Model Calculations Research Articles

Factor mismatch measurement of resource-based cities: Evidence from all-round optimization total factor productivity decomposition framework

In-depth analysis of the factors affecting the transformation of resource-based cities can provide effective support for the transformation and development of resource-dependent regions.How to comprehensively identify the factors affecting the transformation of resource-based cities is a complex problem. This study starts from the total factor productivity model and focuses on the two core basic factors that affect the transformation process of cities reliant on resources. Economic benefits and energy efficiency, respectively, from the economic benefit analysis framework and energy efficiency analysis framework for reconstruction, the two frameworks are combined with the use of distorted prices of resource elements to solve the problem that the synergistic effect of economic benefits and energy efficiency can not be measured. In order to quantitatively analyze the factors that affect the development efficiency of cities reliant on resources under the single or synergistic effect of the comprehensive framework, this study optimizes the directional distance function from three perspectives : exogenous weight, direction vector endogeneity, and absolute distance transformation relative distance, thus achieving an accurate assessment transformation efficiency of cities reliant on resources. Considering the impact of the new coronavirus epidemic, this study only selected the data of resource-based cities from 2003 to 2018, and found through model calculation that the impact on the transformation of cities reliant on resources : (1) Labor mismatch is mainly achieved by affecting the structure about the production of resource-based enterprises and industrial human resources; (2) Capital mismatch is mainly realized by affecting the production of resource-based enterprises ; (3) Energy mismatch is mainly achieved by affecting high energy consumption enterprises and low production technology level enterprises. Further research shows that the main objects of these factors are the four parts of production technology level, energy consumption, total factor productivity and industrial structure. Through these contents, they affect environmental efficiency and deeply affect the transformation process of resource-based cities.

Enhanced Thermoelectric Performance of Cr-doped ZnSb through Lattice Thermal Conductivity Reduction below the Phonon Glass Limit

Zinc antimonide (ZnSb) is a promising thermoelectric material due to its economic viability, elemental abundance, and superior phase stability compared to other Zn-Sb compounds. However, its widespread application is hindered by a low figure-of-merit (zT). Extensive research has explored doping, alloying, and nanostructuring to improve zT. This study investigates the impact of Cr doping in CryZn1-ySb (y = 0.0 – 0.03). Cr doping with y = 0.01 significantly reduces lattice thermal conductivity below the phonon glass limit. Debye-Callaway model calculations suggest a combined effect of point defects and decreased grain size caused by Cr incorporation. This reduction translates to enhanced thermoelectric performance, with the y = 0.01 sample exhibiting a 70% improvement in zT at 673K, reaching ~0.67. Exceeding the Cr substitution limit leads to the formation of a detrimental secondary CrSb2 phase, increasing thermal conductivity. The Single Parabolic Band model calculations predict further zT enhancement in y = 0.01 sample to ~0.2 at 300K through optimized carrier concentration (307% improvement in zT). These findings demonstrate the potential for significant zT improvement in ZnSb via defect engineering and carrier concentration tuning.

Research on large deformation mechanism of recovery roadway under mining stress conditions

Single Recovery Roadway (SRR) is a novel retraction technology in the non-pillars mining innovation system. In previous support withdrawing, single recovery roadway was usually replaced by a dual-recovery roadway or cut the coal wall before the support. This study is set against the background of the longwall panel at Duanshi Coal Mine, where a mechanical model based on the stress characteristics of a composite cantilever beam was constructed to analyze the failure of the main roof in a single recovery roadway. Through numerical analysis, the relationship between deformation failure of the recovery roadway and interlayer slippage structures was explored, as well as how mining-induced stress distribution and the evolution of key strata fractures impact the stability of the roadway. The results indicate that after the connection of the longwall panel and the recovery roadway, the overlying composite interlayered rock strata are affected by the interlayer slippage structures, leading to significant asymmetric deformation in the surrounding rocks. Additionally, borehole observation data support the theoretical calculations of the cantilever beam model. These research results enhance the understanding of the interlayer slip instability mechanism and provide important guidance for mine design under similar geological conditions.

Computational Investigation of the Influencing Parameters on the Solidification of Thermoplastic Beryllium Oxide Slurry in a Cylindrical Shell

This article presents a computational study of the influencing parameters on the solidification of the thermoplastic beryllium oxide slurry in an annular forming cavity. The main purpose of this paper is to study the effect of cooling and casting conditions on the solidification of the BeO suspension by considering the temperature-dependent rheological and physical properties. The results of calculations of the Bingham–Papanastasiou rheological model with experimental data in the intervals of phase transitions with different casting rates of beryllium ceramics have been validated. The use of the regularization parameter made it possible to approximate the flow of the slurry at all levels of its shear rates as highly viscous, followed by a continuous transition to a solid state. The speed of heat removal from the molding during the solidification period is determined by the speed of movement of the slurry and the temperature field on which the width of the transition region depends. The process of solidification of the slurry mass has been evaluated by changing its heat flow distribution and density along the length of the concentric channel. The obtained model calculation results make it possible to control the casting process and eventually realize a uniform structure of castings.

An introduction to semi-automated matrix element computation in particle physics

This paper presents a semi-automated method to compute matrix elements at the Leading Order and the Next-to-Leading Order in the ABC model of particle physics. The ABC model consists of three scalar particles and they interact only when all three particles are present in the interaction. In the Next-to-Leading Order calculations, one often has to deal with ultraviolet divergences. Some of the techniques such as Wick’s rotation, Feynman parameterisation, and dimensional regularization which are useful in Next-to-Leading Order computations are presented by applying them on the ABC model calculations and also implemented in python based programs using Computer Algebra System.

A Novel Model for Instance Segmentation and Quantification of Bridge Surface Cracks—The YOLOv8-AFPN-MPD-IoU

Surface cracks are alluded to as one of the early signs of potential damage to infrastructures. In the same vein, their detection is an imperative task to preserve the structural health and safety of bridges. Human-based visual inspection is acknowledged as the most prevalent means of assessing infrastructures’ performance conditions. Nonetheless, it is unreliable, tedious, hazardous, and labor-intensive. This state of affairs calls for the development of a novel YOLOv8-AFPN-MPD-IoU model for instance segmentation and quantification of bridge surface cracks. Firstly, YOLOv8s-Seg is selected as the backbone network to carry out instance segmentation. In addition, an asymptotic feature pyramid network (AFPN) is incorporated to ameliorate feature fusion and overall performance. Thirdly, the minimum point distance (MPD) is introduced as a loss function as a way to better explore the geometric features of surface cracks. Finally, the middle aisle transformation is amalgamated with Euclidean distance to compute the length and width of segmented cracks. Analytical comparisons reveal that this developed deep learning network surpasses several contemporary models, including YOLOv8n, YOLOv8s, YOLOv8m, YOLOv8l, and Mask-RCNN. The YOLOv8s + AFPN + MPDIoU model attains a precision rate of 90.7%, a recall of 70.4%, an F1-score of 79.27%, mAP50 of 75.3%, and mAP75 of 74.80%. In contrast to alternative models, our proposed approach exhibits enhancements across performance metrics, with the F1-score, mAP50, and mAP75 increasing by a minimum of 0.46%, 1.3%, and 1.4%, respectively. The margin of error in the measurement model calculations is maintained at or below 5%. Therefore, the developed model can serve as a useful tool for the accurate characterization and quantification of different types of bridge surface cracks.

Search for the Chiral Magnetic Effect with charge-dependent azimuthal correlations in Xe–Xe collisions at [formula omitted] TeV

Charge-dependent two- and three-particle correlations measured in Xe–Xe collisions at sNN=5.44 TeV are presented. Results are obtained for charged particles in the pseudorapidity range |η|<0.8 and transverse momentum interval 0.2≤pT<5.0 GeV/c for different collision centralities. The three-particle correlator γαβ≡〈cos⁡(φα+φβ−2Ψ2)〉, calculated for different combinations of charge sign α and β, is expected to be sensitive to the presence of the Chiral Magnetic Effect (CME). Its magnitude is similar to the one observed in Pb–Pb collisions in contrast to a smaller CME signal in Xe–Xe collisions than in Pb–Pb collisions predicted by Monte Carlo (MC) calculations including a magnetic field induced by the spectator protons. These observations point to a large non-CME contribution to the correlator. Furthermore, the charge dependence of γαβ can be described by a blast wave model calculation that incorporates background effects and by the Anomalous Viscous Fluid Dynamics model with values of the CME signal consistent with zero. The Xe–Xe and Pb–Pb results are combined with the expected CME signal dependence on the system size from the MC calculations including a magnetic field to obtain the fraction of CME contribution in γαβ, fCME. The CME fraction is compatible with zero for the 30% most central events in both systems and then becomes positive. This yields an upper limit of 2% (3%) and 25% (32%) at 95% (99.7%) confidence level for the CME signal contribution to γαβ in the 0–70% Xe–Xe and Pb–Pb collisions, respectively.

The impact of metering methods on collective self-consumption: Insights from multi-dwelling buildings in Finland

Globally, legislative reforms have significantly promoted the adoption of solar photovoltaic systems. In many European countries, updated legislation encourages the formation of energy communities and collective self-consumption in residential buildings. This study investigates the financial viability of solar photovoltaic systems in Finnish multi-dwelling buildings, focusing on the impact of recent legislative enhancements supporting collective self-consumption through virtual net-metering, known as the credit calculation model. By analyzing hourly consumption data from two properties in 2018 and 2020, and incorporating simulated photovoltaic production with electricity market prices, our findings highlight the advantages of virtual net-metering. Self-consumption ratios increased from 15% to 38 %, and annual revenue improved by 10 EUR/kWp to 29 EUR/kWp. Comparing the credit calculation model with behind-the-meter approaches using joint electricity subscriptions revealed self-consumption ratio differences of 5 % to 15 % for identical system sizes. Additionally, electricity purchasing cost savings of 16 % to 19 % were identified with behind-the-meter, increasing further compared to costs from other Finnish distribution system operators. This underscores the economic benefits of such arrangements and highlights potential savings across different regional pricing models. These insights demonstrate the financial benefits of collective self-consumption and joint electricity subscriptions in multi-dwelling contexts, signaling the need for extended research across diverse settings to validate these findings.

Hydraulic loss analysis of turbodrill blade cascades based on entropy production theory

Turbodrill is a kind of high-temperature resistant downhole motor which is commonly used in drilling deep and high-temperature wells. It belongs to multi-stage axial flow turbomachinery. There are complex flow losses in turbodrill blade cascades, but conventional flow-loss evaluation methods cannot obtain the location of losses in cascades. The entropy production method constructs the relationship between flow field parameters and flow losses, so the location where flow losses generate can be obtained, which is commonly used to analyze the flow losses in various flows. In this paper, entropy production method is used to obtain the magnitude and position of hydraulic losses in turbodrill blade cascades. The single passage calculation model of three-stage stator and rotor is established, and CFD method is employed to compute the flow field parameters at different viscosities and rotary speeds. Different kinds of entropy production rates and values are calculated. Finally, the total flow loss calculated by entropy production method is compared with that calculated by pressure difference method, and the contrastive result is very similar, which indicates the correctness of entropy production method. The results show that the high entropy production regions are mainly located near the walls and the position changes with variations in rotary speed and viscosity, and the stator entropy production value is always lower than that in rotor. In addition, when the fluid viscosity is low, the main types of entropy production are turbulent entropy production and wall friction entropy production, while when the fluid viscosity is high, the main types of entropy production are direct entropy production and turbulent entropy production. Furthermore, the rotary speed variation has a greater impact on turbulent entropy production and wall friction entropy production compared to viscosity change, while the viscosity change has a greater impact on direct entropy production than the variation rotary speed. This paper introduces entropy production method into flow losses analysis for turbodrill, presenting a new approach for studying flow losses and providing a reference for improving turbodrill design.

A simple numerical simulation model can elucidate the key factors for designing a miniaturized ion trap mass spectrometer

BackgroundMiniature ion trap mass spectrometer enables mass-to-charge ratio analysis of ions via quadrupole field in a low vacuum environment. It plays an important role in on-site detection due to its portability and specificity. In order to gain a deeper understanding of the analysis mechanism of miniature ion trap mass spectrometers, a quadrupole MS ion trajectory numerical simulation model (QITNS) is established in this paper for ions trajectory calculation under the action of quadrupole field, exciting field and neutral gas molecule collision. Compared with the existing methods, the model in this paper is simpler and more direct, which effectively explored the effects of dipole excitation and quadrupole excitation on ion manipulation under high background pressure. ResultsThe simulation results demonstrate that high RF amplitude, low auxiliary AC amplitude and quadrupole excitation can effectively improve the isolation resolution. Besides, it clarified the difference between the analysis mechanism of ion trap mass spectrometers under high background pressure (above 13.332 Pa) and absolute vacuum conditions. The relevant results are consistent with the conclusions of previous experiments and other theories, proving the applicability and accuracy of the proposed calculation model and solution method. SignificanceThis research bears the guiding significance for further understanding the mechanism of quadrupole mass spectrometry as well as designing and developing miniature mass spectrometers.

Seasonal frozen soil area frame beam anchor rod slope support structure frost heave mechanical characteristics simplified calculation model

Seasonal frozen soil area frame beam anchor rod slope support structure frost heave mechanical characteristics simplified calculation model

Fatigue life prediction considering conversion of mean stress for titanium alloy under multiaxial thermo-mechanical random loading

This paper presents a thermo-mechanical fatigue (TMF) life prediction method for titanium alloy TA15 under multiaxial random amplitude loading. Through strain-controlled TMF tests, it was found that under full-reversed cyclic loading, there was a significant presence of mean stress in the stress response. The induced mean stress led to the anomalous phenomenon where the fatigue life of thermal phase angle out-of-phase (TOP) was shorter than that of thermal phase angle in-phase (TIP). Therefore, a new damage calculation model was proposed, which can take into account the pure fatigue damage considering mean stress conversion and the cumulative environmental damage. Uniaxial TMF tests, constant amplitude multiaxial TMF tests, and random amplitude multiaxial TMF tests are conducted to verify the proposed method. The predicted results for all types of tests are in a good agreement with the experimental data.

Study on the Tensile Failure Characteristics and Energy Calculation Model of Coal Seam Hard Roof Considering the Mining Speed

To reveal the influence mechanism of mining speed on roof fracture-type rockburst, the Brazilian split technique combined with acoustic emission monitoring technology was employed to study the effects of loading rates on the tensile failure characteristics and acoustic emission parameters of coal series sandstone. The linear relationship between the tensile strength of the samples and the change rate of tensile stress was determined. The mining speed was introduced into the mechanical model of initial and cyclic fracture of the hard roof, and the quantitative relationship between the maximum rate of change of tensile stress within the hard roof and the mining speed was derived. Based on this, a computational model for the bending elastic energy of the hard roof during initial and cyclic fractures, considering the mining speed, was established. The main findings are as follows: As the loading rate increases, the distribution range of acoustic emission energy in sandstone Brazilian split samples before failure widens, with a significant rise in acoustic emission ring-down counts and energy at failure. At lower loading rates, acoustic emission events primarily occur near sample failure, whereas at higher rates, they mostly happen in the early loading stage. The higher the mining speed, the less opportunity there is for internal micro-fractures to develop and expand before the hard roof fractures, which macroscopically results in increased tensile strength and a larger amount of energy released at the moment of fracture. Bending elastic energy rises approximately linearly with mining speed, and the thicker the hard roof, the more sensitive the bending elastic energy is to changes in mining speed. This effect is even more pronounced during cyclic fractures. Optimizing mining speed is crucial for preventing roof fracture-type rockbursts, especially in mining workfaces with thick and hard roofs.

Реализация методики проектирования теплогенерирующих объектов с использованием автоматизированных расчетов и ориентацией на типовое проектирование

The quality of the project may well determine the operability and cost-effectiveness of the designed facility. There are various design methods, each of which has its advantages and disadvantages, analysis of which can be found in published studies. Thus, a methodology has been developed to reduce the likelihood of an error during system design and to reduce time using calculation programs. The purpose of this study is to implement the developed methodology using the example of designing pumping storage tanks. The study is carried out using a pipeline model designed in the START-Prof software, which allows one to accurately estimate the loads from all impacts (temperature, weight, etc.) on pipelines and equipment. As a result of this study, the authors have developed the methodology based on standard design and using automation tools for strengthening studies. The pumping equipment piping is completed using the developed method and the calculation of the developed model. The load values on the equipment fittings have been obtained. The analysis of the obtained values is presented proving the operability of the system, and therefore the rationality of the chosen method. The results obtained confirm the advantages of the developed methodology. It can be widely used in any field of design in addition to heat generation. Further combining the methodology with various automation tools, for example, the concept of BIM design, will enhance its advantages.

МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ В ДИФФЕРЕНЦИАЛЬНОЙ ДИАГНОСТИКЕ АНЕМИИ ХРОНИЧЕСКИХ ЗАБОЛЕВАНИЙ И ЖЕЛЕЗОДЕФИЦИТНОЙ АНЕМИИ У ПАЦИЕНТОВ С ВОСПАЛИТЕЛЬНЫМИ ЗАБОЛЕВАНИЯМИ СУСТАВОВ

Aim. To develop based on the indicators of clinical blood tests, some biochemical markers, iron metabolism and cytokines a mathematical model that allows with high sensitivity and specificity to conduct differential diagnosis of anemia of chronic diseases (AHD) and iron deficiency anemia (IDA) in patients with inflammatory joint diseases (rheumatoid arthritis (RA), psoriatic arthritis (PSA), ankylosing spondylitis (AS)). Material and methods. The study included 104 patients with inflammatory joint diseases and anemic syndrome (37 males/67 females, age 48.4±5.42 years old), of which 54 patients with RA, 27 patients with PSA and 23 patients with AS. The control group consisted of 22 patients with inflammatory diseases of the joints without anemia (13 males/9 females, age 47.8±3.55 years old), of which 7 patients with RA, 10 with PSA, 5 with AS. For all patients, in addition to hemogram parameters, the concentrations of interleukin-6, interleukin-10, interleukin-1β, interferon-gamma, tumor necrosis factor alpha, ferritin, C-reactive protein, hepcidin, transferrin, soluble transferrin receptor were determined. For quantitative indicators, the median, standard error of the mean, and interquartile range was calculated. The significance of differences between several unrelated groups was determined using the Kruskal-Wallis test. The calculation of a mathematical model for the differential diagnosis of ACD and IDA was carried out using discriminant analysis. Results. As a result of the study, a canonical linear discriminant function (CLDF) was obtained: CLDF = 1.612171-0.002725× Hepcidin -0.005429× Ferritin The coordinates of the centroids are calculated, for ACD it is -1.44222008, and for IDA it is 1.52705656. A patient whose CLDF value is determined based on ferritin and hepcidin concentrations should be classified into the ACD or IDA group based on the minimum distance to the corresponding centroid. The resulting mathematical model has 100% sensitivity and 80% specificity. Conclusions. The equation based on hepcidin and ferritin (obtained from the results of discriminant analysis) allows, with high sensitivity, specificity and information ability, to carry out differential diagnosis of ACD and IDA in patients with inflammatory joints diseases instantly at the stage of initial contact with the doctor. Using of the equation will make it possible to more effectively diagnose and correct these types of anemia in this pathology, including for the purpose of more effective treatment.

How to Support The Algebraic Thinking Skills of Elementary School Students Using The Generative Multi-Representation Learning Model Modification Schema-Based Instruction?

Elementary school teachers still do not fully utilize effective learning models, especially in teaching algebraic concepts. Lack of understanding of algebraic concepts has caused students to have difficulty mastering algebra, including calculation, representation, and mathematical modeling, as well as recognizing algebraic symbols and variables. The purpose of this study is to answer the research question (RQ) How does the Generative Multi Representation Learning Model Modified Schema Based Instruction (MGMRM-SBI) affect the algebraic thinking skills of elementary school students? In this study, the experimental method was used with a posttest-only control group design, where the sample was selected using Cluster Random Sampling with a total sample of 128 students. The research instrument used was an algebraic thinking ability test in the form of description test questions, and data analysis was carried out using a t-test with the help of SPSS statistical software. The results of the t-test showed a significant difference between the algebraic thinking skills of students in the experimental and control classes, with significance values (2 sides) = 0.000 &lt; sig. = 0.05. Based on the results of the study, it can be concluded that the application of the Generative Multi Representation Learning model Modified Schema Based Instruction has a significant effect on the algebraic thinking ability of elementary school students, and is more effective than the expository model.

Modeling of ice-matrix composite fracture

This article discusses the results of a study that used the structural approach to conduct multiscale modeling of composite materials. These materials are composed of an ice matrix that has been enhanced with high-strength basalt fibers. The research involved numerical modeling to analyze the fracture process of composite materials made by freezing fresh water with added basalt fibers. The analysis included experimental data from samples of pure ice and composites with different amounts of filler. The effective modulus of elasticity of the composites was determined by considering the quantity of basalt fiber reinforcement. The discrepancy between the strength obtained by finite element complex ANSYS numerical calculation and the experimental data was revealed by a series of macroscopic test calculations of the composite material sample, according to which the effective modulus of elasticity of the composite was recalculated and corrections were introduced into the Voight and Reuss models, taking into account the non-uniform distribution of the fibers and the non-ideal adhesion between the fibers and water ice. A stochastic model of crack growth at the micro level was also used with the data on the diameter and length of basalt fibers and their random distribution in the layers of the composite material. Using the newly acquired effective elastic moduli and the SmartCrackGrowth algorithm, a satisfactory agreement of the crack growth rate with the obtained by stochastic calculation was achieved. The refined method of effective elastic moduli and multilevel model of stress-strain state calculation of composite materials are recommended for assessing the strength of ice cover and designing winter roads with high load-bearing capacity and long operational duration in the Arctic and Subarctic environments.

Numerical Analysis on Frictional Heat Effect in Polyether-Ether-Ketone (PEEK)/Steel Pair by using OpenFOAM Model

The PEEK material has been applied to a sliding bearing system in a power plant system because of its high mechanical durability. In the solid friction of the PEEK materials, the frictional heat becomes the important factor because the temperature increase due to the frictional heat causes the rapid increase of the frictional coefficient of the specimen. To maintain the low frictional coefficient of the PEEK materials, an effective cooling method for the PEEK materials needs to be developed. In this study, the passive cooling method, which attaches the heat sink to the PEEK materials, was suggested. For evaluating the suggested cooling method of the PEEK materials, the calculation model adopting OpenFOAM, which is open-source software, has been developed. Adopting some functions and libraries of OpenFOAM, the frictional heat, heat resistance, and heat transfer coefficient on the heat sink were modelled. The sliding bearing experiment was conducted and time variation of the temperature and friction coefficient in the ring specimen were measured. The temperature variation in the ring specimen was compared with the calculation result. From the numerical calculation results, the developed calculation model could simulate the temperature-time variation of the ring obtained in the experiment, when the variation of the frictional coefficient, heat resistance, and heat transfer coefficient was modelled appropriately. Based on the friction and wear test results, by applying a heat dissipation mechanism to the ring test piece, the calorific value of the PEEK material can be reduced, and it is stable. It was suggested that the friction was maintained.

Dynamics of the energy spectrum of solar-diural variations in the intensity of cosmic rays in 22–25 cycles of solar activity

Periodic 24-hour variations in the intensity of galactic cosmic rays, continuously observed by ground-based detectors, are called solar diurnal variations. The nature of these variations lies in the existence in the interplanetary medium of an anisotropic spatial distribution of galactic cosmic rays, which arises during the interaction of these particles with the heliosphere. It is believed that the physical factors responsible for the observed anisotropy of galactic cosmic rays are the processes of convection, diffusion and their drift. The combination of these factors determines the main parameters of solar diurnal variations, such as amplitude, phase and energy spectrum. To study the energy spectrum of solar-diurnal variations, we used measurement data from muon telescopes of the Yakutsk Cosmic Ray Spectrograph after A.I. Kuzmin and Nagoya stations (Japan). The research approach is based on the idea of the crossed telescope method, originally designed to take into account the temperature effect. Due to the difference in the receiving characteristics of the crossed northern and southern directions of the above muon telescopes, the intensity variations recorded by them are sensitive to changes in the energy spectrum of solar-diurnal variations. This property was used to assess the dynamics of the energy spectrum of solar-diurnal variations for 22–25 cycles of solar activity. Analysis of the data obtained showed that in the last minimum of solar activity in 2018-2021. An anomalously early phase of solar-diurnal variations was observed. To study this phenomenon, we simulated the ratio and phase difference of a pair of northern and southern crossed directions for both muon telescopes for different types and values of the energy spectrum of solar-diurnal variations. A comparison of model calculations and observational data has made it possible to establish that during periods of minimum solar activity in the positive polarity of the general magnetic field of the Sun, a significant softening of the energy spectrum of solar-diurnal variations is observed. The reasons for the discovered phenomenon are discussed.

Wind influence numerical simulations on stadium structures in RWIND module of the DLUBAL RFEM software

This paper examines the effect of wind load on the stadium building, designed as a possible replacement for the stadium in the city of Mariupol, which was destroyed as a result of hostilities. The problems of using domestic standards in the design of stadium structures are considered. The approach of European regulatory documents to taking into account the effect of wind influence is considered. An analysis of previous scientific studies concerning the determination of aerodynamic parameters for stadium structures has been carried out. An analysis of the domestic regulatory document regulating the collection of wind loads showed the need for additional research into the aerodynamic parameters for stadium structures. Using a special RWIND module as part of the Dlubal RFEM software package, numerical modeling was used to simulate the wind flow flowing around the model of the stadium building, which best corresponded to the adopted design decisions, as if it were carried out in a real wind tunnel. A project was considered for an ellipsoidal stadium, the configuration of the stands and the covering of which is a full bowl with an incomplete covering. The covering over the stadium stands is designed in the form of a canopy formed by cantilever flat steel trusses. The basis of the stadium building frame is made up of vertical steel frames with a rigid connection of nodes, to the central post of which cantilever trusses of the canopy are attached. The result of theoretical testing of the stadium model was distribution diagrams of aerodynamic coefficients, the maximum values of which were used to further determine the values of wind pressure on these structures. An analysis of the research results was was carried out. The use of numerical simulation tools for wind flows made it possible to increase the complexity of the system both at the level of the design solution and at the level of the calculation model. Analysis of the design solution allowed us to competently select the necessary design solutions for load-bearing structures, taking into account the requirements of current design standards and Eurocode 1 regulations.