3. Methodology for studying long-term behavior

The method employed aims to define the relevant parameters characterizing the aged state in order to establish a link between the evolution of mechanical properties and any changes to the matrix in the composite identified by physico-chemical methods. The choice of these parameters is an essential step in the consideration of coupled phenomena.

Behavior is predicted mainly by carrying out accelerated aging tests, which must be as realistic as possible, and by combining temperature exposure with humidity and mechanical stresses intended to best represent the stresses encountered by the CMO in use. The property that is most closely monitored is the one that determines its dimensioning and use.

Certification in the use of CMOs requires :

• successively carry out a chemical and physico-chemical characterization,...