scholarly journals On the Finite Element Analysis of Problems with Nonlinear Newton Boundary Conditions in Nonpolygonal Domains

2001 ◽  
Vol 46 (5) ◽  
pp. 353-382 ◽  
Author(s):  
Miloslav Feistauer ◽  
Karel Najzar ◽  
Veronika Sobotikova
1981 ◽  
Vol 103 (4) ◽  
pp. 385-391 ◽  
Author(s):  
B. S. Thompson

Variational theorems are presented for analyzing the vibrational response of flexible linkage mechanisms and the surrounding acoustic medium in which they are immersed. These theorems are established by generalizing Hamilton’s principle through using Lagrange multipliers to incorporate field equations and boundary conditions within the functional. The same philosophy is adopted to handle the conditions at the fluid-structural interface. When independent arbitrary variations of the system parameters are permitted, these acousto-elastodynamic theorems yield as characteristic equations the equation of motion for each member of the linkage, the acoustical wave equation, the compatibility conditions at the interface between the fluid and solid continua, and also the boundary conditions. These variational statements provide the foundations for several different classes of finite element analysis.


Author(s):  
Y B Park ◽  
D Y Yang

In metal forming, there are problems with recurrent geometric characteristics without explicitly prescribed boundary conditions. In such problems, so-called recurrent boundary conditions must be introduced. In this paper, as a practical application of the proposed method, the precision cold forging of a helical gear (which is industrially useful and geometrically complicated) has been simulated by a three-dimensional rigid-plastic finite element method and compared with the experiment. The application of recurrent boundary conditions to helical gear forging analysis is proved to be effective and valid. The three-dimensional deformed pattern by the finite element analysis is shown, and the forging load is compared with the experimental load. The profiles of the free surface of the workpiece show good agreement between the computation and the experiment.


2018 ◽  
Vol 10 (6) ◽  
pp. 168781401878002 ◽  
Author(s):  
Wei-chen Lee ◽  
Chen-hao Zhang

The objective of this research was to investigate the effects of material models, element types, and boundary conditions on the consistency of finite element analysis. Two cantilever beams were used; one made of stainless steel SUS301 3/4H and the other made of polymer polyoxymethylene. The load–deflection curves of the two cantilever beams obtained by experiments were compared to those obtained by finite element analysis, where the material models—including bilinear, trilinear, and multi-linear—were used. Four element types—beam, plane stress, shell, and solid—were also employed with the material models to obtain the simulated load–deflection curves of the cantilever beams. It was found that bilinear material models had the stiffest behavior due to their overestimated yield strength. In addition, by applying a finite displacement to simulate the grip of the cantilever beams, the discrepancy between the simulated permanent set and the experimental set could be reduced from 80% to 5%. To sum up, both the selection of the material model and the setup of the boundary conditions are critical for obtaining good agreement between the finite element analysis results and the experimental data.


Author(s):  
A. A. Kardak ◽  
G. B. Sinclair

Abstract Submodeling enables finite element engineers to focus analysis on the subregion containing the stress concentrator of interest with consequent computational savings. Such benefits are only really gained if the boundary conditions on the edges of the subregion that are drawn from an initial global finite element analysis (FEA) are verified to have been captured sufficiently accurately. Here, we offer a two-pronged approach aimed at realizing such solution verification. The first element of this approach is an improved means of assessing the error induced by submodel boundary conditions. The second element is a systematic sizing of the submodel region so that boundary-condition errors become acceptable. The resulting submodel procedure is demonstrated on a series of two-dimensional (2D) configurations with significant stress concentrations: four test problems and one application. For the test problems, the assessment means are uniformly successful in determining when submodel boundary conditions are accurate and when they are not. When, at first, they are not, the sizing approach is also consistently successful in enlarging submodel regions until submodel boundary conditions do become sufficiently accurate.


Author(s):  
Amadou Adamou ◽  
Olisaemeka Osadebe

The present work developed a computer application for the finite element analysis of thin rectangular plates under uniformly distributed transverse load. The software, which was developed using Java programming language, is very user-friendly and flexible in the choice of the boundary conditions and mesh size. The choice of Java programming language was guided by its high memory management, which, in turn had a positive effect on the software runtime. The finite element analysis of a Kirchhoff isotropic plate under a uniformly distributed transverse load was carried out using the software. The results obtained agreed accurately with solutions available in literature. Error analysis conducted on the results confirmed that accuracy generally increases with an increase in the number of elements used in the discretization process. Specifically, for a 16 x 16 discretization, an accuracy ranging from 98.41 to 100 percent, and 95.83 to 100 percent was achieved for the five sets of boundary conditions handled, for deflections at the plate’s center and bending moments respectively.


2021 ◽  
Vol 71 (2) ◽  
pp. 161-170
Author(s):  
Adam Faircloth ◽  
Loic Brancheriau ◽  
Hassan Karampour ◽  
Stephen So ◽  
Henri Bailleres ◽  
...  

Abstract Transverse modal analysis of timber panels is a proven effective alternative method for approximating a material's elastic constants. Specific testing configurations, such as boundary conditions (BC) and location of sensor and impact, play a critical role in the accuracy of the results obtained from the experimental assessment. This article investigates signal-specific details, such as the signal quality factor, that directly relate to the damping properties and internal friction as well as frequency shifting obtained from six different BCs. A freely supported (FFFF), opposing minor sides (shorter length) simply supported, and major sides (longest length) free (SFSF), as well as the reverse of the SFSF configuration with minor sides free and major lengths simply supported (FSFS) and all sides simply supported (SSSS) setup, are investigated. Variations into the proposed methods used to achieve an FFFF supported system are also considered. A combination of experimental testing in parallel with finite element analysis was conducted to re-create the setup that would be used within a manufacturing facility for nondestructive assessment of full-size cross-laminated timber panels. The differences between all BC configurations for their resonance frequency quality and location indicate that a freely supported system provides higher-resolution results, good comparison of less than 10 percent error with the finite element analysis and experimental results, and advantages in a simple experimental setup for the intended application.


2014 ◽  
Vol 592-594 ◽  
pp. 1170-1174
Author(s):  
B. Sreenivasa Theja ◽  
Siddharth Kumar Singh

The design of structural modeling is usually based on the different geometric function. Since every component has a definite life span, it is necessary to calculate its core parameters. To find the life span of component, the component must be as input parameter to the Finite Element Analysis. The Finite Element Analysis is nothing but a numerical method for solving Engineering and Mathematical problems. The Analysis of the “Rear Axle Casing of Tractor” using cast iron material with special grade “SG 500” for already existing model, taken in the real time is done by using “ANSYS”. The stress, strain, deformation analysis of the component is done by giving various boundary conditions. These analyzed results help to redesign the rear casing of tractor. The redesigning of rear axel casing of tractor is done using “PRO/E”. During redesigning the component, various criteria’s taken in the real field must be taken into an account. The analysis of the redesigned model is done by giving various boundary conditions for both materials ‘SG 500” and “SG 200”. Then the stress, strain, deformation, structural supports, structural results are evaluated and also cores, dies and patterns are generated and hence the redesigned rear axel casing of tractor is found to be in safer mode. And also the better material for the rear axle casing is given, by comparing the above mentioned materials.


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