The wavenumber-based formulation of the surface variational principle
(SVP) describes the surface pressure and displacement as a comparative
ly small set of interacting waves. It enables one to pose questions of
parametric sensitivity from a global perspective. The present paper i
s the first application of such an approach to the question of the lev
el of detail to which a model must be constructed. It considers a two-
dimensional problem of an elastic plate in an infinite baffle, with pi
nned boundary conditions. A study by Felt and Johnson (1991) demonstra
ted that the signal scattered by the plate is significantly altered by
the presence of an attached mass, and that the distribution of mass a
s well as the total mass, is important. In order to explore these issu
es, a line mass attached to the plate is replaced in the SVP formulati
on by a continuous spatial distribution. The functional form of this d
istribution is described in a spectral manner using Fourier series, wh
ose ascending orders represent successive stages in refinement of the
scale to which a model describes inertial effects. The excitation appl
ied to the plate is taken as a concentrated line harmonic force. With
the excitation held fixed, the influence of each spectral component of
inertial distribution on the surface response and radiated power are
assessed. Evaluations carried out for a range of frequencies shed ligh
t on how small scale inertial heterogeneities can influence macroscopi
c radiation features.