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.

scholarly journals FEM MODELLING OF LUMBAR VERTEBRA SYSTEM / STUBURO JUOSMENS SLANKSTELIŲ SISTEMOS SKAITINIS TYRIMAS BEM

2013 ◽  
Vol 5 (6) ◽  
pp. 591-593
Author(s):  
Rimantas Kačianauskas ◽  
Oleg Ardatov
Keyword(s):  
Finite Elements ◽  
Lumbar Vertebra ◽  
Medical Problem ◽  
Finite Elements Method ◽  
Problem Analysis ◽  
Fem Modelling ◽  
Computer Aided ◽  
Tissue Degradation ◽  
Deformation Test

The article presents modeling of human lumbar vertebra and it‘sdeformation analysis using finite elements method. The problemof tissue degradation is raised. Using the computer aided modelingwith SolidWorks software the models of lumbar vertebra(L1) and vertebra system L1-L4 were created. The article containssocial and medical problem analysis, description of modelingmethods and the results of deformation test for one vertebramodel and for model of 4 vertebras (L1-L4). Santrauka Straipsnyje aprašomas stuburo juosmeninės dalies slankstelio (L1) bei juosmeninės dalies slankstelių (L1-L4) sistemos modeliavimas ir tyrimas baigtinių elementų metodu (BEM). Sukuriamas erdvinis skaitinis modelis programinės įrangos SolidWorks aplinkoje. Sudaroma vieno ir keturių slankstelių (L1-L4) skaičiuojamosios schemos, modeliams suteikiama gniuždymo apkrova. Nagrinėjamas modelių deformavimas, esant gniuždymo apkrovai, kartu simuliuojant senėjimo procesų ir osteoporozės poveikį, kuris pasireiškia audinio silpnėjimu. Nagrinėjami ir lyginami trys atvejai: sveiko audinio apkrovimas, vidutinio osteoporozės lygio paveiktos slankstelių sistemos apkrovimas ir aukšto osteoporozės lygio paveikto modelio apkrovimas.

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 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 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 Stress Analysis of Dental Implant Inserted in the Mandible

2018 ◽  
Vol 68 (1) ◽  
pp. 25-32
Author(s):  
Agnieszka Łagoda ◽  
Adam Niesłony
Keyword(s):  
Finite Elements ◽  
Stress Analysis ◽  
Dental Implant ◽  
Finite Elements Method ◽  
Simplified Models ◽  
Bone Stress

Abstract The aim of the paper is to obtain the values of dental implant stress analysis. The dental implant was inserted in the part of mandible bone. Stress analysis was carried out using the Finite Elements Method and simplified models.

scholarly journals Modelación numérica de la circulación de las aguas en zonas costeras

Respuestas ◽  
2016 ◽  
Vol 2 (1) ◽  
pp. 30-36
Author(s):  
José Agüero-Rojas ◽  
Alina Gaínza-Roche ◽  
Robel Sánchez-Ramírez ◽  
Jorge Pérez-Ronda ◽  
Daniel Gregorio Alfaro-Vigo
Keyword(s):  
Mathematical Model ◽  
Numerical Model ◽  
Finite Elements ◽  
Water Circulation ◽  
Finite Elements Method ◽  
Shallow Waters

En este trabajo se presenta un modelo matemático que describe el proceso de circulación de las aguas en zonas costeras bajas, el mismo es resuelto numéricamente con ayuda del método de los elementos finitos (FEM). Sobre la base del modelo numérico obtenido se implemento un paquete de programas de simulación                  ABSTRACTThis research shows a mathematical model that describes water circulation process on the shallow waters, which is numerically solved trough the use of the finite elements method (FEM). On the basis of the numerical model obtained, a pack of programs for the simulation of this costal process was implemented

scholarly journals Fracture Load of Metal, Zirconia and Polyetheretherketone Posterior CAD-CAM Milled Fixed Partial Denture Frameworks

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 959
Author(s):  
Verónica Rodríguez ◽  
Celia Tobar ◽  
Carlos López-Suárez ◽  
Jesús Peláez ◽  
María J. Suárez
Keyword(s):  
Computer Aided Design ◽  
Testing Machine ◽  
Fracture Load ◽  
Fracture Pattern ◽  
Bending Test ◽  
Weibull Statistics ◽  
Promising Alternative ◽  
Computer Aided ◽  
Cad Cam ◽  
Group 2

The aim of this study was to investigate the load to fracture and fracture pattern of prosthetic frameworks for tooth-supported fixed partial dentures (FPDs) fabricated with different subtractive computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Materials and Methods: Thirty standardized specimens with two abutments were fabricated to receive three-unit posterior FDP frameworks with an intermediate pontic. Specimens were randomly divided into three groups (n = 10 each) according to the material: group 1 (MM)—milled metal; group 2 (L)—zirconia; and group 3 (P)—Polyetheretherketone (PEEK). The specimens were thermo-cycled and subjected to a three-point bending test until fracture using a universal testing machine (cross-head speed: 1 mm/min). Axial compressive loads were applied at the central fossa of the pontics. Data analysis was made using one-way analysis of variance, Tamhane post hoc test, and Weibull statistics (α = 0.05). Results: Significant differences were observed among the groups for the fracture load (p < 0.0001). MM frameworks showed the highest fracture load values. The PEEK group registered higher fracture load values than zirconia samples. The Weibull statistics corroborated these results. The fracture pattern was different among the groups. Conclusions: Milled metal provided the highest fracture load values, followed by PEEK, and zirconia. However, all tested groups demonstrated clinically acceptable fracture load values higher than 1000 N. PEEK might be considered a promising alternative for posterior FPDs.

scholarly journals Finite element modeling of multiple density materials of bone specimens for biomechanical behavior evaluation

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Sebastián Irarrázaval ◽  
Jorge Andrés Ramos-Grez ◽  
Luis Ignacio Pérez ◽  
Pablo Besa ◽  
Angélica Ibáñez
Keyword(s):  
Finite Elements ◽  
Computational Models ◽  
Reaction Force ◽  
Elastic Stiffness ◽  
Finite Elements Method ◽  
Mechanical Resistance ◽  
Assessment Procedure ◽  
Axial Tomography ◽  
Biomechanical Behavior ◽  
Ct Data

AbstractThe finite elements method allied with the computerized axial tomography (CT) is a mathematical modeling technique that allows constructing computational models for bone specimens from CT data. The objective of this work was to compare the experimental biomechanical behavior by three-point bending tests of porcine femur specimens with different types of computational models generated through the finite elements’ method and a multiple density materials assignation scheme. Using five femur specimens, 25 scenarios were created with differing quantities of materials. This latter was applied to computational models and in bone specimens subjected to failure. Among the three main highlights found, first, the results evidenced high precision in predicting experimental reaction force versus displacement in the models with larger number of assigned materials, with maximal results being an R2 of 0.99 and a minimum root-mean-square error of 3.29%. Secondly, measured and computed elastic stiffness values follow same trend with regard to specimen mass, and the latter underestimates stiffness values a 6% in average. Third and final highlight, this model can precisely and non-invasively assess bone tissue mechanical resistance based on subject-specific CT data, particularly if specimen deformation values at fracture are considered as part of the assessment procedure.

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