VIRTUAL ASSEMBLIES AND THEIR USE IN THE PREDIC TION OF VIBRO-ACOUSTIC RESPONSES

VIRTUAL ASSEMBLIES AND THEIR USE IN THE PREDIC
TION OF VIBRO-ACOUSTIC RESPONSES.
JWFt Meggitt, AS Elliott and AT Moorhouse Acoustic Research Centre. University ofSa/Iord, M5 4M
email: j.wr.meggitredu.salford.ac.uk (j[dot]wr[dot]meggitr[at]edu[dot]salford[dot]ac[dot]uk)
1 INTRODUCTION
A drive towards leaner engineering has seen the use of physical prototypes become a limiting factor in
the development of new products. Consequently, alternative prototyping methods are of interest. With
their ability toreduced cost, time to market and optimize products to higher levels of performance and
reliability, virtual methods are generally considered the way forward. Methods for virtual prototyping
with respect to visual design and engineering (i.e CAD and CAE) are particularly well developed.
Unfortunately, the same cannot be said in the realm of acoustics. Although numerical methods such
as FEA and BEM are able to predict, with some accuracy, the passive properties of an assembly,
they lack the ability to confidently model the complex behaviour of vibro-acoustic source mechanisms.
Consequently, the adoption of any virtual acoustic prototyping (VAP) methodology will require some
element of experimental work. While attempts have been made at establishing an experimentally
based VAP frameworkl☁l, lack of measurement protocols and clear guidelines has seen its adoption
within industry hindered. It is therefore the aim of this paper to introduce a set of methodologies
that together provide the tools required to construct virtual assemblies for use in the prediction of
vibro-acoustic quantities. The aims of this paper may be more specifically stated as:
1 Introduce an independent characterisation method for sources of structure-borne sound.
2 Recap the classical impedance summation approach for dynamic substructuring.
3 Introduce a novel method for determining the independent transfer properties of resilient coupling
elements.
4 Provide an experimental case study utilising the above methodologies