A Method to Simulate Structural Intensity Fields in Plates and General Structures Induced by Spatially and Temporally Random Excitation Fields

The structure-borne power in bending waves is well understood, and has been studied by many investigators in ideal beam and plate structures. Most studies to date, however, have considered only the structural intensity induced by deterministic, localized drives. Many structures of practical interest are excited by spatially random pressure fields, such as diffuse and turbulent boundary layer pressure fluctuations. Additionally, such studies typically employ finite differencing techniques to estimate the shear, bending and twisting components of intensity, and are therefore only applicable to simple homogenous uniform structures such as thin plates and beams. Often, however, finite differencing techniques are not applicable to practical structures of interest. The present study introduces a new method to compute the structural intensity induced by spatially random pressure fields in general structures which does not require the use of finite differencing techniques. The results of this method are validated using those obtained using finite-difference based techniques in a thin plate. The simulated fields from the new analytic technique are shown to be similar to those estimated via finite difference-based techniques, thus validating this new method. Both methods show intensity patterns different from those caused by deterministic point drives. The new general method may be applied in the future to complex non-homogenous structures which include discontinuities and curvature.Copyright © 2007 by ASME