Jean-François Maire

Continuum Damage Mechanics, Anisotropy and Damage Deactivation for Brittle Materials Like Concrete and Ceramic Composites

The main lines of a Continuum Damage Mechanics Modelling are reviewed, for applications to brittle materials treated as elastic damageable ones. The proposed damage models consider in the same framework the cases of initially isotropic materials like concrete and anisotropic composites. Attention is focused on the damage deactivation effects and on the possibility to describe irreversible strains directly associated to the damaging processes without any additional dissipation. Finally, the model is applied to two particular SiC/SiC and C/SiC composites.

Development of a Macroscopic Damage Model for Woven Ceramic Matrix Composites

The aim of this article is to propose a macroscopic damage model, which describes the nonlinear behavior observed on woven composites with ceramic matrix. The model is built within a thermodynamic framework with internal variables. First of all, the efficiency of the model to describe the mechanical behavior of carbon fiber-reinforced ceramic matrix composites is outlined. Then, the predictive capability of the model is evaluated with the help of an alternate torsion test.

A coupled analysis of mechanical behaviour and ageing for polymer-matrix composites

The use of organic-matrix composites for long lifetime aeronautics applications leads to a study of the coupling effects between thermo-mechanical stresses and thermal ageing. Taking into account the effects of oxidation in a behaviour law requires first, an understanding of every mechanism of degradation and the interactions between them. The objective of this paper is to present current studies of these subjects and, in particular, our own approach, in order to include oxidation in a macroscopic behaviour law. For the oxidation section, studies have led to establishment of kinetics of thermal-oxidation for several polymer matrixes. For the mechanical section, a visco-elastic model coupled with damage is presented and allows to obtain the multiaxial creep behaviour of any composite laminate from few short-time tests conducted on elementary laminates.