Multi-scale analysis to determine fibre/matrix debonding criterion

摘要

The debonding phenomenon between the fibre and the matrix was studied in a long fibre SiC-Ti metal-matrix composite. The debonding between the two constituents occured by the rupture in the carbon interphase. The analysis was both numerical and experimental and realized in a qualitative and quantitative ways. It shown the feasibility of the following methodology : to determine quantities at the scale of the homogeneous material from microscopic informations and observations (i.e. at the scale of the constituents of the material). An exemple is given for the determination of a mesoscopic debonding criterion. This work is realized without and with consideration of the manufacturing residual stresses. The conclusion is that they have a very significant role in the determination of the critical debonding values. The use of numerical techniques for the experimental analysis seems increasingly necessary because of the complexity of the microstructures of the composite materials and the complexity of the phenomena involved. Although the calculation did not solved all problems, it has partly removed some ambiguities and has led to more finest understanding of the phenomena.