EFFECT OF CORE SHEAR MODULUS ON THETRANSMISSION LOSS OF COMPOSITE HONEYCOMBPANELS

摘要

Composite honeycomb panels are increasingly used in airframe structures. Their high stiffnessto-mass ratio imparts efficient noise transmission, causing acoustic concerns when the noiseinsulation property of the panel is an important design consideration. Unlike most other designparameters, the shear modulus of the core affects the transmission loss (TL) of the honeycombpanel over a broad frequency range. Recommendations have been made to improve the TL ofhoneycomb panels by limiting the core shear modulus so that the bending coincidence can beshifted to high frequencies. However, practical honeycomb panels, such as those used in primaryairframe structures can rarely be designed in this way due to the constraints on the mechanicalproperties. In the present paper, the effect of the core shear modulus on the TL of the compositehoneycomb panels will be more thoroughly studied. This paper documents the literature survey,the analytical predictions with Higher-order Sandwich Plate Theory (HSAPT), the experimentalvalidation and the parametric studies. Finally, recommendations will be given regarding the coreshear modulus to improve the TL of the honeycomb panels with subsonic or supersonic shearwave speed.