Lumped‐element analysis of a fluid‐loaded pipe‐hull coupling

2000 ◽  
Vol 107 (5) ◽  
pp. 2800-2800
Author(s):  
Jayme J. Caspall ◽  
Minami Yoda ◽  
Peter H. Rogers
Keyword(s):  
Element Analysis ◽  
Lumped Element

Nonlinear Identification of a Capacitive Dual-Backplate MEMS Microphone

2005 ◽  
Author(s):  
Jian Liu ◽  
David T. Martin ◽  
Karthik Kadirvel ◽  
Toshikazu Nishida ◽  
Mark Sheplak ◽  
...  
Keyword(s):  
Nonlinear System Identification ◽  
Nonlinear Least Squares ◽  
Order System ◽  
Multiple Time Scales ◽  
Model Parameters ◽  
Multiple Time ◽  
Element Analysis ◽  
System Parameters ◽  
Lumped Element ◽  
Mems Microphone

This paper presents the nonlinear system identification of model parameters for a capacitive dual-backplate MEMS microphone. System parameters of the microphone are developed by lumped element modeling (LEM) and a governing nonlinear equation is thereafter obtained with coupled mechanical and electrostatic nonlinearities. The approximate solution for a general damped second order system with both quadratic and cubic nonlinearities and a non-zero external step loading is explored by the multiple time scales method. Then nonlinear finite element analysis (FEA) is performed to verify the accuracy of the lumped stiffnesses of the diaphragm. The microphone is characterized and nonlinear least-squares technique is implemented to identify system parameters from experimental data. Finally uncertainty analysis is performed. The experimentally identified natural frequency and nonlinear stiffness parameter fall into their theoretical ranges for a 95% confidence level respectively.

scholarly journals Sensitivity and Performances Analysis of a Dynamic Pressure Narrow-Band Electrodynamic Micro-Sensor

2020 ◽  
Vol 25 (1) ◽  
pp. 17-26
Author(s):  
Mohamed Hadj Said ◽  
Fares Tounsi ◽  
Libor Rufer ◽  
Brahim Mezghani ◽  
Laurent A. Francis
Keyword(s):  
Resonant Frequency ◽  
Dynamic Pressure ◽  
Dynamic Performance ◽  
Element Model ◽  
Element Analysis ◽  
Lumped Element ◽  
Sensitivity Curves ◽  
Micro Sensor ◽  
Lumped Element Model ◽  
Different Diameters

This paper presents analytic and numerical modelling of a MEMS electrodynamic micro-sensor of dynamic pressure. Two coaxial planar inductors of different diameters are used in the proposed micro-sensor design. Using finite element analysis, the diaphragm resonant frequency and dynamic displacements are evaluated for different diaphragm thicknesses. Then, the total sensitivity is deduced by coupling different physical domains which contribute in the micro-sensor operation. A lumped element model is built in order to study the micro-sensor sensitivity and define the dynamic performance for different resonant frequencies. This model shows that the best sensitivity, within the mV/Pa range, is obtained around the resonant frequency when operation in the audible frequency range, and decreases to the uV/Pa range for ultrasonic frequencies. The obtained sensitivity curves prove that the undamped inductive micro-sensor can offer high pressure sensitivity within a narrow frequency bandwidth.

Characterization and Modeling of Capacitive Micromachined Ultrasonic Transducers for Diagnostic Ultrasound

2008 ◽  
Author(s):  
Christopher B. Doody ◽  
Robert D. White ◽  
Jaspreet S. Wadhwa ◽  
David F. Lemmerhirt
Keyword(s):  
Laser Doppler Velocimetry ◽  
Computational Models ◽  
Ultrasonic Transducers ◽  
Step Response ◽  
Element Analysis ◽  
Frequency Sweep ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Lumped Element ◽  
Combined Use ◽  
Coupling Frequency

This paper describes the characterization and modeling of capacitive micromachined ultrasonic transducers (cMUTs). Computational models of the transducers were produced through the combined use of finite element analysis (FEA) and lumped element modeling. Frequency response plots were generated for both transducers in air and water environments. Through the use of laser Doppler velocimetry, transient step response and frequency sweep tests were performed on single array elements. These measurements are compared to the predicted results represented in the models. The computational results for both coupled and uncoupled arrays are compared, and show a significant increase in the array bandwidth due to coupling. Frequency sweep tests were also performed on column array elements, and results were compared between driven and adjacent, non-driven columns.

Re-Examination of the Cable Capacitance in the Key Distribution System Using Resistors and Noise Sources

2017 ◽  
Vol 16 (03) ◽  
pp. 1750025 ◽  
Author(s):  
Pao-Lo Liu
Keyword(s):  
Transmission Line ◽  
Transit Time ◽  
Distribution System ◽  
Key Distribution ◽  
Noise Sources ◽  
Element Analysis ◽  
Lumped Element ◽  
Band Limited ◽  
Line Analysis

The effect of cable capacitance in the classical key distribution system based on resistors and band-limited noise sources is re-examined. Both the lumped element analysis and the transmission line analysis are performed. As long as the cable capacitance and inductance are fully taken into account, the lumped element analysis and the transmission line analysis generate identical results. When the cable is bootstrapped with a driven shield, the capacitance can be neglected, but the transit time should not be overlooked.

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