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Cells store triacylglycerol (TAG) within lipid droplets (LDs). A dynamic model describing complete LD formation at the endoplasmic reticulum (ER) membrane does not yet exist. A biochemical‐biophysical model of LD synthesis is proposed. It describes the time‐dependent accumulation of TAG in the ER membrane as the formation of a potential LD (pLD) bounded by spherical caps of the inner and outer monolayers of the membrane. The expansion rate of the pLD depends on the TAG supply, the elastic properties of the ER membrane, and the recruitment of phospholipids (PLs) to the cap‐covering monolayers. Model simulations provided the following insights: (a) Marginal differences in the surface tension of the cap monolayers are sufficient to fully drive the expansion of the pLD towards the cytosol or lumen. (b) Selective reduction of PL supply to the luminal monolayer ensures stable formation of cytosolic LDs, irrespective of variations in the elasto‐mechanical properties of the ER membrane. (c) The rate of TAG supply to the cytosolic monolayer has a major effect on the size and maturation time of LDs but has no significant effect on the TAG export per individual LD. The recruitment of additional PLs to the cap monolayers of pLDs critically controls the budding direction, size, and maturation time of LDs. The ability of cells to acquire additional LD initiation sites appears to be key to coping with acutely high levels of potentially toxic free fatty acids. [ABSTRACT FROM AUTHOR]

High-frequency non-physical oscillations may occur due to shock waves in seismic wavefield and dynamic rupture simulation. In this study, we introduced the alternative flux finite-difference weighted essentially non-oscillatory scheme to address potential shock wave issues in computational seismology effectively. The wavefield of the body-fitted curvilinear domain was accurately computed through conservative grid mapping, ensuring accurate implementation of free surface boundary conditions on irregular surfaces using characteristic boundary conditions and minimizing artificial boundary reflections with exponential decay absorbing layers. Finally, we compared our scheme with the GRTM for flat surfaces and the CGFDM3D-EQR for irregular surfaces to demonstrate its correctness and accuracy, and validated its non-oscillatory characteristics. The aforementioned scheme is anticipated to assume a significant function in simulating more intricate seismic wavefields or dynamic ruptures. [ABSTRACT FROM AUTHOR]

In the current study, a dynamic layer freeze desalination system is simulated numerically. The computational domain is a two-dimensional rectangular channel which contains inlet and outlet flows, and the simulation is performed using computational fluid dynamics. A pre-concentrated mixture is considered as the feed solution with an initial temperature and concentration of 257 K and 0.2 kg/kg, respectively. In this work, since the simulation parameters such as temperature and species mass fraction have high importance across the entire domain, the k–ω shear stress transport turbulence model was selected. A parametric study on the effect of the heat flux of the cold wall on the ice salinity and desalination rate is performed using three cases with heat fluxes of − 1000 , − 1500 , and − 3000 W m − 2 . It is observed that the ice generation speed in the case with a heat flux of − 3000 W m − 2 is 3.28 times greater compared to the case with − 1000 W m − 2 and its desalination rate is only 2.59 % lower. The effect of the inlet velocity on the mentioned parameters is also investigated. It is observed that the cases with turbulent flow have approximately 19 % and 23 % lower ice salinity compared to the case with laminar flow. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to present numerical simulations for a series of flight processes for the postlaunching stage of the "balloon-borne UAV system." It includes the balloon further ascent motion after airborne launching. In terms of unmanned aerial vehicles (UAVs), the tailspin state and the charge-out process with an anti-tailspin parachute-assisted suspending are analyzed. Then, the authors conduct trajectory optimization simulations for the long-distance gliding process. Design/methodology/approach: The balloon kinematics model and the parachute Kane multibody dynamic model are established. Using steady-state tailspin to reduced-order analysis and achieving change-out simulation by parachute suspension dynamic model. A reentry optimization control problem is developed and the Radau pseudo-spectral method is used to calculate the glide trajectory. Findings: The established dynamic model and trajectory optimization method can effectively simulate the motion process of balloons and UAVs. The system mass reduction for launching UAVs will not cause damage to the balloon structure. The anti-tailspin parachute can reduce the UAV attack angles effectively. The UAV can glide to the designated target position by adjusting the attack angle and sideslip angle. The farthest flight distance after launching from 20 km height is 94 km and the gliding time is 40 min, which demonstrates the potential application advantage of high-altitude launching. Practical implications: The research content and related conclusions of this article achieve a closed-loop analysis of the flight mission chain for the "balloon-borne UAV system," which provides simulation references for relevant balloon launching experiments. Originality/value: This paper establishes a complete set of numerical simulation models and can effectively analyze various postlaunching behaviors. [ABSTRACT FROM AUTHOR]

The axial deployment force is an indispensable parameter of a lanyard-deployed coilable mast, which reflects its load capacity in practical applications. However, research on the axial deployment force in the literature is very limited, and there are no mature numerical methods to determine this parameter in the design stage of coilable masts. In this paper, a numerical method for determining the axial deployment force of a lanyard-deployed coilable mast in the local coil mode is presented. Through this method, the designer can quickly obtain the estimated value of the axial deployment force in the design stage, which is convenient for the quantitative design of parameters. To verify the correctness of the proposed method, a dynamic simulation of the coilable mast is carried out, and a microgravity test is performed. The comparison results show that the error between the numerical method and the simulation and experimental results is less than 5%, which proves the correctness of the proposed method. In addition, the coilable mast studied in this paper has been verified by an actual microsatellite deployment in orbit. [ABSTRACT FROM AUTHOR]

In this study, the loess hill site of an elevated bridge section in Tongwei-Qin'an of the Baolan high-speed railroad was selected as the research object, and the vibration acceleration of the loess hill site under the elevated bridge was tested in the field under the train operating load. The results show that under the same intensity of train load, the time range of vibration acceleration observed by field test and numerical simulation decays linearly with increasing distance from the source, while the amplification effect appears in the loess hill site at a greater distance, and the vibration duration also appears to increase. The vibration acceleration waveforms at each observation point observed by field tests and numerical simulations are similar, and the peak vertical acceleration at each observation point obtained from numerical simulations is overall greater than the peak acceleration at each point obtained from field tests, with a Simulated − max / a Observated − max values ranging from 1.04 to 1.63. The Fourier spectrum frequencies recorded by numerical simulation and field test are mainly concentrated in the range of 1∼40 Hz, but the difference between the main frequencies recorded by the two is large. The main frequency of the energy spectrum recorded by the numerical simulation is around 15 Hz, which is the same as the main frequency of the energy spectrum vibration of the input vibration wave, and the main frequency of the energy spectrum vibration recorded by the field test is around 25 Hz. [ABSTRACT FROM AUTHOR]

Numerical simulation based on the discrete phase model and dynamic mesh model can more accurately simulate the working process for hybrid rockets, including the motion and evaporation process of particles and regression process of the fuel grain. The dynamic numerical simulation of combustion and flow in hybrid rocket motors based on a discrete phase model is carried out. Aluminum and aluminum hydride are added to the internal flow field as discrete droplets. Then, a hybrid rocket is designed with 95 % hydrogen peroxide as oxidizer and 38 % aluminum hydride+20 % aluminum+42 % hydroxyl-terminated polybutadiene as the fuel and used to verify the model by firing test. A high degree of agreement between experiment and simulation findings is found. The average deviations for thrust and pressure are 3.6 % and 5.9 %, respectively. It offers the required backing for using the simulation method to investigate the flow and combustion process for the hybrid rockets. The results also demonstrate the transient characteristics of the inner flow field, including the separation and merging of vortexes in the pre-chamber. It is found that a peak of the regression rate appears at the front of the grain and moves backward. This is mainly because the vortex appears here and enhances its heat transfer. Through the discrete phase model, it is worth noting that the aluminum droplet content gradually decreases at the nozzle over time, which is consistent with the firing test. Further research on the impact of aluminum hydride content on the performance of the hybrid rockets has been carried out. The results show that the higher aluminum hydride content can lead to better performance for the hybrid rockets. The thrust, pressure, specific impulse, and characteristic velocity enhance with the increase of aluminum hydride content. An interesting discovery is that the average regression rate is maximum at 48 % aluminum hydride content. This research innovatively couples dynamic mesh and discrete phase models, which can help better understand the working process for hybrid rockets and provide important guidance for the selection of fuel formula. • A simulation model of hybrid rocket motors based on a discrete phase model is established. • The motion and evaporation of particles and regression of the fuel grain are simulated. • A test of hybrid rockets with fuel containing aluminum and aluminum hydride is carried out. • A high degree of agreement between experiment and simulation findings is found. • The impact of aluminum hydride content on the performance of the hybrid rockets is conducted. [ABSTRACT FROM AUTHOR]

Based on the inverse piezoelectric effect and other characteristics of piezoelectric ceramics, a new type of piezoelectric variable friction damper is developed, and the output performance test of piezoelectric ceramic actuator and piezoelectric variable friction damper is carried out, and the parametric mechanical model of the damper is established by using Simulink to carry out numerical simulation, and compared and analyzed with the test results. The results of the study show that the simulation and the test present a good regular agreement. With the increment of loading voltage, the displacement deformation and zero-displacement thrust of piezoelectric ceramic actuator are approximately linear with the loading voltage; when the loading voltage is increased by 15V every time, the test value of the output damping force of the damper increases by 259.66N on average step by step, and the simulated value increases by 256.14N step by step, and the damping force has a linearly incremental relationship with the voltage and the slope of the linear increase is 16.434. [ABSTRACT FROM AUTHOR]

Quantitative characterization of tight sandstone oil migration and accumulation is an emerging research frontier in the field of oil and gas exploration. In this study, a conceptual model containing multiple basic geological elements is developed, and a nonlinear seepage numerical model for tight sandstone oil migration and accumulation is established. The effects of the slip effect, overpressure driving force, buoyancy, and capillary force on the migration and accumulation of tight oil are examined. The results showed that (1) the differences in oil migration and accumulation between tight and conventional reservoirs are reflected in the growth mode of oil saturation, distribution characteristics of oil and water, and extent of the effect of the formation dip angle; (2) the slip effect has a significant impact when the average pore throat radius is less than 150 nm and the overpressure driving force and capillary force are the main mechanical mechanisms controlling oil migration and accumulation in tight sandstone, while the coupling effect of buoyancy, capillary force, and overpressure driving force controls the upper and lower limits of oil saturation. Finally, a dimensional and dimensionless identification chart for rapidly predicting the oil saturation of tight sandstone is proposed and verified using the measured data. This study provides a basis for analyzing the migration and accumulation mechanisms of tight sandstone oil and a new approach for predicting oil saturation. Additionally, we developed digital and visual analysis methods for the migration results, enriching the expression of the dynamics of hydrocarbon accumulation. [ABSTRACT FROM AUTHOR]

One of the most intriguing phenomena in active matter has been the gas–liquid-like motility-induced phase separation (MIPS) observed in repulsive active particles. However, experimentally, no particle can be a perfect sphere, and the asymmetric shape, mass distribution, or catalysis coating can induce an active torque on the particle, which makes it a chiral active particle. Here, using computer simulations and dynamic mean-field theory, we demonstrate that the large enough torque of circle active Brownian particles in two dimensions generates a dynamical clustering state interrupting the conventional MIPS. Multiple clusters arise from the combination of the conventional MIPS cohesion, and the circulating current caused disintegration. The nonvanishing current in non-equilibrium steady states microscopically originates from the motility "relieved" by automatic rotation, which breaks the detailed balance at the continuum level. This suggests that no equilibrium-like phase separation theory can be constructed for chiral active colloids even with tiny active torque, in which no visible collective motion exists. This mechanism also sheds light on the understanding of dynamic clusters observed in a variety of active matter systems. [ABSTRACT FROM AUTHOR]

A mathematical model of a technical RF inductively coupled plasma is presented. Results of a numerical experiment are reported in which key parameters for a system with five coils and a coupled power of 60 kW at the generator frequency 1.76 MHz were assessed. The distributions of temperature, pressure, flow rate, and current and magnetic flux density are displayed. The numerical experiment presented was carried out using the Magnetic Fields, Laminar Flow, and Heat Transfer modules of COMSOL Multiphysics®. [ABSTRACT FROM AUTHOR]

One of the most intensively developing fields of vibratory technologies is focused on improving the design and operational parameters of the excitation mechanisms and drives. The present research is devoted to a novel twin crank-type exciter driven by a permanent-magnet direct-current motor. The research methodology consists of mathematical modeling and computer simulation of the dynamic behavior of a single-mass oscillatory system equipped with the proposed exciter. The obtained results substantiate the possibilities of generating rectilinear, elliptical, and circular oscillations of the working member by applying the corresponding design changes of the transformable vibration exciter. The major scientific novelty of the carried-out investigations consists in determining the influence of specific design parameters of the exciter on the trajectory (path) of the working member motion. The obtained results can have a significant practical value while designing new and improving existent drives of various vibratory equipment (screens, conveyors, sieves, compactors, technological (lapping, polishing) machines, etc.). [ABSTRACT FROM AUTHOR]

Droplet vibration is an important phenomenon in many technical applications. Correctly predicting the occurring behaviour such as droplet detachment is a challenge for numerical simulations. In this work, a so‐called Navier‐Stokes‐Korteweg model that couples a gas‐liquid phase field to the Navier‐Stokes equations is used to simulate a droplet on a horizontally vibrating surface. Additionally, the equilibrium state of a static droplet on a fixed wall is simulated and the eigenshapes of the static system are investigated. It is found that this static eigenvalue analysis yields possible modes of the dynamic system, and some of the obtained eigenshapes can be recovered in the dynamic simulation. [ABSTRACT FROM AUTHOR]

The stability of railway locomotive is closely related to the safety of railway transportation. A new method for assessing the stability of railway locomotives uses Virtual Reality (VR) technology in conjunction with a dynamic simulation exercise. This paper develops the virtual test technology of railway locomotive running stability and its prototype system, thus shortening the development cycle and guaranteeing the running safety. Additionally, this paper uses numerical simulation and VR as technical support to make a more accurate evaluation of locomotive running stability. This paper utilizes the robust scientific calculation and numerical simulation functions of Matlab and Simulink to realize the simulation control of vehicle model motion and realizes the visual interactive display of railway locomotive running stability test results to realize the automatic analysis and calculation of various railway locomotive coefficients. In the meantime, this paper develops and implements a virtual overhaul system of a railway locomotive based on VR technology and simulates the process of equipment overhaul and disassembly on CAD software in order to ensure the daily inspection, maintenance, and repair of mechanical and electrical equipment of EMU. The system's test results demonstrate that: (1) Matlab can be used as the calculation kernel to realize anti-derailment, anti-overturning, numerical simulation analysis, and calculation of hunting stability of railway locomotives, providing more precise data support for the stable operation of locomotives. (2) The VR-based mechanical and electrical equipment maintenance system can satisfy the needs of maintenance personnel's visual inspection and disassembly simulation in the virtual maintenance environment and improve the realism of the simulation. In order to provide a more accurate virtual simulation of running stability and equipment identification of railway locomotives, the real-time presentation of vehicle stability characteristics in dynamic operation is investigated in this paper. [ABSTRACT FROM AUTHOR]

A new approach is considered for increasing the order of accuracy of the grid-characteristic method in the region of coefficient jumps. The approach is based on piecewise polynomial interpolation for schemes of the second and third orders of accuracy for the case where the interface between the media is consistent with a finite-difference grid. The method is intended for numerical simulation of the propagation of dynamic wave disturbances in heterogeneous media. Systems of hyperbolic equations with variable coefficients are used to describe the considered physical processes. The description of the numerical method and the results of its testing are given. [ABSTRACT FROM AUTHOR]

A simplified theoretical model of the AERORail vehicle-bridge coupling system and a corresponding numerical simulation system in Simulink are established. Based on several widely used methods for modelling and simplifying vehicle systems, the Simulink simulation system used in this study, including the vehicle system and the bridge (AERORail) system, is presented. Identification examples using a moving load model and a simplified 1/4-scale vehicle model are established. The simulation results agree with the data of the simplified dynamic model, with errors between 2.9% and 4.72%, and a satisfactory accuracy is achieved even for single-point signal identification, thereby verifying the correctness of the simplified dynamic model of the AERORail system and the improved time-domain method based on the method of moments. [ABSTRACT FROM AUTHOR]

This paper takes the compact tensile specimens manufactured by glass fiber reinforced composites as the research object. Hopkinson tension bar experimental technique was used to study the dynamic fracture toughness. The dynamic fracture toughness of [0/90]n laminated and [45/− 45]n laminated compact tensile specimens was measured by Hopkinson tension bar experimental device; the simulation calculation under the same stress wave loading was carried out by ABAQUS, and the accuracy was verified by comparing with the experimental results; using the verified simulation model, the effect of specimen thickness and crack length on the dynamic fracture toughness of fiber reinforced composites was studied. [ABSTRACT FROM AUTHOR]

The construction of island airports on coral reefs inevitably encounters the impact load of aircraft takeoff and landing. However, previous studies have not presented a detailed description of the dynamic response of the coral sand beneath the runways of island reclamation airports under aircraft load. In the current study, the coral sand of Mischief Reef Airport in the Nansha Islands, China, was selected as the background. The pore water pressure and strain characteristics of reshaped coral sand under aircraft loads with different dynamic stress amplitudes and vibration frequencies were studied using dynamic triaxial tests. Particle discrete element software was employed to study the deformation characteristics of coral sand with different particle sizes and porosities under aircraft loads. Results show that when the dynamic stress amplitude and vibration frequency were small, the pore water pressure and strain of the coral sand samples gradually increased with the number of load cycles, and the growth rate became increasingly small. When the dynamic stress amplitude and vibration frequency were large, the axial strain of the coral sand samples increased with the vibration frequency, and the growth rate exhibited an increasing trend. The deformation of the coral sand samples increased with porosity under aircraft loading. The larger the variation range of the coral sand particle size was, the larger the coral sand deformation caused by aircraft takeoff and landing load was. These results can provide a reference for the treatment and repair of the airstrip foundation of island airports. [ABSTRACT FROM AUTHOR]

A ring mesh is a large-scale manufacturable structure with versatile applications in architecture and for protective systems. However, the static and dynamic numerical simulation of a large-scale ring mesh is a resource-intensive task due to the many nonlinear contact points between the individual rings. To characterize the rigid body behavior of the ring mesh, in this paper, a representative volume element is loaded under different in-plane directions. The Green-Lagrangian strain tensor components are obtained as a result. An implicit one-step algorithm is used for this dynamic relaxation issue, modified by the use of stiff springs. Static convergence positions of a representative volume element are determined in several multiaxial tensile directions. The obtained deformation parameters can be used to simulate large deformations of large-scaled ring meshes. [ABSTRACT FROM AUTHOR]

Dynamic behavior of agricultural implements has always been a challenging topic for researchers. In precision farming, precise control of the agricultural implements is a very important task. To study the dynamics of agricultural implements, Researchers conduct field experiments as well as laboratory tests. These methods are very costly and the measurements are usually associated with some errors. Providing well-controlled experimental conditions in practice is very difficult, if not impossible. In this article, the capability of the SolidWorks in simulation and predicting the dynamic behavior of a conventional sprayer boom is discussed. To validate the results, field tests were conducted using a conventional sprayer boom. The results showed that there was no significant difference at 95% confidence level between results from computer simulation and those obtained from the field test of conventional sprayer boom. [ABSTRACT FROM AUTHOR]

Tests of dry clay were carried out in a uniaxial stress state using the experimental setup which implements the split Hopkinson pressure bar method. Based on the results of these experiments, the compressive strength of clay was determined as an important element of S.S. Grigoryan's model of the soil medium. In addition, the parameters of this model are determined from the results of experiments using the modified Kolsky method with a sample enclosed in a rigid cage. To verify the model of the soil medium, special experiments were carried out on the penetration of striker with conical tips into dry clay in a reversed settings. Using this identified model in the LS-Dyna software package, numerical simulation of penetration into clay was carried out under conditions similar to those carried out the reversed experiments. Comparison of the results of physical and numerical experiments showed their satisfactory agreement at a dry friction coefficient of 0.5. [ABSTRACT FROM AUTHOR]

Laser direct energy deposition (L-DED) can improve the forming efficiency of parts by controlling laser power, scanning speed, powder flow rate, and spot size. It is a good way to complete the processing and repair of complex parts. In this paper, a three-dimensional numerical model is established to study the dynamic cladding process (pool geometry, energy transfer, and dynamic solidification) of Inconel718 alloy during direct energy deposition. The fluid of volume (VOF) method is used to track the free surface of the melt pool, and the powder source model is established by discrete method. The results show that the molten pool size (area, width, height, depth) of the model is relatively uniform and can predict the shape of the molten pool well. The energy transfer in the molten pool is disturbed to some extent by the metal powder flow. The temperature gradient and cooling rate of the cladding layer are relatively large near the mushy area during the solidification process. [ABSTRACT FROM AUTHOR]

A single sheet of Si nanoclusters with an average diameter of about 2 nm has been formed in a 30 nm Si/7 nm SiO2/Si layer stack by 50 and 60 keV Si+ ion-beam mixing at room temperature and fluences between 8.5 ⋅ 1015 and 2.6 ⋅ 1016 ions/cm2 and by subsequent thermal annealing at a temperature above 1000 °C. Computer modeling of the process is accomplished by TRIDYN dynamic ballistic simulation of ion mixing and subsequent lattice kinetic Monte Carlo simulation of the phase decomposition of substoichiometric silicon oxide into Si nanoclusters in a SiO2 matrix. The simulation algorithms are briefly described with special emphasis on the choice of governing parameters for the present system. In comparison to the experimental results, it is concluded that the predicted ion mixing profiles overestimate the interface broadening. This discrepancy is attributed to the neglect of chemical driving forces in connection with thermal-spike induced diffusion, which tends to reconstitute the Si/SiO2 interfaces. With a corresponding correction and a suitable number of Monte Carlo steps, the experimentally obtained areal densities and average diameters of the nanoclusters are successfully reproduced. [ABSTRACT FROM AUTHOR]

The electric field fire extinguishing technology is an efficient, clean, and new fire extinguishing technology that can be operated at a long distance. In order to study the synergistic mechanism of "electric-flow-heat" in the process of transverse AC electric field fire extinguishing, the ionic wind formed by the influence of electric field on each charged particle during the burning process of ethanol–air diffusion flame is simulated by the non-premixed combustion model, and the experimental phenomenon of flame quenching in the transverse AC electric field is reproduced by means of numerical simulation. The accuracy of the numerical model was verified by comparing the temperature and flow velocity in the region obtained from the simulation with the data measured in the experiment. According to both simulated and experimental phenomena, we present a hypothesis of how the flame is quenched under the influence of an electric field. The next research directions are: (1) improving the accuracy of numerical simulation by building fine models; (2) studying the dynamic mechanism of real flames by particle image velocimetry technology. [ABSTRACT FROM AUTHOR]

• A coupling mechanism model of an FSDB unit is developed and verified. • Mathematical analysis is explored to reveal the coupling mechanism of an FSDB system. • Rigid and elastic motions of disk and cyclic blades induce diagonal and cross-coupling terms. • The motion patterns of cyclic blades are classified and clarified. • Effects of motion patterns of cyclic blades on NFs and CSs are applied to interpret and validate the dynamic coupling. This paper focuses on the influence mechanism of cyclic blades on the dynamic coupling of a flexible shaft-disk-blade (FSDB) system through mathematical analysis and numerical simulation. Firstly, a coupling mechanism model of an FSDB unit is developed through a Lagrange method and the assumed mode method (AMM), after considering the coupling behavior among shaft bending, shaft torsion, disk vibration, and blade bending. The modal comparison results between the proposed model and FEM affirm the validity of the model. Then the analytical interpretation is explored by decomposing and discussing the diagonal coupling and cross-coupling matrices of the FSDB system. The mechanism discussion reveals that the coupling matrices originate from the rigid and elastic motions of flexible disk and cyclic blades, indicating that the motions of cyclic blades play an important role in dynamic coupling. Therefore, the motions of cyclic blades are classified and analyzed, and their effects on natural frequencies (NFs) and critical speeds (CSs) are applied to further interpret and validate the dynamic coupling through numerical simulation. The numerical results indicate that motions of cyclic blades can increase, decrease, and eliminate the magnitude of dynamic coupling significantly. [ABSTRACT FROM AUTHOR]

This paper presents an investigation on the compressible flow past spanwise wavy wings with an incoming flow of M ∞ = 0.5 and R e = 10 7 . The scale adaptive simulation is employed here to solve the Favre-averaged equations. Three wings, with the ratio of wavelengths (λ) to chord length (c) respectively equaling to 1/2 (W4), 1/3 (W6), 1/4 (W8), are aerodynamically investigated. The aerodynamic force and separation were compared. The results obtained show that the lift-to-drag ratio of W-8 is 12.7% and 14.4% higher than W-4 and W-6 because of the larger low-pressure regions, while the lift and drag coefficient curves of W-8 oscillate more strongly. Leading edge separated bubbles and dilation-type recirculation regions are observed in the flow field structures. Spanwise momentum transportation and local airflow downwash effect are generated by the flow around the separation regions. Spanwise momentum transportation and downwash effect play important roles in the flow control mechanism of spanwise wavy wings. Three components of three-dimensional velocity vectors are modally decomposed by dynamic mode decomposition method to reveal the flow control mechanisms and vortex structures. The main modes characterizing the motions of arched vortices and shear layer vortices have been obtained. Strouhal number (St) is adopted to define the periodic oscillations of vortex shedding. The St of the modes are related to the scale of the vortex structures in the flow field. Small-scale eddy motions have been decomposed in high-frequency modes, and thus the modes of the flow field are more meticulous for higher St. [ABSTRACT FROM AUTHOR]

Crack behavior at the interface between two materials is the core problem of layered material fracturing. In this paper, first, experimental tests were conducted on layered material using a drop weight test system following the caustics method. The layered material was made of poly (methyl methacrylate) (PMMA) and epoxy resin bonded with Loctite‐330 at two inclination angles (30° and 60°). A corresponding numerical simulation was carried out using continuum–discontinuum element methods. Crack propagation is found to mainly occur in mode I in the PMMA and epoxy resin but follows a mixed cracking mode at the interface. The fracture parameters of the crack tip in the layered materials changed substantially owing to the existence and change of the interface structure. After the crack enters the interface, the crack propagation speed increases significantly. Higher crack dip angles are associated with greater crack propagation speed increases after entering the interface. The simulation results indicate that the interface strength properties affect crack behavior at the interface. This effect also varies as a function of interface inclination and impact velocity. Highlights: Caustics method is used to study fracture parameters of layered material.A mixed‐mode fracture model is implemented into CDEM to simulate interface crack.Effect of strength properties on interface crack are simulated.Effect of impact velocity on interface crack are simulated. [ABSTRACT FROM AUTHOR]

The Francis hydro-turbine is a typical nonlinear system with coupled hydraulic, mechanical, and electrical subsystems. It is difficult to understand the reasons for its operational failures, since the main cause of failures is due to the complex interaction of the three subsystems. This paper presents an improved dynamic model of the Francis hydro-turbine. This study involves the development of a nonlinear dynamic model of a hydraulic unit, given start-up and emergency processes, and the consideration of the effect of water hammer during transients. To accomplish the objectives set, existing models used to model hydroelectric units are analyzed and a mathematical model is proposed, which takes into account the dynamics during abrupt changes in the conditions. Based on these mathematical models, a computer model was developed, and numerical simulation was carried out with an assessment of the results obtained. The mathematical model built was verified on an experimental model. As a result, a model of a hydraulic unit was produced, which factors in the main hydraulic processes in the hydro-turbine. [ABSTRACT FROM AUTHOR]

In this paper, we report numerical simulations for dynamic fracture and fragmentation problems in brittle materials using a recently developed split strain energy diffusive mass-field damage model in terms of standard finite element method (FEM). The enhanced constitutive laws for mass source and mass flux by means of strain energy decomposition are adopted to overcome certain drawbacks of the original non-split model. We present theoretical formulations in a more general way that is suitable and valid for both small and finite deformation regimes. The coupled system of equations is derived in which the momentum is governed to describe the time-dependent deformation of brittle solids whereas the mass-diffusion balance equations are for the evolution of mass density. We also develop simple techniques for determining crack velocity and estimating amount of mass loss. Numerical examples are considered for both small and finite deformations. The accuracy and performance of the developed theory for dynamic brittle fracture are illustrated through comparison and verification, which are to compare the computed results with respect to experimental data and other numerical methods in terms of crack path trajectories, dynamic response, energy dissipation, and other relevant numerical aspects. • Dynamic description of localized mass-field damage model at finite deformation for brittle fracture is presented. • Localized mass-field damage model enhanced by energy decomposition for dynamic analysis is used. • Dynamic crack propagation for problems with complex geometries and fragmentation simulation are studied. • Prediction of dissipated energy agrees well with the theoretical value. • It provides an alternative approach for modeling dynamic fracture in solids. [ABSTRACT FROM AUTHOR]

To alleviate the deterioration in wind turbine performance caused by dynamic stall, the flow control of a pitching NACA0012 airfoil is investigated through numerical simulation of an alternating current dielectric barrier discharge (AC-DBD) plasma actuator at a Reynolds number Re = 135 000. To avoid the harmonic oscillations of aerodynamic force caused by unsteady DBD actuation, this work focuses on improving the control potential for steady actuation. The control mechanisms of actuators at various positions are investigated using five groups of actuators mounted at 0%, 3%, 10%, 45%, and 80% chord lengths c above the upper surface of an airfoil. The actuator at 80%c performs more efficiently in terms of lift enhancement in the initial upstroke and the final downstroke. The actuator at 0%c suppresses the growth of the leading-edge vortex and maintains the suction of the dynamic stall vortex (DSV). After the shedding of the DSV, it suppresses the secondary separation to delay the onset of dynamic stall. At the flow reattachment stage, the actuators at 3%c and 10%c accelerate the boundary layer reattachment by momentum injection. From these results, a multi-DBD control strategy is proposed. The scheme selects the optimal actuator in operation at a certain stage of dynamic stall and takes advantage of actuators at different positions to enhance the average and maximum aerodynamic force, delay the onset of dynamic stall, accelerate flow reattachment, and avoid excessive energy consumption. [ABSTRACT FROM AUTHOR]

• Phase-field virtual modelling method (PFVM) is proposed for dynamic fracture in elasto-plastic materials. • Full-field uncertainties of PFVM enable reliable tracking of non-deterministic cracks. • The exceptional capability of PFVM in complex 3D conditions is demonstrated. • PFVM is validated in practical cases with both precision and efficiency. In modern engineering, dynamic fracture failure because of unexpected load or human faults may lead to catastrophic disasters. Preventive structure design and real-time maintain suggestions based on accurate numerical simulation are critical, especially when plasticity develops. It remains a challenge to efficiently model dynamic crack propagation in elasto-plastic materials while the uncertain factors in service life may significantly increase the difficulty. In this paper, a phase-field virtual modelling method (PFVM), based on the features of the novel extended support vector regression (X-SVR) method, is proposed to tackle this non-deterministic problem. The phase field method is adopted for its outstanding performance in complex fracture problems, which provides solid reference data for the virtual model's training and verification. The PFM application to dynamic elasto-plastic fracture problems is validated in two practical engineering examples. The integrated virtual modelling technique is then proven capable of instantly providing precise crack propagation prediction under multiple complex uncertainties, making up-to-date numerical dynamic fracture simulation achievable and affordable. The proposed PFVM method can minimize the contradiction between accurate modelling and high computational cost and can be utilized in various extensions like sensitivity analysis or design optimization. [ABSTRACT FROM AUTHOR]

Knowledge about factors affecting the dynamic response process is crucial for development of mixed-potential gas sensor for various applications such as hydrogen detection. Based on a double layer capacitor model and the Butler-Volmer equation, the present work studied the dynamic hydrogen sensing process by numerical simulation in combination with experimental assessment. Simulation shows that both response and recovery times are jointly determined by the decrease rate of the net reaction current and the magnitude of response. Increase of standard reaction rate constants, transfer coefficients, standard equilibrium potential, or gas concentrations accelerates both the response and recovery processes, while double layer capacitance has a reverse effect. A power-law concentration dependence of the response/recovery time is obtained under Tafel kinetics. The simulated response curves and behavior agree quite well with the experimental results. These findings shed lights on the sensing kinetics of the mixed-potential hydrogen sensor, and may help guide the sensor design. • Theoretical and experimental study of dynamic mixed-potential gas sensing process. • Factors function via tuning decrease rate of net reaction current and response value. • Materials of high electrochemical activities favor the sensing dynamics. • Power-law concentration dependence of response time under Tafel kinetics. [ABSTRACT FROM AUTHOR]

A 3D dynamic finite element model is developed to study the response of the existing tunnels' concrete structure under the influence of different train speeds and undercrossing with fixed shield excavation. The intersection area of Metro Line 3 in Guangzhou and the intercity railway between Foshan and Dongguan is used as the case study. A programming idea simulating oblique moving-axle loads in the numerical model by using function expressions to constrain activity area is proposed. The Hilber–Hughes–Taylor time-integration scheme is used to calculate the dynamic response parameters of the double-channel rectangular cross section tunnels. Considering fixed excavation steps in the process of shield crossing, acceleration and deformation of the existing tunnels were analyzed under the moving-axle loads of trains at different speeds. From the perspective of the vibration and deformation of existing tunnels, shield excavation and moving speed have their own emphasis on the dynamic influence of the existing tunnel. In addition, the calculation results of the numerical simulation are in good agreement with the data obtained from some field tests, which further verifies the reliability of the calculation method of the numerical model. The results of this research can guide the arrangements for reinforcement measures for existing tunnels in the later stage. [ABSTRACT FROM AUTHOR]

The application of Internet of Things (IoT) technology has realized the transformation of people's production and lifestyle, and also promoted the transformation of education and teaching mode. At present, the application of informatization in the field of product packaging is increasing. Advanced methods and techniques for visual presentation using virtual reality technology. This study has aimed to realize the process optimization of new energy product packaging design in the context of the Internet of Things to promote the ecological development of the product packaging industry. This study has proposed to use the IoT technology and virtual reality technology to know the integration of new energy product packaging and virtual simulation experiments, which is helpful to analyze and solve the objective system imbalance and ecological imbalance in the product packaging system. Drawing on the principles and laws of the IoT and virtual reality technology, the dynamic simulation process of ecological packaging is constructed and optimized to realize the "ecologicalization" of the packaging field. In a study of RFID tag algorithms in the context of IoT, the least data is transmitted at m = 4, which saves an average of 48 bits per identified tag compared to m = 6. Due to the number of queries and the amount of data transferred, the MICT algorithm chooses m = 4 when identifying 96-bit tags. In terms of recognition efficiency, the MICT algorithm achieves about 74%. Therefore, the dynamic simulation design of product packaging is very important at present. [ABSTRACT FROM AUTHOR]

This paper proposes a three degree-of-freedoms (DOFs) cable-driven parallel robot (CDPR), which is actuated by three groups of parallel cables and tensioned by an elastic telescopic rod with a passive spring. Firstly, the architecture of the robot is briefly illustrated with emphasis on the three parallelogram arrangements of the cables and composition of elastic telescopic rod structure. This robot has larger workspace and greater tension than previous under-constrained CDPRs. Secondly, the kinematic and dynamic models of the robot are established. On this basis, the parameters of the spring installed in the telescopic rod are optimized and determined considering both the acceleration and cable force through using the differential evolution (DE) algorithm. Thirdly, dynamic stability analysis of the robot under impulsive disturbances is performed according to the Gauss principle of least constraint (GPLC). The results of a simulation case show that this robot has better dynamic stability in comparison with conventional under-constraint CDPR because of the presence of the elastic telescopic rod. The measurement results in the workspace are obtained through dynamic simulation. Finally, the experiments are performed based on numerical simulation. The feasibility of the CDPR is verified via the experiments and simulations. [ABSTRACT FROM AUTHOR]

Tillage is the most energy-intensive agricultural operation. In the actual energy situation it is important to explore and analyze the physical laws of soil cultivation processes, which demand increased energy, at the border of technical- and agricultural sciences. In this paper, the physical phenomena that occur during soil work with a rotary tiller were studied, and the energy requirements were approximated by computer simulation using Matlab Simulink environment. The model used was a simplified solid model of an FPP-1.3 type rotary tiller, used previously in real experiments to determine fuel consumption at various working parameters. The results obtained by the dynamic simulation were compared with the real measurements. [ABSTRACT FROM AUTHOR]

With the continuous expansion of computer system simulation applications, the dynamic system modeling problems that people face have become more and more complex. This paper mainly studies dynamic system simulation models and algorithms based on artificial neural networks. This article mainly focuses on some practical problems of dynamic system simulation, and studies the artificial neural network model and corresponding algorithm suitable for dynamic system modeling. First, it summarizes the existing artificial neural network simulation models of dynamic systems: multi-layer feedforward network relationship model without feedback, recursive network relationship model with feedback, and their network topology diagrams are drawn. Secondly, a quantum genetic algorithm is proposed to optimize the parameters of artificial neural networks and feedforward process neural networks. To achieve the preprocessing of the parameters. Next, based on the analysis and research of BP neural network theory, this paper comprehensively compares the neural network models established under various network structures and algorithms, and establishes the simulation model based on the BP neural network monitoring data system, and compares the results with the monitoring data obtained in the field. The hidden layer of neural network with 4 and 6 nodes will increase the convergence step. When the number of nodes is 10 and 12, the convergence rate may reach 46 steps. This shows that if the non-display layer with different number of nodes in the same layer is selected for the same system simulation model based on artificial neural network, the repetition number of convergence steps of the prediction model will be different. [ABSTRACT FROM AUTHOR]

Small-caliber steel core projectiles fired by light weapons pose a great threat to metal structures. Coating with polyurea (PU) is a potential option to improve the anti-penetration performance of metal structures. In this work, we carried out numerical simulations to clarify the dynamic characteristics of PU-coated ASTM1045 steel plates subjected to oblique penetration by 5.8-mm small-caliber steel core projectiles. The failure modes, dynamic response process, energy absorption characteristics, and comprehensive protection effects of target plates with different coating positions and thicknesses during the penetration process were compared and analyzed. The result showed that coating with a certain thickness of PU could enhance the protection ability of the steel plate against the oblique penetration of projectiles. In contrast to the results obtained from experiments in which the projectile penetrated the composite plate normally, when the PU coated both sides, the effect of improving the oblique penetration resistance of the steel plate was the best. The effect was lowest with a PU layer only on the back face. This study provides a reference for strengthening the bulletproof performance of various systems, including steel structures, weapons, and vehicles. [ABSTRACT FROM AUTHOR]

This study used two-stage cyclones combined with a full cylinder and a short cone cyclone to recover super-low ash clean coal from the coal slime to solve problems of coal slime such as large production, difficult recovery, and low value-added used. After two-stage cyclones separation and screening, super-low ash clean coal with an ash content of 2.74% was obtained, and the mass yield was 10.56% via a simple and easy method that realized high value-added utilization of coal slime. The separation test indicated that the grading effect caused the first-stage cylinder to remove a large amount of high-ash fine mud in the coal slime and water, decreased the complexity of the particle size, and provided favorable conditions for the density separation of the second-stage cyclone. Through density separation effect in the second-stage cyclone, the recovery of −1.3 g/cm3 density grade in Cyc.O/F is 84.15%, which led to effective coal recovery. Additionally, its cutting density exceeds 2 g/cm3. Computational fluid dynamic simulations indicate that the high turbulence zone corresponds to the main gradation and separation action area and the high turbulence due to the existence of circulating flow, due to its circulating flow, particle separation and grading is obtained. [ABSTRACT FROM AUTHOR]

In this paper, an efficient numerical scheme is proposed to simulate the high-frequency dynamic mechanical response of single-crystalline Ni–Mn–Ga samples. First, based on a three-dimensional setting, the governing equation system for a single-crystalline Ni–Mn–Ga sample is set up, which is composed of the equation of motion and the twin interface movement criteria. In order to solve the governing system, an iterative numerical algorithm is proposed, in which the finite element method and the NewMark-β method are applied. To demonstrate the efficiency of this numerical scheme, the response of a single-crystalline Ni–Mn–Ga sample under some typical loading conditions are studied. In the numerical simulations, a specific discretisation of the sample is adopted, such that the possible positions of the twin interfaces in the sample can be naturally inherited. With the obtained numerical results, the mechanical behaviours of the sample under the different loading conditions are predicted, which show good consistency with the experimental results. The distribution of variant state and the propagation of twin interfaces in the sample can also be simulated. The numerical scheme proposed in the current work is helpful for the design of novel sensors or actuators based on single-crystalline Ni–Mn–Ga alloys. [ABSTRACT FROM AUTHOR]

Background Many THA simulation models rely on a limited set of preoperative static radiographs to replicate sagittal pelvic tilt during functional positions and to recommend an implant orientation that minimizes the risk of prosthetic impingement. However, possible random changes in pelvic or lower extremity angular motions and the effect of coronal and axial pelvic tilt are not included in these preoperative models. Questions/purposes (1) Can prosthetic impingement occur if the pelvic tilt or lower extremity alignment randomly varies up to 6 5° from what is measured on a single preoperative static radiographic image? (2) Do changes in coronal and axial pelvic tilt or lower extremity alignment angles have a similar effect on the risk of prosthetic impingement? Methods A de-identified pelvis and lower-body CT image of a male patient without previous THA or lower extremity surgery was used to import the pelvis, femur, and tibia into a verified MATLAB computer model. The motions of standing, pivoting, sitting, sit-to-stand, squatting, and bending forward were simulated. THA implant components included a full hemispherical acetabular cup without an elevated rim, polyethylene liner without an elevated rim, femoral head (diameter: 28 mm, 32 mm, 36 mm, or 40 mm), and a triple-taper cementless stem with three different neck shaft angles (127°, 132°, or 135°) with a trapezoidal neck were used in this model. A static model (cup anatomical abduction 40°, cup anatomical anteversion 20°, stemanatomical anteversion 10°) with a predefined range of sagittal pelvic tilt and hip alignment (0° coronal or axial tilt, without random ± 5° change) was used to simulate each motion. We then randomly varied pelvic tilt in three different pelvic planes and hip alignments (flexion, extension, abduction, adduction, rotation) up to ± 5° and assessed the same motions without changing the implant's anatomical orientation. Prosthetic impingement as the endpoint was defined as mechanical abutment between the prosthetic neck and polyethylene liner. Multiple logistic regression was used to investigate the effect of variation in pelvic tilt and hip alignment (predictors) on prosthetic impingement (primary outcome). Results The static-based model without the randomvariation did not result in any prosthetic impingement under any conditions. However, with up to 65° of random variation in the pelvic tilt and hip alignment angles, prosthetic impingement occurred in pivoting (18 possible combinations), sit-to-stand (106 possible combinations), and squatting (one possible combination) when a 28-mm or a 32-mm head was used. Variation in sagittal tilt (odds ratio 4.09 [95%CI 3.11 to 5.37]; p < 0.001), axial tilt (OR 3.87 [95% CI 2.96 to 5.07]; p < 0.001), and coronal tilt (OR 2.39 [95% CI 2.03 to 2.83]; p < 0.001) affected the risk of prosthetic impingement. Variation in hip flexion had a strong impact on the risk of prosthetic impingement (OR 4.11 [95% CI 3.38 to 4.99]; p < 0.001). Conclusion The combined effect of 2° to 3° of change in multiple pelvic tilt or hip alignment angles relative to what is measured on a single static radiographic image can result in prosthetic impingement. Relying on a few preoperative static radiographic images to minimize the risk of prosthetic impingement, without including femoral implant orientation, axial and coronal pelvic tilt, and random angular variation in pelvis and lower extremity alignment, may not be adequate and may fail to predict prosthetic impingement-free ROM. Clinical Relevance Determining a safe zone for THA implant positioning with respect to impingement may require a dynamic computer simulation model to fully capture the range of possible impingement conditions. Future work should concentrate on devising simple and easily available methods for dynamic motion analysis instead of using a few static radiographs for preoperative planning. [ABSTRACT FROM AUTHOR]

Digital controllers are involved in every aspect of today's power systems, from local device-level to wide-area supervisory applications. However, the existing dynamic simulation tools are still struggling to capture an accurate response of such systems with adequate computational performance. The reason is that digital controllers introduce numerous discontinuities to the simulation and handling them is computationally expensive, thus forcing the users to compromise between accuracy and simulation performance. This paper investigates different traditional approaches for incorporating digital controllers in power system dynamic simulations and compares them with new interpolation-based approaches in terms of simplicity, accuracy, and performance. • Reviewing methods for numerical simulation of power systems with digital controllers. • Comparing the methods using case studies in terms of accuracy, and performance. • Providing insights on the Jacobian formulation, and their impact on performance. [ABSTRACT FROM AUTHOR]

• The secondary loop system of Hua-long Pressurized Reactor is established. • Steady-state data and dynamic response processes are presented. • Nuclear power unit abnormal operating conditions are simulated. • Model could be used for control strategy development and the results provide reference for safety criteria. Dynamic simulations of nuclear power plant behaviors are critical in plants' lifecycle. However, accurate modeling of nuclear plants is quite a challenge due to the intrinsic complexity involved in the highly coupled processes. In this study, a dynamic model is established to investigate the dynamic characteristics of the secondary circuit system of HPR1000. Specifically, the major components are modeled using lumped parameter method. In addition, model validation is carried out according to the operational data of plants, in which three typical abnormal operating conditions were simulated and analyzed. The results show that the developed model has an error of less than 5% during steady state modeling, and the dynamic response is consistent with the actual operation performance of the plants. Therefore, the dynamic model could be used for control strategy development and accident simulation of the HPR1000. And the simulation provides a basis for the establishment of safety criteria. [ABSTRACT FROM AUTHOR]

In this paper, a novel numerical simulation approach based on the finite element method for dynamically modeling the excavation process of shield tunneling is proposed, with the shield-ground interactions well captured. This method is capable of mimicking the alternating modes of advancing and stopping of a shield boring machine during underground construction, with the important effects of the cutterhead rotation and slurry support pressure considered. Under the cutting action, the soil at the excavation face would experience irreversible deformation and damage, such that additional support needs to be provided by the cutterhead blades and slurry to maintain stability. The impacts of key construction parameters are examined, including cutterhead rotary speed, advance rate, and slurry support pressure, on shield tunneling operations and ground responses. The numerical model is rigorously validated against physical model experiments. This work provides useful insights into the mechanistic processes in the stratum during shield tunneling, including the spatiotemporal evolution of ground deformation patterns and stress redistributions. The results offer valuable guidance for optimizing shield tunneling operations and enhancing tunneling safety and efficiency. [ABSTRACT FROM AUTHOR]

Intersecting orthogonal strike‐slip faults with opposite senses of slip pose the question of what allows rupture to propagate through the junction and through both faults versus confining rupture to a single fault. I conduct dynamic rupture simulations on simplified orthogonal strike‐slip fault systems, to determine which conditions produce rupture on both component faults. In models with uniform initial tractions on both faults, slip on the first fault must reduce normal stress on the second fault for it to rupture. If the first fault ends at the cross fault, a stopping phase causes the cross fault to rupture. In models where I resolve a uniform regional stress field on the faults, only a narrow range of stress orientations allow multifault ruptures. These results will be helpful for evaluating hazard near orthogonal strike‐slip faults. Plain Language Summary: There are many examples around the world where two strike‐slip earthquake faults cross each other at nearly 90° angles. This is not remarkable when only one of the faults in a pair causes an earthquake, but it becomes notable when two or more crossing faults move at the same time. This raises the question of what causes the second fault to get involved, or not. To address this question, I use computer simulations of the physics of the earthquake process to test dozens of different fault configurations and earthquake starting points. I find that the location where the earthquake starts on the first fault controls whether the second fault is made stronger versus weaker, and therefore whether both faults can move together in one earthquake. These results can help us understand earthquake hazard around crossing faults. Key Points: Nucleation location effectively controls whether multifault rupture occurs on orthogonal strike‐slip fault systemsA stopping phase from rupture reaching the end of one fault is often required to initiate rupture on the cross faultOnly a narrow range of regional stress orientations allows both cross‐faults to rupture [ABSTRACT FROM AUTHOR]

Modeling and computer study of a composite nanostructure containing a ferroelectric PVDF polymer and graphene layers were carried out in this work by molecular dynamic simulation and semiempirical quantum PM3 RHF method using the HyperChem software. It is shown here that the inclusion of graphene layers into the PVDF ferroelectric polymer increases the coercive field and decreases the polarization switching time of this composite structure. It is possible due to decrease in the damping coefficient of the Landau-Khalatnikov kinetic equation of the Landau-Ginzburg-Devonshire theory for two-dimensional ferroelectrics. Heterostructures with adjustable polarization switching times can be constructed based on such approach. [ABSTRACT FROM AUTHOR]

A submerged floating tunnel (SFT) is considered an innovative alternative to conventional bridges and underground or immersed tunnels for passing through deep water. Assessment of hydrodynamic performance of SFT under regular wave loading is one of the important factors in the design of SFT structure. In this paper, a theoretical hydrodynamic model is developed to describe the coupled dynamic response of an SFT and mooring lines under regular waves. In this model, wave-induced hydrodynamic loads are estimated by the Morison equation for a moving object, and the simplified governing differential equation of the tunnel with mooring cables is solved using the fourth-order Runge–Kutta and Adams numerical method. The numerical results are successfully validated by direct comparison against published experimental data. On this basis, the effects of the parameters such as the cable length, buoyancy-weight ratio, wave period, wave steepness, and water/submergence depth on the dynamic response of the SFT under wave loading are studied. The results show that tunnel motions and cable tensions grow with wave height and period and decrease with submergence depth. The resonance of the tunnel will be triggered when the wave period is close to its natural vibration period, and the estimation formula of wave period corresponding to tunnel resonance is proposed in this paper. [ABSTRACT FROM AUTHOR]

High-temperature superconducting (HTS) magnetic levitation (maglev) has the potential to be a high-speed transportation mode owing to its passive stabilization. The interaction between the vehicle and the track is an important issue in vehicle dynamics, especially for the engineering application. This paper investigates the relationship between the levitation force and motion displacement and velocity of the engineering prototype by numerical simulation and parameter identification method. Firstly, an electro-magnetic-thermo coupled finite element (FE) model is established to simulate the quasi-static levitation force of an HTS model vehicle. The simulation parameters are obtained by comparing them with the experimental data. Secondly, a motion equation is coupled with the FE model to establish an electro-magnetic-thermo-mechanical coupled dynamic model for the vibration process of the model vehicle. This dynamic FE model is also verified by experimental data. Thirdly, the dynamic model is applied to simulate the vibration process of an engineering prototype. Finally, a mathematical model of dynamic levitation force is established by combining this dynamic FE model with a parameter identification method. The mathematical model provides support for the research of vehicle-track coupled dynamics of engineering vehicles. [ABSTRACT FROM AUTHOR]