Laminated structures have increasingly gained popularity in engineering applications
owing to their advantageous properties. Particularly in aerospace applications,
laminated components, typically comprising fibre-reinforced composites, have
a soaring demand owing to their high strength to weight ratio. However, owing to
the complex nature of the material, several different failure mechanisms may occur;
amongst them is delamination, i.e. the separation at the interface between two
laminates. This defect is often difficult to detect, yet may significantly reduce a
component's load carrying capacity and subsequently may severely affect its safe
working conditions. It is therefore of utmost importance to assess the effects of
delaminations on the structural elements carefully. Since components in aerospace
applications often comprise laminated panels, a geometrically nonlinear plate delamination
model is derived analytically by extending a previously developed two-layer
strut model. This type of structural component is commonly analysed as an engineering
simplification since
at plates are often used as an archetype to simplify
more complex structural forms. Thus, an isotropic plate is currently considered,
which re
ects the simplest constitutive behaviour, and it can represent to some extent
the behaviour of a laminated composite that has a uniform or symmetric lay-up
sequence. A rectangular defect is located in the centre of this uniformly compressed,
isotropic rectangular plated panel representing the delamination. Whilst trigonometric
out-of-plane displacement functions are used in a Rayleigh{Ritz procedure yielding the governing equations that describe the mechanical behaviour of the plate,
in-plane deformations are obtained via von Karman's compatibility equation. An
indication of the residual capacity of the panel after critical buckling is obtained by
investigating the nonlinear postbuckling range, where delamination propagation is
incorporated by introducing a discrete cohesive zone model at the boundaries of the
delaminated region. Different configurations are investigated in the neighbourhood
of the previously evaluated transitional depth of delamination, which constitutes the
boundary between local and global buckling. Initially, a uniformly spreading defect
is investigated for various different defect sizes and depths. Subsequently, geometric
parameters are linked to the response of the panel to generalize the outcomes with
quantitative comparisons being undertaken against previous results and those obtained
with the commercial nite element software ABAQUS. It is found that the model compares well and several criteria for the initial design of the damaged panels
are proposed such that delamination growth may be accommodated safely and
e ciently. Furthermore, uni-directional growth of the delamination is considered in
a pilot study with suggestions being made regarding the growth direction tendency.