Material microstructures often contain non-uniformly distributed features o
f complex geometry. Attributes of three-dimensional microstructural geometr
y have dominant influence on the mechanical behavior of materials. Therefor
e, it is of interest to incorporate quantitative description of actual thre
e-dimensional microstructures in micromechanical analysis of materials. In
this contribution, a methodology has been developed to perform finite eleme
nt (FE)-based simulations on complex three-dimensional microstructures, thr
ough its application to cast microstructure of A356 Al-alloy containing non
-uniformly distributed pores of complex geometry. As expected, the simulati
ons reveal that the distributions of local stresses and strains depend on s
ize, orientation, and spatial arrangement of the pores in a complex manner.
FE-simulations on the three-dimensional pore structure have been used to s
imulate the growth of the voids by the McClintock rule. These simulations c
learly demonstrate that unit cell model can be used in the study the void g
rowth behavior of materials at the stress levels close to global yield stre
ss, and it overestimates the void growth at the stress levels significantly
higher global yield stress. The FE-simulations reveal a general trend that
larger voids have a higher percentage increase in their volume. Therefore,
at a given applied stress level, absolute rate of volume change of a pore
increases with its initial pore Volume in a non-linear manner. These observ
ations are supported by experimental measurements of pore growth. It is sho
wn that micromechanical response does not vary significantly if the pores a
re replaced by equivalent ellipsoids, and such a model can be used to simul
ate the growth of non-uniformly distributed voids of complex geometry at al
l stress levels. (C) 2001 Acm Materialia Inc. Published by Elsevier Science
Ltd. All rights reserved.