Abstract:

Aiming at the common problem that the metal-matrix polymeric composites are easy to induce interface peeling damage and failure， this paper focused on the composite interface strengthening through a short fiber bridge formed at the interface between the polymeric composite layer and adhesive layer by means of the multi-layer composite assembly injection molding. On the basis of a cohesive peeling damage model， a simulation technology was constructed for the failure process of interfacial peeling crack propagation and the fracture failure of the composites with short fiber bridging. A synergetic relevance theory based on the failure critical load-bridging fiber properties-interface peeling fracture toughness （damage crack initiation stress T₀ and critical strain energy release rate G_c） was constructed for the interfacial peeling unstable crack rapid propagation fracture damage failure. The interface strengthening mechanism of short fiber bridging was explored， with the design criterion proposed for preventing the peeling unstable crack rapid propagation fracture damage failure induced by the short fiber bridge strengthening interface. The results indicated that the critical load was increased by 55.9 % with a density of bridging fiber at 20/mm². The critical load was controlled by the density of bridging fiber， initial pre-crack area， damage crack initiation stress and critical strain energy release rate. The critical load was positively correlated with the density of bridging fiber， damage crack initiation stress and critical strain energy release rate， but negatively correlated with the initial pre-crack area.

Key words: metal matrix, polymer, composite, fiber bridging, interface strengthening, delamination failure, preventive design criteria