The microscopic damage and macroscopic mechanical behavior of C

f

/Al composites with different fiber content were investigated by micromechanical and experimental method.Representative Volume Element（RVE）with diagonal regular quadrilateral and regular hexagonal fiber arrangements were established according to the composites microstructure.The damage behavior of matrix alloy was described by ductile damage model and the fiber fracture behavior was simulated using a maximum stress failure criterion.And then a micromechanical finite element model based on cohesive interface was established and the calculation reliability was verified by the experimental results.Based on the micromechanical model

the damage evolution and fracture behavior of the composites with different fiber content were analyzed.It is found that the micromechanical model with regular hexagonal fiber arrangement can predict the elastoplastic behavior of composites accurately.At the first stage

the initial interface damage is accumulated with the increase of strain and induce some local interface failure.At the middle stage

some local matrix damage is initialed and developed near the failed interface.At the last stage

the interface and matrix failure results in the transverse cracking of the composites.The tensile fracture surface exhibits the characteristic of interfacial debonding and matrix tearing.The transverse tensile modulus and ultimate strength of the composite are decreased with the increase of fiber content

which can be attributed to the occurrence of more interface quantity and interface area.