scholarly journals The stability of the wall of the main beam of the movable bridge (application of SP method)

2020 ◽  
Vol 157 ◽  
pp. 06014
Author(s):  
Sergey Chizhov ◽  
Artyom Pismak ◽  
Anatoly Antonyuk

The objects of the article are: analyze the work of the main beams of the movable span of the drop-down system near the axis of rotation; analyze the stress-strain state of the main beams of the movable span of the drop-down system near the axis of rotation; analyze the acceptability of the normative methodology (SP) for calculating the stability of the wall of a continuous steel beam during the design and calculation of movable bridge of the drop-down system. A computational-mathematical model of the movable span of the drop-down system is developed in a modern computational software package based on the finite element method. The main disadvantages of the normative methodology (SP) for calculating the wall stability of a continuous steel beam which used in design and calculation of movable bridge of a drop-down system are presented.

Author(s):  
Oleksij Fomin ◽  
Alyona Lovska ◽  
Oleksandr Safronov ◽  
Olena Soroka

To increase the efficiency of combined transportation, the supporting structure of flat wagon has been created. A feature of the wagon is that the sections have a low center of gravity. This solution allows for the transportation of oversized cargo on a flat wagon within the established dimensions. The design of this flat wagon can be used for the carriage of goods not only by main lines, but also in rail and water traffic when transported by rail ferries. To ensure the safety of transportation of a flat wagon with containers on a railway ferry, their dynamic loading was determined. It is taken into account that a large-capacity container of 1AA standard size is placed on each section. The solution of the mathematical model was carried out in the MathCad software package. The resulting accelerations, as components of the dynamic load, were taken into account when determining the stability of a container on a flat wagon during transportation by a rail ferry. It was found that the stability of the container is ensured at tilt angles up to 25°. A computer simulation of the dynamic loading of the supporting structure of an articulated flat wagon with containers during transportation by a railway ferry has been carried out. The calculation is implemented in the CosmosWorks software package using the finite element method. The fields of distribution of accelerations relative to the supporting structure of the flat wagon and containers are determined. The maximum percentage of discrepancy between the results of mathematical and computer simulation does not exceed 11 %. The research carried out will contribute to the creation of innovative designs of flat wagons, as well as to increase the efficiency of the operation of combined transport in international traffic


2020 ◽  
Vol 13 (2) ◽  
pp. 4-11
Author(s):  
Natal'ya Grebennikova ◽  
Pavel Kuprienko ◽  
S. Nikolenko ◽  
Svetlana Sazonova

In carrying out research on the technical condition of brick buildings, there is a need to study the strength of load-bearing walls. The paper presents the results of determining the strength of silicate brick by a non-destructive diagnostic method, using the ONIX-2.6 shock impulse control device of bricks. Calculation results are presented to determine the cause of cracking in brick walls. Verification calculations of building constructions were performed by the finite element method using the NormFEM application of the licensed version of the NormCAD software package.


2021 ◽  
Vol 258 ◽  
pp. 09085
Author(s):  
Nurilla Noraliev ◽  
Bakhrom Ishniyazov ◽  
Bunyod Safarov ◽  
Oybek Saparov

This article presents the results of a numerical study of the stress concentration around two equal and unequal holes in an orthotropic spherical shell made of composite materials under the action of internal pressure. The influence of geometric (hole radii, shell thickness, distance between holes) characteristics, as well as material orthotropy and shear stiffness, on the stress state of spherical shells made of composite materials is studied. A numerical algorithm based on the finite element method has been developed and a software package has been implemented on a computer that allows solving the problem of stress concentration near two unequal holes in spherical shells made of composite materials.


2022 ◽  
Author(s):  
S.I. Valeev

Abstract. The paper deals with the issue of safe operation of technological equipment with a defect in the base metal of the delamination type. Mathematical modeling of the stress-strain state in the defect zone by the finite element method in ANSYS software package is carried out. The article presents and analyzes the obtained graphs of the distribution of stress intensity factors. Based on the analysis of the obtained dependences, it is shown that stratification of the base metal does not have a significant effect on the performance of the process equipment.


2020 ◽  
Vol 166 ◽  
pp. 02003
Author(s):  
Radomir Timchenko ◽  
Stanislav Popov ◽  
Oleg Nastich ◽  
Dmitry Krishko ◽  
Vladimir Savenko

During the design and operation practice, it is necessary to assess the possibility of deformation of structures located on foundations which are able to precipitate and subside. Only with reliable and accurate determination of the stress-strain state of structures of structures together with soil masses during modeling, it is possible to apply the finite element method in practice. The calculations using the PLAXIS and LIRA programs made it easier to analyze the stress-strain state of the soil mass and the stability of retaining walls: I option is corner retaining wall; II option is retaining wall with a structural surface. With the same soil base (layer geometry and physicomechanical properties), loads and boundary load conditions, it is obvious that for the II option the entire mass of soil is included in the work and the stresses are uniformly distributed over the front and foundation plates (over common stresses), uniform structural deformations are observed and soil base, which, in turn, ensures the stability of the retaining wall (according to the general picture of movements) The validity of the theoretical forecast of the behavior of engineering structures interacting with an unevenly deformed base cannot be obtained on the basis of the regulatory framework. This gap can be filled in when modeling the “base – engineering structure” system using modern calculation programs using the finite element method.


Author(s):  
P. О. Semko

The article presents the results of experimental tests of compressed tubular elements with demountable joints investigated on the central and noncentral compression (with eccentricities 0, 0,25 and 0.5 from the diameter of the sample) and numerical simulation by the finite element method. The obtained results were compared for similar samples and their models. For which using numerical simulation in the Femap software system a stress-strain state was investigated and graphical representations of principal stresses were presented. For comparison the tensions that arose when the shell's steel pipe was reached the yield strength were selected. The mean square deviation and the coefficient of variation of the data obtained varied in the range of 5 – 7%, which indicates the correspondence of the results and allows further research of partial replacement of experimental tests with numerical simulation


2021 ◽  
Vol 227 ◽  
pp. 04002
Author(s):  
Dilbarkhon Sh. Fazilova ◽  
Lola V. Sichugova

This paper presents the results of the GNSS geodetic network deformation analysis in the Tashkent region, as an example of an urban area, where obtaining reliable information for assessing hazard risk is of great importance. A software package in Delphi language has been developed for the assessment of the datum differences between 2009 and 2011 by implementing the 3D Helmert transformation method. The result revealed that there is significant translation and rotation in the network, while the scale of the network remains almost constant during two years period. The area strain was estimated by the finite element method. Most of the Tashkent region can be considered to be in a high compression (negative dilatation) strain state with maximum value -230cl0-8. On the contrary, remarkable positive dilatation strain is concentrated on the coastline of the Charvak water reservoir, where large strain is about 351.l0-8.


2015 ◽  
Vol 3 (1) ◽  
pp. 48
Author(s):  
Elona Shehu ◽  
Elona Meka

The quality of the loan portfolio in Albanian banking system is facing many obstacles during the last decade. In this paper we look at possible determinants of assets quality. During the recent financial crisis commercial banks were confronted with deteriorating asset quality that threatened not only the banking industry, but also the stability of the entire financial system. This study aims to examine the correlation between non-performing loans and the macroeconomic determinants in Albania during the last decade. NPLs are considered to be of a high importance as they represent the high risk exposure of banking system. A solid bank with healthy assets increases the market efficiency. Our approach is based on a panel data regression analysis technique from 2005-2015. Within this methodology this study finds robust evidence on the existing relationship between lending interest rate, real GDP growth and NPLs. We expect to find a negative relationship between lending interest rate and asset quality. Further we assume an inverse relationship between GDP growth and non-performing loans, suggesting that NPLs decrease if the economy is growing. Furthermore this study proposes a solution platform, which looks deeper into the possibility of creating a secondary active market for troubled loans, restructuring the banking system or implementing the Podgorica model. This research paper opens a new lieu of discussion in terms of academic debates and decision-making policies.


2021 ◽  
pp. 1-31
Author(s):  
S.H. Derrouaoui ◽  
Y. Bouzid ◽  
M. Guiatni

Abstract Recently, transformable Unmanned Aerial Vehicles (UAVs) have become a subject of great interest in the field of flying systems, due to their maneuverability, agility and morphological capacities. They can be used for specific missions and in more congested spaces. Moreover, this novel class of UAVs is considered as a viable solution for providing flying robots with specific and versatile functionalities. In this paper, we propose (i) a new design of a transformable quadrotor with (ii) generic modeling and (iii) adaptive control strategy. The proposed UAV is able to change its flight configuration by rotating its four arms independently around a central body, thanks to its adaptive geometry. To simplify and lighten the prototype, a simple mechanism with a light mechanical structure is proposed. Since the Center of Gravity (CoG) of the UAV moves according to the desired morphology of the system, a variation of the inertia and the allocation matrix occurs instantly. These dynamics parameters play an important role in the system control and its stability, representing a key difference compared with the classic quadrotor. Thus, a new generic model is developed, taking into account all these variations together with aerodynamic effects. To validate this model and ensure the stability of the designed UAV, an adaptive backstepping control strategy based on the change in the flight configuration is applied. MATLAB simulations are provided to evaluate and illustrate the performance and efficiency of the proposed controller. Finally, some experimental tests are presented.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1976
Author(s):  
Tomasz Garbowski ◽  
Tomasz Gajewski

Knowing the material properties of individual layers of the corrugated plate structures and the geometry of its cross-section, the effective material parameters of the equivalent plate can be calculated. This can be problematic, especially if the transverse shear stiffness is also necessary for the correct description of the equivalent plate performance. In this work, the method proposed by Biancolini is extended to include the possibility of determining, apart from the tensile and flexural stiffnesses, also the transverse shear stiffness of the homogenized corrugated board. The method is based on the strain energy equivalence between the full numerical 3D model of the corrugated board and its Reissner-Mindlin flat plate representation. Shell finite elements were used in this study to accurately reflect the geometry of the corrugated board. In the method presented here, the finite element method is only used to compose the initial global stiffness matrix, which is then condensed and directly used in the homogenization procedure. The stability of the proposed method was tested for different variants of the selected representative volume elements. The obtained results are consistent with other technique already presented in the literature.


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