Comportement mecanique des matériaux composites SMC

Mechanical behaviour of SMC composite materials

¹ Division Polymères et Composites, Université de Technologie de Compiègne

Abstract

For applications in which protection against fire/toxicity/smoke are essential, SMC composites based on a phenolic matrix show considerable potential for development. In order to understand the mechanism governing deformation in a new type of SMC composites, produced by CDF-Chimie, characterization was undertaken using three point bending, tension and compression tests.

While in the linear region the measured elastic moduli are similar for the three types of loading, the mean failure stresses differ considerably. The growth of a significant damage zone before failure, which disturbs the stress field in flexure specimens, as well as the different deformation mechanisms corresponding to the three loading types are the cause of these differences. The bending failure stresses are higher than those in compression which in turn exceed those in tensile loading. The theorical models proposed to predict tensile properties do not describe these materials behaviour accurately, due to the weakness of the fiber-matrix interface. However, these materials show good elevated temperature behaviour, with no significant reduction of mechanical properties.