Micromechanical model for preferentially oriented short fibre-reinforced materials under cyclic loading

The safety assessment of short-fibre-reinforced (SFR) composites, commonly used in structural applications involving repeated loads, requires to evaluate the degrading phenomena taking place in the matrix and at the fibre–matrix interface. The mechanical behaviour under both static and cyclic loading can be simulated applying damage degradation to the matrix mechanical characteristics, and employing fracture mechanics concepts to examine the fibre–matrix detachment as a 3D growing crack with degrading interface properties. In the present paper, a micromechanical model for unidirectional or random SFR materials under fatigue is developed. Some applications related to SFR polymeric composites found in the literature are presented