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The anomalous-Hall current injection is studied in a Hall device contacted to a lateral load circuit. This anomalous-Hall current is generated inside a Co 75 Gd 25 ferrimagnetic Hall bar and injected into a lateral load circuit contacted at the edges. The current, the voltage, and the power are measured as a function of the magnetization states, the load resistance R l , and the temperature. It is shown that (1) the resistance associated with the anomalous-Hall current flowing inside the Hall bar is that of the portion of the ferrimagnet located between the lateral contacts, (2) the role of the non-uniformity of the current due to the lateral contacts is small, (3) the maximum power efficiency of the current injection into the load circuit corresponds to the condition of the resistance matching of the two sub-circuits, and (4) this maximum power efficiency is of the order of the square of the anomalous-Hall angle. These observations are in agreement with recent predictions based on a non-equilibrium variational approach. [ABSTRACT FROM AUTHOR]

The magnitude of the dipole effect detected by the cutoff energy measurement was modulated for SrTiO3 (STO)/LaAlO3 (LAO)/SrRuO3 (SRO)/STO (001) subs. epitaxial stacks by ultrathin SrAlOx (SAO) insertion prior to LAO deposition. The difference in frictional forces on the LAO surfaces between the stacks with and without SAO insertion was clearly detected by lateral force microscopy (LFM), which indicated the change in dominating surface atomic layers. From the statistical analysis of LFM images, the SAO insertion was found to improve the lateral uniformity of the stacking sequence of charged monatomic layers in epitaxial LAO along the c-axis [(LaO)+ and (AlO2)−], taking account of the inevitable correlation between the surface-terminating atoms with the stacking sequence of the charged monatomic layers in epitaxial LAO. These results are consistently explainable with the proposed model that the interface dipole effect along the c-axis of the perovskite epitaxial stack is determined by the stacking sequence of charged monatomic layers of LAO. [ABSTRACT FROM AUTHOR]

Prestressed concrete solid square (PCSS) piles exhibit superior lateral bearing capacity and durability compared to pretensioned spun concrete pipe piles, and are more suitable for pile foundation engineering in high-intensity seismic regions and corrosive environments. There is still a lack of research on the seismic performances of the pile body of PCSS piles. This paper presents an experimental study and the associated theoretical and finite element (FE) analyses on the seismic performance of PCSS piles. Three full-scale PCSS pile specimens were tested under lateral cyclic loads with various axial force ratios, and the results are analyzed. Following the tests, a theoretical calculation method is proposed for the bearing capacity of PCSS piles. A FE model for PCSS pile specimens is established and validated against the test observations. Based on this model, a parametric analysis is then conducted. The results show that the PCSS pile specimens all exhibit typical flexural failure. Under a low axial force ratio, the failure mode of PCSS pile specimen is governed by the tensile rupture of prestressing tendons. Under a high axial force ratio, the failure is influenced by the crushing of cover concrete, while the concrete in the core zone remains intact, and there is no outward buckling of prestressing tendons and no rupture of stirrups. Increasing the prestressing tendon ratio can simultaneously improve the bearing and deformation capacity under a lower axial force. Under higher axial force ratios, however, increasing the prestressing tendon ratio or concrete strength can improve the bearing capacity but lead to a decline in deformation capacity. Compared to pretensioned spun high-strength concrete (PHC) piles, PCSS piles exhibit better seismic behavior on aspects of deformation capacity and ductility. [ABSTRACT FROM AUTHOR]

The remarkable lateral oscillatory occurrences observed in renowned footbridges, such as the Solferino Bridge in France, the Millennium Bridge in the UK, and the Oda Bridge in Japan, have garnered widespread attention. The intricate nature of pedestrian-induced lateral vibrations necessitates a comprehensive investigation into their underlying mechanisms, with the crux lying in the identification of the lateral excitation model. Presently, most prevailing detection approaches predominantly rely on contact-based equipment, such as force sensors and displacement sensors. However, these approaches suffer from two main drawbacks. Firstly, contact measurement necessitate a substantial number of sensors and entail higher experimental costs. Secondly, when extending contact-based measurements to accommodate multiple individuals, complications arise, including cumbersome installation, heightened technical complexity, and escalated experimental costs. Therefore, we present a novel approach, based on visual technology, to expeditiously recognize the lateral excitation induced by pedestrians. Termed the Dual Perspective of Mediapipe (DPM), this method harnesses the power of Mediapipe, coupled with dual camera models, to precisely unravel pedestrian gait particulars and lateral forces. The efficacy of the proposed approach is validated through a comparative analysis with existing pedestrian gait data. It is noteworthy that this approach offers significant advantages: non-contact with the test pedestrians, thereby ensuring the accuracy of gait information; convenient and straightforward arrangement of measurement equipment; and low experimental costs. [ABSTRACT FROM AUTHOR]

A pile group under lateral loading is a complex pile‒soil-pile interaction problem. In this study, numerical analysis was used to investigate the lateral behavior of pile groups arranged in a 3 × 3 configuration with varying piles spacings. The hypoplastic constitutive model embedded into ABAQUS software through the UMAT subroutine was used to characterize the stress‒strain relationship of Toyoura sand. The effects of the pile spacing on the load‒displacement relationship of the pile group, the bending moment-depth relationship of each pile in the pile group, the deflection-depth relationship, and the soil resistance distribution were investigated. The results indicate that the lateral bearing capacity of the pile group decreases by more than 50% when the pile spacing is reduced from 7D to 3D. When the pile spacing is greater than 5D, the "edge effect" of the laterally loaded pile group gradually decreases, and when the pile spacing is greater than 7D, the "shadowing effect" can be negligible, and the wedge-shaped failure zone of the pile group occurs within a depth of 5D below the mud surface. [ABSTRACT FROM AUTHOR]

The seismic performance of a caisson structure under two types of models with a saturated sandy foundation (CSS) and an expanded polystyrene (EPS) composite soil foundation (CES) are studied using shaking table tests. The macro phenomena of the two different foundation models are described and analyzed. The effects of the replacement of EPS composite soil on seismic-induced liquefaction of backfill and the dynamic performance of a caisson structure are evaluated in detail. The results show that the excess pore water pressure generation in the CES is significantly slower than that in the CSS during the shaking. The dynamic earth pressure acting on the caisson has a triangular shape. The response of horizontal acceleration, displacement, settlement, and rotation angle of the caisson in the CES is smaller than that in the CSS, which means the caisson in the CES has a better seismic performance. Furthermore, the out-of-phase phenomenon between dynamic earth thrust and inertial force in the CES is more obvious than that in the CSS, which is beneficial to reduce the lateral force and improve the stability of the caisson structure. [ABSTRACT FROM AUTHOR]

This paper presents the results of an investigation of dynamic behaviours of strengthened adobe structures. These structures were strengthened using two different schemes which were inexpensive and simple to apply. The dynamic testing was carried out on a shaking table which applied the loading corresponding to the 1995 Kobe earthquake record sequentially in increments of 25%. The structural damage to a model was divided into different damage grades using a quantitative measure of vulnerability. Although some differences were observed in the stiffness of the models in their undamaged state, the stiffness of both of them became similar in the damaged state. The changes in the fundamental frequency of the structure corresponded to the changes in the stiffness. The difference in the base shear demand of both models did not exceed more than 15%. The hysteresis loops of the tested structures turned non-symmetric at a peak ground acceleration of nearly 1.10 g. The models exhibited higher lateral load capacities in one direction of loading as compared to the other direction. The ductility and energy dissipation were also higher in one direction of loading. The performance of the tested structures was categorised into four performance levels and the data of drift, ductility, damping and period corresponding to each level have been reported. [ABSTRACT FROM AUTHOR]

The Coastal Ice Ocean Prediction System for the East Coast of Canada (CIOPS-E) was developed and implemented operationally at Environment and Climate Change Canada (ECCC) to support a variety of critical marine applications. These include support for ice services, search and rescue, environmental emergency response and maritime safety. CIOPS-E uses a 1/36° horizontal grid (~ 2 km) to simulate sea ice and ocean conditions over the northwest Atlantic Ocean and the Gulf of St. Lawrence (GSL). Forcing at lateral open boundaries is taken from ECCC's data assimilative Regional Ice-Ocean Prediction System (RIOPS). A spectral nudging method is applied offshore to keep mesoscale features consistent with RIOPS. Over the continental shelf and GSL, the CIOPS-E solution is free to evolve according to the model dynamics. Overall, CIOPS-E significantly improves the representation of tidal and sub-tidal water levels compared to ECCC's lower resolution systems: RIOPS (~ 6 km) and the Regional Marine Prediction System – GSL (RMPS-GSL, 5 km). Improvements in the GSL are due to the higher resolution and a better representation of bathymetry, boundary forcing and dynamics in the upper St. Lawrence Estuary. Sea surface temperatures show persistent summertime cold bias, larger in CIOPS-E than in RIOPS, as the latter is constrained by observations. The seasonal cycle of sea ice extent and volume, unconstrained in CIOPS-E, compares well with observational estimates, RIOPS and RMPS-GSL. A greater number of fine-scale features are found in CIOPS-E with narrow leads and more intense ice convergence zones, compared to both RIOPS and RMPS-GSL. [ABSTRACT FROM AUTHOR]

In the interest of developing a comprehensive understanding of the drilling process using the hole saw tool, this article aims to build a three-dimensional (3D) micromechanical model representing the orthogonal cutting of CFRP using one tooth of the hole saw tool. For this purpose, a finite element model is developed using Abaqus Explicit code. The influence of various drilling parameters like rake angle, inclination angle and cutting-edge radius on the drilling quality is explored. Especially, chip formation mechanisms, cutting force and lateral damage are analyzed. Through finite element simulations and computational analyses, it is found that these outputs results are highly influenced by drilling parameters. When the fiber orientation angle is set to 0°, increasing the rake angle results in a change in the chip formation mechanism from buckling to bending. In contrast, with a fiber orientation angle of 90°, bending and shear governs the chip formation process, irrespective of the rake angle. In both cases, whether the fiber orientation angle is 0° or 90°, chips tend to fragment more favorably with increasing the inclination angle. Regarding the cutting-edge radius, when the fiber orientation angle is 0°, an increase in the cutting-edge radius leads to a transition in the chip-forming mechanism from buckling to bending. However, for a fiber orientation angle of 90°, the chip formation remains governed by bending even as the cutting-edge radius changes. Decreasing the rake angle, the inclination angle, and the cutting-edge radius contribute to a reduction of the cutting force. As the inclination angle and the cutting-edge radius increase, the lateral damage increases, while the rake angle has showed a negligible impact on the damage. These results provide a guidance on the appropriate hole saw tool parameters for a good drilling quality namely, a rake angle of 20°, an inclination angle of 5° and a cutting-edge radius of 0.03 mm. [ABSTRACT FROM AUTHOR]

Although extinct sloths exhibited a wide range of dietary habits, modes of locomotion, and occupied various niches across the Americas, modern sloths are considered quite similar in their habits. The dietary habits of living sloths can be directly observed in the wild, and understanding the mechanical behavior of their jaws during chewing through finite element analysis (FEA) provides a valuable validation tool for comparative analysis with their extinct counterparts. In this study, we used FEA to simulate the mechanical behavior of sloth mandibles under lateral mastication loads, using it as a proxy for oral processing. Our research focused on the six extant sloth species to better understand their diets and validate the use of FEA for studying their extinct relatives. We found that all living sloths have the predominancy of low‐stress areas in their mandibles but with significant differences. Choloepus didactylus had larger high‐stress areas, which could be linked to a reduced need for processing tougher foods as an opportunistic generalist. Bradypus variegatus and Choloepus hoffmanni are shown to be similar, displaying large low‐stress areas, indicating greater oral processing capacity in a seasonal and more competitive environment. Bradypus torquatus, Bradypus pygmaeus, and Bradypus tridactylus exhibited intermediary processing patterns, which can be linked to a stable food supply in more stable environments and a reduced requirement for extensive oral processing capacity. This study sheds light on extant sloths' dietary adaptations and has implications for understanding the ecological roles and evolutionary history of their extinct counterparts. [ABSTRACT FROM AUTHOR]

This study builds on existing researches to further investigates cyclic responses of the steel tube-confined reinforced concrete (RC) columns, with a primary focus on those subjected to high-axial load. A total of eleven column specimens were tested under lateral displacement reversal and axial load of either 0.3Ag fcm,c or 0.5Ag fcm,c , where Ag and fcm,c refers to concrete cross section area and tested concrete strength of the column, respectively. Three specimens represented the conventional reinforced concrete (RC) columns while the rest were the steel tube-confined circular RC columns. The key test parameters included (1) amount of longitudinal reinforcement, (2) axial load level, (3) continuity of the confining steel tube, and (4) clear cover of the longitudinal reinforcement. Test results showed that all the steel tube-confined RC specimens sustained the target axial load and maximum lateral strength up to around 10% drift ratio. A simple strength model was proposed to reasonably estimate the maximum strength of the steel tube-confined RC columns. The flexural rigidity ratio, (EI)test/Ecm,cIg , for RC specimens and specimens confined by continuous steel tube ranged between 0.6 and 0.8, approximately. Specimens confined by the cutoff steel tube showed lower (EI)test/Ecm,cIg ratio between approximately 0.3 and 0.6. [ABSTRACT FROM AUTHOR]

Self-centering columns (SC), while attracting interest for their high recoverability, do not dissipate seismic energy as efficiently as conventional reinforced concrete or steel columns, potentially leading to a more significant seismic response. This study proposes a concept aimed at enhancing both energy dissipation during earthquakes and postearthquake restoration performance. This is achieved by exhibiting an SC capacity only during restoration. The proposed aseismic column consists of a central component, the SC core constructed from steel tubes filled with high-strength mortar, and energy-dissipation (ED) components made from steel plates. This SC core generates a moderate SC force sufficient to counteract the P-Δ effect. Given the minimal SC force from the SC core, the plasticization effect of the ED components becomes more conspicuous during large earthquakes, resulting in the emergence of a spindle-shaped lateral load capacity, leading to residual displacement in the columns. During restoration after earthquakes, the SC force emerges when the ED components are removed. The residual displacements of the columns can be gradually reduced during this process. Cyclic loading tests are conducted on the proposed column prototype followed by removal tests of the ED components with vertical axial forces acting on the column with residual displacement. In the cyclic loading tests, we confirmed the superior ED performance of the proposed column prototype, although residual displacement occurred in the column. In the ED component removal tests, a substantial reduction in the residual displacement of the column was observed when the ED components were removed. Specifically, the residual displacements were reduced by up to 96.2%, to a value of only 0.13% of the column height. In conclusion, the proposed concept can achieve superior energy absorption during earthquakes and high restoration performance afterward. [ABSTRACT FROM AUTHOR]

Accelerating performance and braking performance are the core performance of a vehicle, and tire load analysis is a prerequisite for performance studying. A calculation and correction method of dynamic tire loads is proposed in this paper. First, the numerical and experimental models of tire dynamic load identification are established, by measuring the acceleration signals at different positions of the steering knuckle arm, the tire deformation in three directions is inversely calculated. Second, the longitudinal force, lateral force and vertical force of the tire are estimated according to the tire stiffness and deformation. Finally, the tire loads are corrected by data filtering and tire stiffness adjustment. The results show that the average agreement between the calculated load and the test load is more than 90%. The calculation and correction method can provide a theoretical basis and reference for analyzing the dynamic change characteristics of tire load. [ABSTRACT FROM AUTHOR]

This sentence discusses a possible solution to overcome the disadvantages of traditional eccentrically braced frame systems (EBFs). The proposed solution involves separating the shear links from the frame beams and utilizing double-tube buckling restrained braces with contact rings. These modifications aim to improve the overall performance of the frame system. To investigate the mechanical characteristics of this structural system, an experimental study was conducted, involving the design of two K-type EBFs and testing four distinct replaceable shear links. The stress distribution, load–displacement curves, and hysteresis curves of this structural system were obtained by conducting cyclic lateral loading tests on these specimens. Subsequently, the hysteretic properties, load bearing capacity, and deformation capacity of the member underwent analysis. An exploration was conducted into the primary influences on the structural mechanical characteristics. The research indicates that the double-tube buckling restrained braces with contact ring enhance the structural strength and synergistically perform with shear links to dissipate energy, while ensuring improved performance. Comparison of the date of different parameters shear links shows that the placement of stiffening rib increased the energy dissipation performance by 41.2% and shear capacity by 14.6% for the same sectional dimension of shear links. In the shear links with two stiffening ribs, the larger sectional dimension improved the energy dissipation performance by 11.3% relative to the shear links with smaller sectional dimension. For the shear links with one stiffening rib, the increase in sectional dimension, on the contrary, reduced the energy dissipation performance by 18.4% [ABSTRACT FROM AUTHOR]

Crosswinds and transverse slopes of the road surface affect the motion of a ground vehicle as disturbances. The objective of this paper is to develop a method for estimating crosswind disturbances and lateral force disturbances caused by transverse slopes of the road surface under the variation of the vehicle speed. Firstly, a dynamical model of a vehicle is described as a Linear Parameter‐Varying (LPV) system in which the value of the coefficient matrices vary with the vehicle velocity. Then, an algorithm to estimate the disturbance is derived based on Moving Horizon Estimation (MHE) and applied to the derived LPV system. Furthermore, a simple control law which counteracts the effects of the disturbances on the lateral velocity and the yaw rate in steady‐state based on the estimates of the disturbances is presented. The effectiveness of the proposed method is demonstrated by a numerical example. © 2024 The Author(s). IEEJ Transactions on Electrical and Electronic Engineering published by Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Braced timber frames (BTFs) are an efficient lateral force resisting system that can effectively resist wind and earthquake loads. It is well-known that the performance of BTFs is strongly dependent on connection behavior, but clear design guidelines are not available for detailing ductile BTFs. Furthermore, conventional connections with steel fasteners can exhibit significant stiffness and strength degradation under earthquake loads and result in large residual deformations. There is a need for more resilient energy-dissipating connections for BTFs and other mass timber systems. This study investigates the behavior of dowel-type and bolted wood-steel-wood connections with superelastic nickel-titanium (NiTi) shape memory alloy (SMA) fasteners. Under bending, the SMA fasteners are able to effectively recover their original shape with negligible residual deformation, even after undergoing large deflections. The SMA connections tested in this research showed significant potential for self-centering. Post-test autopsies of the connection test specimens showed ductile deformation mechanisms and similar levels of wood crushing between the steel and SMA fasteners under cyclic loading. However, the connection displacement ductility ratios of 4.6 and 6.2 observed with SMA fasteners is not sufficient to meet the requirement for moderately ductile frames. Additional research is required to better understand and characterize the behavior of SMA connections at the component and connection levels. [ABSTRACT FROM AUTHOR]

In recent years, the concept of hyperbolic phonon polaritons (HPPs) has revolutionized the field of nanophotonic, enabling unprecedented control over light-matter interactions at the nanoscale. Here, we theoretically propose and study the lateral optical forces in twisted mixed-dimensional MoO3 homostructures. Assisted with the low-symmetry HPPs, we realize a lateral optical force exerted on the Au nanoparticles near the surface of mixed-dimensional MoO3 homostructures with a linear polarized incident light. By controlling the polarization state, incident angle of light and the twisted angle of MoO3, the amplitude and direction of the lateral optical forces can be tailored in the mid-infrared range. Our findings provide a new platform for engineering lateral optical forces to manipulate diverse objects in a flexible and efficient manner. [ABSTRACT FROM AUTHOR]

To investigate how the curve radius parameter affects the safety of high-speed train operation in a wind–sand environment, researchers used the wind–sand section of the Lanzhou–Urumqi high-speed railway as their research backdrop. The Euler‒Lagrange method was used to discretize the sand particles based on train aerodynamics theory, and the wind–sand flow model of the head–middle– tail three-member formation was established. The accuracy of the model was verified by comparing the data from published papers, and then the train's wind– sand load was calculated and extracted. Subsequently, a dynamic model of a CRH2 train was created, and the dynamic response of the train was estimated by choosing various curve radii and adding wind–sand loads. The results demonstrated that as wind speed increases, the forces acting on the train due to wind rise. Due to the different shapes and positions of the carriages, the wind– sand load on each car differs; the middle car is subjected to greater lift, lateral force, and overturning moment, as well as lower resistance, nodding moment, and head shaking moment, while the head and tail cars move in the opposite direction and, as a whole, are exposed more adverse forces. The study found that when the curve radius increased from 7000 to 9000 m, the derailment coefficient and wheel-rail lateral force are reduced by approximately 29%~32%, along with an approximately 20%~23% decrease in the wheel load reduction rate. When the radius reaches 10000 m, there is a decrease in the derailment coefficient and wheel-rail lateral force of approximately 5%~8%, as well as a reduction in the wheel weight load reduction rate of approximately 3%~6%.It has been concluded that increasing the curve radius can significantly reduce the safety indices in the wind-blown sand environment, thus improving operational safety. However, it should be noted that a radius of 8000~9000 m is appropriate, and the effect of further increase is not obvious. The results of this study can provide certain guidance for the selection of curve radius and the evaluation of the operational safety of high-speed trains in windy–sandy areas. [ABSTRACT FROM AUTHOR]

Flying cars, or vertical takeoff and landing (VTOL) aircraft, are revolutionary devices that can address traffic congestion and help build a three-dimensional transportation system in the future. Flight safety could deteriorate in actual flight because ducted fans may suffer from significant thrust fluctuations induced by crosswinds. In this article, we propose a variable-speed control method to reduce thrust fluctuations by applying a speed waveform opposite to the fluctuation waveform. We choose a typical condition of a 5 m/s crosswind for validation. The results of unsteady Reynolds averaged Navier‒Stokes (URANS) calculations show that crosswinds lead to fluctuations in all thrusts with the frequency of the blade passing frequency. The total thrust fluctuation amplitude accounts for 6.2% of the total thrust. By applying the variable-speed control where the frequency is identical to the thrust fluctuation frequency, the phase difference is 180 degrees, and the amplitude is approximately the square root of the fluctuation amplitude, the standard deviation of the thrust fluctuation is reduced by 92% without affecting the mean total thrust. Fluctuations in other performance parameters, such as lateral force and pitching moment, are improved as well. This active control method can achieve accurate control without any auxiliary equipment and has good application prospects. It provides a promising idea for solving the problem of performance fluctuations in turbomachinery. [ABSTRACT FROM AUTHOR]

This research aims to extend prior knowledge of sky bridge isolations in a design case study that complies with building codes, focusing on the design of a multi-tower building linked with a sky bridge and its isolation system. Building Information Modeling (BIM) is used during the design process. Linear time history analysis is performed to capture seismic responses without statistical distortion of response combinations. Link elements are used to simulate the isolations, and the ground motions are excited in bidirectional directions. The experimental results demonstrate that using an isolation system at the sky bridge connection improves torsional behavior, as evidenced by a 12% reduction in torsional mass contribution in the fundamental mode shape of the buildings. Other notable improvements include better lateral force distributions and optimization of reinforcement volume by 36.91% at maximum. Additionally, convenient post-design procedures, such as automated design visualizations and quantity surveys of reinforcements are reported through using BIM. [ABSTRACT FROM AUTHOR]

As a typical feature of traditional Chinese timber structures, columns with floating foot joints are prone to rocking under horizontal force. The column rocking behavior plays an important role in resisting lateral loads. This paper proposes modelling strategies for the rocking behavior of traditional timber columns. The proposed model can capture the contact state of the column foot via a series of distributed axial springs and the possible sliding via a horizontal spring. It has a lower computational cost than refined finite element (FE) models and is independent of numerical calibration compared to rotational spring models. The modelling strategies were validated against refined FE models and experimental data available in the literature. The principle behavior of the approach was carefully investigated including contact stiffness, distribution modes, spring numbers, column bending effects, and computational efficiency. Results show that the effective compression height of the column foot can take the value of the column radius to determine spring stiffness. Column bending needs to be considered in the mechanical analysis of column foot joints for slender columns. The case study on the lateral stiffness of traditional timber frames confirms the applicability of the proposed model in the structural analysis of ancient timber buildings. [ABSTRACT FROM AUTHOR]

Ultra-low friction is crucial for the anti-friction, anti-wear, and long-life operation of nanodevices. However, very few two-dimensional materials can achieve ultra-low friction, and they have some limitations in their applications. Therefore, exploring novel materials with ultra-low friction properties is greatly significant. The emergence of ternary two-dimensional materials has opened new opportunities for nanoscale ultra-low friction. This study introduced nickel phosphorous trisulfide (NiPS3, referred to as NPS), a novel two-dimensional ternary material capable of achieving ultralow friction in a vacuum, into the large nanotribology family. Large-size and high-quality NPS crystals with up to 14 mm × 6 mm × 0.3 mm dimensions were grown using the chemical vapor transport method. The NPS nanosheets were obtained using mechanical exfoliation. The dependence of the NPS nanotribology on layer, velocity, and angle was systematically investigated using lateral force microscopy. Interestingly, the coefficient of friction (COF) of NPS with multilayers was decreased to about 0.0045 under 0.005 Pa vacuum condition (with load up to 767.8 nN), achieving the ultra-low friction state. The analysis of the frictional dissipation energy and adhesive forces showed that NPS with multilayers had minimum frictional dissipation energy and adhesive forces since the interlayer interactions were weak and the meniscus force was excluded under vacuum conditions. This study on the nanoscale friction of a ternary two-dimensional material lays a foundation for exploring the nanoscale friction and friction origin of other two-dimensional materials in the future. [ABSTRACT FROM AUTHOR]

Understanding the agglomeration behavior between inclusions during steelmaking is crucial to control steel quality and cleanliness. This work reviews the state-of-the-art lateral capillary interaction between inclusions attached to the gas/steel or slag/steel interfaces, which is an essential aspect of inclusion agglomeration. The origin of the lateral capillary force, the methodologies to measure the force, and the development of the capillary theory are discussed. High-temperature confocal scanning laser microscopy (CSLM) has been intensively used for the in situ observation of inclusion agglomeration at the gas/steel or slag/steel interfaces. To calculate the lateral capillary force between inclusions from a series of 2D CSLM images, the particle mass, the inter-particle distance, and the drag force on the inclusions are the main input parameters. We compared the capillary force between two ellipsoidal particles obtained from different particle radius approximations (long and short radii, arithmetic mean, equivalent and effective radius, and equivalent volume), separation distances (inter-center and inter-surface), and capillary models (Yin's, Chan's, Mu's, K–P, and sub-particle models). The results highlight the importance of consistency in the parameters used in the force calculation from CSLM images and capillary models. [ABSTRACT FROM AUTHOR]

Corrosion is a major cause of deterioration in conventional steel-reinforced prestressed concrete (PC) piles installed in aggressive (marine) environments. As foundation members in bridges, deteriorated piles may result in failure or expensive repair or reconstruction. Corrosion resistant alternatives for reinforcing piles longitudinally and transversely include carbon fiber composite cables (CFCC) and stainless-steel (SS). However, the cost of these alternatives is prohibitive, which in turn increases the production cost of PC piles. To mitigate the high cost of CFCC and SS piles, the spirals in these corrosion resistant piles can be safely replaced by glass fiber–reinforced polymer (GFRP) bars in spiral form. In this research, the effectiveness of GFRP spirals in confining PC piles is presented by showing results of impact experiments conducted on full-size specimens. One control pile was reinforced with steel strands and spirals, while another pile was reinforced with steel strands and GFRP spirals. The spirals within the piles were instrumented at critical locations with strain gauges to record spiral responses. Externally, pile driving analyzer strain gauges and accelerometers were installed for pile response along loading direction. In addition, to further understand the spatial response of the piles tested, three-dimensional finite-element (FE) models were developed using a commercially available code to simulate the impact test. For the FE model, concrete behavior of was modeled using concrete damaged plasticity model, the behavior of steel strands was simulated using a bilinear elastoplastic material, and the GFRP spiral behavior was modeled using a linear elastic material. The results of the research show that PC piles can be confined with GFRP spirals, without decreasing the load-carrying capacity of the pile. Practical Applications: This research brought forth valuable insights with practical implications, particularly regarding the use of glass fiber–reinforced polymer (GFRP) spirals within prestressed concrete applications. The practical applications encompass several key points that stand to influence engineering practices. Notably, both experimental results and finite-element studies assert that prestressed concrete piles reinforced with GFRP spirals exhibit performance comparable to their traditional counterparts employing steel spirals. This similarity extends to a robust response under impact loads, indicating that prestressed concrete piles featuring GFRP spirals as lateral reinforcement can effectively withstand pile driving forces, rendering them suitable for practical applications. Furthermore, the study introduces the prospect of enhancing corrosion resistance in prestressed concrete piles by incorporating GFRP spirals in combination with corrosion-resistant strands. This development expands the feasibility of deploying corrosion resistant prestressed concrete piles for bridge foundations in marine environments. Engineers engaged in bridge construction projects are thus encouraged to explore the adoption of GFRP-reinforced prestressed concrete piles, anticipating enhanced durability and longevity for bridge structures, especially in regions subject to harsh environmental conditions. This plays a pivotal role in advancing resilient and sustainable infrastructure practices within the realm of civil engineering and construction. [ABSTRACT FROM AUTHOR]

Textile-reinforced ultrahigh-toughness cementitious composite (UHTCC) jackets––herein referred to as TRU jackets––are an innovative strengthening system for reinforced concrete (RC) structures. The ductile UHTCC used for this jacket system exhibits better deformation compatibility with the textile than brittle mortar does. In this paper, we present an experimental study of the seismic performance of RC columns strengthened with TRU jackets using cyclic lateral loading tests. The results indicated that the TRU jacket could effectively restrain the development of cracks in the plastic hinge zone, delay stiffness deterioration, and significantly improve ductility and energy dissipation. Moreover, at a low stirrup ratio of 0.39%, the peak load of the jacketed columns was greatly enhanced compared to the peak load of the RC companion columns. With an increased number of textile layers, seismic performance was improved. When the ratio of axial force to axial capacity was increased from 0.15 to 0.30, ductility and energy dissipation did not drop for the TRU-jacketed columns. As the strengthening height decreased from 2.0 to 1.2 times the cross-sectional height of the columns, the seismic performance of the jacketed columns remained almost unchanged. A numerical model was developed for the seismic simulation of TRU-jacketed columns, and the predicted hysteresis curves agree well with the test data. [ABSTRACT FROM AUTHOR]

During an earthquake, the casualties and economic loss due to infrastructure failure, such as bridges, are prohibitive. In addition, the deterioration in the steel reinforcements in bridges due to corrosion issues leads to significant structural damage and maintenance costs. As a novel form of composite structural member, hybrid fiber-reinforced polymer (FRP)-concrete‐steel double-skin tubular columns (DSTCs), which consist of an inner steel tube, an outer FRP tube, and a sandwich concrete layer between the two tubes, with enhanced corrosion and seismic resistance, could be employed as bridge members (e.g., bridge piers) in harsh environments, seismic zones, or both, to enhance the seismic resistance, and extend the serviceable life of the bridges, achieve a lower maintenance cost, or both. This paper presents an experimental study on the behavior of DSTC-to-RC foundation connections that are subjected to a combination of axial compression and lateral cyclic loading, with the embedment depth of the column footing, axial load ratio of DSTCs, thickness of FRP tubes, and the additional anchoring measures within the foundation connections as the main parameters to be explored. Based on the test results, design suggestions, which include the critical embedment depth of the column footing and reliable structural measures, were proposed for DSTC-to-RC foundation connections. [ABSTRACT FROM AUTHOR]

The surging demand for sustainable and efficacious approaches of enhancing the ground has resulted in the investigation of novel waste materials. This study investigates the utilization of Polyoxymethylene (POM) as a granular column to ameliorate the ability of soft clay soil to resist horizontal loads. The study introduces a new implementation of polyoxymethylene columns as ground improvement approach to tackle the complexities related to soft clay soils. The capability of polyoxymethylene columns was analyzed through a sequence of laboratory experiments, containing engineering characteristic tests, unconfined compressive strength (UCS) tests, and consolidated isotropic undrained (CIU) triaxial tests. The effects of the number of columns, column diameter, column depth, substitute area ratio, depth penetration ratio, column aspect ratio, volume infusion ratio, and confining pressures, were evaluated to analyze the behavior of individual and clustered encapsulated polyoxymethylene columns. The findings verified a notable development in the ability of soft clay soil, when strengthened with polyoxymethylene columns, to oppose the lateral loads and maintain overall stability. Additionally, a regression analysis was implemented to establish a prediction model that estimates the increase in shear strength of POM columns based on different column dimensions. This model is a practical tool for evaluating the performance of reinforced soft clay soils in large-scale projects. This study not only accentuates the mechanical benefits of polyoxymethylene but also accentuates its environmental benefits, prescribing for the implementation of recyclable materials in ground renovation. [ABSTRACT FROM AUTHOR]

A seismic vibration control system, consisting of a swing story substructure, a lateral force resisting substructure and connecting dampers, is recently proposed. The analytical model and optimization method based on the stability maximization and H2 criteria have been established. In this paper, excellent vibration control effects of the proposed system are verified through the small-scale shaking table tests on a two-story model. Experimental results demonstrate the accuracy of the analytical model and the validity of the vibration control strategy. Through numerical analyses of benchmark structures, the input energy of the optimally designed system is remarkably mitigated, and favorable vibration control effects for reducing both inter-story drifts and absolute floor accelerations under earthquake ground motions are verified by comparing with conventional moment-resisting frame structures. In addition, significant control effects can be achieved when the optimal stiffness is greater than the critical buckling stiffness. A seismic design flow chart of the intensity-reduced design method is proposed based on the numerical analyses and the Chinese Seismic Design Code of Buildings. The results indicate that the seismic intensity-reduced design for the proposed system is feasible. [ABSTRACT FROM AUTHOR]

This article conducts experimental research on the influencing factors of the anti-skid performance testing system SCRIM for asphalt pavement. Studied the distribution pattern of anti-skid performance test results of the testing system under different testing speeds, test tires, temperature, water film thickness, test wheel position, tire wear degree, and other factors. Revealed the influence law of various influencing factors on the anti-skid performance of asphalt pavement. The test results indicate that the SFC test value decreases with the increase of vehicle speed. The test results of tires made of different materials vary greatly, and tires with wear exceeding 3 mm cannot be used for testing. The influence of water film thickness on the measured values varies depending on the SFC level. The SFC measurement value of the normal trajectory of the vehicle's driving wheel track is the smallest, and the measurement value of the left trajectory is greater than that of the right trajectory. The SFC measurement decreases as the tire wear increases. [ABSTRACT FROM AUTHOR]

Methane (CH 4) cycling in the Baltic Sea is studied through model simulations that incorporate the stable isotopes of CH 4 (12 C–CH 4 and 13 C–CH 4) in a physical–biogeochemical model. A major uncertainty is that spatial and temporal variations in the sediment source are not well known. Furthermore, the coarse spatial resolution prevents the model from resolving shallow-water near-shore areas for which measurements indicate occurrences of considerably higher CH 4 concentrations and emissions compared with the open Baltic Sea. A preliminary CH 4 budget for the central Baltic Sea (the Baltic Proper) identifies benthic release as the dominant CH 4 source, which is largely balanced by oxidation in the water column and to a smaller degree by outgassing. The contributions from river loads and lateral exchange with adjacent areas are of marginal importance. Simulated total CH 4 emissions from the Baltic Proper correspond to an average ∼1.5 mmol CH 4 m -2 yr -1 , which can be compared to a fitted sediment source of ∼18 mmol CH 4 m -2 yr -1. A large-scale approach is used in this study, but the parameterizations and parameters presented here could also be implemented in models of near-shore areas where CH 4 concentrations and fluxes are typically substantially larger and more variable. Currently, it is not known how important local shallow-water CH 4 hotspots are compared with the open water outgassing in the Baltic Sea. [ABSTRACT FROM AUTHOR]

Nanoparticle adhesion to polymer and similar substrates may be prone to low nano-Newton forces, disrupting the surface bonds and patterning, potentially reducing the functionality of complex surface patterns. Testing this, a functionalised surface reported for biological and medical applications, consisting of a thin plasma-derived oxazoline-based film with 68 nm diameter covalently bound colloidal gold nanoparticles attached within an aqueous solution, underwent nanomechanical analysis. Atomic Force Microscopy nanomechanical analysis was used to quantify the limits of various adaptations to these nanoparticle-featured substrates. Regular and laterally applied forces in the nano-Newton range were shown to de-adhere surface-bound gold nanoparticles. Applying a nanometre-thick overcoating anchored the nanoparticles to the surface and protected the underlying base substrate in a one-step process to improve the overall stability of the functionalised substrate against lower-range forces. The thickness of the oxazoline-based overcoating displayed protection from forces at different rates. Testing overcoating thickness ranging from 5 to 20 nm in 5 nm increments revealed a significant improvement in stability using a 20 nm-thick overcoating. This approach underscores the importance of optimising overcoating thickness to enhance nanoparticle-based surface modifications' durability and functional integrity. [ABSTRACT FROM AUTHOR]

Bulk high-temperature superconductors (HTSs) such as REBa2Cu3O7−x (REBCO, RE = Y, Gd) are commonly used in rotationally symmetric superconducting magnetic bearings. However, such bulks have several disadvantages such as brittleness, limited availability and high costs due to the time-consuming and energy-intensive fabrication process. Alternatively, tape stacks of HTS-coated conductors might be used for these devices promising an improved bearing efficiency due to a simplification of manufacturing processes for the required shapes, higher mechanical strength, improved thermal performance, higher availability and therefore potentially reduced costs. Hence, tape stacks with a base area of (12 × 12) mm2 and a height of up to 12 mm were prepared and compared to commercial bulks of the same size. The trapped field measurements at 77 K showed slightly higher values for the tape stacks if compared to bulks with the same size. Afterwards, the maximum levitation forces in zero field (ZFC) and field cooling (FC) modes were measured while approaching a permanent magnet, which allows the stiffness in the vertical and lateral directions to be determined. Similar levitation forces were measured in the vertical direction for bulk samples and tape stacks in ZFC and FC modes, whereas the lateral forces were almost zero for stacks with the REBCO films parallel to the magnet. A 90° rotation of the tape stacks with respect to the magnet results in the opposite behavior, i.e., a high lateral but negligible vertical stiffness. This anisotropy originates from the arrangement of decoupled superconducting layers in the tape stacks. Therefore, a combination of stacks with vertical and lateral alignment is required for stable levitation in a bearing. [ABSTRACT FROM AUTHOR]

The accurate prediction of the nonlinear flutter response is one of the important prerequisites for accurately evaluating the post-flutter performance of long-span bridges. In fact, as the vibration amplitude increases, the participation of lateral degree-of-freedom (DOF) will become more and more obvious and thus ignoring self-excited forces related to lateral vibration may no longer be applicable. To this end, based on 18 amplitude-dependent flutter derivatives (FDs), a 3-DOFs coupled nonlinear flutter analysis method was proposed in this study. Then, 18 amplitude-dependent FDs of two typical bridge decks were identified, and they were used to calculate the 3-DOF coupled nonlinear flutter responses based on the proposed flutter analysis method. Meanwhile, the correctness of the above flutter analysis method was also verified by compared with the numerical simulation results. Finally, the influence and mechanism of the lateral DOF, structural modal parameters and amplitude-dependent FDs on the nonlinear flutter of these typical bridge decks were investigated. The results show that when the torsional amplitude of the nonlinear flutter is large, the participation of lateral DOF will significantly increase the steady-state amplitude of the nonlinear flutter, and the larger the torsional amplitude, the more significant this increase is. The main reason is the participation of the lateral DOF introduces the negative coupled aerodynamic damping to the system, which then reduces the stability of the system. Besides, for the twin-box section, the influence of the lateral DOF on the nonlinear flutter is relatively smaller compared with the single-box section since the proportion of negative aerodynamic damping by the lateral DOF is smaller. Compared with the single-box section, the mass of the twin-box section has a smaller effect on the critical wind speed, and the torsional structural damping ratio of the twin-box section has a greater effect on the nonlinear flutter. [ABSTRACT FROM AUTHOR]

This paper investigates the seismic performance of thin-walled stiffened steel square box columns, modeling bridge piers subjected to unidirectional cyclic lateral loading with a constant axial load, focusing on local, global, and local-global interactive buckling phenomena. Initially, the finite element model was validated against existing experimental results. The study further explored the degradation in strength and ductility of both thin-walled and compact columns under cyclic loading. Thin-walled, stiffened steel square box columns exhibited buckling near the base, forming a half-sine wave shape. The research also addresses discrepancies from different material models used to analyze steel tubular bridge piers. Analysis using a modified two-surface plasticity model (2SM) yielded results closer to experimental data than a multi-linear kinematic hardening model, particularly for compact sections. The 2SM, which accounts for cycling within the yield plateau and strain hardening regime, demonstrated enhanced accuracy over the multi-linear kinematic hardening model. Additionally, a parametric study was conducted to assess the impact of key design parameters—such as width-to-thickness ratio (Rf), column slenderness ratio (λ), and magnitude of axial load (P/Py)—on the performance of thin-walled stiffened steel square box columns. Design equations were then developed to predict the strength and ductility of bridge piers. These equations closely matched experimental results, achieving an accuracy of 95% for ultimate strength and 97% for ductility. [ABSTRACT FROM AUTHOR]

To meet growing energy demands, offshore wind turbines (OWTs) with higher energy outputs are being developed, presenting increased challenges for their foundation design. Over the past decade, extensive research on the design optimization of OWT support structures has significantly reduced the anticipated costs of offshore wind farm development. Various design methods have been developed and applied in practice, each with its own advantages and limitations. In this study, 3D finite element (FE) modeling, validated against the measured response of a large-scale test monopile, is used to investigate the lateral load response of monopiles with different geometries and slenderness ratios in smaall and large displacements. The results are compared to the standard p–y method, and specific behavioral and design aspects of large-diameter monopiles, such as the moment contribution ratio from different resisting components and the minimum embedment length criteria, are evaluated and discussed. The results showed that the maximum and minimum differences between the 3D FE modeling and one-dimensional (1D) DNV p–y method are 41% and 11% for large displacements, and 32.5% and 13.3% for small displacements, respectively. As the slenderness ratio increases, the discrepancy between the finite element (FE) modeling results and the 1D DNV p–y method decreases, with an average difference of about 13% across all monopile diameters at an L/D ratio of 10, in both small and large displacements, indicating the reasonable accuracy of the 1D method for slenderness ratios of 10 and above. Among the three minimum embedment length criteria examined, the DNV recommended and vertical-tangent criteria offered shorter embedment lengths. The primary resisting moment across all slenderness ratios comes from the distributed lateral load along the monopile shaft ( M C R p − y ), which increases as the L/D ratio increases. [ABSTRACT FROM AUTHOR]

It has been difficult to detach abrasive particles smaller than 50 nm from polished surfaces in post-CMP cleaning. During the cleaning process, the residual nano-particles exert shear force in the inevitable shear flow. In order to understand the cleaning mechanism, it is indispensable to investigate not only the force but also the energy acting on different-sized nano-particles. In this article, we proposed the evaluation of detachment energy (the energy required to detach nano-particles) by using Lateral Force Microscopy. As an example, the dominant detachment energy of the silica nano-particle between the oxide film is the potential energy of the hydrogen bond. It suggested that the silica nano-particle detachment involves the breaking of hydrogen bonds. [ABSTRACT FROM AUTHOR]

The behavior of harmonic functions near corners of the domain boundary has a universal character that may be applied to the study of the flow around slender bodies with sharp edges. Depending of the energy of the potential function near the tip of the corner, this may yield a fast rotating flow or a vortex in its vicinity. For internal angles, such as occur in grooves of the body, a stagnation region or an eddy may occur. Lateral forces are also affected by the presence of corners, yielding configurations that resemble either a circulation lift or a vortex lift. [ABSTRACT FROM AUTHOR]

To examine structural safety and reliability, an accurate prediction of the variability of structural resistance must first be determined. This may be achieved through extensive physical testing or, more commonly in modern research, synthetic data generation, such as stochastic finite element analyses (SFEAs). Due to the prevalence and versatility of such techniques, and the need for a high level of confidence when performing a safety assessment, an understanding of the accuracy of data derived from SFEAs is essential. In this paper, SFEA models have been developed to predict the responses of 16 unreinforced masonry walls tested in a laboratory under cyclic in-plane lateral loading. Each SFEA has been developed to reflect the as-built conditions of these experimental specimens and focus on predicting the shear capacity of the failure mechanisms that unreinforced masonry shear walls are susceptible to. From the results of these SFEAs, the accuracy (quantified as model error) of this modelling strategy has been estimated by comparing the peak in-plane shear resistances of the laboratory and numerical models. [ABSTRACT FROM AUTHOR]

Traditional wheelchairs are pushed from behind the occupant, which hinders eye contact and communication. It was proposed that the wheelchair be pushed from the side using a push bar to place the caregiver beside the occupant. However, this method requires the caregiver to exert continuous effort to maintain a straight trajectory because the force at the lateral push location generates a moment. This study explores simple modifications to the front castor wheel of the wheelchair that allow pushing it from the side without additional effort. We used a three-dimensional dynamic model of the castor wheel to predict the effects of altering its dimensions and rake, cant, and bank angle and present a simplified steady-state solution. Experimental results support the model's predictions, and a proof-of-concept experiment with a wheelchair showed that it is possible to push a wheelchair from the side without increasing forces or moments. The results also confirmed that the lateral ground reaction force generated on the castor wheel is proportional to the normal force and the cant angle, which can counter the moment caused by the lateral push location. The implications of this model extend beyond wheelchair design and can be applied to other applications that use castor wheels, such as robotics, trolleys, and walkers. [ABSTRACT FROM AUTHOR]

Background: The thresholds of mechanical inputs for bruising caused by blunt impact are important in the fields of machine safety and forensics. However, reliable data on these thresholds remain inadequate owing to a lack of in vivo experiments, which are crucial for investigating the occurrence of bruising. Since experiments involving live human participants are limited owing to ethical concerns, finite-element method (FEM) simulations of the bruising mechanism should be used to compensate for the lack of experimental data by estimating the thresholds under various conditions, which requires clarifying the mechanism of formation of actual bruises. Therefore, this study aimed to visualize the mechanism underlying the formation of bruises caused by blunt impact to enable FEM simulations to estimate the thresholds of mechanical inputs for bruising. Methods: In vivo microscopy of a transparent glass catfish subjected to blunt contact with an indenter was performed. The fish were anesthetized by immersing them in buffered MS-222 (75–100 mg/L) and then fixed on a subject tray. The indenter, made of transparent acrylic and having a rectangular contact area with dimensions of 1.0 mm × 1.5 mm, was loaded onto the lateral side of the caudal region of the fish. Blood vessels and surrounding tissues were examined through the transparent indenter using a microscope equipped with a video camera. The contact force was measured using a force-sensing table. Results: One of the processes of rupturing thin blood vessels, which are an essential component of the bruising mechanism, was observed and recorded as a movie. The soft tissue surrounding the thin blood vessel extended in a plane perpendicular to the compressive contact force. Subsequently, the thin blood vessel was pulled into a straight configuration. Next, it was stretched in the axial direction and finally ruptured. Conclusion: The results obtained indicate that the extension of the surrounding tissue in the direction perpendicular to the contact force as well as the extension of the thin blood vessels are important factors in the bruising mechanism, which must be reproduced by FEM simulation to estimate the thresholds. [ABSTRACT FROM AUTHOR]

Decoupling dynamic touch signals in the optical tactile sensors is highly desired for behavioral tactile applications yet challenging because typical optical sensors mostly measure only static normal force and use imprecise multi-image averaging for dynamic force sensing. Here, we report a highly sensitive upconversion nanocrystals-based behavioral biometric optical tactile sensor that instantaneously and quantitatively decomposes dynamic touch signals into individual components of vertical normal and lateral shear force from a single image in real-time. By mimicking the sensory architecture of human skin, the unique luminescence signal obtained is axisymmetric for static normal forces and non-axisymmetric for dynamic shear forces. Our sensor demonstrates high spatio-temporal screening of small objects and recognizes fingerprints for authentication with high spatial-temporal resolution. Using a dynamic force discrimination machine learning framework, we realized a Braille-to-Speech translation system and a next-generation dynamic biometric recognition system for handwriting. A sensitive upconversion nanocrystal-based biometric optical tactile sensor instantaneously and quantitatively decomposes dynamic touch signals into individual components of vertical normal and lateral shear force from a single image in real-time. [ABSTRACT FROM AUTHOR]

The performance of joint connections in composite slabs is crucial for ensuring their bidirectional load-bearing capacity and overall structural integrity. To effectively address the challenge of protruding rebar in precast components, a new structural form of a tightly connected hollow concrete composite slab without protruding rebar on the slab side is proposed. To investigate the mechanical performance and failure modes of this slab-side tight-joint connected hollow concrete composite slab, bending performance tests under monotonic load were conducted on three tightly connected hollow composite slabs and one seamless hollow composite slab. The analysis focused on the failure modes, crack distribution, bending capacity, and bending stiffness of additional steel bars at the joints of the slabs. The results indicate that, under normal operating conditions, the flexural performance development of concrete hollow composite slabs with tightly connected slab sides is generally consistent with that of the non-spliced cast hollow composite slab. Under ultimate conditions, tearing or brittle fracture failure at the joint interface is likely to occur in the composite slabs, leading to a reduction in flexural bearing capacity. With an increase in joints, the bending capacity of the hollow composite slab decreases by 17.1%, Conversely, when joints are positioned away from the most stressed section, the flexural stiffness of the section increases by 13.5%. A comparison of experimental data and theoretical calculations indicates that the additional rebar at the joints effectively contributes to the lateral load transfer in the hollow composite slab, achieving bidirectional load-bearing capacity. This further validates that the design of the single-joint, tight-joint connected hollow concrete composite slab without protruding rebar meets the requirements for bidirectional load-bearing performance. [ABSTRACT FROM AUTHOR]

Drilled shafts with a larger diameter than columns are frequently adopted as the foundation of highway bridge columns due to their superior economic efficiency and lower impact on existing facilities in the urban built‐up area. Different section dimensions lead to a socket connection between the column and the oversized shaft and a noncontact lap splice of their longitudinal bars. The force‐transfer mechanism and failure process of column‐to‐drilled shaft connections were deeply revealed in this study. Detailed FE models were developed at the Diana platform and validated against previous experimental results. Subsequently, a parametric study investigated the effect of the shear span‐to‐depth ratio, diameter ratio of shaft‐to‐column, column embedment depth, and shaft stirrup ratio. Finally, a modified strut‐and‐tie model (STM) was proposed to design stirrups of the transition region efficiently considering the experimental failure mechanism. Results indicate that the numerical models built in the Diana platform can precisely simulate the mechanical behavior of column‐to‐drilled shaft connections. The failure mechanism of column‐to‐drilled shaft connections is shaft stirrups yield at the compressive side induced by extrusion between the embedded column and shaft. The lateral loading capacity of column‐to‐drilled shaft connections increases with the increase of shear span‐to‐depth ratio, diameter ratio of shaft‐to‐column, column embedment depth, and shaft stirrup ratio. The modified STM is able to reveal the variation tendency of shaft transverse reinforcement demand with the various design parameters and give an average stirrup stress ratio of 1.20 and a coefficient of variation of only 8.31%. [ABSTRACT FROM AUTHOR]

In this study, to investigate the factors affecting container semitrailer rollovers while driving on interchange loop ramps, a simulation model was established in TruckSim on the basis of data collected from an in-depth investigation of the vehicle, road, and driving behaviors in a real accident. The established model was validated by reproducing the accident in a simulation. The effects of vehicle speed, the height of the cargo's center of gravity, tractor-semitrailer interactions, and the radius of the circular curve on container semitrailer rollover were investigated using the established model. The results reveal that if the height of the container semitrailer is within the limits in Chinese standards and the container semitrailer is moving at a speed of less than 45.3 km/h, it can safely travel through a loop ramp with a circular curve radius of 60 m. The height of the cargo's center of gravity and the lateral load transfer ratio have a negative relationship, and a higher center of gravity reduces the safe speed for a container semitrailer traveling through a loop ramp. During rollover, the rear axle of the semitrailer first begins to roll over and then drives the tractor to overturn. [ABSTRACT FROM AUTHOR]

The effect of cyclic loading is an essential factor leading to progressive soil strength degradation. Therefore, a comprehensive analysis of the pile‐soil system behavior under cyclic loading is required to ensure the stability of pile group. There is room for improvement in the inherent constraint of the conventional numerical model in terms of approximating the soil resistance distribution along the pile by point loads at element nodes, necessitating a specific element that integrates considerations of pile group effect and cyclic loading within a unified framework. This study aims to develop a newly specific type of element for efficiently predicting nonlinear behavior within the pile‐soil system, addressing simulations involving nonlinear pile‐soil interaction, pile group effect, and cyclic loading. Modified element formulations based on soil stiffness matrices and soil resistance vectors specifically address pile group effect and consider parameters that influence pile behavior under cyclic lateral loading. The numerical solution procedure with Newton‐Raphson iteration allows the calculation of pile responses in geometric and material nonlinear analyses. The validation of the proposed method includes several examples, comparing it with existing numerical solutions and experimental tests of single piles and pile groups under cyclic loading. These comparisons further support the consistency of the proposed method with measured data and validate its accuracy in considering group effect and cyclic loading. The parametric study illustrates the ability of the proposed method to capture cyclic loading parameters while considering the influence of the number and magnitude of load cycles, the cyclic load direction, and the installation methods. [ABSTRACT FROM AUTHOR]

The design speed of high-speed maglev trains is much higher than that of wheel-rail trains, and they will be subject to more operational safety threats under complex wind conditions. The present study uses the improved delayed detached eddy simulation method based on the shear stress transfer k–ω turbulence model to explore the effect of active flow control on the aerodynamic lateral force of a maglev train and examines the main aerodynamic performance differences caused by two active control forms (suction and blowing airflow), involving multiple active flow speeds. In the current scenario, blowing can reduce the lateral force coefficient of the head car by up to 15% while greatly increasing its transient instability, which can be attributed to direct and indirect changes in pressure distribution near the air slots and a larger range of the leeward surface. The suction is believed to suppress the downstream motion of the main vortex on the leeward side of the maglev train and weaken the turbulent kinetic energy of the wake, while the blowing effect reduces the dominance of the main vortex. The application of blowing is proved as an effective means of reducing the risk of operating a maglev train in a crosswind environment, while it requires a careful consideration of both train safety and energy efficiency. [ABSTRACT FROM AUTHOR]

This paper investigates the water entry of a vehicle with angle of attack (AOA) through numerical methods, employing the volume-of-fluid multiphase flow model and overset grid technique. The validity of the numerical model is confirmed through experimental verification. Building upon this, the study analyzes the motion characteristics, cavity evolution, and flow field distribution of the vehicle during water entry, considering the influence of AOA and falling velocity. Numerical findings indicate that the collapse of the right side of the cavity induces a transient lateral force on the vehicle, resulting in vehicle tilting. Moreover, an increase in initial velocity delays vehicle tilt, while an increase in AOA reduces vehicle motion stability, leading to earlier tilting. Initially, the vehicle rotates counterclockwise around the Oz axis of the projectile coordinate system. Subsequent to cavity collapse, the vehicle experiences an opposing moment, leading to a reduction in rotation speed and eventual rotation in the opposite direction. Water impact triggers sudden changes in the vehicle's lift and drag coefficients, while cavity sticking induces a minor abrupt change in the lift coefficient. Following cavity collapse, both lift and drag coefficients exhibit significant oscillations. Unlike typical cavity collapse phenomena, the flow field on the right side of the vehicle undergoes alternating high-pressure and low-pressure regions. [ABSTRACT FROM AUTHOR]

Road grade is important for autonomous vehicles, but it is difficult to measure directly. To address this issue, a hierarchical estimation of road grade is suggested based on the observation of tire forces. First, a 7-degree-of-freedom (DOF) dynamics model, including vehicle longitudinal, lateral, and yaw motions together with wheel rotations, is developed while considering the road grade. Subsequently, a dual-layer road grade estimation strategy is proposed based on an unscented Kalman filter (UKF). The lower-layer UKF estimates the longitudinal and lateral tire forces for road grade observation, and the upper-layer UKF is employed to estimate the road grade by considering the vehicle's lateral acceleration and yaw rate. Finally, CarSim and MATLAB joint simulations and road tests are performed under different conditions to validate the correctness and effectiveness of the proposed estimation method. The results show that the proposed tire force observation-based estimator exhibits a lower mean absolute error and root mean square error on sloping roads and combined curved and sloping roads, and presents a better overall estimation performance on road grade compared with the widely used kinematics and dynamics model-based estimators. [ABSTRACT FROM AUTHOR]