scholarly journals The Influence of Mesh Granularity on the Accuracy of FEM Modelling of the Resonant State in a Microwave Chamber

2021 ◽  
Vol 11 (17) ◽  
pp. 7932
Author(s):  
Anna Ostaszewska-Liżewska ◽  
Dominika Kopala ◽  
Jakub Szałatkiewicz ◽  
Roman Szewczyk ◽  
Peter Råback
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Open Source ◽  
Resonant State ◽  
Point Of View ◽  
Tetrahedral Mesh ◽  
Efficient Design ◽  
Resonant States ◽  
Main Barrier ◽  
Element Method

Microwave technology is widely used in different areas of advanced industry when energy must be provided to water-containing and other materials. The main barrier in the development of microwave devices is the possibility of efficient design by modelling a microwave system in a resonant state. For technical systems, the finite element method is widely used. However, the convergence process in the microwave finite element solver is sophisticated. The process itself and the influence of mesh granularity on the accuracy of modelling of microwave chambers in resonant states have not been investigated previously. The present paper aims to fill this gap. The resonance conditions of a microwave chamber were tested from the point of view of spatial resolution of the tetrahedral mesh used for open-source ELMER FEM software. The presented results experimentally determine the limits of accuracy of the geometry of microwave resonant chamber finite element method-based models. The determined values of microwave resonant chamber dimension tolerances should be considered for both open-source and commercial software for microwave modelling.

Elasto-plastic analysis of a rotating model conical turbine disc

1975 ◽  
Vol 10 (3) ◽  
pp. 167-171 ◽  
Author(s):  
F Ginesu ◽  
B Picasso ◽  
P Priolo
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Limit Analysis ◽  
Point Of View ◽  
Complete Analysis ◽  
The Finite Element Method ◽  
Computational Simplicity ◽  
Rotating Shell ◽  
Good Agreement ◽  
Element Method

Results on the plastic collapse behaviour of an axisymmetric rotating shell, obtained by Limit Analysis and the Finite Element Method, are in good agreement with experimental data. The Finite Element Method, though computationally rather costly, permits, however, a more complete analysis of elasto-plastic behaviour. For the present case, the Limit Analysis has the advantage of greater computational simplicity and leads to a quite satisfactory forecast of collapse speed from the engineering point of view.

scholarly journals Numerical Analysis of the Ability of a Floating Vehicle to Overcome a Water Obstacle

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Krzysztof Kosiuczenko ◽  
◽  
Robert Sosnowicz ◽  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Computational Model ◽  
Difficult Problem ◽  
Point Of View ◽  
Vehicle Safety ◽  
Extreme Conditions ◽  
The Finite Element Method ◽  
Element Method

The paper presents the results of simulation tests of the entry of a floating transporter to a water obstacle. The simulation tests were performed with the use of LS Dyna program, based on the finite element method (FEM). The computational model was developed and used in the simulation of the manoeuvre of entering the water obstacle for the extreme conditions, which are described by NATO standards. For a model, as an example vehicle, the floating transporter PTS-M was used. The results of the application of the elaborated model confirmed the possibility to utilise the method to verify the behaviour of a vehicle in a very important and difficult problem from the point of view of vehicle safety conditions.

Modal Analysis of Automotive Steering System Based on Finite Element Method

2011 ◽  
Vol 121-126 ◽  
pp. 2085-2090 ◽  
Author(s):  
Shu Ming Chen ◽  
Deng Feng Wang ◽  
Gang Ping Tan ◽  
Jian Ming Zan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Modal Analysis ◽  
Excitation Frequency ◽  
Steering System ◽  
Point Of View ◽  
Steering Wheel ◽  
Exciting Frequency ◽  
Wheel Vibration ◽  
Element Method

In order to understand the vibration characteristics of the steering system and provide suggestions for improvement, a model of the steering system was created based on finite element method (FEM). Also, the modal analysis of the steering system was presented, and the first twenty step modes were calculated and analyzed. The steering system was also evaluated from the resonance point of view. The result shows that the frequency of the first step mode is 31.578 Hz which is higher than the exciting frequency of the engine; also, the road roughness excitation frequency has a minor influence on steering wheel vibration.

A Probabilistic Extended Finite Element Approach: Application to the Prediction of Bone Crack Propagation

2007 ◽  
Vol 348-349 ◽  
pp. 77-80 ◽  
Author(s):  
Jorge Grasa ◽  
José Antonio Bea ◽  
Manuel Doblaré
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Crack Propagation ◽  
Extended Finite Element Method ◽  
Partition Of Unity ◽  
Point Of View ◽  
Extended Finite Element ◽  
Neck Fracture ◽  
Element Approach ◽  
Element Method

The Extended Finite Element Method (XFEM), has become a well-known tool to simulate crack propagation problems using non-structured meshes avoiding the remeshing process usually needed in this type of problems and allowing the inclusion of appropriate shape functions that reflect the asymptotic displacement field, near the crack tip, via a partition of unity fracture approach. However, in this kind of numerical applications, all the variables involved have been considered as deterministic (defined by a single given value), despite the well-known uncertainty associated to many of them (external loads, geometry and material properties, among others). The combination of the XFEM and probabilistic techniques is here proposed and formulated allowing treating fracture mechanics problems from a probabilistic point of view. We present the implementation of this probabilistic extended finite element method and apply it to the prediction of the appearance and propagation of a femur’s neck fracture under probabilistic loads.

An Efficient Finite Element Algorithm in Elastography

2016 ◽  
Vol 08 (03) ◽  
pp. 1650037 ◽  
Author(s):  
Eric Li ◽  
W. H. Liao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Soft Tissues ◽  
Tetrahedral Mesh ◽  
Tetrahedral Elements ◽  
Time Harmonic ◽  
Smoothed Finite Element Method ◽  
Complicated Geometry ◽  
First Time ◽  
Element Method

Elastography is an imaging approach to measure the stiffness of tissues to provide diagnostic information. Currently, finite element method (FEM) has been widely used in elastography. However, FEM tends to an overly stiff model that sometimes gives unsatisfactory accuracy, particularly using triangular elements in 2D or tetrahedral elements in 3D. In general, it is difficult or even impossible to generate quadrilateral or brick elements to precisely capture the anatomic details for mechanobiologic modeling as the biologic system can be rather sophisticated. In addition, biologic soft tissues are often considered as “incompressible” materials, where conventional FEM could suffer from volumetric locking in numerical solution. On the other hand, linear triangular and tetrahedral mesh can be automatically generated for complicated geometry, which significantly saves the time for the creation of model. With these reasons, for the first time, smoothed finite element method (SFEM) is developed to analyze elastography problems. A range of numerical examples, including static, dynamic, viscoelastic and time harmonic cases have exemplified herein to validate that SFEM is able to provide more accurate and stable solutions using the same set of mesh compared with the standard FEM. Furthermore, SFEM is also effective to inversely compute the mechanical properties of abnormal tissue.

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