Structural optimisation of deployable scissor structures using new computational methods

Abstract

In architectural engineering, deployable scissor structures are generally used for mobile and temporary applications. They are characterised by their dual functionality as either kinematic mechanisms (during deployment) or loadbearing skeletal structures (after deployment). It is crucial to realise that there is a direct and mutual relationship between the geometry, the kinematics and the structural response of the scissor system. Due to a relatively complex design process it can be highly beneficial to evaluate these structures at a pre-design stage in terms of their structural performance. In order to do so, new computational methods are introduced. Karamba is a finite element plug-in for Grasshopper, fully embedded in the 3D modelling software Rhinoceros, which calculates interactively the response of three dimensional beam structures. The advantage of this new tool is the compatibility with the parametric environment of Grasshopper. These software tools are still in development, but already show their potential in terms of geometric modelling and structural optimisation. In this research it is shown in which way these evolving computational methods can contribute to the design of deployable scissor structures. By using the proposed methodology of preliminary evaluation, the scissor structures are geometrically and structurally optimised at an early stage, thereby enhancing the overall design process and facilitating further detailed analysis. © 2012 WIT Press.