Nonlinear optimization of the shape function in the finite element method when determining cutoff frequencies of waveguides of arbitrary cross section

1988 ◽  
Vol 36 (1) ◽  
pp. 151-152 ◽  
Author(s):  
J.C. Utjes ◽  
G.S. Sarmiento ◽  
P.A.A. Laura
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Nonlinear Optimization ◽  
Cross Section ◽  
Shape Function ◽  
Arbitrary Cross Section ◽  
The Finite Element Method ◽  
Cutoff Frequencies ◽  
Element Method

scholarly journals Study on the simulation of annular axis braiding process and braiding angles’ prediction method

2021 ◽  
Vol 30 ◽  
pp. 263498332110108
Author(s):  
Xi Wang ◽  
Guoli Zhang ◽  
Xiaoping Shi ◽  
Ce Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
Efficient Method ◽  
Process Simulation ◽  
Prediction Method ◽  
Difficult Problem ◽  
The Finite Element Method ◽  
Surface Flattening ◽  
Element Method

A common braiding machine cannot perform continuous braiding using closed annular axis mandrels. To solve this problem, a modified vertical braiding machine was made to braid composite preforms with irregular cross-section mandrels. The finite element method was used to simulate the braiding process, and an efficient method was also derived to predict the braiding angles. The results show that the predicted braiding angles are basically consistent with the actual braiding angles, and the braiding angles at distinctive locations on the braided preform recorded differences of up to 10° or more than 30%. Braiding process simulation via the finite element method can thus effectively and vividly reflect the yarn path on the preform. As such, the braiding angles on the braided preforms can be realized through projection and surface flattening with much better accuracy. It also resolves the difficult problem often faced in measuring the braiding angles at the corner of the mandrel and provides a solid basis for continued research on the performance of its composite reinforcement.

scholarly journals The Fe Analysis and Variation of Composite Top Hat Shaped Beam

2019 ◽  
Vol 69 (3) ◽  
pp. 27-32
Author(s):  
Petr David ◽  
Zdeněk Padovec ◽  
Tereza Zámečníková ◽  
Radek Sedláček
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Static Analysis ◽  
Cross Section ◽  
Main Part ◽  
Fe Analysis ◽  
The Finite Element Method ◽  
Shaped Beam ◽  
Element Method

AbstractThe main goal of this work is to provide a composite alternative to an already existing beam which has top hat cross section. The main part of this work is focused on using the finite element method to solve the problem. Firstly, a duralumin version will be used to calibrate the computation, then the problem will be solved for different options of slightly adjusted geometry. The computation itself will include general static analysis as well as analysis of buckling.

Modeling of the impact of hold-down forces on the accuracy of the workpiece shape using the finite element method

2021 ◽  
pp. 9-20
Author(s):  
A.V. Zaitsev ◽  
A.N. Izosimov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
The Body ◽  
Machining Process ◽  
Mechanical Processing ◽  
The Finite Element Method ◽  
The Cross ◽  
The Impact ◽  
Element Method

In the article, the modeling of the impact of hold-down forces on the accuracy of the shape of the workpiece using the finite element method was carried out. The operation of mechanical processing (turning cut) of a workpiece of the body of rotation type on a milling machine with basing and fixing along the inner cylindrical surface of the workpiece is considered. The study was conducted for four different types of machine retaining devices used on machines of this group. A consistent description and illustration of the method of modeling the process of the impact of hold-down forces on the workpiece is made for each type of the device under consideration. The force constraints and effects imposed on the model are described and illustrated, the parameters of the finite element grid used in modeling are presented, the displacement profiles obtained in the modeling process and the stages of modeling the machining process are described, and the values of the largest deviations from the shape of the workpiece are determined. The results of the modeling are presented: a qualitative picture of the shape errors obtained as a result of mechanical processing — the values of the largest deviation from the roundness and the largest deviation from the cross-section profile of the workpiece to be processed, as well as the shape of the cutting obtained in the cross-section of the workpiece for each type of the devices under consideration. On the basis of the obtained results, estimates of the degree of accuracy of the shape and the relative geometric accuracy provided by the considered devices were made in accordance with GOST 24643–81. The conclusion is made about the suitability of using the considered variants of machine retaining devices for the proposed technological process according to the criterion of the provided accuracy of the shape of the processed surface. English version of the article is available at URL: https://panor.ru/articles/modeling-the-influence-of-the-fastening-forces-on-the-accuracy-of-the-workpiece-shape-using-the-finite-element-method/65043.html

New multi-pass hot channel section rolling design by the finite element method

2013 ◽  
Vol 227 (12) ◽  
pp. 2742-2750 ◽  
Author(s):  
Amir Hosein Sakhaei ◽  
Mahmoud Salimi ◽  
Mahmoud Kadkhodaei
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Power Consumption ◽  
Cross Section ◽  
Production Line ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Explicit Finite Element ◽  
Channel Section ◽  
Element Method

A new multi-pass hot shape rolling was designed based on a three-dimensional analysis of channel section beams in hot rolling by the finite element method. A complete production line in industry containing 13 passes in forming the section including break-down, intermediate, and finishing sequences is modeled. The output geometry and power consumption predicted by this simulation were verified against the practical data and the measured values of the production line of Zobahan Esfahan Company. Then, a sample caliber design process to achieve a specific cross section is prepared. The minimum possible number of passes consistent with the parameters affecting the spread is the main strategy of the new caliber design. Again this new caliber design is simulated using an explicit finite element code. The geometry and dimensions of the exit cross section, the separation force, roll torques, and the power consumption in each stage are calculated. Comparison of the new roll pass parameters and that of the conventional ones in industry is made to demonstrate the advantages of the new caliber design.

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