Electromagnetic coupling and interference predictions using the frequency-domain physical optics method and the time-domain finite-element method [aircraft antenna applications]

2004 ◽  
Author(s):  
D.J. Riley ◽  
N.W. Riley ◽  
W.T. Clark ◽  
H. Del Aguila ◽  
R. Kipp
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Frequency Domain ◽  
Time Domain ◽  
Electromagnetic Coupling ◽  
Physical Optics ◽  
The Time Domain ◽  
Element Method

scholarly journals Fatigue Life Prediction of a Drag Link by Using Finite Element Method

2010 ◽  
Author(s):  
Barıs¸ Koca ◽  
Bu¨lent Ekici
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Life ◽  
Frequency Domain ◽  
Time Domain ◽  
Life Analysis ◽  
Fatigue Life Analysis ◽  
The Time Domain ◽  
Drag Link ◽  
Element Method

The focus of this study is to find fatigue behavior and fatigue life of a drag link in the different road and loading conditions. Finite element method was used for fatigue analysis and fatigue life of the drag link was predicted. Firstly, the historical changes in the concept of the fatigue and fatigue life calculation methods were explained in the chapter one and two. Factor affecting the fatigue performance was explained. Stress and strain based fatigue analysis methods were described clearly. Finally, fatigue life analysis in the frequency domain which is a new method relative to the others was explained. Then, two different steering drag links of a midibus were examined and fatigue life calculations of these two drag links were made. The fatigue life analysis in the time domain of the drag links were made in the static steering conditions and the results were compared with the test results made by the vendor of the drag links. After that, the drag link which has a greater fatigue life than the other was selected, the road loads were taken from another test report which was made by using the same drag link and the fatigue life of the drag link was computed by using the finite element method in the time domain. Finally, the same road loads were converted in the frequency domain and the fatigue life analysis of the same drag link were made in the frequency domain. The results from the time domain and the frequency domain were compared and the advantages of the fatigue life analysis in the frequency domain were expressed.

Time domain finite element method for metamaterial-based low frequency near field systems

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhi Gong ◽  
Shiyou Yang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Frequency Domain ◽  
Time Domain ◽  
Near Field ◽  
Low Frequency ◽  
Electromagnetic Properties ◽  
Content Type ◽  
The Time Domain ◽  
Element Method

Purpose The purpose of this work is to develop a computational paradigm for performance analysis of low-frequency electromagnetic devices containing both magnetic metamaterials (MTMs) and natural media. Design/methodology/approach A time domain finite element method (TDFEM) is proposed. The electromagnetic properties of the MTMs are modeled by a nonstandard Lorentz model. The time domain governing equation is derived by converting the one from the frequency domain into the time domain based on the Laplace transform and convolution. The backward difference is used for the temporal discretization. An auxiliary variable is introduced to derive the recursive formula. Findings The numerical results show good agreements between the time domain solutions and the frequency domain solutions. The error convergence trajectory of the proposed TDFEM conforms to the first-order accuracy. Originality/value To the best knowledge of the authors, the presented work is the first one focusing on TDFEMs for low-frequency near fields computations of MTMs. Consequently, the proposed TDFEM greatly benefits the future explorations and performance evaluations of MTM-based near field devices and systems in low-frequency electrical and electronic engineering.

Transient Analysis of Dam-Reservoir Interaction Based on Dynamic Stiffness of SBFEM

2011 ◽  
Vol 378-379 ◽  
pp. 213-217
Author(s):  
Shang Ming Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Time Domain ◽  
Transient Analysis ◽  
Ground Motions ◽  
Dynamic Stiffness ◽  
Dam Reservoir ◽  
The Time Domain ◽  
Infinite Reservoir ◽  
Element Method

The scaled boundary finite element method (SBFEM) was extended to solve dam-reservoir interaction problems in the time domain and a dynamic stiffness used in the SBFEM of semi-infinite reservoir in the time domain was proposed, which was evaluated by the Bessel function. Based on the dynamic stiffness, transient responses subjected to horizontal ground motions were analyzed through coupling the SBFEM and finite element method (FEM). A dam was modeled by FEM, while the whole fluid in reservoir was modeled by the SBFEM alone or a combination of FEM and SBFEM. Two benchmark examples were considered to check the accuracy of the dynamic stiffness. Results were compared with those from analytical or substructure methods and good agreements were found.

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