Prediction of the sound transmission loss of sandwich structures based on a simple test procedure
2010 (English)In: 17th International Congress on Sound and Vibration 2010, ICSV 2010, 2010, 109-116 p.Conference paper (Refereed)
Sandwich and honeycomb materials are increasingly used by the vehicle and building industries. Consequently, the prediction of the acoustic properties and in particular the sound transmission loss of sandwich structures is of importance. The dynamic and acoustic properties of a composite sandwich beam or plate depend on the geometry of the structure as well as on the material properties of core and laminates. The method of bonding laminates to core can also influence the dynamic properties of sandwich constructions. For example a bonding substance can increase the spacing between the laminates. In general, the construction of a sandwich plate is often symmetric with respect to the centerline. The thickness of the lightweight core is typically of the order 5 to 75 mm whereas the thickness of the laminates could vary between 0.5 and 8 mm. The E-modulus for a laminate is typically high and much higher than the corresponding modulus for the core. Some of the basic parameters of a sandwich structure can be determined by means of some simple tests on a beam element of the structure. For the test the beam is suspended by strings to simulate free-free boundary conditions. By exciting the beam by an impedance hammer the first ten or more natural frequencies of the beam can be determined. Based on these measurements of natural frequencies and the weight and dimensions of the beam, the static bending stiffness, shear modulus of the core and bending stiffness of the laminates are determined. The data is used to calculate the sound transmission loss of a plate structure being constructed in the same way as the beam. The model can also be used for parameter studies of the influence on the sound transmission loss due to changes of dimensions of laminates, core etc.
Place, publisher, year, edition, pages
2010. 109-116 p.
Basic parameters, Beam elements, Bending stiffness, Bonding laminates, Building industry, Centerlines, Composite sandwich beam, Dynamic property, E-modulus, Honeycomb materials, Material property, Parameter studies, Plate structure, Sandwich construction, Sandwich plates, Sound transmission loss, Static bending, Test procedures, Acoustic properties, Construction industry, Geometry, Natural frequencies, Sandwich structures, Stiffness, Testing, Laminates
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-148856ScopusID: 2-s2.0-84871400433ISBN: 978-161782255-1OAI: oai:DiVA.org:kth-148856DiVA: diva2:737851
17th International Congress on Sound and Vibration 2010, ICSV 2010, 18 July 2010 through 22 July 2010, Cairo, Egypt
QC 201408132014-08-142014-08-142014-08-14Bibliographically approved