Thin-film membrane structures are a common element in many of the structures
that are currently envisaged for space missions and the presence of wrinkles
in these membrane structures may significantly influence both the static
and dynamic behaviour of space systems. It is, therefore important
to carry out an in-depth study of the highly geometrically nonlinear behaviour
of wrinkled structures.
This dissertation investigates a square membrane of uniform, elastic,
isotropic material, with four edges clamped to two identical rigid square
frames on both surfaces. The tensions rays, and hence the membrane
stresses, amplitude and wavelength of the wrinkles due to shear load are
A simple analytical approach is proposed to predict the wrinkle wavelength
and out-of-plane amplitude. An initial analytical model is based on
the assumption that a membrane is able to resist a small critical buckling
stress once it has wrinkled. Two different methods are used to predict
the wrinkle amplitude. Following a comparison with the results from
simulation and experiments, further corrections are introduced on the expression
for the amplitude.
A finite element analysis has been carried out to analyse and predict
the wrinkle patterns by using the ABAQUS commercial package. The details
of the stress field, wavelength and the amplitude are obtained from the simulation.
This study shows that Finite Element Method (FEM) can provide good
estimates of the wrinkle behaviour.
An experimental study of a square membrane attached to aluminium frames
is done. The results show consistency of the wrinkle evolution patterns
with the analytical model and the simulation results. Although there
are some differences between them, the experimental results generally are
in good agreement with the parameters of wrinkles, in particular, wavelength
and amplitude obtained from the simulation and theoretical analysis.
[Cambridge University | CUED | Structures Group | Geotechnical Group]