scholarly journals JUSTIFICATION OF THE STRESS-STRAIN STATE OF THE PILE FOUNDATION USING SOFTWARE COMPLEXES

2021 ◽  
pp. 13-18
Author(s):  
O. I. DUBINCHYK ◽  
L. O. NEDUZHA
Keyword(s):  
Numerical Analysis ◽  
Pile Foundation ◽  
Strain State ◽  
Operating Conditions ◽  
Design Solution ◽  
Bridge Structure ◽  
Stress Strain ◽  
Stress Strain State ◽  
Software Packages ◽  
Pile Cap

Purpose. Bridge supports with a high pile caps require more attention when calculating their strength due to the difficult operating conditions of the piles. The purpose of the scientific article is to substantiate the stress-strain state of the pile foundation of the bridge structure using software computing systems SCAD and LIRA-CAD. Methodology. An analysis of software used to automate the design of foundations was conducted. The main parameters of SCAD and LIRA-CAD software packages are yielded. With their help, finite-element models of the pile foundation of the bridge support with a high pile cap were built. The developed models maximally reflect the properties of the soil base and foundation, its pile cap and piles, geometric characteristics and the influence of the finite elements meshing is considered. Calculations were performed in SCAD and LIRA-CAD software packages with monitoring of the calculation process. Findings. During the numerical analysis of the pile foundation of the bridge structure with a high pile cap, vertical displacements, force factors (normal forces and bending moments) in the piles and stresses in the body of the support and piles were determined. Based on these results, an analysis was performed, which is combined with a comparison of the obtained results. Implementation of SCAD and LIRA-CAD software allows to significantly reduce design time, to reduce project costs, to improve the quality and efficiency of investments. Originality. A comparison of the stress-strain state obtained during the numerical analysis of SCAD and LIRA-CAD software, which proved the difference in the approach to modeling in these complexes, was conducted. Practical value. The results of substantiation of the stress-strain state of the pile foundation with the use of software complexes made it possible to verify the design solution of all elements of the foundation of the bridge structure with a high pile cap.

scholarly journals COMPREHENSIVE ANALYSIS OF THE SHAFT STRUCTURE OF THE DNIPRO METRO

2021 ◽  
pp. 91-98
Author(s):  
O. L. TIUTKIN ◽  
V. А. MIROSHNYK ◽  
I. V. HELETIUK
Keyword(s):  
Numerical Analysis ◽  
Strain State ◽  
Complex Analysis ◽  
Comprehensive Analysis ◽  
Design Solution ◽  
Mine Shaft ◽  
Stress Strain ◽  
Stress Strain State ◽  
Deformed State ◽  
Shaft Lining

Purpose. The construction of the Dnipro Metro, which today is characterized by high efficiency and widespread introduction of new technologies, has proved the need for predesign, design and construction work. The purpose of the scientific article is to identify during the complex analysis of the structure of the mine shaft its stress-strain state, which was obtained during the numerical analysis and geodetic monitoring. Methodology. During the complex analysis of the shaft № 16-bis of the Dnipro Metro, prognostic calculations of the stress-strain state were performed. To do this, a finite-element model is built, in which fully reflects the geometric features of the shaft, the load on it and boundary conditions. Part of the comprehensive analysis is geodetic monitoring, which is carried out during the construction of the shaft and during its operation. The works included the measurement of deformations both in the lining of the shafts and in the sections of the mine workings, as well as on the surface near the houses along the route in the area of influence of the working workings. Findings. During the numerical analysis of the structure of the shaft № 16-bis of the Dnipro Metro, displacement and force factors (normal forces and bending moments) were determined. Based on these results, the reinforcement of the elements of the shaft lining (bored pile, cap beam, reinforced concrete ring beam) was selected. The value of the deformed state obtained from the prognostic analysis indicates on the insignificant displacements of the designed structure. During the geodetic monitoring, horizontal and vertical deformations of the № 16-bis shaft lining were recorded, which were caused by the influence of public transport and heavy vehicles. But the values of these deformations reached 1 … 2 mm, which for their effect on buildings and structures is within normal limits. Originality. A comparison of the deformed state obtained during numerical analysis and geodetic monitoring, which proved the high accuracy of the prognostic calculation. Practical value. The results of a comprehensive analysis of the mine shaft of the Dnipro Metro made it possible to carry out a test the design solution and ensure high strength and stability of the lining made of bored piles.

scholarly journals Interaction of outer hull structures with flexible lines

2019 ◽  
pp. 123-129
Author(s):  
Sergey Bratelev ◽  
Igor Rozоv
Keyword(s):  
Finite Length ◽  
Strain State ◽  
Stress Strain ◽  
Stress Strain State ◽  
Software Packages ◽  
Loading Patterns ◽  
Analytical Expressions

This paper investigates stress-strain state of hull with longitudinal and transverse stiffeners under compression due to flexible lines (straps). Architecturally, two hull variants have been studied: rectangular with roundings at bilges and cylindrical. The problem was solved as per well-known analytical expressions, whereas stress-strain parameters of “hullstrap” system, depending on strap stiffness and presence of “loose” contact with the strap and the plating, were updated in ANSYS and LS-DYNA software packages. The study yielded the following data: stress-strain parameters of plating taking into account longitudinal and transverse stiffeners; loading patterns for separate hull elements (plate, stiffener) depending on strap stiffness; and loading patterns for separate hull elements in case of “loose” contact with straps in the areas of finite length.

scholarly journals CONTROL OF ACTIONS OF STEEL TANK IN WORKING

2018 ◽  
Vol 22 (4) ◽  
pp. 66-74 ◽  
Author(s):  
A. A. Vasilkin
Keyword(s):  
Strain State ◽  
Low Cycle Fatigue ◽  
Operating Conditions ◽  
Maximum Effect ◽  
Safe Operation ◽  
Stress Strain ◽  
Load Bearing ◽  
Stress Strain State ◽  
Steel Tank ◽  
Steel Tanks

In steel tanks made by the method of rolling, defects of a geometric shape often occur in the area of the welded welded joint of the wall. Subsequently, in these areas, as a result of low cycle fatigue, an unacceptable defect appears in the form of a crack, which makes it necessary to remove the reservoir from operation and carry out a set of measures for its repair. To determine the terms of safe operation of vertical steel tanks with geometric defects, it is proposed to use the methodology control of the actions of structures of load-bearing structures, one of the directions of which is the regulation of the stress-strain state of steel structures. To implement the possibility of regulating construction, it is necessary to identify such parameters, the change of which will give the maximum effect in achieving the set goals. As the indicated parameters, the design characteristics (material properties, design scheme, geometric characteristics) and factors of external influences (load, operating conditions) can act. To regulate the stress-strain state design of vertical steel tanks, the following regulators are proposed: product loading height, wall deflection arrow and permissible number of tank loading cycles. By numerical calculation of the VAT of the vertical steel tank design with geometric defects, the necessary values and values of the stress state are determined. Further, using known analytical dependencies from the field of fracture mechanics, it is possible to determine the permissible number of loading cycles of the reservoir before the appearance of a crack-like defect. The application of the methodology control of the actions of structures load-bearing structures, by means of a certain change in the established control parameters, allows increasing the number of loading cycles of the reservoir, thereby increasing the period of safe operation of the defective reservoir and thereby increasing the economic efficiency of the tank farm.

Numerical Analysis of Stress-Strain State and Crack Propagation in Welded Samples

2017 ◽  
Vol 265 ◽  
pp. 507-512
Author(s):  
M.S. Bisong ◽  
P.V. Sivtsev ◽  
V.V. Lepov
Keyword(s):  
Numerical Analysis ◽  
Crack Growth ◽  
Heat Affected Zone ◽  
Strain State ◽  
Stochastic Modelling ◽  
Hardness Test ◽  
Crack Size ◽  
Stress Strain ◽  
Mechanical Heterogeneity ◽  
Stress Strain State

The numerical analysis of stress-strain state of low-alloyed welded steel samples test has been considered. The mechanical heterogeneity has been estimated by the micro hardness test. The stress-strain state analysis is based on the models of linear elasticity, which are described by Lame equations for displacement. In this case the samples are considered as perfect welded samples without any welding defects. The discretization of the system of equations is done through the finite element method, and the numerical realization of the method is performed on collection of free software FEniCS. The defects influence has been estimated by stochastic modelling of viscous crack growth. The data for crack size in weld and heat affected zone was obtain from microscopic observation, and for mechanical properties from microhardness testing. The result obtained shows that, the distribution of displacement in all samples are almost the same. Between the welded zone, the heat affected zone and the external elliptic zone, the Von Mizes stress is almost the same in all three samples. Concerning the crack growth, the velocity of it propagation in welded zone is higher as much again than that in the heat affected zone. This research is beneficial to welders, modellers of structures, researches as a whole.

scholarly journals REGULARITIES OF THE LINING STRESS-STRAIN STATE DURING OF THE PYLON METRO STATION CONSTRUCTION

2021 ◽  
pp. 19-27
Author(s):  
D. O. BANNIKOV ◽  
V. P. KUPRII ◽  
D. YU. VOTCHENKO
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Elements ◽  
Strain State ◽  
Finite Element Models ◽  
Bending Moments ◽  
Stress Strain ◽  
Normal Forces ◽  
Stress Strain State ◽  
Station Structure

Purpose. Perform numerical analysis of the station structure. Take into account in the process of mathematical modeling the process of construction of station tunnels of a three-vaulted station. Obtain the regularities of the stress-strain state of the linings, which is influenced by the processes of soil excavation and lining construction. Methodology. To achieve this goal, a series of numerical calculations of models of the deep contour interval metro pylon station was performed. Three finite-element models have been developed, which reflect the stages of construction of a three-vaulted pylon station. Numerical analysis was performed on the basis of the finite element method, implemented in the calculation complex Lira for Windows. Modeling of the stress-strain state of the station tunnel linings and the soil massif was performed using rectangular, universal quadrangular and triangular finite elements, which take into account the special properties of the soil massif. Station tunnel linings are modeled by means of rod finite elements. Findings. Isofields of the stress-strain state in finite-element models reflecting the stages of construction are obtained. The vertical displacements and horizontal stresses that are characteristic of a three-vaulted pylon station are analyzed. The analysis of horizontal stresses proved that at the stage of opening of the middle tunnel the scheme of pylon operation is rather disadvantageous. The analysis of bending moments and normal forces was also carried out and the asymmetry of their distribution was noted. Originality. Based on the obtained patterns of distribution of stress-strain state and force factors, it is proved that numerical analysis of the station structure during construction is necessary to take measures to prevent or reduce deformation of frames that are in unfavorable conditions. Practical value. In the course of research, the regularities of changes in stresses, displacements, bending moments and normal forces in the models of the pylon station, which reflect the sequence of its construction, were obtained.

scholarly journals Numerical analysis of the stress-strain state of laminated springs

2009 ◽  
Vol 2 (2) ◽  
pp. 74-84
Author(s):  
V.M. Pestrenin ◽  
I.V. Pestrenina ◽  
N.F. Talantsev
Keyword(s):  
Numerical Analysis ◽  
Strain State ◽  
Stress Strain ◽  
Stress Strain State

scholarly journals Stress-strain state analysis of the design of full-turning vertical empennage for aero-spacecraft

2021 ◽  
Vol 22 (1) ◽  
pp. 36-42
Author(s):  
Andrey A. Chistyakov ◽  
Valery P. Timoshenko
Keyword(s):  
Numerical Simulation ◽  
Strain State ◽  
Dynamic Pressure ◽  
Operating Conditions ◽  
Structural Scheme ◽  
Stress Strain ◽  
Mechanical Loads ◽  
Stress Strain State ◽  
Distributed Load ◽  
Calculation Results

In this work, the most rational schemes to designing the skin of a full-turning vertical empennage element (stabilator) have been studied. Skin designing schemes were chosen according to aero-spacecraft operating conditions in the re-entry trajectory. During designing process, the requirements for reusable structures of tourist-class aero-spacecrafts were taken into account, such as: maximum simplicity and endurance of the product. To determine the mechanical loads acting on the keel during its movement in the air, a numerical simulation of the aerodynamic flow-around the stabilator profile at 5 arbitrary points on the flight path was carried out. The parameters used for the analysis are: flight velocity, density and viscosity of the air. Of the 5 obtained fields of dynamic pressure acting on the stabilator, the field that creates the largest distributed load was used as the boundary condition for the analysis of the stress-strain state of the structure. The problem of mechanical loading of the stabilator was solved separately for each of the previously studied structural schemes of the skin. Based on the obtained calculation results the optimal skin structural scheme was chosen by comparing the displacements on the line connecting ribs.

scholarly journals Modeling and assessment of the stress-strain state of above-ground pipelines at different types of compensation sections

2021 ◽  
Vol 266 ◽  
pp. 01022
Author(s):  
Z.A. Besheryan ◽  
I.F. Kantemirov
Keyword(s):  
Strain State ◽  
Complex Stress ◽  
Operating Conditions ◽  
The Arctic ◽  
Design Parameters ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Actual Operating ◽  
Different Types

The development of Russian fuel and energy complex in the short term is connected with the development of new hydrocarbon field in the permafrost zone and the need to build Arctic pipelines north of the 60th parallel. The ground-based structural scheme of pipeline laying is the most optimal while constructing trunk pipelines in permafrost areas in the Arctic and subarctic latitudes. The actual operating conditions of these systems are insufficiently studied. The above-ground pipeline in permafrost is in an complex stress-strain state. This study presents the results of the assessment of the stress-strain state of linearly extended above-ground pipelines at different compensation sections (triangular compensator; trapezoidal compensator; U-shaped compensator) under actual operating conditions. Using the finite element method on mathematical models, the dependences of the transverse displacements of the pipeline on movable supports and stresses arising in dangerous sections of the typical pipeline section during self-compensation of deformations on the variable design parameters of the system for various load combinations were established (the simulation was carried out in the ANSYS software package).

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