Uniform Damping and Stiffness Control of Structures With Distributed Actuators

Washington, Gregory; Silverberg, Larry

doi:10.1115/1.2801294

“…Utilizing NCT leads to a controlled system that has frequency and modal invariance and uniform damping [2]. Silverberg and Washington [3] added bias or steady state calibration to this work, and Rosetti and Sun [4] extended the work to rings. Since UDNC was developed primarily in the modal domain, specially designed, collocated sensors and actuators are needed, and the implementation of the theory until now has remained elusive.…”

Section: Introductionmentioning

confidence: 99%

Spatial aperture shading of polyvinylidene fluoride applied to distributed systems for uniform damping control

Isler¹,

Washington²

2003

Smart Mater. Struct.

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This paper introduces a model for a vibration control system in which spatially etched polyvinylidene fluoride (PVDF) was utilized to implement uniform damping control on a distributed system. Uniform damping node control (UDNC) theory states that near optimal vibration control can be achieved when the following criteria are met: all modes are damped at the same exponential decay rate, the open-loop and closed-loop natural frequencies of the structure are identical and the closed-loop modal shapes are identical to the open-loop modal shapes. To help accomplish this, in a system with N modes participating in a response, sensor/actuator pairs are placed at the nodes of the N + 1 modes. Spatially shaded PVDF actuators are distributed actuators that produce pseudo-discrete forces due to the special weighting applied to the etched electrodes. The system was demonstrated using a spring steel cantilevered beam and spatially etched PVDF actuators that were placed according to nodal control theory. When given the set of gains that are attributed to UDNC, the modes de-couple, reducing spillover. This experiment marks the first time that uniform damping control has been realized experimentally.

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“…Utilizing NCT leads to a controlled system that has frequency and modal invariance and uniform damping [2]. Silverberg and Washington [3] added bias or steady state calibration to this work, and Rosetti and Sun [4] extended the work to rings. Since UDNC was developed primarily in the modal domain, specially designed, collocated sensors and actuators are needed, and the implementation of the theory until now has remained elusive.…”

Section: Introductionmentioning

confidence: 99%

Scanning Tunneling Microscopy and Near Edge X-ray Absorption Fine Structure Studies of Adsorption of Trans-2-butene on Pd(110)

Katano

¹

,

Kim

²

,

Furukawa

³

et al. 2002

Jpn. J. Appl. Phys.

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This paper introduces a model for a vibration control system in which spatially etched polyvinylidene fluoride (PVDF) was utilized to implement uniform damping control on a distributed system. Uniform damping node control (UDNC) theory states that near optimal vibration control can be achieved when the following criteria are met: all modes are damped at the same exponential decay rate, the open-loop and closed-loop natural frequencies of the structure are identical and the closed-loop modal shapes are identical to the open-loop modal shapes. To help accomplish this, in a system with N modes participating in a response, sensor/actuator pairs are placed at the nodes of the N + 1 modes. Spatially shaded PVDF actuators are distributed actuators that produce pseudo-discrete forces due to the special weighting applied to the etched electrodes. The system was demonstrated using a spring steel cantilevered beam and spatially etched PVDF actuators that were placed according to nodal control theory. When given the set of gains that are attributed to UDNC, the modes de-couple, reducing spillover. This experiment marks the first time that uniform damping control has been realized experimentally.

show abstract