Achievements of dense ESPI complex-valued full-field receptances in experiment-based Rayleigh integral approximations of sound radiation from a vibrating plate

Abstract

Where can the exploitation of high spatial resolution optical full-field technologies – in complex-valued representation – bring, for an experiment-based extension of the Rayleigh integral approximation of sound radiation from a vibrating plate? Dense receptance maps may cope with the challenges of the most advanced Noise and Vibration Harshness (NVH) testing for the characterisation of the structural dynamics of the actual set-up, with damping and boundary conditions coming from the mounting and manufacturing, with all the potential delays of the responses caught around the superposition of a modally dense dynamics, but without the need of a Finite Element Model (FEM), especially in the case of lightweight structures. Sound radiations are explored in the complex-valued details of vibro-acoustic transfer functions and of pressure fields, by feeding the well-known Rayleigh formulation with Electronic Speckle Pattern Interferometry (ESPI)-based receptances, obtained from a simple thin rectangular plate, designed as a lightweight structure with a complex structural dynamics, its real constraints and damping characteristics. The contribution of dense experiment-based full-field receptances to the radiated sound fields at different distances is discussed in a broad frequency domain.