ZAMM 73, T423-T426, 1993
C.A. Abel, E. Weissenbek and F.G. Rammerstorfer
Institute of Lightweight Structures and Aerospace
TU Wien, Vienna, Austria
Two different types of damage - depending on the interface strengh - are
investigated for a composite system consisting of an Al matrix (99.9%)
reinforced with Al2O3.SiO2 (Sumitomo-ALTEX)
A finite element study is conducted using a two-dimensional axisymmetric
unit cell model with special boundary conditions to investigate an aligned
periodic array of staggered and unstaggered fiber arrangements embedded
in a matrix.
For strong interfaces (perfect interfaces), a damage indicator based upon a
void nucleation and growth mechanism is used to represent the extent of
matrix damage due to plastification.
The damage parameter has been found to be a better indicator of the
overall composite's strength than the global stress-strain behavior.
The weak interface is represented as unbonded with frictional contact.
A damage failure mechanism is postulated based upon the sequence of debonding
along the fiber to account for the unexpected global behavior of a negative
Poisson's ratio (a volume inrease) in response to an axial tensile
loaded MMC with specific fiber arrangement.