scholarly journals Experimental and Numerical Investigation on the Flow-Induced Interior Noise Based on Pellicular Analysis

2021 ◽  
Vol 26 (1) ◽  
pp. 18-27
Author(s):  
Pan Zuofeng ◽  
Hou Hangsheng ◽  
Lu Wenbo ◽  
Ji Changwei ◽  
Du Mintao ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wave Number ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Wind Noise ◽  
Mode Decomposition ◽  
Turbulent Pressure ◽  
Rearview Mirror ◽  
The Difference

Turbulence caused by the rearview mirror and A-pillar is the main source of interior wind noise. Because of the difference in energy and transfer efficiency of acoustic and turbulent pressure, it is important to accurately identify the two kinds of pressure on the window surface when studying interior wind noise. Wave Number Decomposition (WND) and Pellicular Mode Decomposition (PMD) are successfully applied to decompose the pressure on the window. Furthermore, the transfer function calculated by pellicular analysis is used to calculate the interior wind noise, and the result is compared with the result calculated by the Finite Element Method (FEM) and measured by the experiment. The results revealed that the interior wind noise calculated by the pellicular analysis method is almost the same as the result calculated by the FEM, and that it presents obvious advantages in computational efficiency.

scholarly journals The Search of Spatial Functions of Pressure in Adjustable Hydrostaticradial Bearing

2015 ◽  
Vol 9 (1) ◽  
pp. 23-26 ◽  
Author(s):  
Dmytro Fedorynenko ◽  
Sergiy Boyko ◽  
Serhii Sapon
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Elastic Deformation ◽  
Tangential Direction ◽  
The Finite Element Method ◽  
Radial Bearing ◽  
Operational Characteristics ◽  
Service Conditions ◽  
The Difference ◽  
Element Method

Abstract The analysis of spatial functions of pressure considering the geometrical deviations and the elastic deformation of conjugate surace have been considered. The analysis of spatial functions of pressure is performed by the finite element method. The difference of the size of pressure in a tangential direction of a pocket of a support under various service conditions has been investigated. A recommendation for improving of operational characteristics in regulated hydrostatic radial bearing has been developed.

The Qualification of Safety Critical Structures by Finite Element Analytical Methods

1996 ◽  
Vol 210 (2) ◽  
pp. 203-207 ◽  
Author(s):  
A J Morris
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Error Control ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Method Error ◽  
Safety Critical ◽  
Critical Situation ◽  
Error Treatment

The paper introduces the concept of certifying or qualifying structures in a safety critical situation using the finite element method. Error control and error treatment methods for this purpose are discussed together with the associated role of testing. The underlying methodology follows the principles laid down in the SAFESA (SAFE Structural Analysis) method which is described in outline.

Development of Bifurcation Analysis Method for Rate Dependent Materials

2019 ◽  
Vol 794 ◽  
pp. 220-225
Author(s):  
Daiki Towata ◽  
Yuichi Tadano
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Bifurcation Analysis ◽  
Stiffness Matrix ◽  
Computational Method ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Tangent Stiffness Matrix ◽  
Rate Dependent ◽  
Element Method

In this study, a novel numerical method to analyze the bifurcation problemof a rate dependent material using the finite element method is proposed. The consistent stiffness matrix, which is required for a bifurcation analysis using the finite element method, for a rate dependent material is generally hard to compute, therefore, a computational method to calculate the tangent stiffness matrix based on a numerical differential is introduced so that exact bifurcation analyses for the rate dependent material can be conducted. A numerical example of the proposed method is demonstrated, and the adequacy of the proposed method is discussed.

scholarly journals Application of a new vector mode solver to optical fiber-based plasmonic sensors

2016 ◽  
Vol 30 (07) ◽  
pp. 1650075 ◽  
Author(s):  
V. A. Popescu ◽  
N. N. Puscas ◽  
G. Perrone
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Analytical Method ◽  
Distilled Water ◽  
The Finite Element Method ◽  
Plasmonic Sensor ◽  
Plasmonic Sensors ◽  
Vector Mode ◽  
Hankel Functions ◽  
The Difference

Our analytical method uses a linear combination of the Hankel functions [Formula: see text] and [Formula: see text] to represent the field in the gold region of a fiber-based plasmonic sensor. This method is applied for different structures made from three, four and five layers. When the analyte is distilled water, the difference between the resonant wavelengths calculated with the finite element method and the analytical method is very small (0.00 nm for three layers, 0.19 nm for four layers and 0.07 nm for five layers with two gold layers). The important characteristics of the Bessel and Hankel functions at the loss matching point are analyzed.

Nonlinear Analysis Method Research of Multi-Bolt Connection Structure of Primary Equipment Support

2017 ◽  
Author(s):  
Jianrong Zou ◽  
Shaochong Zhou
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Steam Generator ◽  
Support System ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Reactor Coolant ◽  
Asme Code ◽  
Bolt Connection ◽  
Coolant System

The main equipments of the reactor coolant system include the steam generator, the reactor coolant pump, the pressurizer and the reactor coolant loop. The reactor coolant system is equipped with a steam generator for each of the two loops, and pressurizer is connected with the hot leg of loop 1 using the surge line. The main loop support system design of AP series greatly simplifies the RCS loop support system. Pressurizer supports consist of columns, lower lateral supports, upper lateral support and ring girder, and the steam generator supports consist of columns, lower lateral supports, upper lateral supports and intermediate lateral supports. Ring Girder of pressurizer consists of two semi-circular girders, vertical supports and splice connection of girder and the two half-ring girders are connected with splice connection using 11 bolts. The steam generator upper lateral support is mainly composed of bracket, snubber, pin and ubar and the ubar and the steam generator is connected via 16 bolts in the initial design. These bolts are to ensure the support junction can withstand the force and torque of various conditions of the reactor coolant system, which are important components of the main equipment support. There are large numbers of bolts in the splice connection of ring girder and ubar of upper lateral support of steam generator, and the bolts load was calculated using the uniform method in the general engineering design and analysis. During the design review it was found that the bolts load was uneven and in order to determine the non-uniformity of the bolts the finite element method was used to calculate the load on each bolt, and the resulting stress ratio was greater than 1 did not meet the requirements of the ASME Code. In this paper, the calculation method was studied and the design improvements for parts was made using the nonlinear analysis method to meet the requirements of ASME Code in the case of master supports of main equipment supports have been made good. At the same time the impact of bolts load because of gap was studied. It had very good economic benefits. The calculation and research of this paper show that the finite element method can calculate the force of bolts finely, and can get a more reasonable result than the empirical formula. It can be referred to when the multi-bolt connection structure needs to be refined, such as flange connection of important equipments and valves and flange and bolt design optimization.

Modelling of ballraceway contacts in a slewing bearing with non-linear springs

2011 ◽  
Vol 225 (4) ◽  
pp. 827-831 ◽  
Author(s):  
X H Gao ◽  
X D Huang ◽  
H Wang ◽  
J Chen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Area ◽  
The Finite Element Method ◽  
Simple Method ◽  
Slewing Bearing ◽  
Combined Loads ◽  
Non Linear ◽  
The Difference ◽  
Supporting Structures

During the operation, a slewing bearing is always subjected to a set of combined loads. It is the source of deformation of ballraceway contacts, rings, and even supporting structures. In practice, deformation of rings and supporting structures is often neglected for simplification, that is, they are supposed to be ideally stiff. To take elasticity of rings and supporting (fixed) structures into consideration, the finite-element method (FEM) is applied. Due to hundreds of contact pairs and the difference in the scale of contact area and rings or supporting structures, it is difficult to simultaneously model both local ballraceway contacts and the global slewing rings in a slewing bearing. The article developed a simple method to solve the problem, where the contacts are replaced by non-linear springs.

scholarly journals INTEGRATED SLOPE STABILITY ANALYSIS (SSA) WITH TRANSIENT GROUNDWATER FINITE ELEMENT METHOD FOR EMBANKMENT ANALYSIS

2021 ◽  
Vol 83 (5) ◽  
pp. 9-17
Author(s):  
Supandi Sujatono
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stability Analysis ◽  
Slope Stability ◽  
Slope Stability Analysis ◽  
Clay Material ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Element Method ◽  
Storage Facilities

The content of level has a big enough role in the value of the physical characteristic and the mechanical of material. The behavior of water in these materials needs to be analyzed first in order to support the slope stability analysis. Modeling of water behavior in materials in the construction of Tailing Storage Facilities (TSF) will be integrated in the slope stability analysis. This study aims to provide an explanation about the analysis of the Fishing Storage Facilities (TSF) which integrates transient groundwater analysis using the finite element method in supporting the stability analysis of the embankment of Tailing Storage Facilities (TSF). The variables that are used in the analysis, they are the parameters of physical properties and mechanic material for embankment and permeability parameters in analyzing groundwater. The analysis method for geotechnical and geohydrology modeling uses the finite element method. The results of analysis showed that groundwater behavior in the embankment material can be known in detail so that it can be integrated with stability analysis.   It can be seen that there is a decrease in the value of the slope safety factor using the Integrated Slope Stability Analysis method compared to the conventional method. Adding an impermeable layer using a thickness of 5 m of clay material and a thickness of 20-30 m to support the retaining wall/foot is the criterion of optimal stability. The required lining material thickness (D) can be expressed by the following drawdown percentage equation function:  reduction percentage = (1-0.8661D (-0.031)) * 100%.  

scholarly journals Comparative analysis of finite element formulations at plane loading of an elastic body

2020 ◽  
Vol 16 (2) ◽  
pp. 139-145
Author(s):  
Natalia A. Gureeva ◽  
Anatoly P. Nikolaev ◽  
Vladislav N. Yushkin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Elastic Body ◽  
Stiffness Matrix ◽  
Strain State ◽  
Mixed Formulation ◽  
The Finite Element Method ◽  
Displacement Method ◽  
Internal Forces ◽  
The Difference

The aim of the work - comparison of the results of determining the parameters of the stress-strain state of plane-loaded elastic bodies based on the finite element method in the formulation of the displacement method and in the mixed formulation. Methods. Algorithms of the finite element method in various formulations have been developed and applied. Results. In the Cartesian coordinate system, to determine the stress-strain state of an elastic body under plane loading, a finite element of a quadrangular shape is used in two formulations: in the formulation of the method of displacements with nodal unknowns in the form of displacements and their derivatives, and in a mixed formulation with nodal unknowns in the form of displacements and stresses. The approximation of displacements through the nodal unknowns when obtaining the stiffness matrix of the finite element was carried out using the form function, whose elements were adopted Hermite polynomials of the third degree. Upon receipt of the deformation matrix, the displacements and stresses of the internal points of the finite element were approximated through nodal unknowns using bilinear functions. The stiffness matrix of the quadrangular finite element in the formulation of the displacement method is obtained on the basis of a functional based on the difference between the actual workings of external and internal forces under loading of a solid. The matrix of deformation of the finite element was formed on the basis of a mixed functional obtained from the proposed functional by repla-cing the actual work of internal forces with the difference between the total and additional work of internal forces when loading the body. The calculation example shows a significant advantage of using a finite element in a mixed formulation.

Development of Impact Resistant Optical Pick-Up for Portable Disk Products

2000 ◽  
Author(s):  
Yukihiro Iwata ◽  
Hiroto Inoue ◽  
Kenji Tsuji ◽  
Kazuhiko Hosokawa
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Failure Mechanism ◽  
Impact Analysis ◽  
Impact Resistance ◽  
Drop Impact ◽  
Optical Disk ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Element Method

Abstract Concerning the development of portable optical disk products, higher impact resistant of the optical pick-up is required. Conventionally, cut and try measures, mainly based on experiment were applied to these problems, and it took much time and cost. Therefore, we developed this drop impact analysis of the optical pick-up based on the Finite Element Method (FEM) and clarified the failure mechanism of the suspension wire breaking with drop impact. With this analysis method, we also developed a new optical pick-up with a curved suspension wire, and realized much higher impact resistance.

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