Micromechanical modelling of unidirectional fiber reinforced composites considering random fiber diameter and inclination

A new modelling method is proposed to obtain the representative volume element (RVE) with a random distribution of fiber position, diameter, and inclination. The proposed RVE model was validated with experimental results. The effect of maximum fiber inclination on elastic properties was discussed using the proposed RVE model. The results show that the diameter and inclination in unidirectional fiber-reinforced polymer (UD-FRP) composites follow the normal distribution. The proposed RVE can predict the elastic properties of UD-FRP more accurately than the existing RVEs. Moreover, the transverse properties predicted by the RVE with a diamond fiber layout are different obviously from those predicted by other RVEs with square and random fiber layouts. The maximum fiber inclination angle can significantly affect the prediction of E 11 , G 31 , ν 21 , and ν 23 . In the case of the UD-FRP with the fiber volume ratio of 25%, E 11 decreases by 14.81% when the fiber inclination angle reaches 18°. The newly proposed RVE model can predict the elastic properties of composites more accurately.