scholarly journals Modeling and Semi-Analytic Stability Analysis for Dynamics of AC Machines

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 644
Author(s):  
Mohamed El-Borhamy ◽  
Essam Eddin M. Rashad ◽  
Ismail Sobhy ◽  
M. Kamel El-Sayed
Keyword(s):  
Stability Analysis ◽  
Perturbation Parameter ◽  
Experimental Results ◽  
Electrical Machines ◽  
Relative Movement ◽  
Ac Machines ◽  
Analytical Technique ◽  
Analytical Results ◽  
Analytic Stability

In this article, a semi-analytical technique is proposed to predict stable sustained periodic responses of AC electrical machines. Based on such desired outputs, the proper selections of machine variables are captured, such as the perturbation parameter arisen from the relative movement between the stationary and rotating parts. Compared to the experimental results, the derived analytical results are relatively well-fitted with the studied practical cases.

An Analysis of Pipe Flange Connections Using Epoxy Adhesives/Anaerobic Sealant Instead of Gaskets

1995 ◽  
Vol 117 (4) ◽  
pp. 298-304 ◽  
Author(s):  
T. Sawa ◽  
R. Sasaki ◽  
M. Yoneno
Keyword(s):  
Stress Distribution ◽  
Internal Pressure ◽  
Theory Of Elasticity ◽  
Experimental Results ◽  
Clamping Force ◽  
Bonding Force ◽  
Epoxy Adhesives ◽  
Analytical Results ◽  
Sealing Performance ◽  
Circle Diameter

This paper deals with the strength and the sealing performance of pipe flange connections combining the bonding force of adhesives with the clamping force of bolts. The epoxy adhesives or anaerobic sealants are bonded at the interface partially instead of gaskets in pipe flange connections. The stress distribution in the epoxy adhesives (anaerobic sealant), which governs the sealing performance, and the variations in axial bolt force are analyzed, using an axisymmetrical theory of elasticity, when an internal pressure is applied to a connection in which two pipe flanges are clamped together by bolts and nuts with an initial clamping force after being joined by epoxy adhesives or anaerobic sealant. In addition, a method for estimating the strength of the combination connection is demonstrated. Experiments are performed and the analytical results are consistent with the experimental results concerning the variation in axial bolt force and the strength of combination connections. It can be seen that the strength of connections increases with a decrease in the bolt pitch circle diameter. Furthermore, it is seen that the sealing performance of such combination connections in which the interface is bonded partially is improved over that of pipe flange connections with metallic gaskets.

scholarly journals Modeling of microwave applicators with an excitation through the wave guide using TLM method

2005 ◽  
Vol 2 (2) ◽  
pp. 137-146
Author(s):  
Tijana Randjelovic ◽  
Jugoslav Jokovic ◽  
Bratislav Milovanovic
Keyword(s):  
Experimental Results ◽  
Wave Guide ◽  
Analytical Results ◽  
Resonant Modes ◽  
Impulse Excitation ◽  
Wave Guides ◽  
Tlm Method ◽  
Microwave Applicator ◽  
Good Agreement ◽  
Microwave Applicators

In this paper, a real microwave applicator with a wave guide used to launch the energy from the source into the cavity is analyzed using 3D TLM method. In order to investigate the influence of the positions and number of feed wave guides to the number of the resonant modes inside the cavity, obtained results are compared with analytical results and results obtained by using TLM software with an impulse excitation as well. TLM method is applied to the both empty and loaded rectangular metallic cavity, and a very good agreement between simulated and experimental results is achieved.

An Algorithm for the Solution of Impurity Diffusion under Finite Reaction Rates

1982 ◽  
Vol 37 (8) ◽  
pp. 931-938 ◽  
Author(s):  
K. Lackner ◽  
K. Behringer ◽  
W. Engelhardt ◽  
R. Wunderlich
Keyword(s):  
Stability Analysis ◽  
Reaction Rates ◽  
Computational Effort ◽  
Unconditional Stability ◽  
Impurity Diffusion ◽  
Time Dependent ◽  
Recombination Rates ◽  
Fast Solution ◽  
Analytic Stability ◽  
Diffusion Problems

An algorithm allowing a fast solution of stationary and time dependent 1-d diffusion problems for the case of finite ionization and recombination rates is presented. Results of numerical computations and an analytic stability analysis show its unconditional stability. The computational effort involved rises only linearly with the number of ionization stages included. An application to the diffusion of oxygen and iron impurities in JET is described

On the Determination of Stress, Strain, Strain-Rate Relations From Dynamic Beam Tests

1969 ◽  
Vol 36 (3) ◽  
pp. 632-634 ◽  
Author(s):  
P. P. Gillis ◽  
J. M. Kelly
Keyword(s):  
Strain Rate ◽  
Dynamic Testing ◽  
Direct Method ◽  
Bending Moment ◽  
Experimental Results ◽  
Stress Strain ◽  
Analytical Technique ◽  
Flexural Response ◽  
Flexural Tests

A direct method is proposed for the determination of stress, strain, strain-rate relations from dynamic flexural tests in which bending moment is given in terms of curvature and curvature rate, or any other suitable deformation parameter and deformation rate parameter. The method is demonstrated by application to published experimental results. It is found that the stress, strain, strain-rate relations that are derived from the flexural test data are in significantly better accord with uniaxial data on the same material, than moment, curvature, curvature-rate relations predicted from the uniaxial data correspond with the experimental results. It appears that the process of reducing flexural data to uniaxial relations by the method proposed is much less sensitive than that of predicting flexural response from uniaxial data. Since flexural tests have many experimental advantages over uniaxial tests this analytical technique seems to open up possibilities for improved dynamic testing methods.

Dynamic Response of a Cylindrical Shell in a Potential Fluid

1979 ◽  
Vol 46 (4) ◽  
pp. 772-778 ◽  
Author(s):  
G. E. Cummings ◽  
H. Brandt
Keyword(s):  
Cylindrical Shell ◽  
Dynamic Response ◽  
Circular Cylindrical Shell ◽  
Time History ◽  
Experimental Results ◽  
Scale Model ◽  
Solution Technique ◽  
Analytical Technique ◽  
Forcing Function ◽  
Potential Fluid

A numerical solution technique is presented for determining the dynamic response of a thin, elastic, circular, cylindrical shell of constant wall thickness and density, in a potential fluid. The shell may be excited by any radial forcing function with a specified time history and spatial distribution. In addition, a pressure history may be specified over a segment of the fluid outer boundary. Any of the natural shell end conditions may be prescribed. The numerical results are compared to experimental results for a 1/12-scale model of a nuclear-reactor core-support barrel. Natural frequencies and modes are determined for this model in air, water, and oil. The computed frequencies are within 15 percent of experimental results. A sample application compares the numerical technique to an analytical solution for shell beam modes. The comparison resolves an uncertainty concerning the proper effective mass to use in the analytical technique.

Effect of Mechanical Processing on Intrinsic Stress and its Distribution in Polycarbonate Screw Cap

2017 ◽  
Vol 727 ◽  
pp. 471-475
Author(s):  
Qiang Yang ◽  
Jun Liu ◽  
Ming Zhen Li ◽  
Qi Long Wei
Keyword(s):  
Heat Treatment ◽  
Experimental Results ◽  
Intrinsic Stress ◽  
Mechanical Processing ◽  
Analytical Results

The polycarbonate (PC) screw cap part had cracking problem during storage, which mechanism needed to be studied. The effect of mechanical processing on the intrinsic stress and its distribution in PC screw cap part was investigated in the paper. The analytical results indicated that the round pieces cut from polycarbonate bar had certain intrinsic stress residue from processing course, which decreased obviously after de-stress heat treatment. Mechanical processing also led to obviously increased intrinsic stress in screw cap part, which could be decreased obviously by another de-stress heat treatment. But the heat treatment increased the aging degree and cracking probability for polycarbonate screw cap part, and was not suggested to carry out on screw cap. Based on the experimental results, some suggestions were also given to lower the intrinsic stress in screw cap.

Belt Forces With Grinding

1988 ◽  
Vol 110 (3) ◽  
pp. 201-211 ◽  
Author(s):  
H. Kim ◽  
K. M. Marshek
Keyword(s):  
Experimental Results ◽  
Belt Grinding ◽  
Abrasive Belt ◽  
Analytical Results

This paper investigates belt forces in abrasive belt grinding. The distribution of normal and tangential belt forces are determined analytically and experimentally for belt grinding with both a driving and a driven pulley contact wheel. The experimental results are compared with the analytical results.

An Improved Three-Strut Model for Masonry Infills in RC Frame Structures

2010 ◽  
Vol 163-167 ◽  
pp. 4129-4132
Author(s):  
Chang Hai Zhai ◽  
Xiao Min Wang ◽  
Shuang Li ◽  
Li Li Xie
Keyword(s):  
Wenchuan Earthquake ◽  
Experimental Results ◽  
Frame Structures ◽  
Rc Frame ◽  
Infilled Frames ◽  
Infilled Frame ◽  
Masonry Infills ◽  
Analytical Results ◽  
Rc Frame Structures ◽  
Column Element

In Wenchuan Earthquake, masonry-infilled frames have the quite critical failures. In this paper, the reason of the failure phenomenon is analyzed and the influence of the infilled wall to performance of the frame is highlighted. An improved three-strut model for masonry-infilled frame structures is presented. Then, two RC frame specimens, which are modeled by the presented three-strut model and force-based beam-column element combined with fiber section considering compression-bending coupling in Opensees, are analyzed. The analytical results agree well with the experimental results. It is shown that the presented three-strut model is sufficient to simulate the performance of the infilled wall.

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