Development of the Corrected Force Analysis Technique for laminated composite panels

Abstract

The aim of this paper is to propose a methodology for identifying the pressure field applied on a laminated composite plate from its measured vibration response. The general framework of this study is the Corrected Force Analysis Technique (CFAT), which was previously used on isotropic plates. This method estimates the spatial derivatives of the equation of motion with a finite difference scheme and corrects the bias error generated by this approximation. The paper presents an extension of this technique to deal with laminated panels. In a first instance, the finite difference scheme has been expanded to allow the identification of the 5 spatial derivatives that compose the equation of motion of such structures. The correction, considered in the wavenumber domain, has also been adapted and is now calculated numerically. In a second instance, the effect of measurement noise has been treated with the implementation of a regularisation technique based on the adaptation of the size of the scheme as function of the frequency. Numerical simulations and contact-less measurements have been conducted on different carbon fibers composite plates. Results are presented in terms of identified pressure fields and input force magnitude.

Experimental methodology to assess the dynamic equivalent stiffness properties of elliptical orthotropic plates

“…Note that the computation time of the fitting procedure would be significant for orthotropic or anisotropic plates since the number of unknown characteristics increases in these cases. Another interesting research line could be to compare the proposed Hankel fitting approach with the recent extension of the CFAT approach for anisotropic plates [24].…”