Paper number 710

IDENTIFICATION OF THE THROUGH-THICKNESS STIFFNESSES OF THICK LAMINATES BY INVERSE ANALYSIS

Fabrice PIERRON^*, Sergei ZHAVORONOK^**, and Michel GREDIAC^***

*SMS/ Département Mécanique et Matériaux, École Nationale Supérieure des Mines
de Saint-Étienne, 158, cours Fauriel, 42023 Saint-Étienne Cedex 2, France
**Moscow State Aviation Institute, Technical University
Dept. 603, 125871Volokolamskoie shosse 4, Moscow, Russia
***LERMES, Université Blaise Pascal, 24, avenue des Landais, 63174 Aubière Cedex, France

Summary

This paper presents a method to determine the four through-thickness stiffnesses of thick laminated composite rings cut from thick tubes. Only one ring specimen submitted to a diametrical compression test is required. The procedure is based on a suitable use of the principle of virtual work with four independent virtual fields. This leads to a system of four linear equations where the through-thickness stiffnesses are the unknowns. This sytem involves integrals of the strain components and the points coordinates. The system is finally inverted to determine the stiffnesses. Finite element simulations have been carried out to validate the approach and to show its stability.

Keywords

thick composites, thick tubes, thick rings, diametrical compression test, stiffness measurement, identification, inverse problem, virtual fields method.