Computational Investigation of the Structural Response of Bistable Scissor Structures

Abstract

In many civil engineering applications (emergency shelters, exhibition and recreational structures...), structures need to be easily moveable, or assembled at high speed on unprepared sites. For this purpose, preassembled deployable scissor structures, which consist of beam elements connected by hinges, are highly effective: besides being transportable, they have the advantage of speed and ease of erection and folding, while offering a huge volume expansion.
Intended geometric incompatibilities between the members can be introduced as a design strategy, to instantaneously achieve a structural stability at deployment that can be sufficient for small loads. In so-called bistable scissor structures, these incompatibilities result in compression and bending of some specific members that are under compression with a controlled snap-through behaviour. Despite the advantages bistable scissor structures have to offer, few have successfully been realized because of the complexity they add in
the design process.
The main goal of this project is the development of a 3D nonlinear structural model for the simulation of the deployment of bistable scissor structures. Starting from an initial simplified polygonal module, the computational model is refined in several stages and the influence of the main design parameters on the structural response is investigated.
Since imperfections will unavoidably take place because of manufacturing defects, their influence on the deployment behaviour is studied. The main types of tolerances that are investigated are the finite hinge size, imperfections on the length of the beams, eccentricity of the pivot points, finite hinge stiffness, hinge misalignment and friction.
The computational tool is applied to structures consisting of multiple modules and the influence of imperfections on such structures is investigated.

Date of Award	Jun 2017
Original language	English
Awarding Institution	Vrije Universiteit Brussel
Supervisor	Thierry J. Massart (Promotor), Niels De Temmerman (Co-promotor) & Peter Berke (Advisor)