Multi-axis 3D printing of material reduced shell structures on a reconfigurable supporting system using topology optimization principles

Abstract

The last few decades, the application of 3D Printing (3DP) techniques in construction scale has shown an increased trend, with advantages as well as limitations, mainly related to overhanging angle restrictions during printing of complex geometries including free-form shell structures. This work suggests a five steps methodology as an alternative approach for their design and then their 3DP. In particular, in the first stage, parametric design based on the catenary concept is used for the overall geometrical configuration of free-form shells, aiming at minimization of exercised tension and compression forces. Then, Topology Optimization (TO) principles are applied, in order to reduce total material volume and at the same time to achieve structural stability of the selected shell system. This is followed by an approach for alternating individual unit members based on the functionally graded cellular structures concept, which aims at material distribution and customization in different areas. In the fourth stage, a reconfigurable formwork system is developed and used as a supporting structure for on-site 3DP in different angles and for different design configurations. Finally, the 3DP process of toolpath development and simulation are demonstrated, accompanied by real scale physical experimentation. The work is assessed in providing initial information regarding the effectiveness of the process to be used in the construction of shell structures through multi-axis 3DP assisted by reconfigurable supporting systems.