Research on Piezoelectric Tube Stack for Radial Vibration Mode

2013 ◽  
Vol 721 ◽  
pp. 437-442
Author(s):  
Chao Zhong ◽  
Li Kun Wang ◽  
Lei Qin ◽  
Jing Jing Zhou ◽  
Cui Ying Chen ◽  
...  
Keyword(s):  
Vibration Mode ◽  
Analytical Calculation ◽  
Fem Simulation ◽  
Average Radius ◽  
Radial Vibration ◽  
Mechanical Equivalent ◽  
Thin Tube ◽  
Resonance Frequencies ◽  
Simulation Results ◽  
The Relationship

According to electro-mechanical equivalent principle, piezoelectric tube stack electro-mechanical equivalent circuit is derived by the admittance of single piezoelectric thin tube. The resonance frequency of piezoelectric tube stack for radial vibration mode is also calculated. The relationship between resonance frequencies and average radius, thickness and height with radial vibration mode are obtained through analytical calculation. And radial vibration mode is simulated by FEM .Analytical calculation and FEM simulation results are compared. They coincide well with each other.

Study on the Radial Vibration of an Annular Plate Ultrasonic Concentrator with Edge Section

2011 ◽  
Vol 215 ◽  
pp. 95-102
Author(s):  
H. Xu ◽  
S.Q. Liu
Keyword(s):  
Radial Displacement ◽  
Vibration Mode ◽  
Second Order ◽  
Radius Ratio ◽  
Displacement Amplitude ◽  
Radial Vibration ◽  
Order Resonance ◽  
Resonance Frequencies ◽  
The Relationship ◽  
Edge Section

The radial vibration of an annular ultrasonic concentrator with edge section is studied. Based on the electromechanical analogy, the radial equivalent circuit and the frequency equation of the concentrator are derived, the radial displacement amplitude magnification and the nodal circle equation are given. The relationship between the radial displacement amplitude magnification and radius ratio of the annular vibrator at the first and second order vibration mode is obtained. The relationship between the first and the second order radial resonance frequencies and the radius ratio of the annular edge section concentrator is analyzed. The displacement amplitude magnification of the annular vibrator at the second order resonance is lager than that of the first order vibration mode. Especially, when the radius ratio tends to one, the second order resonance frequency of the annular vibrator tends toward infinity. It can be concluded that there is no higher order vibration mode for a thin-walled circular ring. Furthermore, the experimental results show that the theoretical resonance frequencies and the amplitude magnification are in good agreement with the measured results.

Finite element analysis of piping defect formation in the sheet-extrusion process

2015 ◽  
Vol 06 (01) ◽  
pp. 1550010
Author(s):  
Wiriyakorn Phanitwong ◽  
Sutasn Thipprakmas
Keyword(s):  
Finite Element ◽  
Defect Formation ◽  
Fem Simulation ◽  
Extrusion Process ◽  
Machining Process ◽  
Work Piece ◽  
Element Analysis ◽  
Simulation Results ◽  
Sheet Extrusion ◽  
The Relationship

The pressing process, as compared to the machining process, makes good utilization of work piece material and shortens the production time, and as such it is increasingly used for production of complex shaped parts. A particular type of pressing is sheet-extrusion which controls the flow of material into special punch and die sets to produce an extruded shape. However, some particularly complex shaped parts cannot be made by sheet-extrusion due to the formation of piping defects. In this study, the finite element method (FEM) was used to investigate the formation of piping defects. In addition, the relationship between the characteristic dimensions of the extruded shape and the piping defect was also examined. Laboratory pressing experiments were performed to validate the accuracy of the FEM simulation results. Based on the stress distribution and velocity profiles within the extruded work piece, the relationship between the extruded shape and the piping defect was clearly identified. Furthermore, the FEM simulation results showed good agreement with the experimental results with regards to the dimensions of the extruded shape and the piping defect.

scholarly journals Modeling of German Low Voltage Cables with Ground Return Path

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1265 ◽  
Author(s):  
Johanna Geis-Schroer ◽  
Sebastian Hubschneider ◽  
Lukas Held ◽  
Frederik Gielnik ◽  
Michael Armbruster ◽  
...  
Keyword(s):  
Low Voltage ◽  
Measurement Data ◽  
Analytical Calculation ◽  
Laboratory Measurement ◽  
Model Parameters ◽  
Calculation Methods ◽  
Modeling Approach ◽  
Measurement Results ◽  
Simulation Results ◽  
Return Path

In this contribution, measurement data of phase, neutral, and ground currents from real low voltage (LV) feeders in Germany is presented and analyzed. The data obtained is used to review and evaluate common modeling approaches for LV systems. An alternative modeling approach for detailed cable and ground modeling, which allows for the consideration of typical German LV earthing conditions and asymmetrical cable design, is proposed. Further, analytical calculation methods for model parameters are described and compared to laboratory measurement results of real LV cables. The models are then evaluated in terms of parameter sensitivity and parameter relevance, focusing on the influence of conventionally performed simplifications, such as neglecting house junction cables, shunt admittances, or temperature dependencies. By comparing measurement data from a real LV feeder to simulation results, the proposed modeling approach is validated.

Fem Simulation of Micro-Rotating-Structures and Their Applications in Measurement of Residual Stresses in Thin Films

1997 ◽  
Vol 505 ◽  
Author(s):  
Xin Zhang ◽  
Tong-Yi Zhang ◽  
Yitshak Zohar
Keyword(s):  
Thin Films ◽  
Residual Stresses ◽  
Fem Simulation ◽  
Sensitivity Factor ◽  
Local Measurement ◽  
Micro Structure ◽  
Micro Raman Spectroscopy ◽  
Before And After ◽  
Polysilicon Films ◽  
Simulation Results

ABSTRACTFEM simulation of micro-rotating-structures was performed for local measurement of residual stresses in thin films. A sensitivity factor is introduced, studied and tabulated from the simulation results. The residual stress can be evaluated from the rotating deflection, the lengths of rotating and fixed beams, and the sensitivity factor. The micro-structure technique was applied to measure residual stresses in both silicon nitride and polysilicon thin films, before and after rapid thermal annealing (RTA), and further confirmed by wafer curvature method. Residual stresses in polysilicon films at different RTA stages were also characterized by micro-Raman spectroscopy (MRS). The experimental results indicate that micro-rotating-structures indeed have the ability to measure spatially and locally residual stresses in MEMS thin films with appropriate sensitivities.

TCAD Study of the Raised SiGe Source/Drain in 40nm PMOS

2015 ◽  
Vol 645-646 ◽  
pp. 70-74 ◽  
Author(s):  
Min Zhong ◽  
Yu Hang Zhao ◽  
Shou Mian Chen ◽  
Ming Li ◽  
Shao Hai Zeng ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Critical Role ◽  
Sige Layer ◽  
Strain Engineering ◽  
Effect Transistor ◽  
Simulation Results ◽  
Aided Design ◽  
The Relationship ◽  
Growth Experiments ◽  
Good Agreement

An embedded SiGe layer was applied in the source/drain areas (S/D) of a field-effect transistor to boost the performance in the p channels. Raised SiGe S/D plays a critical role in strain engineering. In this study, the relationship between the SiGe overfilling and the enhancement of channel stress was investigated. Systematic technology computer aided design (TCAD) simulations of the SiGe overfill height in a 40 nm PMOS were performed. The simulation results indicate that a moderate SiGe overfilling induces the highest stress in the channel. Corresponding epitaxial growth experiments were done and the obtained experimental data was in good agreement with the simulation results. The effect of the SiGe overfilling is briefly discussed. The results and conclusions presented within this paper might serve as useful references for the optimization of the embedded SiGe stressor for 40 nm logic technology node and beyond.

scholarly journals DOA Estimation for Coprime Linear Array Based on MI-ESPRIT and Lookup Table

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3043 ◽  
Author(s):  
Weike Zhang ◽  
Xi Chen ◽  
Kaibo Cui ◽  
Tao Xie ◽  
Naichang Yuan
Keyword(s):  
Linear Array ◽  
Estimation Algorithm ◽  
Doa Estimation ◽  
Spatial Spectrum ◽  
Angle Measurement ◽  
Lookup Table ◽  
Signal Parameters ◽  
Estimation Precision ◽  
Simulation Results ◽  
The Relationship

In order to improve the angle measurement performance of a coprime linear array, this paper proposes a novel direction-of-arrival (DOA) estimation algorithm for a coprime linear array based on the multiple invariance estimation of signal parameters via rotational invariance techniques (MI-ESPRIT) and a lookup table method. The proposed algorithm does not require a spatial spectrum search and uses a lookup table to solve ambiguity, which reduces the computational complexity. To fully use the subarray elements, the DOA estimation precision is higher compared with existing algorithms. Moreover, the algorithm avoids the matching error when multiple signals exist by using the relationship between the signal subspace of two subarrays. Simulation results verify the effectiveness of the proposed algorithm.

scholarly journals Research on the Performance of Electric Vehicles in Peak Load Shifting

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Qingshan Xu ◽  
Yujun Liu ◽  
Maosheng Ding ◽  
Pingliang Zeng ◽  
Wei Pan
Keyword(s):  
Potential Energy ◽  
Electric Vehicles ◽  
Peak Load ◽  
Load Shifting ◽  
Vehicle To Grid ◽  
Capacity Level ◽  
Simulation Results ◽  
The Relationship

Electric vehicles (EVs) are developing remarkably fast these years which makes the technology of vehicle-to-grid (V2G) easier to implement. Peak load shifting (PLS) is an important part of V2G service. A model of EVs’ capacity in V2G service is proposed for the research on PLS in this paper. The capacity is valued in accordance with three types of situations. Based on the model, three different scenarios are suggested in order to evaluate the capacity with MATLAB. The evaluation results indicate that EVs can provide potential energy to participate in PLS. Then, the principle of PLS with EVs is researched through the analysis of the relationship between their power and capacity. The performance of EVs in PLS is also simulated. The comparison of two simulation results shows that EVs can fulfill the request of PLS without intensely lowering their capacity level.

scholarly journals Barycenter Theorem in Phase Characteristics of Symmetric and Asymmetric Windows

Symmetry ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 329
Author(s):  
Jiufei Luo ◽  
Haitao Xu ◽  
Kai Zheng ◽  
Xinyi Li ◽  
Song Feng
Keyword(s):  
Frequency Estimation ◽  
Random Noise ◽  
Estimation Algorithm ◽  
Frequency Component ◽  
Phase Response ◽  
Numeric Simulation ◽  
Simulation Results ◽  
The Time Domain ◽  
Short Time ◽  
The Relationship

Asymmetric windows are of increasing interest to researchers because of the nonlinear and adjustable phase response, as well as alterable time delay. Short-time phase distortion can provide an essential improvement in speech coding, and also has better performance in speech recognition. The merits of asymmetric windows in the aspect of spectral behaviors have an important function in frequency component detection and parameter estimation. In this paper, the phase response of windows were further studied, and the phase characteristics of symmetric and asymmetric windows are described. The relationship between the barycenter of windows in the time domain, and the phase characteristic at the center of the main lobe in the frequency domain, was established. In light of the relationship, an improved version of the asymmetric window- based frequency estimation algorithm was proposed. The improved algorithm has advantages of straightforward implementation and computational efficiency. The numeric simulation results also indicate that the improved approach is more robust than the traditional method against additive random noise.

scholarly journals BER Performance Analysis of Non-Coherent Q-Ary Pulse Position Modulation Receivers on AWGN Channel

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6102
Author(s):  
Xianhua Shi ◽  
Yimao Sun ◽  
Jie Tian ◽  
Maolin Chen ◽  
Youjiang Liu ◽  
...  
Keyword(s):  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Theoretical Formula ◽  
Pulse Position Modulation ◽  
Error Performance ◽  
Optimal Receiver ◽  
Awgn Channel ◽  
Simulation Results ◽  
The Relationship ◽  
Better Than

This paper introduces the structure of a Q-ary pulse position modulation (PPM) signal and presents a noncoherent suboptimal receiver and a noncoherent optimal receiver. Aiming at addressing the lack of an accurate theoretical formula of the bit error rate (BER) of a Q-ary PPM receiver in the additive white Gaussian noise (AWGN) channel in the existing literature, the theoretical formulas of the BER of a noncoherent suboptimal receiver and noncoherent optimal receiver are derived, respectively. The simulation results verify the correctness of the theoretical formulas. The theoretical formulas can be applied to a Q-ary PPM system including binary PPM. In addition, the analysis shows that the larger the Q, the better the error performance of the receiver and that the error performance of the optimal receiver is about 2 dB better than that of the suboptimal receiver. The relationship between the threshold coefficient of the suboptimal receiver and the error performance is also given.

Estimation of Strain-Hardness Correlation in Cold-Forged Austenitic Stainless Steel

2014 ◽  
Vol 622-623 ◽  
pp. 179-185 ◽  
Author(s):  
Piotr Skubisz ◽  
Maciej Rumiński ◽  
Łukasz Lisiecki
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Strain Hardening ◽  
Effective Strain ◽  
Cold Deformation ◽  
Metal Flow ◽  
Fem Simulation ◽  
Large Head ◽  
The Relationship

The paper presents selected aspects of analysis cold micro-forging process of a screw made of austenitic stainless steel, concerning relation between strain and hardness. Strain hardening character of a material in consecutive forming operations was analyzed experimentally by the measurement of hardness distribution made on longitudinal axial sections of screws. The relationship between hardness and effective strain (hardness curve) was determined, which made it possible to obtain strain distributions in different regions of a material subjected to cold deformation on the basis of strain distribution numerically estimated with FEM simulation performed using QForm2D/3D commercial software. Conclusions were formulated concerning strain inhomogeneity and strain-hardening intensity with respect to the correlation between strain and hardness. It was also concluded, that nonuniformity of hardening rate in a bulk can lead to local variations in flow stress and eventually, to occurrence of the metal flow related defects, which was illustrated with a case study of cold heading of self-tapping screw of AISI 304Cu stainless steel, with large head diameter to shank diameter ratio. In order to validate the obtained results, the same method was used for analysis of hardness development in steel 19MnB4.

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