scholarly journals The analysis of gas filtration model with use of fractional derivatives in time

2017 ◽  
pp. 82-89
Author(s):  
Nazariy Lopuh
Keyword(s):  
Numerical Analysis ◽  
Numerical Model ◽  
Finite Elements ◽  
Initial Data ◽  
Pressure Distribution ◽  
Fractional Derivatives ◽  
Finite Elements Method ◽  
Gas Filtration ◽  
Definition Of ◽  
Filtration Model

In work on the basis of a finite elements method it is offered numerical model of gas filtration in porous non-uniform environments with use of fractional derivatives in time. Kaputto and Rimman- Liouville's fractional derivatives are considered. The numerical analysis with use of experimental initial data is made. The received results can be used for a research of filtrational properties of the vicinity of the well, definition of its output depending on pressure distribution.

scholarly journals Influence of foundation settlements in load redistribution on columns in a monitoring construction - Case Study

2010 ◽  
Vol 3 (3) ◽  
pp. 346-356 ◽  
Author(s):  
G. Savaris ◽  
P. H. Hallak ◽  
P. C. A. Maia
Keyword(s):  
Numerical Analysis ◽  
Numerical Model ◽  
Finite Elements ◽  
Load Distribution ◽  
Numerical Models ◽  
Normal Load ◽  
Finite Elements Method ◽  
Load Redistribution

The objective of this article is to present the results obtained in a study on the interaction between the behavior of the structure and the foundation settlements and verify the influence of normal load distribution on the columns. In this mechanism, known as structure soil interaction (SSI), as the building is constructed, a transfer of loads occurs from the columns which tend to settle more to those that tend to settle less. The study was conducted in a building which had its settlements monitored from the beginning of construction. For this purpose, a linear tridimensional numerical model was constructed and numerical analysis was performed, using the finite elements method. In these analyses, numerical models corre- sponding to the execution of each floor were used, considering the settlements measured in each stage of the construction. The results of analy- ses showed that the effect of SSI are significant for calculating the normal efforts on the columns, particularly on those located in the first floors.

scholarly journals Numerical analysis of stress distribution generated in spherical polyethylene inserts by knee joint endoprotheses’ sleds

2019 ◽  
Vol 21 (2) ◽  
pp. 1-5
Author(s):  
Marcin Nabrdalik ◽  
Michał Sobociński
Keyword(s):  
Numerical Analysis ◽  
Finite Elements ◽  
Stress Distribution ◽  
Knee Joint ◽  
Titanium Alloys ◽  
Numerical Method ◽  
Ti6al4v Alloy ◽  
Finite Elements Method ◽  
Weak Points ◽  
Metal Materials

Abstract The paper presents analysis of stress distribution in the friction node of knee joint endoprosthesis where sleds are made of various titanium alloys and CoCrMo cooperate with spherical polyethylene inserts. Currently used titanium alloys consists of Nb, Ta, Zr or Mo and with lesser value of Young’s modulus than Ti6Al4V alloy, or steel CoCrMo, which significantly varies from other metal materials. The obtained results make it possible to indicate the “weak points” of the accepted solution, and thus counteract the subsequent effects resulting from premature wear of endoprosthesis elements. The analysis was conducted with numerical method of ADINA System 8.6. The Finite Elements Method allowed to compute and present stress distribution quickly in all elements of the model.

scholarly journals The finite element method in the analysis of the stress and strain distribution in polyethylene elements of hip and knee joints endoprostheses

2019 ◽  
Vol 254 ◽  
pp. 02025
Author(s):  
Marcin Nabrdalik ◽  
Michał Sobociński
Keyword(s):  
Numerical Analysis ◽  
Finite Elements ◽  
Finite Elements Method ◽  
Knee Joints ◽  
Stress And Strain ◽  
The Finite Element Method ◽  
Artificial Joints ◽  
Material Fatigue ◽  
Weak Points ◽  
Stress And Strain Distribution

The paper presents the numerical analysis of stress and strain occurring in the most wearable parts of hip and knee joints endoprostheses. The complexity of the processes taking place in both, natural and artificial joints, makes it necessary to conduct the analysis on the 3D model based on already existing mathematical models. Most of the mechanical failures in alloplasty are caused by material fatigue. To cut down the risk of it, we can either increase the fatigue resistance of the material or decrease the load strain. It is extremelly important to indicate the areas where damage or premature wear may occur. The Finite Elements Method makes it possible to calculate the stress and strain in particular elements of the tested models. All presented numerical calculations define quality conclusions concerning the influence of some parameters of endoprostheses on the values of stress and strain that are formed in polyethylene parts of endoprotheses of hip and knee joints. The obtained results help to reveal “weak points” in examined models and thus, counteract the subsequent effects resulting from premature wear of endoprosthesis elements. The numerical analysis was performed basing on the finite elements method using Autodesk Simulation Mechanical 2017 software and the ADINA 7.5.1.

Prediction of Rail Profile Wear with the Increase of Vehicle Speed

2013 ◽  
Vol 716 ◽  
pp. 659-662
Author(s):  
Dong Hyong Lee ◽  
Jeong Won Seo ◽  
Seok Jin Kwon ◽  
Ha Young Choi
Keyword(s):  
Numerical Analysis ◽  
Finite Elements ◽  
Boundary Conditions ◽  
Rolling Contact ◽  
Finite Elements Method ◽  
Vehicle Speed ◽  
Two Dimensional ◽  
Contact Wear ◽  
Rail Wear ◽  
Finite Elements Model

A method to simulate rolling contact wear in a rail surface was developed using the finite elements method and numerical analysis. A two-dimensional finite elements model was used in order to reduce the calculation time and boundary conditions to prevent excessive deformation of a wheel and a rail were applied. A numerical analysis of rail wear at rolling contact was predicted using the Archards equation. In addition, the characteristics of rail wear with the increasing speed of vehicle were analyzed. Results show that there was not a large difference in the depths of wear on the rail head with increasing vehicle speed, but the wear on the rail gauge corner increased with increasing vehicle speed.

scholarly journals Análise numérica de ligação parafusada semirrígida em perfis formados a frio

ForScience ◽  
2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Emerson Cardoso de Castro ◽  
Flávio Teixeira de Souza ◽  
Arlene Maria Cunha Sarmanho
Keyword(s):  
Numerical Analysis ◽  
Numerical Model ◽  
Finite Elements ◽  
Three Dimensional ◽  
Structural Performance ◽  
Similar Tendency ◽  
Von Mises ◽  
Von Mises Stresses ◽  
Bolt Connection ◽  
Force Displacement

O presente trabalho constitui-se de uma análise numérica, por meio de elementos finitos, objetivando a reprodução via software de um ensaio experimental de ligação parafusada semirrígida em perfis formados a frio, dada no âmbito tridimensional. A análise consistiu-se a partir da reprodução da geometria do protótipo, das condições de contorno e aplicação de carregamento. Para melhor previsão do comportamento da ligação, foram inseridas ao modelo a não linearidade física e geométrica. Foram obtidas as curvas força-deslocamento e a evolução das tensões de Von Mises para os diferentes componentes do protótipo. Os resultados indicaram que o modelo numérico é cerca de duas vezes mais rígido que o experimental. Todavia, foi possível observar que o comportamento do modelo numérico possui tendência similar ao do modelo experimental e também foi possível avaliar a contribuição dos elementos da ligação para o desempenho da mesma.Palavras-chave: Análise numérica. Ligação parafusada semirrígida. Perfis formados a frio. Desempenho estrutural.Numerical analysis of semi-rigid bolt connection in cold formed profilesAbstractThe current paper is based on a numerical analysis by means of finite elements aiming at the software reproduction of an experimental test of semi-rigid bolt connection in cold formed profiles occurred in the three-dimensional scope. The analysis consisted of the reproduction of the prototype geometry, the boundary conditions, and the loading application. For a better forecast of the connection behavior, physical and geometric non-linearity were inserted to the model. The force-displacement curves and the evolution of the Von Mises stresses for the different prototype components were obtained. The results indicated that the numerical model is about twice as rigid as the experimental one. However, it was possible to observe that the behavior of the numerical model has a similar tendency  if compared to  the experimental model and it was still possible to evaluate the contribution of the connection elements to its performance.Keywords: Numerical analysis. Semi-rigid bolt connection. Cold-formed profiles. Structural performance.

scholarly journals Stochastic and reliability analysis of a propeller with model reduction

2009 ◽  
pp. 195-215
Author(s):  
Othmane Bendaou ◽  
Jhojan Enrique Rojas ◽  
Abdelkhalak El Hami ◽  
Abdeslam Aannaque ◽  
Mohamed Agouzoul
Keyword(s):  
Numerical Model ◽  
Finite Elements ◽  
Model Reduction ◽  
Reliability Analysis ◽  
Synthesis Method ◽  
Point Of View ◽  
Finite Elements Method ◽  
Component Mode Synthesis ◽  
Design Parameters ◽  
Cpu Time

Nowadays, design based on purely deterministic analyses has been replaced by stochastic and reliability analyses which consider the uncertainties affecting the design parameters. But from a numerical point of view, these analyses become costly for industrial mechanical applications (modelled by finite elements method) because of their great number of freedom degrees. In this work, we take an interest in reducing the CPU time for stochastic and reliability analyses of an industrial mechanical application by the modal condensation of his numerical model with the component mode synthesis method. The example of a propeller is studied to validate the proposed methods. The results of this study tend to show the considerable gain in CPU which we save by the using of our methodology.

scholarly journals Modelling of Powered Roof Support Cooperation with the Floor of Low Bearing Capacity in the aspect of Shaping the Section Design

2017 ◽  
Vol 62 (1) ◽  
pp. 177-188
Author(s):  
Józef Markowicz ◽  
Sylwester Rajwa ◽  
Stanisław Szweda
Keyword(s):  
Computer Simulation ◽  
Finite Elements ◽  
Bearing Capacity ◽  
Pressure Distribution ◽  
Finite Elements Method ◽  
Factors Influencing ◽  
Section Design ◽  
Simplifying Assumptions ◽  
Roof Support

Abstract The problem of cooperation of powered roof support with the floor in the aspect of shaping its design is presented. From the analysis of the simplifying assumptions considered so far in the methods for determination of roof support’s base pressure on the floor, it results that they are not satisfied in the case of bases of the catamaran type, commonly used in currently manufactured roof supports. Model of cooperation of the base lying on the floor, prepared by the finite elements method is described and the results of computer simulation of the base action on the floor are given. Considering the results of numerical analyses, the factors influencing the pressure distribution of the base on the floor as well as its maximal value, have been identified.

scholarly journals FEM MODELLING OF OSTEOPOROTIC VERTEBRA L1 DUE TO BENDING LOAD / OSTEOPOROTINIO SLANKSTELIO L1 ĮTEMPTOJO BŪVIO SKAITINIS TYRIMAS BEM ESANT LENKIMO APKROVAI

2016 ◽  
Vol 7 (6) ◽  
pp. 649-652
Author(s):  
Oleg Ardatov ◽  
Algirdas Maknickas ◽  
Rimantas Kačianauskas
Keyword(s):  
Numerical Model ◽  
Finite Elements ◽  
Stress Analysis ◽  
Lumbar Vertebra ◽  
Finite Elements Method ◽  
Bending Test ◽  
Intervertebral Disks ◽  
Bending Load ◽  
Computer Aided ◽  
Tissue Degradation

The article presents modeling of human lumbar vertebra L1 and it‘s stress analysis using finite elements method. The problem of tissue degradation is raised. Using the computer aided modeling with SolidWorks software the numerical model of lumbar vertebra and intervertebral disks were created. The article contains statistics of spreading of osteoporosis, description of modeling meth-ods and the results of bending test for various types of tissue degradation. Straipsnyje yra atliekamas stuburo juosmeninės dalies slankstelio (L1) modeliavimas ir tyrimas baigtinių elementų metodu (BEM). Yra sukuriamas erdvinis skaitinis modelis programinės įrangos SolidWorks aplinkoje. Sudaroma slankstelio skaičiuojamoji schema, modeliui suteikiama lenkimo apkrova sagitalinėje ir frontalinėje plokštumoje. Nagrinėjamas modelio įtemptasis būvis kartu simuliuojant senėjimo procesų ir osteoporozės poveikį, kuris pasireiškia audinio silpnėjimu. Audinio degradacija yra modeliuojama taikant empiriniu būdu nustatytas išraiškas, kurios nurodo priklausomybes tarp mechaninių savybių ir akytojo kaulo tankio.

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