Dynamic Interaction Analysis Research Articles

Dynamic Interaction Analysis and Damping Control Strategy of Hybrid System With Grid-Forming and Grid-Following Control Modes

The dynamic behavior of converters with different synchronous control modes is significantly different. Therefore, the renewable energy grid-connected system cannot be equivalent as the same type of power electronics equipment. There are dynamic interactions among the multiple time scale controllers of each equipment, which may lead to the small signal instability of the hybrid system. In this paper, a hybrid grid-connected system with phase-locked loop (PLL) controlled doubly fed induction generator (DFIG) and virtual synchronous generator (VSG) controlled converter is studied. On the basis of the open-loop modal resonance theory, the mechanism of small signal instability of hybrid system is revealed from the perspective of mode interaction. Furthermore, a design method of additional damping controller is proposed based on normal matrix, which can achieve the minimum eigenvalue sensitivity of the hybrid system and avoid the interaction between different control loops. Finally, a hybrid system including a grid-forming VSG system and a grid-following DFIG wind farm is investigated in this paper. The correctness and effectiveness of interaction analysis and damping control strategy are confirmed by the results of modal analysis and simulation.

An isoparametric element permutation method for railway tunnel–soil interaction modeling in train–track–tunnel–soil dynamic analysis

For evaluating the ground vibration involving metro tunnel operation, it is of necessity to extend the train-track-tunnel near-filed vibration to the train-track-tunnel-soil far-filed vibration in viewpoint of numerical analysis. It therefore becomes a key technology to achieve the tunnel-soil coupling simulation. In this work, a isoparametric element permutation method is proposed, where the 6-node triangular prismatic elements and 8-node spatial isoperimetric elements have been effectively integrated to achieve the finite elemental modelling of the soil system with the tunnel penetrating. The tunnel and soil subsystems are coupled by the spring-dashpot elements. Once the tunnel satisfies symmetrical property in geometry, the proposed method can be applied to build the tunnel-soil interaction by parametric finite element modelling. Through a combination of this proposed tunnel-soil interaction model and the train-track-tunnel dynamic model, a unified model for characterizing the train–track–tunnel–soil dynamic interaction analysis is constructed within the finite element framework. By comparing the simulation results to the measurements in site, the effectiveness of this model is validated, through which track, tunnel, and ground vibrations can be assessed in an entirely coupled way. Through the numerical studies, it is known that both the number of tunnel lines and the number of trains in operation and their running modes hold significant influence and show different vibration attenuation law on ground vibrations, and quantitative analysis can be achieved through this present work.

Resonance reduction for linked train cars moving on multiple simply supported bridges

The dynamic interaction of a moving train over a series of railway bridges with equal spans can result in a coupled vibration problem of wave transmission between two periodic structures. Dual resonance occurs when both systems vibrate in phase and the train travels at a resonant speed. The objectives of this paper are to (1) develop an active pitching resonator (APR) to attenuate resonance waves in a train; (2) study the dispersion relation for pitching motion control of periodically linked train cars; (3) investigate the key parameters that affect the dispersion band gaps of wave attenuation in a train; (4) present an active vibration cancellation method to enhance the control performance of the APR; and (5) demonstrate the effectiveness of using the optimal APRs to reduce resonance of a moving train. Through dispersion analysis, the optimum APR can not only shift the target frequency level away from resonance of a moving train, but also create a wide resonance band gap to reduce wave transmission in the train. Finally, the effectiveness of the optimum APR unit in reducing the resonance and attenuating the waves of a train travelling over multiple-span simple beams is demonstrated by dynamic finite element analysis of the train-bridge interaction.

Evaluation of Module Dynamics in Functional Brain Networks After Stroke.

The brain's functional network can be analyzed as a set of distributed functional modules. Previous studies using the static method suggested the modularity of the brain function network decreased due to stroke; however, how the modular network changes after stroke, particularly over time, is far from understood. This study collected resting-state functional MRI data from 15 stroke patients and 15 age-matched healthy controls. The patients exhibit distinct clinical symptoms, presenting in mild (n = 6) and severe (n = 9) subgroups. By using a multilayer network model, a dynamic modular structure was detected and corresponding interaction measurements were calculated. The results demonstrated that the module structure and interaction had changed following the stroke. Importantly, the significant differences in dynamic interaction measures demonstrated that the module interaction alterations were not independent of the initial degree of clinical severity. Mild patients were observed to have a significantly lower between-module interaction than severe patients as well as healthy controls. In contrast, severe patients showed remarkably lower within-module interaction and had a reduced overall interaction compared to healthy controls. These findings contributed to the development of post-stroke dynamics analysis and shed new light on brain network interaction for stroke patients.Clinical relevance- Dynamic module interaction analysis underpins the post-stroke functional plasticity and reorganization, and may enable new insight into rehabilitation strategies to promote recovery of function.

Dynamic interaction analysis of a high-speed train vehicle and a thin-walled curved box-girder bridge with a sub-track system by finite element method

Dynamic interaction analysis of a high-speed train vehicle and a thin-walled curved box-girder bridge with a sub-track system by finite element method

Isobaric Stable Isotope N-Phosphorylation Labeling (iSIPL) for Ultrasensitive Proteome Quantification.

Stable isotope chemical labeling methods have been widely used for high-throughput mass spectrometry (MS)-based quantitative proteomics in biological and clinical applications. However, the existing methods are far from meeting the requirements for high sensitivity detection. In the present study, a novel isobaric stable isotope N-phosphorylation labeling (iSIPL) strategy was developed for quantitative proteome analysis. The tryptic peptides were selectively labeled with iSIPL tag to generate the novel reporter ions containing phosphoramidate P-N bond with high intensities under lower collision energies. iSIPL strategy are suitable for peptide sequencing and quantitative analysis with high sensitivity and accuracy even for samples of limited quantity. Furthermore, iSIPL coupled with affinity purification and mass spectrometry was applied to measure the dynamics of cyclin dependent kinase 9 (CDK9) interactomes during transactivation of the HIV-1 provirus. The interaction of CDK9 with PARP13 was found to significantly decrease during Tat-induced activation of HIV-1 gene transcription, suggesting the effectiveness of iSIPL strategy in dynamic analysis of protein-protein interaction in vivo. More than that, the proposed iSIPL strategy would facilitate large-scale accurate quantitative proteomics by increasing multiplexing capability.

Dynamic analysis of layered soil-pile interaction based on the nearly continuous model

A new nearly continuous model of layered soil-pile interaction (LSPI) is developed in this paper. The surrounding soil is modelled as an axisymmetric continuum and stratified in the vertical direction with consideration of the continuity of adjacent soil layers. The pile is modelled as an elastic cylindrical rod. The Cosine transform method is introduced to obtain theoretical solutions for the dynamic impedance and velocity of the pile head under vertical dynamic load. The reasonability and superiority of the LSPI model are validated by comparisons with previous solutions and field testing results. Dynamic analysis is conducted by a series of practical arithmetic examples, which demonstrate that soil heterogeneity leads to an increase in the number of cut-off frequencies and the dynamic behaviors of piles are more significantly influenced by the upper soil layer. Results obtained provide valuable insight into the dynamic design of piles and the signal analysis of pile integrity tests.

Dynamic Interaction Analysis and Running Safety Assessment of the Wind–Train–Bridge System Considering the Moving Train’s Aerodynamic Coupling with Crosswind

Trains tend to be faster and lighter to meet the increasing public travel needs and interact with crosswind to produce a strong aerodynamic interaction, leaving a safety hazard for the operation. This paper presents a study into the dynamic response and running safety of the train–bridge system accounting for this aerodynamic interaction. The threedimensional flow features of a moving train in crosswinds are first investigated by a computational fluid dynamics method, and then an aerodynamic model for simulating unsteady crosswind force is developed. Furthermore, the dynamic responses of the train and bridge are calculated by using a wind–train–bridge dynamic interaction equation, and finally, the characteristic wind curve and surface are defined to evaluate the train’s running safety. The results show that the lateral response of the train–bridge system significantly increases as the crosswind increases, and the head car can experience a high derailment risk and determine the running safety of the train due to the aerodynamic coupling effect of a moving train and crosswind. Variations in the wind direction need to be factored into the safety assessment for low train speeds, and the train is at greater danger when the crosswind appears perpendicular to the car body.

Study on the Interaction Effect between the Intensity of Government Low-Carbon Subsidies and the Growth Ability of Green and Low-Carbon Emerging Enterprises.

With the development of science and technology and society, people's demand for a healthy living environment is increasing, and the expression "low carbon" has become a daily feature of people's lives. The emergence of a low-carbon economy, the impact on the traditional industrial structure and the formation of a new economic landscape make China, a developing country, eager to seize this opportunity to enhance its international competitiveness. To achieve this, it is necessary to establish a low-carbon concept, to actively restructure industrial and develop low-carbon industries; only in this way can we take advantage of the new round of industrial restructuring and grasp the initiative of development. Therefore, this paper selects data from enterprises in the emerging low-carbon industry, and uses a SVAR model to conduct a dynamic interaction analysis between government subsidy intensity, enterprise profitability, asset growth capacity and enterprise size. The results of the study show that the intensity of government subsidies in the first period has a certain positive effect on a company's current profitability and asset growth, the improvement being most significant on its profitability. Among the larger companies, asset growth and profitability in the first period had a significant positive impact on current earnings, and the contribution of profitability to the company's own performance was much larger than the average; among the smaller companies, asset growth and profitability in the first period had a significant positive impact on current earnings, and the contribution of asset growth to the company's own performance was much larger than the average. The intensity of prior government subsidies in the Highs group has a significant positive relationship with the intensity of current government subsidies, the firm's asset growth capacity and profitability; the intensity of prior government subsidies in the Lows group only has a significant positive impact on the asset growth capacity in the current period. In addition, the interaction between the three core variables in the Highs group is also significantly higher than that in the Lows group. This indicates that the government should implement differential policies and financial subsidies according to the actual needs of enterprises to maximize the effect of capital use and promote the development and growth of emerging enterprises.

Gd3+-Trityl-Nitroxide Triple Labeling and Distance Measurements in the Heterooligomeric Cobalamin Transport Complex in the Native Lipid Bilayers.

Increased efforts are being made for observing proteins in their native environments. Pulsed electron-electron double resonance spectroscopy (PELDOR, also known as DEER) is a powerful tool for this purpose. Conventionally, PELDOR employs an identical spin pair, which limits the output to a single distance for monomeric samples. Here, we show that the Gd3+-trityl-nitroxide (NO) three-spin system is a versatile tool to study heterooligomeric membrane protein complexes, even within their native membrane. This allowed for an independent determination of four different distances (Gd3+-trityl, Gd3+-NO, trityl-NO, and Gd3+-Gd3+) within the same sample. We demonstrate the feasibility of this approach by observing sequential ligand binding and the dynamics of complex formation in the cobalamin transport system involving four components (cobalamin, BtuB, TonB, and BtuF). Our results reveal that TonB binding alone is sufficient to release cobalamin from BtuB in the native asymmetric bilayers. This approach provides a potential tool for the structural and quantitative analysis of dynamic protein-protein interactions in oligomeric complexes, even within their native surroundings.

Dynamic interaction analysis among different control loops and stability enhancement strategy for MMC-HVDC systems

This paper presents the dynamic interaction analysis method among different control loops of MMC-HVDC (Modular Multilevel Converter High Voltage Direct Current) systems, and proposes an improved control strategy with feedback regulation loop and low-pass filter loop for stability enhancement. The small-signal cascade model of MMC with dc voltage control loop, ac current control loop and differential-mode ripple capacitor voltages loop is firstly established, which clearly shows the analytical interactions of inner capacitor voltage response and system input power’s dynamics with simplified closed/open-loop transfer functions. Then the small-signal dynamic analysis of MMC is conducted based on the derived closed/open-loop transfer functions, which reveals the interactions between the system stability and key control loops, as well as the main parameters of the MMC-HVDC system by both the Nyquist criteria and the pole-zero theory. Next, the feedback regulation loop and low-pass filter loop are proposed and introduced in the MMC control system to maximize stability enhancement performance during disturbances, and system dynamic response under the proposed control with different parameters are also explored through theoretical analysis. Finally, several cases on a benchmark two-terminal MMC-HVDC simulation model are carried out in PSCAD/EMTDC to verify the proposed control strategy.

Investigation of Soft Impacts in Elements of Pipe Robots

Vibrators with deformable impact support under harmonic excitation are especially useful in the case when their stationary regimes of motion are stable. This is useful in practice by applying those vibrators to single direction manipulators and various robots of space type.
 For practical application it is necessary to reveal dynamical qualities of the system from where it would be possible to determine optimal regimes. For this purpose investigations of dynamics of the system by numerical methods were performed.
 Investigation of dynamics of impact interactions in elements of robots is an important engineering problem. Dynamics of soft impacts in elements of manipulators and robots is investigated. The model of the investigated system is described. Numerical investigations for various parameters of the system are performed. Free and forced vibrations are investigated.
 From the presented results it can be noted that for the smaller values of the coefficient of stiffness of the support period of steady state motion coincides with the period of the exciting force, while for the higher values of the coefficient of stiffness of the support period of steady state motion is equal to two periods of the exciting force. Thus it is concluded that with the increase of the coefficient of stiffness of the support behavior of the investigated vibro impact system with soft impacts experiences essential changes.
 Main characteristics of steady state motion as functions of frequency of excitation are investigated. From the presented results the minimum and maximum inter impact intervals as functions of frequency of excitation, minimum and maximum velocities before impact as functions of frequency of excitation, minimum and maximum minimum displacements in inter impact intervals as functions of frequency of excitation are seen. Three resonant zones of expected single valued motions are observed in the presented results. They correspond to optimal regions of operation of the vibro impact system with soft impacts.
 Results of the performed analysis of dynamic interactions with soft impacts in the elements of manipulators and robots are used in the process of design of pipe robots of advanced type.

An efficient method for train–track–substructure dynamic interaction analysis by implicit-explicit integration and multi-time-step solution

In this work, a method is put forward to obtain the dynamic solution efficiently and accurately for a large-scale train–track–substructure (TTS) system. It is called implicit-explicit integration and multi-time-step solution method (abbreviated as mI-nE-MTS method). The TTS system is divided into train–track subsystem and substructure subsystem. Considering that the root cause of low efficiency of obtaining TTS solution lies in solving the algebraic equation of the substructures, the high-efficient Zhai method, an explicit integration scheme, can be introduced to avoid matrix inversion process. The train–track system is solved by implicitly Park method. Moreover, it is known that the requirement of time step size differs for different sub-systems, integration methods and structural frequency response characteristics. A multi-time-step solution is proposed, in which time step size for the train–track subsystem and the substructure subsystem can be arbitrarily chosen once satisfying stability and precision demand, namely the time spent for m implicit integral steps is equal to n explicit integral steps, i.e., mI = nE as mentioned above. The numerical examples show the accuracy, efficiency, and engineering practicality of the proposed method.

The determination of the effect(s) of solute carrier family 22-member 2 (SLC22A2) haplotype variants on drug binding via molecular dynamic simulation systems

Single nucleotide polymorphisms detected in the solute carrier member family-22 has been shown to result in a variable response in the treatment of type 2 diabetes mellitus with Metformin. This study predicted a three-dimensional protein structure for the SLC22A2 protein sequence using AlphaFold 2 and modelled five haplotypes within SLC22A2 protein structure observed in the Xhosa population of South Africa. The protein models were used to determine the effect(s) of haplotype variations on the transport function of Metformin and 10 other drugs by the SLC22A2 protein. Molecular dynamic simulation studies, molecular docking and interaction analysis of the five SLC22A2 haplotypes were performed in complex with the ligand 5RE in a POPC lipid bilayer to understand the mechanism of drug binding. Weakest binding free energy was found between 5RE and haplotype 1. Molecular docking studies indicated the top binding ligands as well as Metformin to bind inside the transport channel in all haplotypes increasing the probability of Metformin inhibition during co-administration of drugs. Metformin showed reduced binding affinity and number of interactions compared to the top four binding molecules. Molecular dynamic simulation analysis indicated that haplotypes 1, 3 and 4 were less stable than 2 and 5. The findings suggest haplotypes 4 and 5 having stronger preference for large inhibitor molecule binding in the active site and this could result in haplotypes 4 and 5 demonstrating reduced Metformin clearance via the SLC22A2 transporter during co-administration of drugs. The current study is the first to investigate the potential effect(s) of haplotype variation on the protein structure of SLC22A2 to assess its ability to transport Metformin in an indigenous South African population.

Influence of seismic wave type and incident direction on the dynamic response of tall concrete-faced rockfill dams

Owing to the stochastic behavior of earthquakes and complex crustal structure, wave type and incident direction are uncertain when seismic waves arrive at a structure. In addition, because of the different types of the structures and terrains, the traveling wave effects have different influences on the dynamic response of the structures. For the tall concrete-faced rockfill dam (CFRD), it is not only built in the complex terrain such as river valley, but also its height has reached 300 m level, which puts forward higher requirements for the seismic safety of the anti-seepage system mainly comprising concrete face slabs, especially the accurate location of the weak area in seism. Considering the limitations of the traditional uniform vibration analysis method, we implemented an efficient dynamic interaction analysis between a tall CFRD and its foundation using a non-uniform wave input method with a viscous-spring artificial boundary and equivalent nodal loads. This method was then applied to investigate the dynamic stress distribution on the concrete face slabs for different seismic wave types and incident directions. The results indicate that dam-foundation interactions behave differently at different wave incident angles, and that the traveling wave effect becomes more evident in valley topography. Seismic wave type and incident direction dramatically influenced stress in the face slab, and the extreme stress values and distribution law will vary under oblique wave incidence. The influence of the incident direction on slab stress was particularly apparent when SH-waves arrived from the left bank. Specifically, the extreme stress values in the face slab increased with an increasing incident angle. Interestingly, the locations of the extreme stress values changed mainly along the axis of the dam, and did not exhibit large changes in height. The seismic safety of CFRDs is therefore lower at higher incident angles from an anti-seepage perspective. Therefore, it is necessary to consider both the seismic wave type and incident direction during seismic capacity evaluations of tall CFRDs.

A hybrid computing framework for risk‐oriented reliability analysis in dynamic PSA context: A case study

AbstractNowadays, the emerging digital technologies and digitalization trend in safety‐critical industrial process systems are bringing great opportunities for system performance improvements. However, new big challenges are also encountered in the reliability and safety evaluation of large complex industrial process systems due to its multi‐state, multi‐phase dynamic interactions, resilience on software and inter‐dependencies among digital components. The objectives of this study are i) to present an introductory overview of a hybrid computing framework as a supplementary to conventional fault tree analysis toolkit for risk‐oriented reliability analysis in dynamic probabilistic safety assessment context; ii) to illustrate how to combine the three methods of DDET, Markov/CCMT, and GO‐FLOW for integrated risk solutions by a case study of small‐break LOCA in nuclear power plants. Within the hybrid computing framework, the DDET model is implemented based on graph‐based search and sequence diagram refactoring by linking with Markov/CCMT and GO‐FLOW solver for branch probability estimation. The dynamic event tree model is adopted to represent the accident sequence of small‐break LOCA, where the heading events of system failure of digital RPS and phased‐mission ECCS in realization of safety‐critical functions of reactivity control and emergency core cooling are respectively modeled and analyzed by Markov chain and GO‐FLOW method. The demonstration results show that the failure analysis of complex dynamic process interactions together with time‐dependent mission reliability analysis of safety systems involved in accident prevention and mitigation can be easily implemented with accurate modeling and fast evaluation within the hybrid integration platform. The core algorithms and principles implemented for dynamic risk scenarios development by DDET, modeling, and analysis of dynamic process interactions by Markov/CCMT, time‐dependent and multi‐phase mission reliability analysis by GO‐FLOW as well as their integration to provide comprehensive solutions for the application of dynamic reliability in risk assessment are also discussed as open problems for future research.

Reduced T-shaped soil domain for nonlinear dynamic soil-bridge interaction analysis

The one-directional three-component wave propagation in a T-shaped soil domain (1DT-3C) is a numerical modeling technique, in a finite element scheme, to investigate dynamic soil-structure interaction (SSI) coupled with seismic site effects, under the assumption of vertical propagation of three-component seismic motion along a horizontal multilayered soil. A three-dimensional elasto-plastic model is adopted for soils, characterized using their shear modulus reduction curve.In this research, the 1DT-3C wave propagation modeling technique is proposed as an efficient tool for bridge design to take into account directly the spatial variability of seismic loading. This approach, in the preliminary phase of bridge study and design, allows the reduction of the soil domain and the easier definition of boundary conditions, using geotechnical parameters obtained with only one borehole investigation for each pier. This leads to a gain in modeling and computational time.

Improvement to the fictitious pile method for pile-soil interaction problems

Dynamic pile-soil interaction analysis is often a key task in many civil engineering problems and several methods have been developed and applied. To many researchers, the fictitious pile method is a good candidate because of its high computational efficiency compared with the three-dimensional finite element method (FEM) and boundary element method (BEM). However, due to the assumptions made in the method, application of the method to dynamic pile-soil interaction at sufficiently high frequency may be problematic. A study on this issue is performed in this paper by comparing with FEM. It is found that the assumption that the vertical load (termed the patch load) applied by the fictitious pile to the ground is uniformly distributed on the cross-section is an important factor invalidating the method at high frequencies. Upon this founding, the original fictitious pile method is then improved by replacing the uniformly distributed patch load with a series of ring loads which make the vertical displacements at the intermediate radii of the ring loads identical. A set of linear algebraic equations are established to determine the ring loads. Results from both the improved and original fictitious pile methods are compared with those from FEM as benchmark. The comparisons show that the improved fictitious pile method has a much better accuracy (or for a given accuracy, works to higher frequencies) than the original one but the calculation efficiency remains similar. Although for the cases studied in this paper the improved fictitious pile method is much more accurate than the original one, the effectiveness of former may be still unsatisfactory for other cases. Therefore, the effect of parameters, including soil Young's modulus, pile radius and pile length, on the accuracy of the fictitious pile method is also investigated. It turns out that the pile radius and length have adverse effects on the accuracy of the fictitious pile method while stiffer soil makes the method work better. Based on the parameters of the pile and soil, a critical frequency is derived below which the fictitious pile method can be well applied.

Equivalent dynamic stiffnesses and 3D wave propagations of a transversely isotropic elastic ground in rocking and torsional interactions with a harmonically loaded rigid foundation

An advanced theoretical formulation along with a robust numerical evaluation method are employed to study the 3 D wave propagations and equivalent dynamic stiffnesses of a transversely isotropic elastic ground in rocking and torsional interactions with a harmonically loaded rigid foundation. Using appropriate dynamic Green’s functions presented in the literature, the rocking and torsional harmonic oscillations of the foundation are formulated analytically in terms of several Fredholm integral equations of the second kind. Then the dynamic stiffnesses and flexibilities are presented analytically for rocking and torsional oscillations. To validate the analytical results, they are reduced to two simpler cases reported in the literature: the static problem and the case of isotropic materials. The semi-infinite integrals appeared in the solutions are evaluated numerically by utilizing the contour integration and residue theorem along with several commands of the Mathematica software. A complete discussion on the elastic wave propagations due to oscillations of the foundation are presented and a detailed comparison is performed between different waves propagate within the half-space and full-space elastic grounds including the P, SV, SH and the Rayleigh waves. Our results showed that due to rocking oscillation of the foundation, the Rayleigh wave does not propagate in the full-space medium but it propagates in the half-space medium. However due to torsional oscillation, the Rayleigh wave does not propagate neither in the full-space nor in the half-space elastic medium. In addition, due to rocking oscillation, the body waves including P, SV and SH propagate within both half-space and full-space elastic mediums; but due to torsional oscillation, only SH-wave propagates within both full-space and half-space elastic mediums. In some tables, numerical values and mathematical formulas for the dimensionless wave numbers and wave velocities are provided for the P, SV, SH and the Rayleigh waves. The Gaussian quadrature method is implemented for definite integrals appeared in the dynamic stiffnesses. Some graphical figures are provided to represent the dimensionless rocking and torsional dynamic stiffnesses and flexibilities versus the dimensionless frequency for different transversely isotropic materials. The effects of anisotropy of materials and the frequency of excitations on the responses are discussed. The results presented in this paper including the dynamic stiffnesses and wave propagations have direct applications in dynamic soil-structure interaction analyses in civil engineering.

Axis-symmetric analysis of layered transversely isotropic saturated elastic soils containing a monopile under time-harmonic vibration

The axis-symmetric dynamic soil-pile interaction analysis is of fundamental significance in geotechnical, seismic and transportation engineering. In addition, soils tend to show an obvious stratification after the long-term deposition. Physical and mechanical properties of soils are generally transversely isotropic due to the orientation of soil particles in deposition. Therefore, the axis-symmetric analysis of layered transversely isotropic saturated elastic soils containing a monopile under time-harmonic vibration is carried out in this study. Firstly, the extended precise integration method (EPIM) is employed to obtain the dynamic fundamental solution for layered transversely isotropic saturated soils, which would be utilized as the kernel function of the boundary element method (BEM). Moreover, by modeling the pile as a one-dimensional bar, the motion equation of the monopile under steady-state vibration is acquired based on the finite element method (FEM). Finally, the coupled BEM-FEM formulation representing the soil-pile interaction is developed and the axis-symmetric solution for layered soils containing a monopile is acquired. Compared with existing results, the accuracy of the proposed method is verified. Numerical examples are conducted to analyze the influence of frequency, transverse isotropy, the stratification of soils and the length-radius ratio of piles on soil-pile interaction behaviors.