Role of fiber arrangement in the thermal expanding behavior of unidirectional metal matrix composites

Abstract

The influence of fiber arrangement on thermal expanding behavior of unidirectional fiber-reinforced metal matrix composites (MMCs) is evaluated using a unit cell micromechanical approach. Both regular and random fiber arrangements are considered in the MMC simulation by extending the number of sub-cells of the representative volume element (RVE). Moreover, the unit cell micromechanical model is used to investigate the role of fiber cross-section on the coefficients of thermal expansion (CTEs) of unidirectional MMCs. The validity of the model is verified by comparing the predictions and those available experimental measurements. The effective axial CTEs are not dependent on the MMC microstructure with different types of fiber arrays and cross-sections. However, the results show that besides the volume fraction, shape and the arrangement type of fibers plays a significant role in the effective transverse CTEs of MMCs. The discrepancy between the transverse predictions of the model with a random fiber arrangement and those of the model with a regular fiber arrangement increases with the rise of difference between the constituent material properties. Also, the effects of different statistical distributions of the random fiber arrangement, the number of RVE sub-cells and fiber orientation on the MMC thermal expanding response are examined.