The Numerical Analysis of Accuracy of Hydraulic Leg Cylinder in Modeling Using Solid Works Simulation

2015 ◽  
Vol 770 ◽  
pp. 456-460 ◽  
Author(s):  
G.D. Buyalich ◽  
A.V. Anuchin ◽  
A.A. Dronov
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Elements ◽  
Strain State ◽  
Research Work ◽  
Simulation Software ◽  
Central Angle ◽  
Stress Strain ◽  
Maximum Performance ◽  
Solid Works

The research work on the influence of an angle α at centre and the finite element sizes in modeling a hydraulic leg cylinder has been done to determine the stress-strain state by FEM using SolidWorks Simulation software. Based on the analysis results the reasonable values of the central angle and finite elements for the cylinder and weld have been defined in terms of the smallest error and maximum performance computation.

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.

Estimation of the accuracy of numerical analysis for the deformed state of power structures of technical objects

2018 ◽  
Author(s):  
А.Н. Рогалев ◽  
С.В. Доронин ◽  
В.В. Москвичев
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Safety Factor ◽  
Stiffness Matrix ◽  
Strain State ◽  
Power Structures ◽  
Safety Factors ◽  
Rounding Errors ◽  
Stress Strain ◽  
Stress Strain State

Под силовыми конструкциями понимают технические устройства, составленные из различных частей, воспринимающие комплекс эксплуатационных нагрузок в штатных и аварийных режимах нагружения. При решении прикладных задач исследования напряженно-деформированных состояний силовых конструкций важна оценка степени близости к точному приближенного решения, полученного на вполне определенной сетке конечных элементов с конечной величиной шага сетки. С учетом влияния ошибок округления сходимость метода конечных элементов контролировать сложно: при большом числе конечных элементов решение может расходиться из-за накапливающихся ошибок округления, даже если условия сходимости выполняются. Описанное в статье применение методов обратного анализа ошибок позволяет достаточно точно контролировать точность численных оценок деформированного состояния силовых конструкций, что подтверждают расчеты, выполненные для практических задач. The solution of applied problems of technogenic safety, survivability, risk and protection is performed for structures which are close to limiting states. These states are characterized by decreasing safety factors down to one. In this case a mistaken estimation for safety factor may cause the situation when the calculated safety factor will be greater than one but the real safety factor will be less than one. Safety factors estimation is performed on the basis of calculation for stress-strain state characteristics. Thus, the issues of accuracy and reliability of determining stresses and deformations are an integral part of the problem of man-made safety. In the numerical analysis of the stress-strain state, the stiffness matrix of the design model is formed, the dimension of which reaches up to tens of millions. A large number of computations for tasks of this dimension is presumably leading to significant rounding errors. Ensuring the grid convergence of results by decreasing the grid spacing is inconsistent with the growth of computational errors due to rounding. For finite element analysis of power structures of technical objects, methods of a posteriori reverse error analysis are proposed that control the effect of rounding errors on the result when solving a solving system of linear algebraic equations. The coefficient matrix of this system is the stiffness matrix of the finite element model. The basic idea is to obtain and solve a system of equations with a known exact solution. Comparison of the results of exact and numerical solutions allows us to estimate the magnitude of the error.

FEM Study of Stress-Strain State of Elements of Harmonic Gear Drive with Hollow Shaft and Intermediate Rollers

2015 ◽  
Vol 770 ◽  
pp. 464-468
Author(s):  
V.V. Aksenov ◽  
V.Yu. Timofeev ◽  
A.A. Dronov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
Simulation Software ◽  
Stress Strain ◽  
Hollow Shaft ◽  
Gear Drive ◽  
Stress Strain State ◽  
Rolling Elements ◽  
Element Method

Stress-strain state (SSS) of the separator as one of the main elements of the geokhod harmonic gear drive with rolling elements with hollow shaft is considered. The study was conducted by Finite Element Method (FEM) using SolidWorks Simulation software.

scholarly journals ANALYSIS OF FEATURES OF APPLIED SOFTWARE “LIRA” IN CALCULATIONS OF NON-CIRCULAR TUNNEL LININGS

2019 ◽  
pp. 41-50
Author(s):  
V. P. KUPRIY ◽  
O. L. TIUTKIN ◽  
P. YE. ZAKHARCHENKO
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Software Package ◽  
Strain State ◽  
Element Model ◽  
Finite Element Models ◽  
Stress Strain ◽  
Stress Strain State ◽  
The Finite Element Model

Purpose. The article examines the effect on the stress-strain state of the parameters of the finite-element model created in the “Lira” software package in a numerical analysis of non-circular outlined tunnels. Methodology To achieve this goal, the authors developed finite element models of the calotte part of the mine during the construction of a double track railway tunnel using “Lira” software. In each of the models in the “Lira” software package, the interaction zone with temporary fastening was sampled in a specific way. After creation of models, their numerical analysis with the detailed research of his results was conducted. Findings. In the finite element models, the values of deformations and stresses in the horizontal and vertical axes, as well as the maximum values of the moments and longitudinal forces in the temporary fastening were obtained. A comparative analysis of the obtained values of the components of the stress-strain state with a change in the parameters of the finite element model was carried out. The graphs of the laws of these results from the discretization features of the two models were plotted. The third finite element model with a radial meshing in the zone of interaction of temporary support with the surrounding soil massif was investigated. Originality It has been established that in the numerical analysis of the SSS of a tunnel lining of a non-circular outline, its results substantially depend on the shape, size and configuration of the applied finite elements, on the size of the computational area of the soil massif, and also on the conditions for taking into account the actual (elastic or plastic) behavior of the soil massif.  Practical value. The features of discretization and the required dimensions of the computational area of the soil massif were determined when modeling the “lining – soil massif” system, which provide sufficient accuracy for calculating the parameters of the stress-strain state of the lining.

scholarly journals Influence of the choice of the base model on the stress-strain state of the vertical load-bearing elements of a monolithic-frame house

2020 ◽  
pp. 45-54
Author(s):  
Viktor Nosenko ◽  
Ostap Kashoida
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Strain State ◽  
Mutual Influence ◽  
Vertical Load ◽  
Soil Environment ◽  
Stress Strain ◽  
Single Node ◽  
Load Bearing ◽  
Stress Strain State

Comparison of the stress-strain state of vertical elements of the frame of a monolithic house (basement, first and fourth floors), depending on the method of modeling the soil environment and piles, is carried out. The use of pile foundations is due to the fact that they provide the transfer of loads to deeper soil layers and, as a rule, a greater bearing capacity compared to shallow foundations. In the design of foundations, engineers face the question of how to model the soil environment and piles? This paper presents the influence of the decision taken (the selected soil model and the method of modeling piles) on the stress-strain state of the vertical load-bearing elements of the house frame. Comparison of the stress-strain state of vertical elements of the frame (basement, first and fourth floors), which were obtained using the following models of the system «base - pile foundation - overhead supporting structures»: 1) the piles are modeled by single-node finite elements, have only vertical stiffness according to the results of testing the piles for vertical static pressing loads, the mutual influence of piles and soil characteristics are not taken into account (FE-56 hereinafter, this is the number of the finite element in the library of elements of the PС «Lira -SAPR») 2) the piles are modeled by single-node finite elements, are located with a given step along the length of the pile and have rigidity in different directions and approximately take into account the surrounding soil around the pile and under its tip (FE-57); 3) the soil environment is modeled by volumetric elastic finite elements; piles - rod finite elements. It is shown that the choice of the foundation model carries stress-strain state not only for the foundation structures, but also for the vertical bearing elements of the house. When using various options for modeling the base: using a single-node finite element that simulates a smoke like elastic ligature (FE-56), using a chain of single-node skinned elements (FE-57), or a volumetric soil massif, it is possible to obtain quantitative differences in stresses from 2 to 20%, and a qualitative change, which is observed in a change in the sign of bending moments.  

scholarly journals Contact Deformation of the Pipeline Sealing Unit

2020 ◽  
Vol 23 (4) ◽  
pp. 52-62
Author(s):  
Andrii O. Kostikov ◽  
◽  
Serhii A. Palkov ◽  
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Physical Model ◽  
Strain State ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Steam Line ◽  
Stress Strain ◽  
Stress Strain State ◽  
Sealing Unit

The features of the turbine steam line sealing unit stress-strain state are examined on the basis of the usage of a three-dimensional design model of the construction and contacting surfaces. The considered unit consists of the pipeline, a crimp casing consisting of two halves with an outlet in one of them, and a gasket. A mathematical model that takes into account the mechanical loads caused both by the internal steam pressure on the steam line wall and by the casing fasteners tightening has been formed. This model also includes contact interaction in the sealing unit on the contact surface of the pipeline, the upper and lower halves of the casing. This contact problem solving method, based on the application of the finite element method, is proposed. The finite element model is based on twenty-unit three-dimensional finite elements with three degrees of freedom at each unit. Eight-unit contact finite elements were used to describe contact and sliding between surfaces. Contact conditions are taken into account with the penalty method usage. The verification of the model and the software that implements the proposed method is carried out by comparing the calculation results and experimental data obtained on the physical model of the pipeline. The physical model was made from a low-modulus material with full geometric similarity and the same ratio of the elastic moduli of materials as in a real object. The stress-strain state of the sealing unit of a real pipeline in a three-dimensional setting was determined and the most stressed zones in the unit, which require increased attention during the design and operation of pipelines and their connections, were identified. The developed approach and software make it possible to determine the contact pressure for the horizontal joint flanges of highly stressed cylinder bodies of powerful steam turbines, which helps to avoid a large number of expensive experimental studies.

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.

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.

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