Characteristics Of Dynamic Interaction Research Articles

Numerical simulation of the dynamic interaction characteristics between Wood’s metal and water under coolant injection mode

The accident of the steam generator tube rupture in the lead-bismuth-cooled fast reactor or the core meltdown in the light water reactor may cause violent heat and mass transfer between the melt and the coolant, potentially further damaging the reactor. Therefore, it is essential to study the corresponding mechanisms. In this study, numerical simulations are utilized to investigate the dynamic interactions between Wood’s metal and subcooled water in the coolant injection (CI) mode, focusing on jet behavior and critical cavity parameter changes. By analyzing these factors, this research aims to clarify the interfacial evolution and interaction mechanisms between the melt, water, and air, thereby tackling the problem of inadequate observation in experiments. A user-defined function (UDF) was employed to simulate the flow characteristics of the melt during the solidification process. This approach effectively addressed the limitation of Fluent’s inherent solidification model, where the fluid no longer participates in turbulent velocity calculations after solidification. In addition, an equivalence method was proposed according to the characteristics of two-dimensional simulations in Fluent. Comparisons with Cheng’s experimental results show that the equivalent model can accurately predict jet penetration characteristics while significantly reducing the demand for computational resources. According to this equivalence method, this research developed a new correlation for predicting the maximum jet penetration depth in the CI mode. The above results provide new perspectives for understanding the dynamic interactions between metals and coolants, which is significant for the application and optimization of technologies in the nuclear field.

A collaborative training approach for multi energy systems in low‐carbon parks accounting for response characteristics

AbstractExisting researches lack systematic design of the operation mechanism and overall implementation process of park oriented multi‐state energy system; The existing researches on multi‐state energy systems ignored the dynamic response characteristics of load and the coupling effect of units considering the impact of carbon emissions, and did not go deep into the collaborative management of multiple multi state energy system parks. To this end, this paper first proposes a two‐stage multi‐energy system operation architecture for low carbon parks, and establishes a mathematical model considering carbon emissions, operating costs and other objectives. The response space of load is optimized by considering the dynamic interaction characteristics of load response and the coupling characteristics of unit operation. Then, considering the problems of data security and training efficiency, F‐DDPG technology is used to conduct collaborative training for multiple campus systems. Finally, an example is given to prove the effectiveness of the method, which is not only conducive to reducing the operating cost of the system and the carbon emissions on the supply side, but also improves the convergence of model training. In the case of collaborative training in multiple parks, the method in this paper converges faster and has better economic benefits.

Comparative Study on Shaking Table Tests for a Pile–Nuclear Island Structure under Different Soil Conditions

In this paper, the shaking table tests of a Seismic–Soil–Pile–Superstructure Interaction (SSPSI) in medium-soft and hard base soil were carried out. Silted clay with a unit weight of 1.70 g/cm3 and a shear wave velocity of 175 m/s was adopted to simulate the medium-soft soil, while the composite soil obtained by adding 20% quicklime to silted clay with a unit weight of 1.75 g/cm3 and a shear wave velocity of 300 m/s was adopted to simulate the hard soil in the tests. By inputting the artificial seismic motion time history with different amplitudes synthesized by the RG1.60 response spectrum commonly used in nuclear power engineering to the models, the dynamic interaction characteristics and seismic response laws of the soil–pile–nuclear island structure in the medium-soft and hard base soil were compared, the internal force and deformation distribution characteristics of the pile foundation under different ground conditions were analyzed, and the site conditions and mechanism of seismic failure of the pile group foundation were described. The research results can provide a reference for site selection and seismic design of a nuclear power plant.

Study on the spatial–temporal patterns and evolution characteristics of ecological security based on dynamic evaluation in the Three Gorges Reservoir Area

Monitoring ecological security in the Three Gorges Reservoir Area (TGRA) is the prime objective of the ecosystem research on the Yangtze River basin. The comprehensive dynamic evaluation model of ecological security based on the “Pressure-State-Benefit” and four dimensions of “time–space” was designed in this study. Furthermore, comparative analysis and coefficient of sensitivity (CS) were used to verify the rationality and scientificity of this model. This study interpreted and determined the land use data of the TGRA from 2000 to 2020. The coupling coordination degree model, the spatial correlation model and the cluster analysis model assisted in determining the spatial pattern distribution and dynamic interaction characteristics of ecological security at the grid-county-watershed scales in the TGRA. The analytical results demonstrated that the ecological security index (ESI) in the TGRA was generally not very high due to resource constraints and background environmental conditions. The ESI was significantly clustered in space. The initial impoundment of the TGRA significantly impacts ecological security. Implementing dot-shaped ecological restoration projects has greatly improved unsafe and low-security state areas. However, the non-significant growth in the high-security state level region can be attributed to the lack of overall planning and implementation scale. The ecological pressure caused by economic and social development in the main urban area has led to a substantial decline in regional ecological benefit. Therefore, it is necessary to balance the coordinated development relationship between economic-social and ecological benefit in the region. These findings will provide references and supportive data for environmental protection and ecological restoration in the TGRA.

Seismic Responses and Damage Mechanisms of Deep-Buried Underground Powerhouse in Layered Rock Mass

Layered rock mass generally has adverse effects on the seismic stability of deep-buried underground powerhouses. Aiming at the complexity of seismic wave field in deep-buried underground powerhouses, the obliquely input methods of P and SV waves considering the incident direction and multi-incident surfaces are constructed in this study, respectively. It can convert the seismic wave input problem into the problem of solving equivalent nodal force acting on the artificial boundaries. Based on the characteristics of dynamic interaction between interlayers in layered rock mass, an explicit dynamic contact force method considering the seismic deterioration effect and bond-slip characteristics of interface is also presented to simulate various contact states such as bond, separation, and sliding. The combined application of the above methods to analyze the seismic response of underground powerhouse at Azad Pattan hydropower station shows that they could accurately simulate the seismic damage evolution process of deep-buried underground powerhouses in layered rock mass. The numerical results indicate that the obliquely incident seismic waves contribute to a larger seismic reaction of underground powerhouses, which largely lies in the amplitudes of the displacement and stress fluctuations. After considering the dynamic contact, the obvious seismic deterioration effect and interlaminar dislocation displacement occur between soft and hard rock, and the sidewalls suffer more severe deterioration degree than the top arch. The seismic damage area of lining structure is mainly distributed in the place where the soft rock strata pass through and the upper structure with larger free surface. Additionally, two major damage modes of underground powerhouses in layered rock mass, namely, damage due to structural deformation and interlaminar dislocation, are derived from the numerical results and can be reasonably explained by the corresponding damage mechanisms.

Dynamic interaction of medium–low-speed maglev train running on the turnout made of steel structures

To evaluate the dynamics of the coupled medium–low-speed maglev train-turnout system, a rigid-flexible dynamics model of the coupled system was developed based on multi-body dynamics theory and finite element method. The modal and dynamic responses results obtained from the model calculations were compared with the field test results, and the dynamic interaction characteristics of the coupled system under different operating conditions were investigated using the validated simulation model. Research results show that both the increase in the support stiffness of the turnout and the rational choice of some key parameters of the coupled system will ensure the levitation stability of the train. Increasing the support stiffness of the turnout by means of adding a trolley to support in the middle of the long-span girder (LSG) facilitates the stable levitation of the train when standing still above the turnout and improves the dynamic performance of the coupled system. By optimising some key parameters, including limiting the flatness of the magnetic pole surface of the turnout track within 1.5 mm, and taking the vertical damping of the air springs for overloaded train within 9000∼11,000 N·s/m, significant improvements in the dynamic performance of the train and the turnout can also be achieved.

Investigation of functional brain network reconfiguration during exposure to naturalistic stimuli using graph-theoretical analysis

Objective. One of the most significant features of the human brain is that it can dynamically reconfigure itself to adapt to a changing environment. However, dynamic interaction characteristics of the brain networks in naturalistic scenes remain unclear. Approach. We used open-source functional magnetic resonance imaging (fMRI) data from 15 participants who underwent fMRI scans while watching an audio–visual movie ‘Forrest Gump’. The community detection algorithm based on inter-subject functional correlation was used to study the time-varying functional networks only induced by the movie stimuli. The whole brain reconfiguration patterns were quantified by the temporal co-occurrence matrix that describes the probability of two brain regions engage in the same community (or putative functional module) across time and the time-varying brain modularity. Four graph metrics of integration, recruitment, spatio-temporal diversity and within-community normalised centrality were further calculated to summarise the brain network dynamic roles and hub features in their spatio-temporal topology. Main results. Our results suggest that the networks that were involved in attention and audio–visual information processing, such as the visual network, auditory network, and dorsal attention network, were considered to play a role of ‘stable loners’. By contrast, ‘unstable loner’ networks such as the default mode network (DMN) and fronto-parietal network tended to interact more flexibly with the other networks. In addition, global brain network showed significant fluctuations in modularity. The ‘stable loner’ networks always maintained high functional connectivity (FC) strength while ‘unstable loner’ networks, especially the DMN, exhibited high intra- and inter-network FC only during a low modularity period. Finally, changes in brain modularity were significantly associated with variations in emotions induced by the movie. Significance. Our findings provide new insight for understanding the dynamic interaction characteristics of functional brain networks during naturalistic stimuli.

Research on User Experience Based on Competition Websites

The design of the website interface has an impact on the user experience in all aspects. A set of relatively perfect interactive interface is often in line with the needs, cognition and behavior of the target user to form a good experience. In order for users to have a good experience in their use, subjective evaluation and usability evaluation methods are usually used to test and tune after the interface is designed. This analysis method has its limitations. For example, it cannot reveal the thinking process and psychological activities of the user and the interface in the interaction process for the designer, and provide the tester with the time and space information of the user’s search and processing process. This paper adopts more cutting-edge research methods. First, we analyze the usability of three websites of the same type and different structure, such as evaluating the effectiveness by task completion rate and error rate, and evaluating efficiency by operating time and operating path. Secondly, conduct eye movement experiments on users, further assist and re-verify the usability evaluation method, and analyze its dynamic interaction characteristics, and conduct a comprehensive user experience research on competition websites from qualitative and quantitative perspectives.

Non-Hertzian contact analysis of heavy-haul locomotive wheel/rail dynamic interactions under changeable friction conditions

Wheel/rail dynamic interactions of heavy-haul locomotives are highly nonlinear and complicated due to large traction/braking loads, frequent anti-slip control and complex wheel/rail interface environment. The wheel/rail dynamic interactions, as well as the interface wear, have been broadly studied by means of Hertzian contact analysis, but the wheel/rail contact is essentially a non-Hertzian contact matter. This paper presents an investigation of wheel/rail dynamic interaction characteristics of a heavy-haul locomotive subjected to traction loads and dry/wet/greasy contact conditions by using a non-Hertzian contact method. For this purpose, a comprehensive dynamics model for heavy-haul train-track coupled system is established. A non-Hertzian normal contact algorithm and the corresponding creep algorithm are employed to solve wheel/rail normal and tangential contact forces, respectively. The locomotive wheel/rail dynamic interactions under different contact conditions and traction efforts are discussed. The simulation results indicate that traction effort and friction conditions have a significant influence on the contact forces, distributions of contact stress, and adhesion-slip region in the wheel/rail contact patch. The adhesion-slip distributions were found to reach full-slip under the lowest-adhesion conditions, and the wear index was found to be much greater than that under dry condition.

DOTA Glycodendrimers as Cu(II) Complexing Agents and Their Dynamic Interaction Characteristics toward Liposomes

Copper (Cu)(II) ions, mainly an excess amount, play a negative role in the course of several diseases, like cancers, neurodegenerative diseases, and the so-called Wilson disease. On the contrary, Cu(II) ions are also capable of improving anticancer drug efficiency. For this reason, it is of great interest to study the interacting ability of Cu(II)–nanodrug and Cu(II)–nanocarrier complexes with cell membranes for their potential use as nanotherapeutics. In this study, the complex interaction between 1,4,7,10-tetraazacyclododecan-N,N′,N′′,N′′′-tetraacetic acid (DOTA)-functionalized poly(propyleneimine) (PPI) glycodendrimers and Cu(II) ions and/or neutral and anionic lipid membrane models using different liposomes is described. These interactions were investigated via dynamic light scattering (DLS), ζ-potential (ZP), electron paramagnetic resonance (EPR), fluorescence anisotropy, and cryogenic transmission electron microscopy (cryo-TEM). Structural and dynamic information about the PPI glycodendrimer and its Cu(II) complexes toward liposomes was obtained via EPR. At the binding site Cu–N2O2 coordination prevails, while at the external interface, this coordination partially weakens due to competitive dendrimer–liposome interactions, with only small liposome structural perturbation. Fluorescence anisotropy was used to evaluate the membrane fluidity of both the hydrophobic and hydrophilic parts of the lipid bilayer, while DLS and ZP allowed us to determine the distribution profile of the nanoparticle (PPI glycodendrimer and liposomes) size and surface charge, respectively. From this multitechnique approach, it is deduced that DOTA-PPI glycodendrimers selectively extract Cu(II) ions from the bioenvironment, while these complexes interact with the liposome surface, preferentially with even more negatively charged liposomes. However, these complexes are not able to cross the cell membrane model and poorly perturb the membrane structure, showing their potential for biomedical use.

Dynamic Response Simulation of Lining Structure for Tunnel Portal Section under Seismic Load

Portal section is the weak link of seismic fortification for tunnel structure. Assuming that seismic wave is the vertical incident elastic plane wave, the plane wave input method for the portal section was discussed in this paper; that is, the wave input problem can be converted to the problem of calculating equivalent nodal force at artificial boundaries. Based on different damage evolution processes of concrete under tension and compression conditions, the tension and compression damage variables were defined and solved, respectively. And then a simple elastic dynamic damaged constitutive model for concrete lining was built. According to the characteristics of dynamic interaction between the lining and rock, and based on the dynamic contact force algorithm, an analytical model for joint loading between the lining and rock was built. This model can simulate lining features such as bond, separation, and slip under seismic load. The dynamic response characteristics of lining structure for the portal section under seismic load were analyzed by taking example for an exit section of Dianzhong diversion project in strong earthquake area. The results show that the relative displacement magnitudes of the lining parts are related to the vibration direction of the seismic wave, and the peak displacements decrease gradually to the fixed values from the portal to the interior. The damage coefficients of the lining parts accumulate gradually over time, and the farther the lining is away from the portal, the less serious the seismic damage is. The separation and slip zone distributions of the lining are basically consistent with its severe seismic damage area, which are mainly at haunch, spandrel, and arch foot within a certain range of distance from the portal. The seismic fortified length and key fortified parts of tunnel structure for the portal section can be determined according to the calculation results.

Development of Approaches to Creation of Active Vibration Control System in Problems of the Dynamics for Granular Media

The article deals with the development of mathematical models and evaluation criteria of the vibration field in the dynamic interactions of the elements of the vibrational technological machines for the processes of vibrational strengthening of long-length parts with help of a steel balls working medium. The study forms a theoretical understanding of the modes of motions of material particles in interaction with a vibrating surface of the working body of the vibration machine. The generalized approach to the assessment of the dynamic quality of the work of vibrating machines in multiple modes of tossing, when the period of free flight of particles is a multiple of the period of the surface oscillations of the working body, is developed in the article. For the correction of vibration field of the working body, the characteristics of dynamic interactions of granular elements of the medium are taken into account using original sensors. The sensors that can detect different particularities of interaction of the granular medium elements at different points of the working body are proposed to evaluate the deviation from a homogeneous and one-dimensional mode of vibration field. Specially developed sensors are able to register interactions between a single granule, a system of granules in filamentous structures, and multipoint interactions of the elements in a close-spaced cylindrical structure. The system of regularization of the structure of vibration fields based on the introduction of motion translation devices is proposed using the multi-point sensor locations on the working body. The article refers to analytical approaches of the theory of vibration displacements. For the experimental data assessment, the methods of statistical analysis are applied. It is shown that the peculiar features of the motion of granular medium registered by the sensors can be used to build active control systems of field vibration.

Bora wind and heavy persistent precipitation: atmospheric water balance and role of air–sea fluxes over the Adriatic Sea

The Adriatic basin is regularly affected by cold, strong and gusty bora winds blowing from the northeast, especially during winter. These events are characterized by intense air–sea interactions and produce important meteorological effects not only over the eastern Adriatic basin, where bora originates and attains its maximum intensity, but also downstream over the Italian peninsula where heavy rainfall and snowfall can occur.The present study aims at evaluating the impact of surface fluxes of sensible and latent heat, that characterize air–sea interaction during a bora episode, on wind strength and profiles over the Adriatic Sea, in relation to intense precipitation affecting the Apennines and the Italian coast. High‐resolution numerical simulations are used in order to assess the role of surface fluxes in modulating the atmospheric water balance, modifying the thermodynamic characteristic of the boundary layer and, in turn, the dynamics of the orographic flow regime.Results show that while surface evaporation is responsible for a relatively small contribution to the total atmospheric water budget over the Adriatic area, surface fluxes still have a remarkable impact on precipitation via dynamical processes. Both sensible and latent heat fluxes modify the speed, temperature and moisture profiles of the low‐level bora wind, sensibly changing the dynamical characteristics of interaction of the flow with the downstream orography. The orographic flow regime determines the intensity and location of orographically induced uplift and hence precipitation. Therefore, the picture that directly associates the precipitation amount upstream and over the Apennines with the degree of moistening of air during its passage over the sea and with orographic uplift is shown to be too simplistic. The variations of the wind speed and static stability due to surface fluxes involve complex and nonlinear effects, changing the flow regime in response to the orographic forcing and thus determining amount and location of heavy precipitation.

3차원 다물체동역학 시뮬레이션 기반 자기부상열차와 3경간 연속교 동적상호작용 해석

This study aims to investigate dynamic interaction characteristics between Maglev train and 3 span continuous guideway. The integrated model including a 3D full vehicle model based on multibody dynamics, flexible guideway by a modal superposition method, and levitation electromagnets with the feedback controller is proposed. The proposed model was applied to the Incheon Airport Maglev Railway to analyze the dynamic response of the vehicle and guideway from the numerical simulation. Using field test data of air gap and guideway deflections, obtained from the Incheon Airport Maglev Railway, the analysis method is verified. From the results, it is confirmed that Maglev railway system are designed and constructed safely according to the design criteria.

Interaction characteristics and development pattern of sustainability system in BHR (Bohai Rim) and YRD (Yangtze River) regions, China

The well-run structure, function and dynamics of complex regional sustainability system are critical for maintaining regional sustainability stability, so exploring the interaction characteristics and development pattern of the system should be considerably significant. Based on the new comprehensive index system of sustainability system, the indices of social, economic and eco-environmental dimensions and nine thematic indices are firstly presented for BHR (Bohai Rim) and YRD (Yangtze River) regions during the period 2001–2010, and then the regional sustainability changes are further tracked by regional sustainability index (RSI) and regional coordination index (RCI). Furthermore, we mainly focus on the dynamic interaction characteristics and propose green development index (GDI) to reflect the development pattern of BHR and YRD from the perspective of taking all indicators into account. The study results show that: the average annual growth rates of the indices of social, economic and eco-environmental dimensions of the BHR region are 10.00%, 19.11% and 0.37% during the study period, while the ones of YRD region are 7.32%, 20.25% and 0.46%, respectively, demonstrating that economic progress is the fastest-improving pillar for RSI of the two regions; the standard deviations of the indices of three dimensions that can construct a triangle diagram and the amount of that failed to construct are both decreasing from 2001 to 2012, showing that the RCI of two regions have made some progresses; BHR have stayed in some positions where eco-environmental level gradually decreases (from 0.50 to 0.45) with the progression of socioeconomic situations (from 0.20 to 0.50), while BHR in a position where eco-environmental level gradually increases (from 0.53 to 0.57) with the progression of socioeconomic situations (from 0.25 to 0.55), revealing dynamic interaction characteristics, and then in their evolution trajectories, YRD has been principally at the intermediate sustainable development stage while BHR always at the potentially unsustainable one; the green social or economic development degree, associated with the uneven resource utilization and eco-environment occupancy among provinces, should contribute most to regional development pattern. The study guides a direction where the policy makers need to improve in regional sustainability management.

자기부상열차/가이드웨이 동적상호작용 해석

This study aims to investigate the dynamic interaction characteristics between Maglev vehicles and an elevated guideway. A more detailed model for the dynamic interaction of the vehicle/guideway is proposed. The proposed model incorporates a 3D full vehicle model based on prototyping, flexible guideway by a modal superposition method, and levitation electromagnets including the feedback controller into an integrated model. The proposed model was applied to an urban transit Maglev developed for a commercial application to analyze the dynamic response of the vehicle and guideway, and the effect of the surface roughness of the rail, mid-span guideway deflections, and air gap variations are then investigated from the numerical simulation.

Study on Dynamic Relationship between Economic Growth and Energy Consumption in Chongqing - Based on 1980-2011 Data

Analyzed the dynamic interaction characteristics of Chongqing Economic growth and energy consumption between 1980-2011 based on vector auto regression model, impulse response function. The results showed that: 1 Between the Chongqing's economic growth and energy consumption exist the positive long-term stable equilibrium relationship, Chongqing's economic development depending on energy consumption is too high, to keep the economy in Chongqing's rapid economic development, energy relatively insufficient supply sustainable development must rely on the energy market, which will restrict the development of Chongqing's economy. 2At this stage, Chongqing continuing emphasis on optimizing the industrial structure to improve energy efficiency at the same time, the key is to establish and improve the energy consumption intensity and total energy demand "dual control" under the security system, weakening the energy bottleneck effect on economic growth.

AN APPROACH ON DYNAMIC GEOSPAITAL INFORMATION SERVICE COMPOSITION BASED ON CONTEXT RELATIONSHIP

Abstract. For the new demand of dynamic integration of spatial data, the model and collaboration of processing functions caused by characteristics of dynamic interaction and the participants random demand for information in geo-collaboration work system, for instance, during on-line consultation meeting, the paper presented an approach considering context dynamic service composition information. Firstly, the paper introduced the dividing method of context relation in consultation from the user and GI services, interaction between services and service perspective, constructed GI service context relation, and established GI service description model considering service's context relation based on OWL-S. For the problems above, the paper proposed an approach on GI service dynamic composition based on context relationship. Then, the paper provided a framework for GI services dynamic composition, and discussed every important component of framework. Finally, an experiment about checking illegal construction on boundary was implemented to illustrate the concepts and ideas discussed in the paper.

EFFECTS OF SIDE AND BASE ELEMENTS OF EMBEDDED SPRED FOUNDATIONS ON DYNAMIC SOIL-STRUCTURE INTERACTION AND CONVENTIONAL ESTIMATION METHODS FOR SOIL SPRINGS BY COMPOSING THE IMPEDANCE OF EACH ELEMENT

In this paper, we research a conventional evaluation method of soil springs in the dynamic soil-structure interaction analysis of buildings with embedment foundations. First of all, the bottom element and the side elements are decomposed from the embedment foundation and the dynamic interaction characteristics that each element possesses are examined. The estimation method developed by WEN and Fukuwa(2006) are applied to this examination. Based on the above results, it is mentioned that the soil spring of the embedment foundation which is composed with the impedance of both side and bottom elements is overestimated. Finally, we discuss impedance evaluation methods in the limit strength method and the sway-rocking model with embedment.

根入れ基礎をもつ複数の構造物群の連成振動について (1)

This paper follows the author's preceeding two papers : dynamic characteristics of a structure with buried foundation (1) and (2). In this paper are considered dynamic interaction characteristics of structures embeded in a perfectly elastic layer medium over a half-space when subjected to horizontal base rock motion. In Sec. 2 is derived the set of governing equation on soil-structures interaction system subjected to base rock motin. In Sec. 3 are derived the analytical expressions of the sway and the rotational spring constants of sub-side soil ground when the basement wall vibrates horizontaly or rotationally by taking account of the adjacent basement one. In Sec. 4 are derived the analytical solutions of the dynamic wave pressure which operates on the basement wall subjected to horizontal base rock motion.