. The enhanced formulation at the core of the proposed model addresses this challenge by incorporating a circular deflection function. This function posits that each deformed segment of the structural member can be represented by a circular arc, with its curvature and length related to the internal axial force and bending moment at the midpoint section of the segment. This feature facilitates the exact representation of curvature, offering the proposed model a unified approach capable of addressing both small- and large-curvature problems. The paper details the formulation and verification of the theoretical model, with an emphasis on its application to representative cases of FRP-enabled arches. [ABSTRACT FROM AUTHOR]

The considerable increase in train velocity has intensified mutual aerodynamic effects between a train and a tunnel. How to effectively reduce the micro-pressure wave (MPW) amplitude at the high-speed railway tunnel exit is significantly important and has been recognized as an extremely challenging study, especially for the high-speed maglev tunnel when the train travels through it at 400 km/h or even more. To effectively mitigate the phenomenon of "sound explosion" caused by micro-pressure waves, this study provided a newly novel solution to mitigate the micro-pressure wave amplitude, which breaks up the traditional design idea and introduces a completely new arch lattice-shell structure inside the tunnel hood. In addition, the effect of the arch lattice-shell length on initial compression waves at high-speed maglev tunnel entrance and MPWs at exit were analyzed. The findings indicate that compared to the typical section-expanded tunnel hood, the new section-expanded lattice-shell hoods have a positive effect on the mitigation of micro-pressure waves emitted at the high-speed maglev tunnel exit. As the hood length increases, the alleviating effect is strengthened, resulting in a substantial decrease in the peak of the pressure gradient (Pg) and amplitudes of MPWs. When the section-expanded lattice-shell hoods are 50, 80, and 100 m in length, the pressure gradient peaks (Pg) are decreased by 6.2%, 34.9%, and 41.8%, respectively, while the corresponding amplitudes of MPWs are reduced by 9.4%, 46.8%, and 51.9%, respectively. Therefore, the new arch lattice-shell structure added inside the section-expanded tunnel hood can significantly mitigate the amplitudes of MPWs, which provides a newly novel solution for the tunnel hood design during the high-speed train passing through the tunnel at a higher speed. [ABSTRACT FROM AUTHOR]

Jalan Majalengka-Rajagaluh is a road located in several sub-districts that is a link to the city and one of the connecting roads to Cirebon City. This design planning began in Cigasong sub-district and continued to Rajagaluh sub-district with a length of 5.3 kilometers on the Majalengka-Rajagaluh road. The results of the geometric design are visualized in the form of drawings using AutoCAD 2D. The design speed (Vd) is set at 60 km/h with a horizontal curve radius of 358 m, a maximum slope of 4%, and an elevation (e max) of 8%. Based on this design criterion, a spiral curve with a circular arch length (Lc) of 74,996 m was obtained. Furthermore, the results of the calculation of the vertical alignment of the length (L) of one type of convex curve in the PPV are also calculated. [ABSTRACT FROM AUTHOR]

At present, the large-span porous steel corrugated plate arch culvert reinforced with composite beams of concretesteel corrugated plate (referred to as "concrete ring") has been preliminarily applied in actual projects. However, the force anddeformation characteristics in the construction process have not been studied in depth. This paper combines the in-situ test ofa9 m span steel corrugated plate arch culvert with 4 holes to monitor the mechanical behaviour of the concrete ring and the steelcorrugated plate, establish a refined finite element model, compare the force and deformation characteristics of the structure indifferent sections, and study the influence of the concrete ring on the structure. The results show that: 1) different arch spansand the presence or absence of the concrete ring have little effect on the deformation of arch culverts; 2) in the backfilling ofthe arch, the stress of the steel corrugated plate and rebar of the side span are greater than the corresponding position of themiddle span, and the maximum difference is 47.26 MPa and 49.75 MPa, respectively; 3) the concrete ring can significantlyreduce the stress of the steel corrugated plate, which is about 10% of its design strength. [ABSTRACT FROM AUTHOR]

In view of the instability issues of surrounding rock in super-large-section chambers, this study takes the super-large-section chambers of the underground agitation station at Jinfeng Gold Mine as the research object, establishes a rock quality index model for the mining area using the mine's geological drilling database, and based on this model, determines the optimal location for the agitation station construction to be at the 150 m level. Through laboratory tests, field investigations, and ground stress measurements, the parameters and stress distribution characteristics of the surrounding rock were determined. The stability of the chamber after excavation was analyzed using the Phase2 rock mechanics software for numerical simulation. Based on the analysis results and the engineering analogy method, a joint support scheme was proposed for the surrounding rock, which includes pipe-slit bolts, hanging mesh, wet shotcrete, resin bolts, long anchor cables, grouting behind walls, and anti-heave reverse arch concrete. The reinforcement effect was evaluated through numerical simulation and field application monitoring, and the results showed that the maximum deformation of the reinforced chamber was 31 mm, the maximum principal stress was 25 MPa, no damage occurred to the bolts (cables), and all safety factors of the concrete lining units were greater than 1.2. The support structure was in a reasonable and effective stress state, indicating that the chamber remained stable after reinforcement, with good support effects. The research findings have important reference value for similar engineering projects. [ABSTRACT FROM AUTHOR]

Introduction: Midfoot osteoarthritis (OA) is a painful and disabling condition. Arch contouring foot orthoses have been recommended for midfoot OA, yet there is no high‐quality evidence from randomised controlled trials to support their use. This clinical trial aims to evaluate the efficacy of arch contouring foot orthoses for midfoot OA. Methods: This will be a parallel‐group randomised controlled superiority trial. One‐hundred and forty community‐dwelling people with painful midfoot OA will be randomised to receive either arch contouring foot orthoses or flat sham inserts. Outcome measures will be obtained at baseline, 4, 8 and 12 weeks; the primary endpoint for assessing efficacy being 12 weeks. The primary outcome measure will be average midfoot pain whilst walking over the last 7 days on an 11‐point numerical rating scale. Secondary outcome measures include function (walking/standing subscale of the Manchester–Oxford Foot Questionnaire), participants' perception of overall treatment effect (self‐reported global rating of change on a 15‐point Likert scale), physical activity (Incidental and Planned Exercise Questionnaire), general health‐related quality of life (Short Form‐12 Version® 2.0), use of co‐interventions and adverse events. Discussion: This trial will evaluate the efficacy of arch contouring foot orthoses for relieving pain and improving function, physical activity and health‐related quality of life in people with midfoot OA. The findings will provide high‐quality evidence as to whether arch contouring foot orthoses are efficacious and will help to inform clinical guidelines about the use of foot orthoses for midfoot OA. Trial registration: Australian and New Zealand Clinical Trial Registry (ACTRN12623000953639). [ABSTRACT FROM AUTHOR]

Rock anchors, which can withstand substantial forces and are essential for securing the foundations of the built environment, can fail due to steel tensile failure, bond detachment, or rock mass fracturing through uplift. In this study, uplift failure of the rock mass surrounding rock anchors was simulated using both physical and numerical models. The physical models used a specially designed testing rig with predefined sizes and different joint layouts to simulate rock mass uplift failure. The numerical models were calibrated using the physical models and used to investigate scenarios involving increased complexity and greater depths. This paper presents the load distribution within rock masses with orthogonal joints when exposed to an anchor load. Extensive analysis of the numerical models revealed that symmetrical load arches were induced in rock masses that contained a joint set oriented parallel to the loading direction. However, joints that were obliquely oriented relative to the anchor axis induced asymmetrical load arching. The greatest displacement occurred in the direction parallel to the joint set with the smallest angle to the anchor loading axis. Large-scale models with zero or near-zero in situ horizontal stress revealed that the load capacity in a rock mass with continuous vertical joints was relatively low, especially when compared to rock masses with discontinuous vertical joints. It was observed that the uplift capacity of the rock mass around an anchor decreased if the load arches of adjacent anchors overlapped; consequently, a decrease in anchor spacing was found to correspond to a decrease in uplift capacity. Highlights: Symmetrical load arches are induced within a rock mass if the joint sets are oriented parallel to or close to parallel to the anchor axis. An oblique orientation of the joints relative to the anchor axis results in asymmetrical load arching in the rock mass when the anchor is loaded. Rock masses with continuous vertical joints have a low load capacity, especially compared to rock masses with discontinuous vertical joints. In a row of rock anchors, the rock mass uplift capacity of individual anchors is decreased if the anchor spacing is too low. [ABSTRACT FROM AUTHOR]

A new consolidation system for prestressed reinforced concrete (PSRC) beams of girder bridges is presented and evaluated. The system consists of two arch-shaped steel trusses placed alongside the lateral faces of the beam to be consolidated. The arches develop longitudinally along the entire span of the beam and in elevation using the available height of the PSRC cross-section. The consolidation system is characterised by its own external constraints, independent from those serving the pre-existing element. The efficiency of the system with respect to variable parameters is examined, focusing on the ratio between the load discharged by the consolidation system and the total applied load. Referring to a case study, consolidation of a PSRC beam adopting the proposed system is compared with the usually adopted external prestressing technique. The cross-sectional properties of the steel arch-shaped trusses are defined by means of a structural optimisation process using a genetic algorithm to identify the minimum steel consumption. Finally, a preliminary cost–benefit analysis is performed for the proposed solution and compared with other commonly adopted techniques. [ABSTRACT FROM AUTHOR]

The curved beam finite element approach based on the potential energy formulation is widely recognized as a versatile tool for lateral torsional buckling analysis of arches. However, there exist a variety of potentials, which were developed with distinct assumptions. The diversity of energy-based curved beam theories introduces confusions in practical applications. This paper aims to examine various potential energy formulations as to whether or not they obey the rigid body rule which is a prerequisite for valid second-order analysis. The induced moments at the ends of curved beam element that have been neglected from and/or the distributed moments that should be removed from available potentials are identified to help them become rigid body qualified. Based on the revised potential functional, a curved beam finite element formulation has been developed to effectively predict yet with less effort the out-of-plane critical load for circular and parabolic arches subject to various loading and constraint conditions. The results of numerical examples demonstrate that a potential energy formulation eligible for describing the out-of-plane behavior of curved beam is required to be rigid body qualified by fulfilling two aspects: (i) the neglected end moments that are imperative for satisfying the rigid body rule must be considered unless the virtual work done by them vanishes, and (ii) undesirable distributed moments that may be induced when undergoing the rigid body motion should be removed by considering all essential potential components. [ABSTRACT FROM AUTHOR]

The Partially Concrete Filled Steel Tube (PCFST) structure has gradually been applied to bridges as the main load carrying components in recent years, owing to the advantages of light weight and high stability. The failure mechanism and load carrying capacity of PCFST structure highly depends on the concrete filling ratio. For this purpose, the failure mechanism and parametric analysis of a single arched PCFST cable stayed bridge tower are investigated by using both refined solid element simulation and quasi-static experiment. The results shows that the PCFST arched tower experiences asymmetrical instability failure subjected to quarter span symmetrical loading, and the plastic hinges appears firstly at the tower arch closely above the tower columns, and then the bottom of the tower columns, forming a rotating mechanism leading to the instability failure. Filling concrete or not will result in two opposite deforming propagations of the plastic hinges, and when the concrete filling length exceeds the length of plastic hinge, the initial rigidity and ultimate load carrying capacity of the PCFST structure will sharply increase. Finally, according to the results of the extended parametric analysis based on the real size simulation, an improved initial stress reduction coefficient of PCFST structure is then suggested. [ABSTRACT FROM AUTHOR]

After excavation of tunnels in interbedded surrounding rock, accidents such as rock peeling and arch crown collapse are prone to happen. In response to this issue, we first established an analysis model for the excavation of the interbedded surrounding rock tunnel through theoretical analysis, proposed corresponding failure criteria, and analyzed the reasons for the easy failure of the interbedded tunnel support structure based on the concept of principal stress difference. We also created interfaces in FLAC3D (version 6.0) software to restore the actual interbedded interface, verifying the effectiveness of principal stress difference in analyzing the deformation characteristics of the tunnel. Then, the instability forms of the interbedded surrounding rock tunnel were divided into two types, and effective support methods for the corresponding instability forms were proposed. Finally, based on the analysis results of the study, support was provided for the collapsed tunnel on site. A grouting large pipe shed was put to innovative use to support the tunnel arch waist, stabilizing the surrounding rock that is prone to shear slip and fracture at the upper part of the arch waist. The results indicate that the surrounding rock control effect is good. This study has a good reference value for on-site rapid construction and support design, and is of great significance for the instability prevention and control of interbedded surrounding rock tunnels. [ABSTRACT FROM AUTHOR]

Similar to the deep-buried tunnel, the lining of the cut-and-cover tunnel (CCT) exhibits varying degrees of cracking failure during ultrahigh backfill. To explore the whole progressive failure process of a high-filled cut-and-cover tunnel lining structure from the mesodamage to the macrolocal failure and then to the overall instability during backfill, based on the discrete-element program PFC2D, we simulated the mechanical behavior and fracture characteristics of the CCTs with rectangular, circular, and arch lining section features with the backfill height. Two load-reduction measures—load-reduction material (LRM) and the interaction of LRM and concrete walls—were then further proposed, and the impact of load-reduction measures on the progressive failure of CCT lining was analyzed. The simulation results show that the various lining section features indicate differences in the distribution and value of lining stress and fracture. But the CCT lining with features of the three sections exhibits a progressive failure process from cracking to local collapse and falling and finally to overall instability as the backfill height increases. Furthermore, the LRM and concrete walls can effectively reduce the vertical stress of the lining vault and the horizontal stress of the haunch, respectively, to ensure the stability and integrity of the CCT. [ABSTRACT FROM AUTHOR]

In response to the issues of vibrations affecting the construction safety, speed, and accuracy of suspended structures due to dynamic disturbances during lifting, environmental disturbances, and improper operator actions, this paper investigates the application of the Active Rotary Inertia Driver (ARID) system for double-rope suspended structures, namely analyzes, and applies control to the vibration response of double-rope suspended structures under external excitations. Taking the double-rope suspended structure as an example, a dynamic analytical model of the double-rope suspended structure is established based on D’Alembert’s principle. Through shake table tests, the dynamic response characteristics and vibration control effects of the double-rope suspended structure under various external excitations are studied, and the influence of the twisting radius of the suspended structure on the control effect is analyzed. The experimental results show that the ARID control system achieves significant control effects on the swing and torsional vibrations of the suspended structure, which validates the accuracy of the theoretical model for the ARID control system and demonstrates its feasibility for practical applications. [ABSTRACT FROM AUTHOR]

The fast progress in electronic devices demands superior anti‐reflective performance of electromagnetic interference shielding materials. However, high‐performance shielding strategies are mainly dependent on reflection effects and this inevitably results in a trade‐off between shielding and anti‐reflective properties during structural designs. Herein, this work proposes a novel gradual heterogeneity design to fundamentally overcome the contradiction. The different steric hindrances in MXene nanosheets and aramid nanoclusters endow the competitively assembled laminal aerogel films with a unique Janus architecture. This Janus structure presents continuous gradient asymmetries and abundant cavities that enable prolonged energy attenuation paths and minimized reflection. Comparing to isotropic counterparts, the gradient design performances a 2174% reduction in reflection coefficient (0.0039) and a 53% increase in shielding efficiency (60.49 dB) in the terahertz band, both of which significantly outperform most state‐of‐the‐art anti‐reflective shielding structures. Moreover, the Janus architecture comprising interconnected arch‐shaped substructures provides the aerogel films with anisotropic EMI and thermal management capabilities, coupled with robust structural and performance stability. This work provides a conceptually novel platform for developing asymmetric architecture for advanced shielding materials. [ABSTRACT FROM AUTHOR]

A three-lobed helical pipe was installed downstream of the bend of a vertical-horizontal pneumatic pipeline. The swirl characteristics under different helical pipe structures were investigated. Results show that: (a) the maximum velocity region rotates quasiperiodically, and the smaller the pitch, the faster the rotation; (b) the 3D morphological changes of the axial velocity distribution in downstream sections are similar: from an arch to a pit and finally to a uniform flat top. The tangential velocity appears as a Rankine vortex near the wall; (c) the swirl decays rapidly along the downstream. The initial swirl intensity, proportional to the helical pipe length, increases first and then decreases with decreasing pitch, whereas the structural parameters have minimal effect on the swirl decay rate; (d) the helical tube remarkably increases the system energy consumption, and the total pressure drop is inversely proportional to the pitch and proportional to the length. [ABSTRACT FROM AUTHOR]

SATB2‐associated syndrome (SAS, glass syndrome, OMIM#612313) is a neurodevelopmental autosomal dominant disorder with frequent craniofacial abnormalities including palatal and dental anomalies. To assess the role of Satb2 in craniofacial development, we analyzed mutant mice at different stages of development. Here, we show that Satb2 is broadly expressed in early embryonic mouse development including the mesenchyme of the second and third arches. Satb2−/− mutant mice exhibit microglossia, a shortened lower jaw, smaller trigeminal ganglia, and larger thyroids. We correlate these findings with the detailed clinical phenotype of four individuals with SAS and remarkable craniofacial phenotypes with one requiring mandibular distraction in childhood. We conclude that the mouse and patient data presented support less well‐described phenotypic aspects of SAS including mandibular morphology and thyroid anatomical/functional issues. [ABSTRACT FROM AUTHOR]

This work focuses on the bending examination of three-dimensional (3D) functionally graded carbon nanotube (CNT) reinforced composite (FG-CNTRC) cylindrical shell exposed to internal pressure. The composite cylindrical shell is assumed to be reinforced in the longitudinal axis. Mechanical properties of the constituents are applied based on the modified rule of the mixture. Distribution of CNTs across the shell thickness is assumed to be uniform and three types of functionally gradients. The governing equations are developed using the Principle of Virtual Displacements (PVDs) based on Carrera's Unified Formulation (CUF) and then differential quadrature method (DQM) is used to solve the governing equations for different combinations of simply supported and clamped boundary conditions. The comparison studies between the obtained results and those available in the literature demonstrate the accuracy and computational efficiency of the present formulation and method. The roles of different factors including the volume fraction of CNTs ( V CN * ), boundary conditions, distributions of CNTs, length-to-radius ratios ( L / r), and mechanical loads, are investigated in the outcomes. The results illustrate that the non-dimensional maximum deflections of functionally graded (FD) distributions are higher than the uniform distributions for different boundary conditions. [ABSTRACT FROM AUTHOR]

The structural elements of buildings have recently required the development of efficient design solutions due to increased dynamic and thermal loads. The main solution for improving the efficiency of such elements involves creating lightweight non-uniform beam and arch structures from alloyed steel, which has better mechanical characteristics. The most promising approach is the use of welded beams and arches with perforated partitions and composite beams, which are often used together, for instance, as structural elements of cylindrical shells. The development of an effective cross-sectional shape for perforated beams and crane girders is considered, taking into account the strength, local stability, resistance to flat bending, and fatigue deformation. It has been shown that the effective form for perforated beams is a box-shaped structure made of perforated shvellers. Calculations for selecting a rational design from the assortment of hot-rolled shveller profiles have demonstrated that a significant reduction in the weight of the structure can be achieved by using the proposed cross-sectional shape. An evaluation of the fatigue strength of composite metal crane girders operating in harsh conditions has shown the effectiveness of using hot-rolled I-beams as their upper flange, as well as the necessity of using hot-rolled I-beams to ensure strength in their lower part. When choosing the rational parameters of an arch design, multiple recalculations of its bending with respect to technological cutouts in the thickness are necessary; hence, simplified calculation schemes are commonly used. Some authors simplify this process by replacing an arch with a cutout with a solid arch reduced in height by the cutout radius. We have shown that this model does not accurately describe the actual distribution of forces and displacements, leading to inadequate results. We have developed a simplified methodology for the preliminary calculation of a circular arch with a cutout, which includes correction coefficients calculated by us. A calculation of the flat stress–strain state of an elastic circular metal arch with a central semicircular cutout under various ratios of design parameters and uniform external pressure was conducted. A dependence of the stress concentration coefficient at the cutout's apex on the ratio of the cutout radius and arch thickness was obtained. These results can be generalized for reinforced non-uniform shells and for the fuzzy application of external influences. [ABSTRACT FROM AUTHOR]

This technical note presents the optimal shape of an arch carrying a central point load to two pinned supports for maximum in-plane bifurcation buckling load. The arch shapes considered are triangular, parabolic, circular, catenary, and ogival. It is assumed that the arches are elastic and inextensible and their flexural rigidity is uniform throughout the arch length. The Hencky bar-chain model was used for elastic buckling analysis. It is found that the optimal arch shape depends on the arch apex height to length (h/L) ratio. The optimal arch shape changes from circular to catenary to parabolic and finally to triangular from h/L=0.1 to 1. This shows that the funicular triangular arch shape for the central point load is not the optimal arch shape against in-plane buckling when h/L is less than 0.528. For maximum buckling load, one may use either the circular, catenary, or parabolic arch with h/L approximately equal to 0.3. [ABSTRACT FROM AUTHOR]

The arching effect, which relates to load transfer and stress redistribution, is relevant in various aspects of the engineering field. However, understanding of the development and degeneration mechanisms of the arching effect in mesoscale remains limited. This paper presents discrete-element modelling (DEM) simulations of the 2D trapdoor test to investigate the arching effect in 2D granular materials with different porosity. Complex network theory is adopted for the analysis of mesoscale mechanisms of the development and degeneration of the arching effect. The results show that the variation of arching ratio with trapdoor displacement can be attributed to the evolution of arched force chains and particle contact force in a specific zone (where the vertical displacement of particles is larger than 0.1δ but <0.9δ). In this zone, the normal contact force between particles increases rapidly and robust force chains with large normal contact force are generated during the development process of the arching effect. This evolution of normal contact force and force chains becomes more obvious as the sample porosity decreases. During the degeneration process of the arching effect, the robust force chains in this zone are degenerated gradually, leading to the decrease of normal particle contact force at the microscale and the increase of arching ratio at the macroscale. [ABSTRACT FROM AUTHOR]

This document provides an overview of the advancements in energy harvesting technologies and their integration into the Internet of Things (IoT) and wireless sensor networks. It includes 31 papers covering various energy harvesting devices, optimization techniques, and potential applications. The research aims to improve the efficiency and sustainability of wireless sensor networks while minimizing energy consumption. The articles explore different methods of energy harvesting, such as solar, thermal, vibrational, and radio frequency energy, and discuss their application in various fields, including wearable devices, solar energy harvesting, and IoT-enabled smart meters. Overall, this collection offers a comprehensive overview of the current research and advancements in energy harvesting for sensor networks. [Extracted from the article]

To investigate the effects of long-term prestress loss on concrete box girders strengthened with external prestressing, a large-span box girder, in service for over 20 years and strengthened with external prestressing, was monitored for four months. Prestress loss in the longitudinal, vertical, and transverse directions of the box girder was calculated according to Chinese code requirements. Magnetic flux rope force transducers were used to monitor the prestress loss in the external prestressing cables. Fiber Bragg Grating (FBG) sensors were used to monitor deflection changes at the mid-span of the bridge. Finally, the effect of prestress loss in the longitudinal, vertical, and transverse tendons on mid-span deflection was investigated through simulations using ABAQUS software. The results show that instantaneous prestress loss accounts for most of the total loss compared to long-term loss, and that longitudinal prestress loss has the most significant effect on mid-span deflection. The impact of longitudinal prestress loss on deflection before and after strengthening was also compared. The downward deflection and up-ward arch caused by longitudinal tendon prestress loss were reduced after strengthening, con-firming the effectiveness of the external prestressing method. [ABSTRACT FROM AUTHOR]