scholarly journals Addressing geometric nonlinearities with cantilever microelectromechanical systems: Beyond the Duffing model

2010 ◽  
Vol 82 (23) ◽  
Author(s):  
E. Collin ◽  
Yu. M. Bunkov ◽  
H. Godfrin
Keyword(s):  
Microelectromechanical Systems ◽  
Geometric Nonlinearities ◽  
Duffing Model

A Modified Matlock–Duffing Model for Two-Dimensional Ice-Induced Vibrations of Offshore Structures With Geometric Nonlinearities

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Hugh McQueen ◽  
Narakorn Srinil
Keyword(s):  
Oil And Gas ◽  
Numerical Models ◽  
Wedge Angle ◽  
Offshore Structures ◽  
Two Dimensional ◽  
Geometric Nonlinearities ◽  
Oil And Gas Exploration ◽  
Nonlinear Stress ◽  
Exploration And Production ◽  
Duffing Model

Oil and gas exploration and production have been expanding in Arctic waters. However, numerical models for predicting the ice-induced vibrations (IIV) of offshore structures are still lacking in the literature. This study aims to develop a mathematical reduced-order model for predicting the two-dimensional IIV of offshore structures with geometric coupling and nonlinearities. A cylindrical structure subject to a moving uniform ice sheet is analyzed using the well-known Matlock model, which, in the present study, is extended and modified to account for a new empirical nonlinear stress–strain rate relationship determining the maximum compressive stress (MCS) of the ice. The model is further developed through the incorporation of ice temperature, brine content, air volume, grain size, ice thickness, and ice wedge angle effects on the ice compressive strength. These allow the effect of multiple ice properties on the ice–structure interaction to be investigated. A further advancement is the inclusion of an equation allowing the length of failed ice at a point of failure to vary with time. A mixture of existing equations and newly proposed empirical relationships is used. Structural geometric nonlinearities are incorporated into the numerical model through the use of Duffing oscillators, a technique previously proposed in vortex-induced vibration studies. The model is validated against results from the literature and provides new insights into IIV responses including the quasi-static, randomlike chaotic, and locked-in motions, depending on the ice velocity and system nonlinearities. This numerical Matlock–Duffing model shows a potential to be used in future IIV analysis of Arctic cylindrical structures, particularly fixed offshore structures, such as lighthouses, gravity bases, and wind turbine monopiles.

Charge Trapping and Degradation Properties of PZT Thin Films for MEMS

1996 ◽  
Vol 444 ◽  
Author(s):  
Hyeon-Seag Kim ◽  
D. L. Polla ◽  
S. A. Campbell
Keyword(s):  
Thin Films ◽  
Loss Factor ◽  
High Field ◽  
Microelectromechanical Systems ◽  
Charge Trapping ◽  
Metal Organic ◽  
Electrical Reliability ◽  
Silicon Based ◽  
Degradation Properties ◽  
Organic Decomposition

AbstractThe electrical reliability properties of PZT (54/46) thin films have been measured for the purpose of integrating this material with silicon-based microelectromechanical systems. Ferroelectric thin films of PZT were prepared by metal organic decomposition. The charge trapping and degradation properties of these thin films were studied through device characteristics such as hysteresis loop, leakage current, fatigue, dielectric constant, capacitancevoltage, and loss factor measurements. Several unique experimental results have been found. Different degradation processes were verified through fatigue (bipolar stress), low and high charge injection (unipolar stress), and high field stressing (unipolar stress).

Development perspective microelectromechanical systems (MEMS)by methods of semi-real simulation

2006 ◽  
Vol 4 ◽  
pp. 288-305
Author(s):  
A.B. Migranov
Keyword(s):  
Virtual Environment ◽  
Microelectromechanical Systems ◽  
Testing And Debugging ◽  
Development Perspective

The article deals with the issues related to the construction of microelectromechanical systems (MEMS), and the problems arising from their manufacture. Particular attention is paid to micromechanical parts of robot, which were developed by methods of semi-simulation using the virtual environment for designing, testing and debugging MEMS.

Embedded Microelectromechanical Systems (MEMS) for Measuring Strain in Composites

2000 ◽  
Vol 19 (4) ◽  
pp. 268-277 ◽  
Author(s):  
CHARLES HAUTAMAKI ◽  
SHAYNE ZURN ◽  
SUSAN C. MANTELL ◽  
DENNIS L. POLLA
Keyword(s):  
Microelectromechanical Systems

New fourth-order convergent algorithm for analysis of trusses with material and geometric nonlinearities

2021 ◽  
pp. 030932472110005
Author(s):  
Luiz Antonio Farani de Souza ◽  
Douglas Fernandes dos Santos ◽  
Rodrigo Yukio Mizote Kawamoto ◽  
Leandro Vanalli
Keyword(s):  
Fourth Order ◽  
Nonlinear Behavior ◽  
Path Following ◽  
System Of Nonlinear Equations ◽  
The Finite Element Method ◽  
Step Method ◽  
Geometric Nonlinearities ◽  
Standard Procedures ◽  
Elastoplastic Constitutive Model ◽  
Convergent Algorithm

This paper presents a new algorithm to solve the system of nonlinear equations that describes the static equilibrium of trusses with material and geometric nonlinearities, adapting a three-step method with fourth-order convergence found in the literature. The co-rotational formulation of the Finite Element Method is used in the discretization of structures. The nonlinear behavior of the material is characterized by an elastoplastic constitutive model. The equilibrium paths with limit points of load and displacement are obtained using the linearized Arc-Length path-following technique. The numerical results obtained with the free program Scilab show that the new algorithm converges faster than standard procedures and modified Newton-Raphson, since the approximate solution of the problem is obtained with a smaller number of accumulated iterations and less CPU time. The equilibrium paths show that the structures exhibit a completely different behavior when the material nonlinearity is considered in the analysis with large displacements.

scholarly journals Coulomb-actuated microbeams revisited: experimental and numerical modal decomposition of the saddle-node bifurcation

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Anton Melnikov ◽  
Hermann A. G. Schenk ◽  
Jorge M. Monsalve ◽  
Franziska Wall ◽  
Michael Stolz ◽  
...  
Keyword(s):  
Finite Element ◽  
Microelectromechanical Systems ◽  
Dynamic Range ◽  
Dynamic Performance ◽  
Major Step ◽  
Element Analysis ◽  
Electrostatic Actuators ◽  
Voltage Range ◽  
Drive Voltage ◽  
Depth Analysis

AbstractElectrostatic micromechanical actuators have numerous applications in science and technology. In many applications, they are operated in a narrow frequency range close to resonance and at a drive voltage of low variation. Recently, new applications, such as microelectromechanical systems (MEMS) microspeakers (µSpeakers), have emerged that require operation over a wide frequency and dynamic range. Simulating the dynamic performance under such circumstances is still highly cumbersome. State-of-the-art finite element analysis struggles with pull-in instability and does not deliver the necessary information about unstable equilibrium states accordingly. Convincing lumped-parameter models amenable to direct physical interpretation are missing. This inhibits the indispensable in-depth analysis of the dynamic stability of such systems. In this paper, we take a major step towards mending the situation. By combining the finite element method (FEM) with an arc-length solver, we obtain the full bifurcation diagram for electrostatic actuators based on prismatic Euler-Bernoulli beams. A subsequent modal analysis then shows that within very narrow error margins, it is exclusively the lowest Euler-Bernoulli eigenmode that dominates the beam physics over the entire relevant drive voltage range. An experiment directly recording the deflection profile of a MEMS microbeam is performed and confirms the numerical findings with astonishing precision. This enables modeling the system using a single spatial degree of freedom.

scholarly journals A Low-g MEMS Accelerometer with High Sensitivity, Low Nonlinearity and Large Dynamic Range Based on Mode-Localization of 3-DoF Weakly Coupled Resonators

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 310
Author(s):  
Muhammad Mubasher Saleem ◽  
Shayaan Saghir ◽  
Syed Ali Raza Bukhari ◽  
Amir Hamza ◽  
Rana Iqtidar Shakoor ◽  
...  
Keyword(s):  
Microelectromechanical Systems ◽  
Dynamic Range ◽  
Proof Mass ◽  
Amplitude Ratio ◽  
Silicon On Insulator ◽  
Coupled Resonators ◽  
Mode Localization ◽  
Mems Accelerometer ◽  
Weakly Coupled ◽  
Input Acceleration

This paper presents a new design of microelectromechanical systems (MEMS) based low-g accelerometer utilizing mode-localization effect in the three degree-of-freedom (3-DoF) weakly coupled MEMS resonators. Two sets of the 3-DoF mechanically coupled resonators are used on either side of the single proof mass and difference in the amplitude ratio of two resonator sets is considered as an output metric for the input acceleration measurement. The proof mass is electrostatically coupled to the perturbation resonators and for the sensitivity and input dynamic range tuning of MEMS accelerometer, electrostatic electrodes are used with each resonator in two sets of 3-DoF coupled resonators. The MEMS accelerometer is designed considering the foundry process constraints of silicon-on-insulator multi-user MEMS processes (SOIMUMPs). The performance of the MEMS accelerometer is analyzed through finite-element-method (FEM) based simulations. The sensitivity of the MEMS accelerometer in terms of amplitude ratio difference is obtained as 10.61/g for an input acceleration range of ±2 g with thermomechanical noise based resolution of 0.22 and nonlinearity less than 0.5%.

Stability of Ring-Type MEMS Gyroscopes Subjected to Stochastic Angular Speed Fluctuation

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Samuel F. Asokanthan ◽  
Soroush Arghavan ◽  
Mohamed Bognash
Keyword(s):  
Angular Velocity ◽  
Degrees Of Freedom ◽  
Microelectromechanical Systems ◽  
Damping Ratio ◽  
Operating Conditions ◽  
System Stability ◽  
System Response ◽  
Ring Type ◽  
Mems Gyroscopes ◽  
The Stability

Effect of stochastic fluctuations in angular velocity on the stability of two degrees-of-freedom ring-type microelectromechanical systems (MEMS) gyroscopes is investigated. The governing stochastic differential equations (SDEs) are discretized using the higher-order Milstein scheme in order to numerically predict the system response assuming the fluctuations to be white noise. Simulations via Euler scheme as well as a measure of largest Lyapunov exponents (LLEs) are employed for validation purposes due to lack of similar analytical or experimental data. The response of the gyroscope under different noise fluctuation magnitudes has been computed to ascertain the stability behavior of the system. External noise that affect the gyroscope dynamic behavior typically results from environment factors and the nature of the system operation can be exerted on the system at any frequency range depending on the source. Hence, a parametric study is performed to assess the noise intensity stability threshold for a number of damping ratio values. The stability investigation predicts the form of threshold fluctuation intensity dependence on damping ratio. Under typical gyroscope operating conditions, nominal input angular velocity magnitude and mass mismatch appear to have minimal influence on system stability.

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