Mechanical model of stiffness coefficients prediction of curved fiber reinforced composites considering fiber distribution and aggregation

In this paper, a mechanical model is built to numerically predict the stiffness coefficients of curved fiber reinforced composites. Aiming to quantitatively describe the geometrical morphology of a curved fiber, a curve parameter and an orientation angle are both defined. For a composite with abundant curved fibers, distribution functions are introduced to describe the various curve parameters and angles. To quantitatively express the probability and degree of fiber aggregation, a probability function and an aggregating parameter are also proposed. Validation examples for composite with unidirectional straight fibers, orthogonal distributed straight fibers or unidirectional curve fibers are given to verify the correctness and accuracy of the current model as well as the numerical process. Numerical examples considering composites with ordered and disordered distributed fibers are carried out to show the predicted stiffness coefficients of typical curved fiber reinforced composites. Universality of the model is obvious through the numerical examples.