Fabrication-aware structural optimisation of lattice additive-manufactured with robot-arm

Abstract

Architectural structures achieving high strength and stiffness with intelligent, but intricate geometry may now be materialisable through additive manufacturing (AM). However, conventional layer-based AM also produces parts with inconsistent structural strength -thereby limiting AM's end-use applications. Expanding on robotics-enabled AM techniques addressing this limitation, a novel design-fabrication framework for producing structurally optimised lattices is presented here. Lattices are geometrically morphed to maximise their structural stiffness-to-weight ratio while respecting fabrication constraints imposed by the robotic printing process, and converted into tool-paths for PLA extrusion with a custom-built end effector mounted on an industrial robot arm. The printing process leverages thermal imaging for Lattice additive-manufactured with robot-arm 121 calibration, and develops a novel joint detail to increase the reliability and load-transfer capabilities of the print. Together, these techniques and methods -validated through comparative structural load testing -show promise for architecture-scale AM that combines structurally driven geometry with complexity-agnostic materialisation in new and exciting ways. (2018) 'Fabrication-aware structural optimisation of lattice additivemanufactured with robot-arm', Int. J. Rapid Manufacturing, Vol. 7, Nos. 2/3, pp.120-168. Biographical notes: Kam-Ming Mark Tam is an Integration Engineer at Thornton Tomasetti's CORE Studio and a researcher at the Digital Structures research group (DS) of Massachusetts Institute of Technology's (MIT)Building Technology (BT) programme, where he investigates approaches for design space exploration that combine both structural and fabrication considerations. Specifically, he has developed methods to simplify the design modelling and analyses of complex structural systems, and robotic-enabled additive manufacturing (AM) techniques to create high-performance AM-produced parts. He earned a MEng in Civil Engineering from MIT, and a MArch and a HBAS (with Economics Minor) from the University of Waterloo. He has taught in the Singapore University of Technology and Design and Pratt Institute, and practiced in several architectural firms.