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

Abstract

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.

Gentle dry etching of P(VDF-TrFE) multilayer micro actuator structures by use of an inductive coupled plasma

“…In the manufacturing process of a P(VDF-TrFE) based pyroelectric sensor, Setiadi and Regtien [12] used 30 • C methyl-ethylketon (MEK) to etch a silicon dioxide patterned matrix array of sensors. The same solution was reported to be used in combination with a mask by Isler and Washington [13]. Moanohara et al used a direct pattern transfer method to photo etch P(VDF) by using x-rays [14].…”

Spatial Filtering for the Control of Smart Structures

“…Most notably is the work of Lee et al [42], Isler and Washington [43] and Collins et al [44]. Most notably is the work of Lee et al [42], Isler and Washington [43] and Collins et al [44].…”

Design of distributed piezoelectric modal sensor for a rotating beam with elastic boundary restraints

“…Effectiveness of the designed sensor was also validated through experimental measurement, and it was found that such piezoelectric polymer modal sensor can avoid the observer spillover and reduce the complexity of signal processing. Subsequently, some investigation on the PVDF modal sensor has been conducted by Isler and Washington (2003) and Nishigaki (2009). Most of the existing studies mentioned above are focused on the beam structure with classical boundary conditions, such as simply supported, clamped, or free.…”

“…Modal sensing/filtering technology is of great importance for avoiding the observation/control spillover in active control of structural vibration and/or its sound radiation, in which all the unwanted modes will be filtered out over the frequency bandwidth of interest by designing the sensor or filter properly, with the aim to guarantee the control stability. With the rapid development of piezoelectric material science and engineering, polyvinylidene fluoride (PVDF) has been proposed and investigated for applications in structural vibration control (Isler and Washington, 2003; Nishigaki, 2009; Tanaka et al, 1998) and active structural acoustic control (Clark et al, 1993; Hsu et al, 1998; Mao, et al, 2003; Preumont et al, 1999; Tanaka and Sanada, 2009; Tanaka et al, 1996; Wang, 1998). Thanks to its excellent lightweight, tailoring easily, and spatial integral properties, various investigations on the PVDF sensor are also conducted for the experimental modal testing (Wang and Wang, 1997), force identification (Chesne and Pezerat, 2015), and structural health monitoring (Friswell and Adhikari, 2010).…”