scholarly journals A study on resonance characteristics of hydraulic structures and buildings conducted using small-size models

Vestnik MGSU ◽  
2021 ◽  
pp. 1452-1461
Author(s):  
Konstantin N. Makarov ◽  
Elena E. Yurchenko ◽  
Erik K. Biryukbaev ◽  
Vasilisa E. Yurchenko
Keyword(s):  
Mathematical Modeling ◽  
Organic Glass ◽  
Physical Models ◽  
Dynamic Effects ◽  
Mutual Correlation ◽  
Software Packages ◽  
Resonance Frequencies ◽  
Structural Responses ◽  
Different Response ◽  
Free Bearing

Introduction. The study focuses on resonance characteristics of a hydraulic engineering structure, such as a groin, land retention works on an artificial island, and a school building. Any structure, exposed to dynamic effects of natural or man-induced origin, can be validly simulated as a mechanical resonator. Models are made of materials that have electro-elastic properties allowing to measure responses to induced oscillations, or changes in an alternating electric field, and reevaluate the physical characteristics later. Materials and methods. Small-size physical models of structures are made of electro-elastic materials, such as organic glass and ABS plastic, used for 3D printing. A laboratory test bench, composed of an oscillator and a personal computer, used as an oscillograph, was applied to conduct the testing. Mathematical modeling was performed using SolidWorks software packages. Oscillation modes and structural responses, featuring different response amplitudes, were identified. Models of structures were studied in different contexts, including restraint and free bearing. Results. It has been found that frequencies of the first mode of oscillations in a restrained model correspond to the fourth mode of a model in case of free bearing. Mutual correlation of eigenfrequencies of oscillations in small-size models, made of ABS plastic and organic glass, is demonstrated. Conclusions. The applicability of ABS plastic as the material of small-size physical models of buildings and structures has been proven for the purpose of identifying resonance frequencies of the prototypes. The co-authors have developed an integrated physical and mathematical modeling method that entails the use of SolidWorks software packages. This method allows to identify resonance frequencies, which are most dangerous for structures. Different structure support patterns allow to apply the geometric scale to obtain resonance frequencies when translating small-size model results to natural values and, hence, identify the vulnerability of structures to dynamic effects.

Modeling of Characteristics of Water-Ring Vacuum Pumps

2019 ◽  
pp. 70-77 ◽  
Author(s):  
N.L. Velikanov ◽  
V.A. Naumov
Keyword(s):  
Mathematical Modeling ◽  
Physical Models ◽  
Hydraulic Calculation ◽  
Suction Pressure ◽  
Gas Compression ◽  
Physical And Mathematical Modeling ◽  
Empirical Coefficients ◽  
Isothermal Gas ◽  
Pumping Units ◽  
Water Ring

Physical and mathematical modeling of characteristics of water-ring vacuum pumps has a number of specific features. Isothermal efficiency, i.e. the ratio of the isothermal gas compression power to the pump power consumed is used as an efficiency indicator. The article describes the existing methods of hydraulic calculation of pumping units. An analysis of physical models, numerical values of empirical coefficients is carried out. An improved algorithm for calculating water-ring vacuum pumps of different manufacturers in the framework of previously developed models is presented. The calculations of compressors manufactured by ZAO Beskom (VVN-3, VVN1-6, VVN1-12) and ERSTVAK (ELRS-45, ELRS-57) are considered as examples. The results of tests of vacuum pumps published by the manufacturers in the open press are used as the initial data for the calculations. The experimental dependences of the performance, power expended, isothermal efficiency of water-ring vacuum pumps on the suction pressure are presented. The results obtained make it possible to improve the accuracy and reliability of predicting the amount of displaced liquid or steam during the operation of the pumping unit.

Mathematical Modeling of a Two Spool Flow Control Servovalve Using a Pressure Control Pilot1

2002 ◽  
Vol 124 (3) ◽  
pp. 420-427 ◽  
Author(s):  
Randall T. Anderson ◽  
Perry Y. Li
Keyword(s):  
Mathematical Modeling ◽  
Flow Control ◽  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Pressure Control ◽  
Dynamic Effects ◽  
Nonlinear Dynamic Model ◽  
Two Stage ◽  
Matlab Simulink ◽  
Proposed Model

A nonlinear dynamic model for an unconventional, commercially available electrohydraulic flow control servovalve is presented. The two stage valve differs from the conventional servovalve design in that: it uses a pressure control pilot stage; the boost stage uses two spools, instead of a single spool, to meter flow into and out of the valve separately; and it does not require a feedback wire and ball. Consequently, the valve is significantly less expensive. The proposed model captures the nonlinear and dynamic effects. The model has been coded in Matlab/Simulink and experimentally validated.

Mathematical Modeling of a Two Spool Flow Control Servovalve Using a Pressure Control Pilot

2000 ◽  
Author(s):  
Randy T. Anderson ◽  
Perry Y. Li
Keyword(s):  
Mathematical Modeling ◽  
Flow Control ◽  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Pressure Control ◽  
Dynamic Effects ◽  
Nonlinear Dynamic Model ◽  
Two Stage ◽  
Proposed Model

Abstract A nonlinear dynamic model for an unconventional, commercially available electrohydraulic flow control servovalve is presented. The valve is a two-stage valve and differs from the conventional servovalve in that it does not require a feedback wire and ball, and the boost stage uses two spools, instead of a single spool, to meter flow into and out of the valve separately. Consequently, the valve is significantly less expensive. The proposed model captures the nonlinear and dynamic effects not present in previous models. The model has been coded in Simulink and experimentally validated.

Development and distribution of karst and suffusion processes on the territory of the Belgorod region, assessment of their impact on the environment

2021 ◽  
Vol 27 (2) ◽  
pp. 42-51
Author(s):  
D. Sarychev ◽  
◽  
А. Sarychev ◽  
I. Arkhiptsev ◽  
N. Demchenko ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Agricultural Land ◽  
Integrated Approach ◽  
Physical Models ◽  
Negative Consequences ◽  
Economic Activities ◽  
Industrial Enterprises ◽  
Geological Processes ◽  
Industrial Buildings ◽  
The Impact

Relevance. The problem of studying karst-suffusion processes is that soluble rocks in Russia occupy large areas. The Belgorod region is rich in Cretaceous deposits, which are widespread throughout the territory. Due to the fact that carbonate rocks are susceptible to dissolution by surface and groundwater leads to the formation of karst forms. Such forms open and form places of karst waters’ accumulation, open fissure and cave systems and are becoming areas with an increased environmental hazard to the life of people, infrastructure, civil and industrial buildings. Dangerous exogenous geomorphological processes negatively affect the economic development of the region. The purpose of the article is to study the factors influencing the development and distribution of karst and suffusion processes, the reasons for their occurrence, as well as the impact on the environment. Among hazardous exogenous geological processes, karst-suffusion processes are the most unpredictable. Their occurrence has negative consequences for the economics and economic activities of the region. The main methods used in this study are observation method, laboratory experiment and mathematical modeling. The method of mathematical modeling has relatively recently come into the use by the researchers and allows for a better reproduction of processes on physical models. This study is aimed at determining the interaction of karst and suffusion processes, as well as assessing their impact on the environment. The zoning of the karst and suffusion distribution on the territory of the Belgorod region has made it possible to identify the causes of these processes. To prevent the development and spread of karst-suffusion processes, an integrated approach to the analysis of manifestation, drawing up a forecast plan and measures to counter negative consequences is required. Based on the results of the study, measures were proposed to minimize damage to agricultural land, residential and farm buildings, as well as measures to combat karst and suffusion processes. It should be noted that the results of the study and the developed measures to prevent the negative consequences of karst and suffusion processes can be used in human agricultural activities, construction of civil and industrial enterprises, their reconstruction, laying of communications and development of carbonate new deposits

scholarly journals Application of additive technology for the study of resonance oscillations in structures

2018 ◽  
Vol 251 ◽  
pp. 04001 ◽  
Author(s):  
Konstantin Makarov ◽  
Evgeny Yurchenko ◽  
Elena Yurchenko
Keyword(s):  
Physical Modeling ◽  
Physical Models ◽  
Small Scale ◽  
Additive Technology ◽  
Harmonic Oscillations ◽  
Resonance Frequencies ◽  
Scale Models ◽  
Concrete Building ◽  
Resonance Oscillations

The methodic of studying the vibrations of small-sized physical models using additive technology has been developed. The results of the experimental determination of the resonance frequencies for harmonic oscillations and the calculation of the phase shift for two small-scale models of a three-story reinforced concrete building with a nonrigel frame has been presented. It has been shown that the production of models on a 3-D printer makes it possible to reduce the laboriousness of their manufacture, and also to expand the possibilities for accounting of operational defects in buildings and structures derived from seismic, vibrational and other types of vibrational influences based on physical modeling.

scholarly journals Synchronization system in wireless sensor networks of oil and gas complex

2020 ◽  
Vol 164 ◽  
pp. 03030
Author(s):  
Dmitry Onyshko ◽  
Dmitry Fugarov ◽  
Olga Purchina ◽  
Anna Poluyan ◽  
Nikolay Rasteryaev ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Analytical Models ◽  
Wireless Sensor ◽  
Gas Industry ◽  
Synchronization System ◽  
Software Packages

The aim of this work is to study the synchronization system in wireless sensor networks of remote objects of the oil and gas complex. The objective of the study is to ensure the timely collection of reliable information about the parameters of the process. In the course of the study, methods of theoretical circuitry and mathematical modeling were used, in particular, regression and analytical models, methods of probability theory and mathematical statistics using MathCad and Matlab software packages. The conducted studies indicate a high vulnerability of the radio links of the infocommunication system for monitoring the parameters of remote objects of the oil and gas complex from attacks on the synchronization system when using deterministic synchronization signals in it. The results achieved allow us to provide the specified requirements for reliability and timeliness when deploying modern wireless sensor networks in the oil and gas industry.

Modeling the reinforced concrete shell with a protective structure

2021 ◽  
Vol 8 (3) ◽  
pp. 391-399
Author(s):  
I. I. Karhut ◽  
◽  
O. V. Krochak ◽  
S. B. Maksimovich ◽  
◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Reinforced Concrete ◽  
Strain State ◽  
Experimental Studies ◽  
Physical Models ◽  
Protective Structure ◽  
Temperature Problem ◽  
Annular Section ◽  
Concrete Shell ◽  
Protective Structures

The results of the mathematical modeling and experimental studies for the stress-strain state of the annular section of the reinforced concrete shell with the protective structure are presented. Computer simulation has been formulated as a stationary temperature problem. The distribution of deformations and stresses is shown using the equations of the elastic theory. A comparison of theoretical dependences on the results of experimental studies of physical models is given. Conclusions are drawn about the possibility of using them in the calculations of reinforced concrete protective structures.

scholarly journals Embedded fuzzy controller for water level control

2022 ◽  
Vol 12 (1) ◽  
pp. 277
Author(s):  
Javier Eduardo Martinez Baquero ◽  
Jairo Cuero Ortega ◽  
Robinson Jimenez Moreno
Keyword(s):  
Mathematical Modeling ◽  
Steady State ◽  
Water Level ◽  
Fuzzy Controller ◽  
Low Cost ◽  
Process Control System ◽  
Level Control ◽  
Output Variable ◽  
The Difference ◽  
Different Response

This article presents the design of a fuzzy controller embedded in a microcontroller aimed at implementing a low-cost, modular process control system. The fuzzy system's construction is based on a classical proportional and derivative controller, where inputs of error and its derivate depend on the difference between the desired setpoint and the actual level; the goal is to control the water level of coupled tanks. The process is oriented to control based on the knowledge that facilitates the adjustment of the output variable without complex mathematical modeling. In different response tests of the fuzzy controller, a maximum over-impulse greater than 8% or a steady-state error greater than 2.1% was not evidenced when varying the setpoint.

Construction of Concepts Images from Mathematical Models Obtained with the Tracker Software

2021 ◽  
Vol 2 (2) ◽  
pp. 245-255
Author(s):  
Radael de Souza Parolin ◽  
Alex Sandro Gomes Leão ◽  
Tatiane Zago Bonorino ◽  
Maria Eduarda Berro Sabin Santos
Keyword(s):  
Mathematical Modeling ◽  
Visual Perception ◽  
Mathematical Models ◽  
Undergraduate Students ◽  
Exploratory Study ◽  
Physical Models ◽  
Function Concepts ◽  
Modeling Methodology ◽  
Concept Images

This work aims to investigate the potential of combining the Mathematical Modeling methodology with the use of the software Tracker with undergraduate students in Mathematics in the reconstruction of physical models for the construction of function concepts. For this, a qualitative and exploratory study of bibliographic and experimental character was carried out, involving field activities. Our results point to a greater understanding in the construction of the models, since the mathematical models can be recreated from the correlation to physical models already validated. We also verified that the Tracker software enables an excellent visual perception of different concept images.  

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