Active control of cylindrical shells using the weighted sum of spatial gradients control metric

2015 ◽  
Vol 137 (4) ◽  
pp. 2258-2258
Author(s):  
Pegah Aslani ◽  
Scott D. Sommerfeldt ◽  
Jonathan D. Blotter
Keyword(s):  
Active Control ◽  
Cylindrical Shells ◽  
Weighted Sum ◽  
Spatial Gradients ◽  
Control Metric

scholarly journals Active Structural Acoustic Control of Clamped Flat Plates Using a Weighted Sum of Spatial Gradients

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
William R. Johnson ◽  
Daniel R. Hendricks ◽  
Scott D. Sommerfeldt ◽  
Jonathan D. Blotter
Keyword(s):  
Rectangular Plate ◽  
Acoustic Radiation ◽  
Wave Number ◽  
Effective Control ◽  
Weighted Sum ◽  
Rectangular Plates ◽  
Flat Plates ◽  
Spatial Gradients ◽  
Acoustic Control ◽  
Structural Acoustic Control

The weighted sum of spatial gradients (WSSG) control minimization parameter is developed for use in active structural acoustic control (ASAC) on a clamped flat rectangular plate. The WSSG minimization parameter is measured using four accelerometers grouped closely together on the test structure. In previous work, WSSG was developed on a simply supported flat rectangular plate and showed promise as a control metric. The displacement on the clamped plate has been modeled using an approximate analytical solution assuming shape functions corresponding to clamped-clamped beams. From the analytical formulation, weights, which were found to be the reciprocal of the wave number squared, have been derived to produce a uniform WSSG field across the plate. In active control simulations, this quantity has been shown to provide better global control of acoustic radiation than volume velocity. Analysis is presented which shows that comparable control, regardless of the sensor location, can be achieved using WSSG. Experimental results are presented which demonstrate that WSSG works effectively in practice, with results similar to the simulations. The results show that minimization of WSSG can be used as an effective control objective on clamped rectangular plates to achieve attenuation of acoustic radiation.

scholarly journals Active structural acoustic control of transmitted sound through a double panel partition by weighted sum of spatial gradients

2017 ◽  
Vol 36 (1) ◽  
pp. 27-42 ◽  
Author(s):  
Kiran Chandra Sahu ◽  
Jukka Tuhkuri
Keyword(s):  
Lead Zirconate Titanate ◽  
Power Transmission ◽  
Acoustic Radiation ◽  
Lead Zirconate ◽  
Sound Attenuation ◽  
Sound Power ◽  
Weighted Sum ◽  
Spatial Gradients ◽  
Volume Velocity ◽  
Zirconate Titanate

Active control of harmonic sound transmission through an acoustically baffled, rectangular, simply supported double panel partition has been analytically studied. Velocity potential method is used for the vibro-acoustic modeling unlike the commonly used cavity mode method. It is very well-known that at high frequencies uncontrolled double panel partition mostly radiates sound due to the dipole-type motion of the radiating panel, which the volume velocity method can't be able to detect, therefore, weighted sum of spatial gradients is used to control these modes and achieves sound attenuation in a broad frequency band. A piezoceramic actuator (lead zirconate titanate) is attached on one side of the panel surface, and the optimal magnitude and phase of the voltage supplied to the lead zirconate titanate for minimizing the weighted sum of spatial gradients and volume velocity at the error sensor locations are calculated using a simple-gradient based algorithm. Numerical results of sound power transmission ratio and averaged quadratic velocity of panels indicate that lead zirconate titanate should be placed on the incident panel and minimization of the control quantities should be done on the radiating panel to achieve better sound attenuation. The acoustic radiation mode analysis shows that the weighted sum of spatial gradients is able to control multiple acoustic radiation modes and, thereby, accomplishes better reduction of sound power transmission compared to volume velocity.

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