scholarly journals Subsidence deformations of the foundations of hydraulic structures

2021 ◽  
Vol 264 ◽  
pp. 03069
Author(s):  
Rustam Хujakulov ◽  
M Zaripov ◽  
U Normurodov
Keyword(s):  
Stressed State ◽  
Strain State ◽  
Stress Redistribution ◽  
Hydraulic Structures ◽  
Physical Processes ◽  
Irrigation Systems ◽  
Stress Strain ◽  
Regulatory Documents ◽  
Stress Strain State

One of the most important tasks in designing and constructing reclamation network structures on loess subsidence soils is to ensure their long-term trouble-free operation. The improvement of methods for the design of hydraulic structures on subsidence foundations requires further study of very complex physical processes occurring in the foundations of structures during their construction and operation. This is confirmed by the fact that even if all the requirements and recommendations of regulatory documents for the design of irrigation systems on subsiding soils are observed, the deformations of the foundations of structures often significantly exceed the calculated ones, which can cause a loss of serviceability of irrigation structures. This determines the need for further study peculiarities of interaction of irrigation structures with their subsidence bases. This article is devoted to this problem, in particular, to the study of the influence of stress redistribution in wetted subsidence foundations of hydraulic structures on the stressed state of their elements and the stress-strain state of loess subsidence foundations on the models of float bets of hydraulic structures in the Karshi steppe.

scholarly journals SEISMIC STABILITY OF THE MOORING WALL ACCORDING TO THE RESULTS OF NUMERICAL SIMULATION

2019 ◽  
pp. 2-2
Author(s):  
Victor A. Esinovsky
Keyword(s):  
Numerical Simulation ◽  
Spectral Theory ◽  
Strain State ◽  
Dynamic Theory ◽  
Seismic Stability ◽  
Hydraulic Structures ◽  
Seismic Loads ◽  
Stress Strain ◽  
Stress Strain State ◽  
Seismic Forces

Introduction. New building codes provide for a significant increase in the magnitude of seismic loads that should be perceived by hydraulic structures. In this regard, even in areas with low seismic activity, there may be a problem of ensuring the seismic stability of hydraulic structures. This is particularly acute in berthing facilities. As a rule, they are not so massive to withstand seismic loads. The issue of seismic stability of berthing facilities has not yet been properly considered. The results of numerical simulation of the seismic stability of the mooring-dividing wall during a 7-point earthquake are considered. A structure about 24 m high located on a non-rock base was investigated. Materials and methods. The seismic stability of the mooring structure was estimated by calculating its stress-strain state under the action of seismic forces. Calculations were carried out by the finite element method. Seismic loads on the structure were determined in two ways — by linear-spectral theory and by dynamic theory. For the calculation of seismic loads, 30 lower frequencies and the natural mode of the structure were determined together with an array of its base. When calculating according to the dynamic theory, the seismic effect was specified in the form of an accelerogram adopted for similar conditions. The direction of seismic impact was assumed horizontal. Results. According to the dynamic theory, seismic loads turned out to be lower than according to linear-spectral theory. However, the results of the calculation of the stress-strain state of the mooring structure were close. It was found that the seismic forces on the mooring wall will reach about a quarter of the weight of the structure. Under the influence of such forces, the mooring wall will lose its stability. Conclusions. To ensure seismic stability, it is recommended to combine the mooring wall and the base plate into a single monolithic structure, as well as to strengthen the lower part of the structure and facilitate the upper one.

scholarly journals Mathematical simulation in the system of safety monitoring of hydraulic structures and automated control systems of stress-strain state

Vestnik MGSU ◽  
2021 ◽  
pp. 1582-1591
Author(s):  
Dmitry S Dmitriev ◽  
Alexander A. Uchevatkin
Keyword(s):  
Mathematical Models ◽  
Control Systems ◽  
Strain State ◽  
Numerical Models ◽  
Safety Monitoring ◽  
Hydraulic Structures ◽  
Monitoring Systems ◽  
Stress Strain ◽  
Automated Control ◽  
Stress Strain State

Introduction. The article describes the features of the systems for monitoring the safety of hydraulic structures, which are based on the apparatus of mathematical and computer modeling. Prospects for the use of automated control systems for the stress-strain state of building structures of hydraulic structures are considered. Materials and methods. An analytical review of foreign examples of the implementation of monitoring systems for high-pressure hydraulic structures based on mathematical models is presented. The results of computational studies of the Zagorsk PSPP complex within the framework of the hardware and software complex for safety monitoring are shown. The concept of automated stress-strain state control systems is described. Results. The advantages and limitations of widely used, domestic and foreign automated information and diagnostic systems are outlined. On specific examples of the integration of numerical models of hydraulic structures into integrated systems for monitoring the safety of hydraulic structures, methods of expanding the capabilities of monitoring systems in terms of analyzing the stress-strain state of structures and predictive estimates are demonstrated. Insufficient elaboration of the issues of management of the stress-strain state of structures is noted, but the need to develop special structural elements with variable parameters to influence the stress-strain state of hydraulic structures is substantiated. Conclusions. The data presented in the article confirm the need to develop systems for monitoring the safety of hydraulic structures based on complex, multiphysics mathematical models, which can significantly expand the functionality of monito­ring systems and, as a result, improve the safety of hydraulic structures. The analysis of world experience indicates the growing lag of the Russian hydropower industry in terms of the integration of mathematical models into the safety monitoring systems for hydraulic structures, which obviously requires additional research and practical work in this area.

scholarly journals Application of a computational and experimental method of analysis the complexly stressed state of rubber membranes for effective solutions for their production

2021 ◽  
Vol 83 (2) ◽  
pp. 230-236
Author(s):  
D. V. Kudelin ◽  
T. N. Nesiolovskaya
Keyword(s):  
Stressed State ◽  
Experimental Method ◽  
Strain State ◽  
Physical And Mechanical Properties ◽  
Standard Test ◽  
Spherical Indenter ◽  
Bag Filter ◽  
Stress Strain ◽  
Rubber Membrane ◽  
Stress Strain State

The competitiveness of rubber membranes determined by their durability, quality, reliability, including the time required to create. During operation, the membranes undergo complex deformations, as a result of which a large number of potential destruction zones of a different nature arise, which can lead to the failure of the product. The standard test methods used in the development of formulations for membranes involve testing the material under uniaxial tension conditions in most cases and do not take into account the actual loading conditions of the product during operation, which significantly increases the development time of new formulations for membranes. The paper presents and applies in practice a computational and experimental method of analysis the complexly stressed state of rubber membranes, including carrying out simple laboratory tests in a heterogeneous complexly stressed state, which is realized during the operation of rubber membranes, and analyzing the stress-strain state by the finite element method. An inhomogeneous complexly stressed state was realized by forcing the rubber membrane with a spherical indenter. The application of a computational-experimental method for analyzing the complexly stressed state of rubber membranes is considered on the example of a rubber corrugated membrane of an automatic valve of a bag filter purge system. An assessment of the physical and mechanical properties of rubbers in a heterogeneous complexly stressed state was carried out, as well as an analysis of the stress-strain state of the membrane when it was loaded with a spherical indenter, which made it possible to identify the most dangerous zones of the section. The complex use of this method made it possible to improve the resource of this corrugated membrane by thirty five percent in comparison with the standard, while reducing the creation time.

Flexible bar buckling under short-time and long-term compressions

2020 ◽  
Vol 17 (1) ◽  
pp. 199-210
Author(s):  
Anton Egorov ◽  
Vitaly Egorov
Keyword(s):  
Dynamic Analysis ◽  
Mechanical Behaviour ◽  
Strain State ◽  
Stress Strain ◽  
Content Type ◽  
Stress Strain State ◽  
Bar Buckling ◽  
Comparison Of The Results ◽  
Short Time

PurposeThe purpose of this paper is to expand possibilities of stability computing method when performing a dynamic analysis of bar- or rod-shaped elements for actual structures.Design/methodology/approachThe methodology is based on the changes of stress–strain state of the bar-shaped elements at the moment of buckling. The proposed method is based on three assumptions. Firstly, the spatial stress–strain state is determined in the bar. Secondly, technological deviations inherent in real structures are introduced into the bar. Thirdly, mechanical behaviour of the bar is investigated in the mode of real time, which makes it possible to take into account wave deformation processes in the bar. To implement the suggested method of analysis, LS-DYNA package was selected in a dynamic formulation using solid finite elements.FindingsValidity of the proposed method is shown by an example of dynamic stability analysis of a steel flat thin bar with two types of loads: short-time and long-term axial compressions. Comparison of the results showed different nature of the mechanical behaviour of the bar: wave processes are observed under short-time loading, and continuous monotone ones are stated under long-term loads.Practical implicationsResearch results are applicable in the rocket and space industry.Originality/valueA new computer-based methodology for dynamic analysis of heterogeneous elastic-plastic bar-, rod-shaped structures under shock axial compressive loads is proposed.

Stress-strain state of an arch dam based on data of long-term on-site observations

1981 ◽  
Vol 15 (6) ◽  
pp. 360-365 ◽  
Author(s):  
I. F. Blinov ◽  
E. M. Mirzak ◽  
Yu. P. Shaikin
Keyword(s):  
Strain State ◽  
Arch Dam ◽  
Stress Strain ◽  
Stress Strain State

Sealing of Pipelines Flange Connections in Conditions of Fasteners Tightening Torque Reducing

2014 ◽  
Vol 630 ◽  
pp. 283-287 ◽  
Author(s):  
Oleg Bondarenko ◽  
Anatoliy Dziuba
Keyword(s):  
Strain State ◽  
Pipe Material ◽  
Space Technology ◽  
Stress Strain ◽  
Tightening Torque ◽  
Flange Connection ◽  
Stress Strain State ◽  
Technical Systems ◽  
Natural Will

Flanged connections are widely used in pipelines of various technical systems. Task of reducing the consumption of materials pipelines , ensuring their long-term tightness is highly relevant for shipbuilding , aviation and space technology and other mashinebuilding. In this paper, the task of deliberately reducing torque fasteners flange connection at build pipelines to ensure the initial tightness of the connection , reducing the weight of the pipeline , the alignment of the stress- strain state of the compound and determining the residual torque fasteners, providing connections for leaks. With decreasing torque fasteners ( intentional or natural ) will be sealed flanged if the remaining torque is sufficient to compensate for the pressure in the pipeline and prevent shear movement of the flange and gasket relative to each other . Found that the flange connection remains sealed with natural and deliberate reduction torque fasteners to 75-80 % compared to the initial .Sealing flange connections using technology and standard fastenings to reduce their weight by 10-50 %, and the replacement of flanges and pipe material - a whole lot of pipelines at 30-65 %.

scholarly journals Research on the Stress-Strain State of the Base of Operating Low-Pressure Hydraulic Structures

2019 ◽  
Vol 9 (1) ◽  
pp. 5257-5260
Keyword(s):  
Hydrostatic Pressure ◽  
Strain State ◽  
Low Pressure ◽  
Technical Condition ◽  
Hydraulic Structures ◽  
Stress Strain ◽  
Stress Strain State ◽  
Weak Soils ◽  
Calculated Model

The analysis of the stress-strain state of one of the operated low-pressure hydraulic structures on weak soils is considered in the paper. Calculated model on estimation of technical condition of designed and operated HS (hydraulic structures) and their bases taking into account a load of own weight of structures and hydrostatic pressure of water of the upper high relief is offered.

One approach to evaluating and monitoring the stress—Strain state of hydraulic structures

1998 ◽  
Vol 32 (2) ◽  
pp. 113-116 ◽  
Author(s):  
M. V. Kurlenya ◽  
V. D. Baryshnikov ◽  
L. N. Gakhova
Keyword(s):  
Strain State ◽  
Hydraulic Structures ◽  
Stress Strain ◽  
Stress Strain State

scholarly journals Stress-strain state analysis of the leading car body of DPKr-2 diesel train under action of design and operational loads

2019 ◽  
Vol 294 ◽  
pp. 03018 ◽  
Author(s):  
Sergei Kostritsa ◽  
Alexander Pshinko ◽  
Lyudmila Ursulyak ◽  
Andriy Kuzyshyn ◽  
Maxim Kramarenko ◽  
...  
Keyword(s):  
Strain State ◽  
Experimental Studies ◽  
The Body ◽  
Operational Mode ◽  
Structural Element ◽  
Stress Strain ◽  
Car Body ◽  
Regulatory Documents ◽  
Stress Strain State ◽  
Strength And Durability

Purpose.Provision of strength and durability of the main structural element of DPKr-2 diesel train -the leading car body. Methodology. A spatial solid-state 3-D model of the body is built and durability calculations are carried out concerning action of loads stipulated by regulatory documents operating in Ukraine. In particular, the following main estimated modes are considered: mode 1 – a notional safety mode which takes into account the possibility of considerable longitudinal forces arising during shunting movements, transportation and accidental collision; mode 2 – an operational mode which takes into account forces acting on a train during acceleration to constructional speed, coasting or braking from this speed while passing a curve. Results. Based on the results of theoretical and experimental studies a conclusion has been made that the leading car body construction of DPKr-2 diesel train meets the requirements of regulatory documents regarding strength and durability. Practical relevance. A complex of calculation and experimental work concerning assessment of stress-strain state of the leading car body of DPKr-2 diesel train under action of design and operational loads allowed the creation of construction which meets not only operational requirements but also strength and durability ones.

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