scholarly journals Stereometry of compressed conoids and physical adequacy of q8 element bases

2021 ◽  
Vol 3 (134) ◽  
pp. 40-48
Author(s):  
Anatoliy Khomchenko ◽  
Olena Lytvynenko ◽  
Oleh Dudchenko ◽  
Igor Astionenko
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Elements ◽  
Trigonometric Functions ◽  
The Finite Element Method ◽  
Standard Element ◽  
Elegant Method ◽  
New Models ◽  
Historical Importance ◽  
Serendipity Elements

The paper considers new models of bases of serendipity finite elements (FE) Q8. The standard element Q8 has been used in the finite element method (FEM) for more than 50 years despite the physical inadequacy of the spectrum of equivalent nodal loads.In recent years, the library of serendipity finite elements has been significantly replen-ished with non-standard (alternative) models. The reasons for the inadequacy of the spectrum were identified and "recipes" were proposed to eliminate this shortcoming of standard serendipity models. New approaches to modeling bases with the help of hierarchical forms force to abandon conoids - linear surfaces that are associated with intermediate nodes of standard elements. According to the authors, these Catalan surfaces (1843) are insufficiently studied and deserve the attention of modern researchers. Therefore, research is being conducted today, and it is not necessary to give up conoids. The paper shows how by compressing the surface of the conoid it is possible to obtain a mathematically sound and physically adequate spectrum of nodal loads. It is interesting that such capabilities are embedded in trigonometric functions, the popularity of which in the FEM is growing steadily.The purpose of the research is to constructively prove the existence of mathematically substantiated and (most importantly) physically adequate models of serendipity elements Q8 with the help of trigonometric bases.Trigonometric models of the finite element Q8 once again confirmed that serendipity elements are an inexhaustible source of important and interesting information. It should be noted that today it is not necessary to give up conoids for the sake of physical adequacy of the model. Conoids are also of "historical" importance to FEM. The first bases of serendipity FEs were constructed from conoids (1968).Taylor's elegant method (1972) is also based on conoids. New results show that trigo-nometric bases are able to preserve conoids and ensure the physical adequacy of the models.

scholarly journals Non-linearity of the contact layer between elements joined in a multi-bolted connection and the preload of the bolts

2016 ◽  
Vol 165 (2) ◽  
pp. 3-8
Author(s):  
Rafał GRZEJDA
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Elements ◽  
Cylinder Head ◽  
Contact Layer ◽  
Rigid Support ◽  
The Finite Element Method ◽  
Bolted Connection ◽  
Winkler Model ◽  
Engine Cylinder

The paper presents modeling and calculations of multi-bolted connections at the assembly stage on an example of the engine cylinder head-block connection. The physical model of the connection was introduced as a combination of three subsystems: the set of bolts, the joined element and the contact layer between the joined element and the rigid support. The finite element method (FEM) was used for the modeling. Bolts were replaced with hybrid elements. The joined element was modeled with spatial finite elements. The Winkler model of the contact layer has been taken into consideration. The truth of the theorem has been examined, according to which non-linearity of the contact layer has a negligible impact on the final values of the bolt forces in the case of sequential preloading of the multi-bolted connection. The results of the calculations of a selected multi-bolted connection have been compared with the experimental results.

Teaching Electromagnetics through Finite Elements. Part I: The Rationale

1988 ◽  
Vol 25 (1) ◽  
pp. 33-49 ◽  
Author(s):  
S. Ratnajeevan H. Hoole
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Elements ◽  
Special Solution ◽  
The Finite Element Method ◽  
Solution Methods ◽  
Element Method

The rationale for teaching undergraduate electromagnetics partly through the finite element method, is put forward. Properly presented, the finite element method, easily within the ken of the engineering undergraduate, promotes clarity and helps to replace large portions of syllabi devoted to special solution methods, with problems of industrial magnitude and character.

Analysis of the Local Deformations in Machine Joints

1979 ◽  
Vol 21 (1) ◽  
pp. 25-32 ◽  
Author(s):  
M. Burdekin ◽  
N. Back ◽  
A. Cowley
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Elements ◽  
Pressure Distribution ◽  
Surface Finish ◽  
The Finite Element Method ◽  
Theoretical Formulation ◽  
Apparent Area ◽  
Finish Material ◽  
General Method

This paper presents a general method for calculating the pressure distribution and the deformations in machine joints. This method assumes that the components of the joint are connected through finite elements which are defined as a function of the surface finish, material and pressure at the apparent area of contact. The system so established is solved in an iterative manner using the finite-element method, obtaining, as a final result, the pressure distribution at the contacting surfaces of the components and the deformations of the surrounding body. To prove the validity and precision of the theoretical formulation, several examples of joints are considered where the correlation between the calculated and measured deflections is shown to be good.

scholarly journals Models of stents – Comparison and applications

2007 ◽  
pp. S115-S121
Author(s):  
J Záhora ◽  
A Bezrouk ◽  
J Hanuš
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Analytical Model ◽  
Model Evaluation ◽  
Structural Mechanics ◽  
Theoretical Background ◽  
Measurement Equipment ◽  
The Finite Element Method ◽  
Basic Properties ◽  
New Models

The aim of this study was to analyze the possibilities of various types of stent modeling and to develop some new models. A brief survey of basic properties of stents and a list of basic designs of stents is presented. Two approaches to stent modeling were identified. Structural mechanics is the theoretical background of our analytical model of a spiral stent. The finite element method was also used. The measurement equipment for model evaluation was developed.

HIGHER-ORDER MASS-LUMPED FINITE ELEMENTS FOR THE WAVE EQUATION

2001 ◽  
Vol 09 (02) ◽  
pp. 671-680 ◽  
Author(s):  
W. A. MULDER
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wave Propagation ◽  
Wave Equation ◽  
Finite Elements ◽  
Finite Difference Method ◽  
Seismic Wave Propagation ◽  
The Finite Element Method ◽  
Efficient Scheme ◽  
The Finite Difference Method

The finite-element method (FEM) with mass lumping is an efficient scheme for modeling seismic wave propagation in the subsurface, especially in the presence of sharp velocity contrasts and rough topography. A number of numerical simulations for triangles are presented to illustrate the strength of the method. A comparison to the finite-difference method shows that the added complexity of the FEM is amply compensated by its superior accuracy, making the FEM the more efficient approach.

A Numerical Solution of the Elastohydrodynamic Lubrication Problem Using Finite Elements

1972 ◽  
Vol 14 (4) ◽  
pp. 229-237 ◽  
Author(s):  
C. Taylor ◽  
J. F. O'Callaghan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Elements ◽  
Numerical Solution ◽  
Elastohydrodynamic Lubrication ◽  
The Finite Element Method ◽  
Galerkin Approach ◽  
Recent Developments ◽  
Element Method ◽  
Isoparametric Elements

This paper comprises a report on recent developments in the application of the finite element method in the analysis of elastohydrodynamic lubrication (e.h.l.) problems. The basic formulation is effected, using the Galerkin approach and the domain under investigation is discretized using isoparametric elements. The techniques used to locate the inlet and outlet boundaries and those employed during successive iterations are illustrated by application to particular examples.

scholarly journals Ultrasonic Sensors Enabling Early Detection of Emergency Trends and Analysis of Structure Inclination and Stability by Means of Highly Accurate Level Measurements

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1789
Author(s):  
Leszek Ornoch ◽  
Paweł Popielski ◽  
Andrzej Olszewski ◽  
Adam Kasprzak
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Early Detection ◽  
Water Levels ◽  
The Finite Element Method ◽  
Ultrasonic Sensors ◽  
Temperature Changes ◽  
New Models ◽  
Object Behavior

Building inclinations can be measured through the use of ultrasonic hydrostatic levelers. These are used to measure long-term relative displacements of vertical parts of structures and utilize the principle of communicating vessels (similar to the classic water scales). The presented ultrasonic displacement measurement technique was developed by Ultrasystem in the 1990s and was applied to several objects in Poland. Long-term measurements enabled the development of a model of object behavior under the influence of various factors. Among these are the annual cycle of temperature changes, fluctuating water levels, turbine chamber emptying, etc. Such a model can facilitate the prediction of failure based on the appearance of changes deviating from typical behavior (e.g., a much stronger dependence of the inclination as a function of the water level). The results obtained with the help of ultrasonic sensors enable the observation of subtle deformations of the object, which is valuable when developing and calibrating new models of the object (e.g., by means of the finite element method).

scholarly journals 10.36.910. RESEARCHING OF DETAIL’S CONSTRUCTION WITH METHOD OF FINAL ELEMENTAL ANALYSIS

2019 ◽  
pp. 46-51
Author(s):  
O.V. Voloshko Assistant, S. P. Vysloukh Ph.D. Assoc. Prof.
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Elements ◽  
Computer Modelling ◽  
Elastic State ◽  
The Finite Element Method ◽  
Software Environment ◽  
Element Analysis ◽  
Deformed State

The advantages of using computer modelling for the study of the detail’s elastic-deformed state during the process of its operation are given. It is proposed to use the method of finite elements for such researches. It is shown that FEMAP is an effective software environment based on finite element analysis. An example of using the finite element method for modelling the detail’s elastic state operating in conditions of alternating loads is given. Наведено переваги використання комп’ютерного моделювання для дослідження пружно-деформований стан деталі в процесі її експлуатації. Запропоновано для таких досліджень використовувати метод скінченних елементів. Показано, що ефективним програмним середовищем, яке базується на кінцево-елементному аналізі, є система FEMAP. Наведена приклад використання методу скінченних елементів для моделювання пружного стану деталі, що працює в умовах знакозмінних навантажень.

scholarly journals The study of the lifting mechanism of the crane arm to a barge

2020 ◽  
Vol 2 (1) ◽  
pp. 91-96
Author(s):  
C. Fratila ◽  
T. Axinte ◽  
R. C. Cojocaru ◽  
C. Berescu ◽  
I.C. Scurtu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Life ◽  
Finite Elements ◽  
Safety Factor ◽  
The Finite Element Method ◽  
Ship Owner ◽  
Loading And Unloading ◽  
Lifting Equipment ◽  
Boom Crane

During cargo loading and unloading, the vessels’ lifting gear, even if anchored or moored, is affected by the pitch and roll movements, in addition to the usual stresses, a similar shore crane is subjected to. This paper aims at presenting an analysis of the lifting operations of a boom crane pertaining to a self-propelled barge. The analysis starts with the meshing with triangle elements, the stresses and the embedding using the finite elements method. The crane and the pertaining boom were modeled using CAD design, NX 10.0 from Siemens. The lifting equipment of the ships boom crane may be subject to dangerous defects occurring during the loading and unloading process. Subsequently, the research emphasizes the stresses occurred in the piston rod and in the eye of the lifting equipment, using the finite element method (FEM). After the stress analysis, several fatigue matters are studied: fatigue safety factor, fatigue life, strength safety factor and crack. The damaging or breaking of the eye or of the piston rod from the lifting equipment of the ships boom crane is leading to the blocking of the cylinder with the result of unfavorable events, such as deformation of the boom crane, damaging the loads and even the danger of sinking the barge. The results of this analysis provide ship-owner and maintenance engineers a useful tool to take appropriate decision during inspection of the lifting gear of the ship, prior commencement of the loading and unloading operations.

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