Modelling of the folding of thin-film space structures

Background
Structures made of very thin polymer films (1 micrometre thick) have for a long time been investigated for use in space. Examples are inflatable antennas and solar sails. These structures are folded into a very small package before launch and then deployed to a large operational configuration by inflation of gas or by other means. The sharp folding of the structure induced sharp creases that might damage the material. See http://www.lgarde.com for examples of space structures.

Project
The aim of the present project is to analyse the stresses conditions in the thin polymer film at the sharp folds. Of special interest are the intersections where two or more folds meet. The analysis of the structures will be made in either of the finite element software ABAQUS or ANSYS/LS-DYNA. Some simple experiments will be performed to verify the numerical simulations. The analysis will focus on two types of structures: a single sheet and an inflatable tube, for which the folding patterns are different. This project is a continuation of a previous MSc project so some results are already available for the single sheet.

Requirements
Good knowledge in mechanics and solid mechanics and experience in MATLAB programming.

Organisation
The department of Mechanics at KTH has extensive experience in the field of deployable space structures and finite element modelling of non-linear dynamic phenomena. A recently completed study for the European Space Agency analysed the centrifugal deployment of a very large cable net in space using the software LS-DYNA.