Piezoelectric-Based Vibration Reduction of Turbomachinery Bladed Disks via Resonance Frequency Detuning

AIAA Journal ◽  
2012 ◽  
Vol 50 (5) ◽  
pp. 1137-1144 ◽  
Author(s):  
Jeffrey L. Kauffman ◽  
George A. Lesieutre
Keyword(s):  
Resonance Frequency ◽  
Vibration Reduction ◽  
Frequency Detuning ◽  
Bladed Disks

Switch Triggers for Optimal Vibration Reduction via Resonance Frequency Detuning

2014 ◽  
Author(s):  
Garrett K. Lopp ◽  
Jeffrey L. Kauffman
Keyword(s):  
Resonance Frequency ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
Electromechanical Coupling Coefficient ◽  
Peak Strain ◽  
Frequency Detuning ◽  
Optimal Frequency ◽  
Response Dynamics

For systems subjected to linear frequency sweep excitation, piezoelectric-based resonance frequency detuning provides vibration reduction by altering the stiffness state of the material as it passes through resonance. This vibration reduction technique applies to turbomachinery experiencing changes in rotation speed, for example on spool-up and spool-down. The peak response dynamics are determined by the system’s sweep rate, modal damping ratio, electromechanical coupling coefficient, and, most importantly, the frequency at which the stiffness state is altered. An analytical approach is employed to solve the nondimensional single degree of freedom equation of motion and is scaled to incorporate the altered system frequency following the stiffness state switch. This paper provides an extensive study over a range of sweep rates, damping ratios, and electromechanical coupling coefficients to determine the optimal frequency switch trigger that minimizes the response envelope. This switch trigger is primarily a function of the electromechanical coupling coefficient and the phase of vibration at which the switch occurs. As the coupling coefficient increases, the switch trigger decreases and is approximately linear with the square of this coupling coefficient. Furthermore, as with other state-switching techniques, the optimal frequency switch occurs when the phase of vibration is at the point of maximum displacement, or peak strain energy.

scholarly journals Vibration Reduction of Mistuned Bladed Disks Via Piezoelectric-Based Resonance Frequency Detuning

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Garrett K. Lopp ◽  
Jeffrey L. Kauffman
Keyword(s):  
Resonance Frequency ◽  
Electromechanical Coupling ◽  
Short Circuit ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
Sweep Rate ◽  
Open Circuit ◽  
Frequency Detuning ◽  
Blade Vibration ◽  
Direct Numerical Integration

This paper extends the resonance frequency detuning (RFD) vibration reduction approach to cases of turbomachinery blade mistuning. Using a lumped parameter mistuned blade model with included piezoelectric elements, this paper presents an analytical solution of the blade vibration in response to frequency sweep excitation; direct numerical integration confirms the accuracy of this solution. A Monte Carlo statistical analysis provides insight regarding vibration reduction performance over a range of parameters of interest such as the degree of blade mistuning, linear excitation sweep rate, inherent damping ratio, and the difference between the open-circuit (OC) and short-circuit (SC) stiffness states. RFD reduces vibration across all degrees of blade mistuning as well as the entire range of sweep rates tested. Detuning also maximizes vibration reduction performance when applied to systems with low inherent damping and large electromechanical coupling.

Switch Triggers for Optimal Vibration Reduction Via Resonance Frequency Detuning

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Garrett K. Lopp ◽  
Jeffrey L. Kauffman
Keyword(s):  
Resonance Frequency ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Vibration Reduction ◽  
Excitation Frequency ◽  
Electromechanical Coupling Coefficient ◽  
Peak Strain ◽  
Frequency Detuning ◽  
Response Dynamics ◽  
Modal Damping

Resonance frequency detuning (RFD) reduces vibration of systems subjected to frequency sweep excitation by altering the structural stiffness state as the excitation frequency passes through resonance. This vibration reduction technique applies to turbomachinery experiencing changes in rotation speed, for example, on spool-up and spool-down, and can be achieved through the inclusion of piezoelectric material and manipulation of its electrical boundary conditions. Key system parameters—the excitation sweep rate, modal damping ratio, electromechanical coupling coefficient, and, most importantly, the switch trigger that initiates the stiffness state switch (represented here in terms of excitation frequency)—determine the peak response dynamics. This paper exploits an analytical solution to a nondimensional single degree-of-freedom equation of motion to provide this blade response and recasts the equation in scaled form to include the altered system dynamics following the stiffness state switch. An extensive study over a range of sweep rates, damping ratios, and electromechanical coupling coefficients reveals the optimal frequency switch trigger that minimizes the peak of the blade response envelope. This switch trigger is primarily a function of the electromechanical coupling coefficient and the phase of vibration at which the switch occurs. As the coupling coefficient increases, the frequency-based switch trigger decreases, approximately linearly with the square of the coupling coefficient. Furthermore, as with other state-switching techniques, the optimal stiffness switch occurs on peak strain energy; however, the degradation in vibration reduction performance associated with a switch occurring at a nonoptimal phase is negligible for slow sweep rates and low modal damping.

Resonance Frequency Detuning With Application Towards Blade Mistuning

2017 ◽  
Author(s):  
Garrett K. Lopp ◽  
Jeffrey L. Kauffman
Keyword(s):  
Resonance Frequency ◽  
Electromechanical Coupling ◽  
Short Circuit ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
Sweep Rate ◽  
Frequency Detuning ◽  
Lumped Parameter ◽  
The Difference ◽  
Direct Numerical Integration

This paper extends the Resonance Frequency Detuning vibration reduction approach by analyzing the performance in cases of turbomachinery blade mistuning. A lumped parameter mistuned blade model with included piezoelectric elements is utilized and an analytical solution for frequency sweep excitation is presented and validated using direct numerical integration. A Monte Carlo statistical analysis is then conducted to provide insight regarding vibration reduction performance over a range of parameters of interest such as the degree of blade mistuning, linear excitation sweep rate, damping ratio, and the difference between the open- and short-circuit stiffness states. Vibration reduction is shown to exist across all degrees of blade mistuning as well as the entire range of sweep rates tested. This vibration reduction performance is also maximized for systems with low inherent damping and large electromechanical coupling values.

scholarly journals Inverse Task of Vibration Active Reduction of Mechanical Systems

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Andrzej Dymarek ◽  
Tomasz Dzitkowski
Keyword(s):  
Free Vibration ◽  
Resonance Frequency ◽  
Dynamic Characteristics ◽  
Dynamic Properties ◽  
Vibration Reduction ◽  
Mechanical Systems ◽  
Graphic Method ◽  
Active Vibration

The paper presents the problem of discrete vibration reduction in mechanical systems depending on the desired dynamic properties. The conditions for physical feasibility of dynamic characteristics have been defined, in the form of impedance and mobility, for passive and active vibration reduction. The authors have presented a graphic method for determining the free vibration drop coefficient, based on the desired value of the reduced resonance frequency amplitude.

scholarly journals Magnetorheological Self-Powered Vibration Reduction System with Current Cut-Off: Experimental Investigation

2018 ◽  
Vol 12 (2) ◽  
pp. 96-100 ◽  
Author(s):  
Łukasz Jastrzębski ◽  
Bogdan Sapiński
Keyword(s):  
Experimental Investigation ◽  
Resonance Frequency ◽  
Laboratory Testing ◽  
Vibration Reduction ◽  
Mr Damper ◽  
Entire System ◽  
Electrolytic Capacitors ◽  
Reduction System ◽  
Self Powered ◽  
A Current

Abstract The paper summarises the results of laboratory testing of an energy harvesting vibration reduction system based on a magne-torheological (MR) damper whose control circuit incorporates a battery of bipolar electrolytic capacitors (current cut-off circuit). It is de-signed to reduce the undesired effects in vibration reduction systems of this type, associated with the increasing amplitude of the sprung mass vibration under the excitation inputs whose frequency should exceed the resonance frequency of the entire system. Results have demonstrated that incorporating a current cut-off circuit results in a significant decrease of sprung mass vibration amplitudes when the frequency of acting excitation inputs is higher than the resonance frequency.

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