scholarly journals Stress-strain state analysis of structures based on the monitoring data

2018 ◽  
Vol 196 ◽  
pp. 01023
Author(s):  
Dmitriy Sidorov ◽  
Vladimir Dorozhinskiy
Keyword(s):  
Strain State ◽  
Human Factor ◽  
Monitoring Systems ◽  
Construction Technology ◽  
Stress Strain ◽  
Stress Strain State ◽  
Standards And Regulations ◽  
Internal Forces ◽  
Routine Inspection ◽  
Supporting Structures

Advances in construction technology result in increased complexity and multi-functionality of modern buildings and structures. This is especially true for unique structures with large spans and heights. Based on the current standards, such structures must be monitored as well as the stress-strain state (SSS) of supporting structures. In addition, the SSS must be continuously checked during operation. Indeed, facilities of higher complexity are more prone to errors or discrepancies, which can reduce the reliability of some structures as well as the whole system. This can be caused by human factor, variability of external and internal forces and impacts, specifics of erection and installation, and many other reasons. Therefore, unique buildings and structures must be built with monitoring systems or operated under routine inspection. This way we can determine if the behavior of the erected structure complies with the standards and regulations.

scholarly journals On the issue of dynamic loading of supporting structures of special wheeled chassis

2019 ◽  
pp. 73-83
Author(s):  
V. I. Tarichko ◽  
P. I. Shalupina
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Loading ◽  
Strain State ◽  
Element Model ◽  
Stress Strain ◽  
Full Size ◽  
Equivalent Stresses ◽  
Stress Strain State ◽  
Supporting Structures

The paper focuses on a method for assessing the dynamic loading of the frame of a special wheeled chassis when it moves on roads of various categories. Based on the developed finite element model of the frame, we obtained and analyzed full-size patterns of the stress-strain state of the frame and oscillograms of equivalent stresses in the most loaded zones of the frame.

scholarly journals A transient dynamic process in a structural nonlinear system “beam – two-parameter foundation”

2020 ◽  
Vol 310 ◽  
pp. 00007
Author(s):  
Vladimir Gordon ◽  
Pavel Morrev ◽  
Olga Pilipenko
Keyword(s):  
Cross Section ◽  
Strain State ◽  
Shear Stiffness ◽  
Arbitrary Cross Section ◽  
Forced Oscillations ◽  
Stiffness Parameter ◽  
Stress Strain ◽  
Stress Strain State ◽  
Internal Forces ◽  
Two Parameter

A method for analytical assessment of dynamic added stress in elastic loaded beam resting on elastic two-parameter Pasternak’s foundation due to sudden destruction a part of foundation is proposed. Equations of static bending, natural and forced oscillations are written in a matrix form using state vectors including deflection, rotational angles, bending moments, and shear forces at arbitrary cross section of a beam and also using the matrices of the initial parameters influence on the stress-strain state in arbitrary cross section. The influence of foundation failure on beam’s stress-strain state, taking into account a relation between the stiffness parameters of foundation, is analyzed. The condition of smallness for the shear stiffness parameter (Pasternak’s parameter) in comparison with the stretching-compressing stiffness parameter (Vinkler’s parameter) is accepted. It is shown that the accounting of Pasternak’s parameter reduces the level of dynamic added stress in a beam when sudden destructing of a foundation. The factor of sudden defect occurrence in the system “beam – foundation” increases considerably the internal forces in a beam in comparison with quasistatic formation of the same defect.

scholarly journals Stress-strain state of shell of revolution analysis by using various formulations of three-dimensional finite elements

2020 ◽  
Vol 16 (5) ◽  
pp. 361-379
Author(s):  
Natalia A. Gureeva ◽  
Yuriy V. Klochkov ◽  
Anatoly P. Nikolaev ◽  
Vladislav N. Yushkin
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Hermite Polynomials ◽  
Mixed Formulation ◽  
Shell Of Revolution ◽  
Shells Of Revolution ◽  
Displacement Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Internal Forces

The aim of the work is to perform a comparative analysis of the results of analyzing arbitrarily loaded shells of revolution using finite element method in various formulations, namely, in the formulation of the displacement method and in the mixed formulation. Methods. To obtain the stiffness matrix of a finite element a functional based on the equality of the actual work of external and internal forces was applied. To obtain the deformation matrix in the mixed formulation the functional obtained from the previous one by replacing the actual work of internal forces in it with the difference of the total and additional work was used. Results. In the formulation of the displacement method for an eight-node hexahedral solid finite element, displacements and their first derivatives are taken as the nodal unknowns. Approximation of the displacements of the inner point of the finite element was carried out through the nodal unknowns on the basis of the Hermite polynomials of the third degree. For a finite element in the mixed formulation, displacements and stresses were taken as nodal unknowns. Approximation of the target finite element values through their nodal values in the mixed formulation was carried out on the basis of trilinear functions. It is shown on a test example that a finite element in the mixed formulation improves the accuracy of the strength parameters of the shell of revolution stress-strain state.

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 Accounting for the flexibility of nodes in the design of steel mesh dome

2018 ◽  
Vol 245 ◽  
pp. 08006
Author(s):  
Egor Kanaev ◽  
Daria Demidova ◽  
Sergey Zimin
Keyword(s):  
Strain State ◽  
High Strength ◽  
Stress Strain ◽  
Strain Capacity ◽  
Stress Strain State ◽  
Semirigid Connections ◽  
Different Types ◽  
Internal Forces ◽  
The City ◽  
Geodesic Dome

This paper presents the results of a study of the stress-strain state of a geodesic dome covering the planetarium designed in the city of Nizhny Novgorod. Four design schemes were created in the SCAD with different types of node modeling. A comparative analysis of the effect of the strain capacity of the “BrGTU” type unit on the stress-strain state of the dome cover has been carried out. The results are obtained on the change in the displacements of the structure nodes and internal forces in the dome bars, with rigid and hinged mates. The option of increasing the diameter of high-strength bolts to reduce the overall deformability of the system is considered. On the basis of the obtained results, it was concluded that it is necessary to take into account the strain capacity of the semirigid connections when designing mesh steel domes.

scholarly journals Experimental studies of the stress-strain state of reinforced concrete structures strengthened by prestressed basalt-composite rebar

2021 ◽  
Vol 17 (3) ◽  
pp. 288-298
Author(s):  
Oleg D. Rubin ◽  
Sergey E. Lisichkin ◽  
Oksana V. Zyuzina
Keyword(s):  
Reinforced Concrete ◽  
Strain State ◽  
Concrete Structures ◽  
Hydraulic Structures ◽  
Reinforced Concrete Structures ◽  
Theoretical Studies ◽  
Stress Strain ◽  
Stress Strain State ◽  
Internal Forces ◽  
Construction Joints

Relevance. In recent years, composite materials have become widespread in the construction of reinforced concrete structures for industrial, civil and transport structures. It is proposed to strengthen the reinforced concrete structures of hydraulic structures with prestressed basalt composite rebar. It took an experimental and theoretical substantiation of technical solutions to strengthen the reinforced concrete structures of hydraulic structures with prestressed basalt composite reinforcement. The aim of the work was to carry out a set of experimental and theoretical studies of the stress-strain state and internal forces in low-reinforced concrete structures of hydraulic structures reinforced with prestressed basalt composite rebar. Methods. Experimental studies of the stress-strain state and internal forces were carried out on the basis of low-reinforced concrete beam-type models with interblock construction joints, harden with prestressed basalt composite reinforcement in the stretched (compressed) zones of the models. Theoretical studies of the stress-strain state and internal forces were carried out on the basis of the theory of reinforced concrete and structural mechanics. Results. As a result of the research carried out on typical low-reinforced concrete structures of hydraulic structures with interblock construction joints, the main stages of the stress-strain state of hydraulic reinforced concrete structures were formulated. Based on the data of experimental and theoretical studies, taking into account the reinforcement with prestressed basalt composite rebar, as well as with prestressed clamps in the shear zone, a method was developed for calculating the strength of low-reinforced hydrotechnical reinforced concrete structures with interblock construction joints.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

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