Determination of the fiber direction and the C-tensor of a UD carbon/epoxy composite by means of the ultrasonic polar scan

The pulsed ultrasonic polar scan relies on the simple amplitude measurement of the transmitted (or reflected) sound pulse for a 2D range of oblique incidence angles. It has been conjectured in the 80's that the ultrasonic polar scan provides a unique fingerprint of the underlying elasticity tensor at the insonified material spot. Until now, that premise has not been thoroughly investigated, nor validated, despite the enormous opportunities this would create for NDT and materials science in general. In this paper, we report on the first-ever implementation of an inverse modeling technique on the basis of a genetic optimization scheme in order to extract quantitative information from an ultrasonic polar scan. We validate the optimization approach for synthetic data, and apply it to experimentally obtained ultrasonic polar scans of an isotropic as well as an orthotropic material. The obtained results clearly indicate the great potential of the ultrasonic polar scan to become a full quantitative methodology for complex composite materials.

Jaar van publicatie:2013

Trefwoorden:ultrasonic polar scan, characterization, composites