Experimental Validation of the EBF3PanelOpt Vibroacoustic Analysis of Stiffened Panels

Vibroacoustic experiments are performed at the Structural Acoustics Loads and Transmission facility of NASA Langley Research Center to measure the sound radiation from and transmission loss of two panels with straight and curvilinear stiffeners, respectively. The focus of the work addressed in this paper is to validate the vibroacoustic analysis methods implemented in a multi-objective design optimization framework, EBF3PanelOpt. The stiffened test panels with six stiffeners have been designed using EBF3PanelOpt for turbulent boundary-layer excitation. To build the confidence in finite-element models, free-vibration tests of the manufactured stiffened panels are also performed. The excited experimental mode shape and eigenfrequencies match quite well with the finite element analysis results for the free-vibration test. A medium-density fiberboard and aluminum frame is used to clamp the stiffened panels in the Structural Acoustics Loads and Transmission loss window. Because of strong coupling of the stiffe...

[1]  Bilong Liu.  Acoustical Characteristics of Aircraft Panels , 2006 .

[2]  Sameer B. Mulani,et al.  Vibro-Acoustic Optimization of Turbulent Boundary Layer Excited Panel with Curvilinear Stiffeners , 2012 .

[3]  Ralph D. Buehrle,et al.  Vibroacoustic Model Validation for a Curved Honeycomb Composite Panel , 2001 .

[4]  Sameer B. Mulani,et al.  Multi-objective vibro-acoustic optimization of stiffened panels , 2011, Structural and Multidisciplinary Optimization.

[5]  Tiziano Polito.  The vibroacoustic behaviour of aerospace structures. Experimental measurements and simulations accounting for uncertainties , 2008 .

[6]  Tongan Wang,et al.  Sound transmission loss of honeycomb sandwich panels , 2006 .

[7]  J. Chung,et al.  Cross‐spectral method of measuring acoustic intensity without error caused by instrument phase mismatch , 1978 .

[8]  M. Guerich,et al.  An experimental validation of vibro-acoustic prediction by the use of simplified methods , 2005 .

[9]  Rakesh K. Kapania,et al.  Design Optimization for Minimum Sound Radiation from Point-Excited Curvilinearly Stiffened Panel , 2009 .

[10]  Bert Pluymers,et al.  VIBRO-ACOUSTIC STUDY OF LIGHTWEIGHT COMPONENTS BASED ON A NEW EXPERIMENTAL SETUP , 2011 .

[11]  C. A. Powell,et al.  Noise transmission characteristics of advanced composite structural materials , 1984 .

[12]  Bert Pluymers,et al.  Study of the vibro-acoustic behaviour of composite sandwich structures by means of a novel test setup , 2012 .

[13]  Ignazio Dimino,et al.  Vibro-acoustic design of an aircraft-type active window. Part 1: Dynamic modelling and experimental validation , 2012 .

[14]  F. Fahy.  Sound and structural vibration , 1985 .

[15]  F. Fahy.  Measurement of acoustic intensity using the cross‐spectral density of two microphone signals , 1977 .