Modeling of interfacial separation of MMC composites
by
M. Sejnoha, J. Sejnoha and P. Prochazka
Abstract
An efficient micromechanics-based approach is used to evaluate local
stress and strain fields in two phase composite medium with debonded
or imperfectly bonded interfaces. An finite element analysis of the
unit cell model of a fibrous ply is used to obtain changes in local
stress and strain fields caused by normal and tangential separation
at the fiber-matrix interfaces. The evolution of decohesion process
confined to a narrow region between the fiber and matrix is analyzed
with the help of a simple cohesive zone model. In the present work,
the onset of interfacial damage is governed by critical normal and
shear tractions that are prescribed as interface fracture criterion.
In addition, the constant shear resistance is assumed to account
for presence of asperities at sliding parts of the interface. An
interface element, derived to carry out the numerical analysis, is
incorporated into representative unit cell and the local fields are
found with the ABAQUS finite element code. Examples are presented
for metal matrix SCS6/Timetal-21S system. The effect of time
dependent behavior of titanium based alloys is also considered.
Last modified: Nov 4 2000