Ductile failure of an interleaf tension specimen consisting of a metal inte
rleaf bonded between two elastic substrates, with a crack located in the ce
ntre of the metal, is studied by means of detailed finite element (FE) anal
yses. The rate-independent version of the Gurson model is used. This accoun
ts for ductile failure mechanisms of micro-void nucleation, growth and coal
escence within the framework of a finite deformation plasticity theory. Als
o, the rapid evolution of void density due to coalescence, which leads to u
ltimate failure, is considered. The effect of the interleaf thickness on fa
ilure (crack initiation and limited amount of crack growth) is investigated
. The results show that the interleaf thickness affects crack initiation on
ly slightly. For all specimens considered, crack initiation takes place at
the crack tip. However, after crack initiation, the interleaf thickness aff
ects stress and strain distributions significantly. Reducing the interleaf
thickness significantly increases the load-carrying capacity. Moreover, red
ucing the interleaf thickness increases the maximum hydrostatic stress in t
he interleaf, which is no longer developed at the crack tip but at a distan
ce far away from the crack tip. The resulting fracture toughness thus decre
ases as the interleaf thickness decreases. The shielding of the crack tip d
ue to constrained plasticity is observed at higher load levels for interlea
f specimens.