Dynamic Analysis of MEMS Resonators Under Primary-Resonance Excitation

2005 ◽  
Author(s):  
Ali H. Nayfeh ◽  
Mohammad I. Younis ◽  
Eihab M. Abdel-Rahman
Keyword(s):  
Dynamic Analysis ◽  
Microelectromechanical Systems ◽  
Initial Conditions ◽  
Electrostatic Force ◽  
Primary Resonance ◽  
Period Doubling ◽  
Resonance Excitation ◽  
Global Dynamics ◽  
Mems Resonators ◽  
Primary Resonance Excitation

We present a dynamic analysis and simulation of electrically actuated microelectromechanical systems (MEMS) resonators under primary-resonance excitation. We use a shooting technique, perturbation techniques, and long-time integration of the equation of motion to investigate the global dynamics of the resonators. We study the dynamic pull-in instability and show various scenarios and mechanisms for its occurrence. Our results show that dynamic pull-in can occur through a saddle-node bifurcation, a period-doubling bifurcation, or homoclinic tangling, depending on factors such as the initial conditions of the device and the level of the electrostatic force.

Subharmonic Excitation for Electrically Actuated Microbeams

2005 ◽  
Author(s):  
Ali H. Nayfeh ◽  
Mohammad I. Younis
Keyword(s):  
Frequency Response ◽  
Rf Mems ◽  
Electrostatic Force ◽  
Primary Resonance ◽  
Resonance Excitation ◽  
Global Dynamics ◽  
Response Curves ◽  
Electrically Actuated ◽  
Subharmonic Excitation ◽  
Order Of Magnitude

We present analysis of the global dynamics of electrically actuated microbeams under subharmonic excitation. The microbeams are excited by a DC electrostatic force and an AC harmonic force with a frequency tuned near twice their fundamental natural frequencies. We show that the dynamic pull-in instability can occur in this case for an electric load much lower than that predicted with static analysis and the same order-of-magnitude as that predicted in the case of primary-resonance excitation. We show that, once the subharmonic resonance is activated, all frequency-response curves reach pull-in, regardless of the magnitude of the AC forcing. Our results show a limited influence of the quality factor on the frequency response. This result and the fact that the frequency-response curves have very steep passband-to-stopband transitions make the combination of a DC voltage and a subhormonic of order one-half a promising candidate for designing improved high-sensitive RF MEMS filters.

scholarly journals Global Period-Doubling Bifurcation of Quadratic Fractional Second Order Difference Equation

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Senada Kalabušić ◽  
M. R. S. Kulenović ◽  
M. Mehuljić
Keyword(s):  
Asymptotic Stability ◽  
Difference Equation ◽  
Global Asymptotic Stability ◽  
Local Stability ◽  
Initial Conditions ◽  
Period Doubling ◽  
Period Doubling Bifurcation ◽  
Global Dynamics ◽  
Second Order Difference Equation ◽  
The Difference

We investigate the local stability and the global asymptotic stability of the difference equationxn+1=αxn2+βxnxn-1+γxn-1/Axn2+Bxnxn-1+Cxn-1,n=0,1,…with nonnegative parameters and initial conditions such thatAxn2+Bxnxn-1+Cxn-1>0, for alln≥0. We obtain the local stability of the equilibrium for all values of parameters and give some global asymptotic stability results for some values of the parameters. We also obtain global dynamics in the special case, whereβ=B=0, in which case we show that such equation exhibits a global period doubling bifurcation.

scholarly journals Global Dynamics of Delayed Sigmoid Beverton–Holt Equation

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Toufik Khyat ◽  
M. R. S. Kulenović
Keyword(s):  
Difference Equation ◽  
Initial Conditions ◽  
Period Doubling ◽  
Basins Of Attraction ◽  
Global Dynamics ◽  
Order Difference ◽  
Second Order Difference Equation ◽  
Order Difference Equation ◽  
The Difference

In this paper, certain dynamic scenarios for general competitive maps in the plane are presented and applied to some cases of second-order difference equation xn+1=fxn,xn−1, n=0,1,…, where f is decreasing in the variable xn and increasing in the variable xn−1. As a case study, we use the difference equation xn+1=xn−12/cxn−12+dxn+f, n=0,1,…, where the initial conditions x−1,x0≥0 and the parameters satisfy c,d,f>0. In this special case, we characterize completely the global dynamics of this equation by finding the basins of attraction of its equilibria and periodic solutions. We describe the global dynamics as a sequence of global transcritical or period-doubling bifurcations.

Investigation of a Delayed Feedback Controller of MEMS Resonators

2013 ◽  
Author(s):  
Karim M. Masri ◽  
Mohammad I. Younis ◽  
Shuai Shao
Keyword(s):  
Microelectromechanical Systems ◽  
Electrostatic Force ◽  
Time Integration ◽  
Basins Of Attraction ◽  
Delayed Feedback ◽  
Feedback Controller ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Delayed Feedback Controller ◽  
Long Time

Controlling mechanical systems is an important branch of mechanical engineering. Several techniques have been used to control Microelectromechanical systems (MEMS) resonators. In this paper, we study the effect of a delayed feedback controller on stabilizing MEMS resonators. A delayed feedback velocity controller is implemented through modifying the parallel plate electrostatic force used to excite the resonator into motion. A nonlinear single degree of freedom model is used to simulate the resonator response. Long time integration is used first. Then, a finite deference technique to capture periodic motion combined with the Floquet theory is used to capture the stable and unstable periodic responses. We show that applying a suitable positive gain can stabilize the MEMS resonator near or inside the instability dynamic pull in band. We also study the stability of the resonator by tracking its basins of attraction while sweeping the controller gain and the frequency of excitations. For positive delayed gains, we notice significant enhancement in the safe area of the basins of attraction.

Nonlinear Dynamics of Closed Spherical Shells

2005 ◽  
Author(s):  
Ali H. Nayfeh ◽  
Haider N. Arafat
Keyword(s):  
Multiple Scales ◽  
Equations Of Motion ◽  
Primary Resonance ◽  
Resonance Excitation ◽  
Internal Resonances ◽  
Spherical Shells ◽  
Linear Eigenvalue Problem ◽  
Nonlinear Responses ◽  
Nonlinear Equations Of Motion ◽  
Primary Resonance Excitation

We investigate the axisymmetric dynamics of forced closed spherical shells. The nonlinear equations of motion are formulated using a variational approach and surface analysis. First, we revisit the linear eigenvalue problem. Then, using the method of multiple scales, we assess the possibility of the activation of two-to-one internal resonances between the different types of modes. Lastly, we examine the shell’s nonlinear responses to an axisymmetric primary-resonance excitation and analyze their bifurcations.

U -sequence in electrostatic microelectromechanical systems (MEMS)

2006 ◽  
Vol 462 (2075) ◽  
pp. 3435-3464 ◽  
Author(s):  
Sudipto K De ◽  
N.R Aluru
Keyword(s):  
Microelectromechanical Systems ◽  
Dynamic Properties ◽  
Electrostatic Force ◽  
Period Doubling ◽  
Chaotic State ◽  
Electrostatic Mems ◽  
Nonlinear Dynamic Properties ◽  
Mass Spring ◽  
Intermittent Chaos ◽  
Period Doubling Bifurcations

In this paper, the presence of U (Universal)-sequence (a sequence of periodic windows that appear beyond the period doubling (PD) route to chaos) in electrostatic microelectromechanical systems (MEMS) is reported. The MEM system is first brought to a nonlinear steady state by the application of a large dc bias close to the dynamic pull-in voltage of the device. An ac voltage (the bifurcation parameter) is next applied to the system and increased gradually. A sequence of PD bifurcations leading to chaos is observed for resonant and superharmonic excitations (frequency of the ac voltage). On further increase in the ac voltage (beyond where chaos sets in), U -sequence is observed in the system. Under superharmonic excitation, the sequence is found to be a modified form of the U -sequence referred to as the ‘ UM -sequence’ in this paper. The appearance of a periodic window with K oscillations per period or K -cycles in the normal U -sequence is replaced by a corresponding periodic window with KM -cycles in the UM -sequence. M stands for the M th superharmonic frequency of excitation. The formation of the periodic windows from a chaotic state in the UM -sequence takes place through intermittent chaos as the ac voltage is gradually increased. On the other hand, the periodic states/cycles formed through intermittent chaos transform back into a chaotic state through the period doubling route. A sequence of period doubling bifurcations of the UM -sequence cycles result in the formation of -cycles in electrostatic MEMS. n corresponds to the n th period doubling bifurcation in the sequence. A simplified mass–spring–damper (MSD) model for MEMS is used to understand the physical mechanism that gives rise to these nonlinear dynamic properties in MEMS. The nonlinear nature of the electrostatic force acting on the MEM device is found to be responsible for the reported observations.

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