Adapting the correction for CFAT application in time domain

Abstract

The Corrected Force Analysis Technique (CFAT) is an experimental method that allows to identify a force distribution (or pressure field) that excites a structure for which an analytical model is available, such as beams or plates. This is an inverse problem, the principle consists in measuring the displacement field of a structure and injecting it into its discrete equation of motion. The CFAT approach differs from the classical FAT method in the fact that the regularization minimizing the amplification of measurement noise is based on a filtering obtained by correcting the finite difference scheme that discretizes the equation of motion. The advantage is that the technique can be deployed with a simple antenna and few sensors. In this paper, we are showing a time domain extension of the CFAT method, which could be used to study transient or strongly spatially uncorrelated excitations, such as turbulent flows. In this way, the antenna can then be seen as a simple sensor providing the signal of the co-located excitation at the center of the antenna. In a first part, a description of the real-time adaptation of the method is presented in one dimension. The need for development of adapted corrective coefficient is then highlighted. The effectiveness of the method is eventually displayed using simulation data for beams.