Comput.Mater.Sci. 1, 177-194, 1993
H.J. Böhm, F.G. Rammerstorfer and E. Weissenbek
Institute of Lightweight Structures and Aerospace
TU Wien, Vienna, Austria
Abstract - The influence of the fiber arrangement on the
microscale stress and strain fields and on the overall thermoelastoplastic
properties of two classes of unidirectional metal matrix composites (MMCs)
A micromechanical approach employing the Finite Element method is used,
which is based on analyzing the nonlinear response of periodically
repeating unit cells.
By applying suitable boundary conditions, microgeometries which are
modified from regular fiber arrays are modeled at relatively low
When applied to discontinuously reinforced composites, this strategy
allows the investigation of materials containing regular arrangements of
two or more different types of aligned short fibers.
In the case of continuously reinforced composites, periodic hexagonal
arrays as well as regular, modified and clustered square arrangements of
parallel fibers are considered.
The influence of the fiber arrangement on the overall thermomechanical properties of the damage-free composites is generally found to be small, the main exception being the overall response to transverse mechanical loading. The computed microfields, however, are predicted to depend noticeably on the microgeometry, and, consequently, damage-related parameters such as the hydrostatic microstresses, the interfacial stress distributions and the shakedown limits show a marked sensitivity to the fiber arrangement.