Identification of the local stiffness reduction of a damaged composite plate using the virtual fields method

In the present study, a damage detection problem is formulated as the identification of the spatial stiffness distribution in a damaged composite plate. Full-field heterogeneous curvature fields obtained from an optical deflectometry technique are processed by using the virtual fields method adapted to retrieve the 2D stiffness distribution map of a damaged carbon-epoxy plate. The method not only picks up the location of the damage but also provides a fairly good estimate of the stiffness reduction in the damaged area. In this paper, the procedure is described, validated on simulated measurements and some initial experimental results are given. � 2007 Elsevier Ltd. All rights reserved

The Virtual Fields Method for Extracting Constitutive Parameters From Full-Field Measurements: a Review

http://www3.interscience.wiley.com/journal/121488316/abstract?CRETRY=1&SRETRY=0 (DOI indiqué sur le site ne fonctionne pas.)International audienceThe virtual fields method has been developed for extracting constitutive parameters from full-field measurements provided by optical non-contact techniques for instance. It is based on the principle of virtual work written with some particular virtual fields. This paper can be regarded as a general review summarising some 15 years of developments of this method. The main aspects of the method are first recalled in the case of both linear and non-linear constitutive equations. They are then illustrated by some recent relevant examples. Some studies underway as well as relevant issues to be addressed in the near future are eventually discussed