Design and Optimization of Extrusion System for a Mobile Cement 3D Printer via CFD Simulation and Physical Testing
The construction industry faces increasing pressure to reduce environmental waste and accelerate project timelines, particularly in concrete applications where formwork and labor-intensive methods remain dominant. Existing large-scale 3D concrete printers are constrained by their physical footprints and limited build heights, restricting deployment and scalability. This thesis builds off of PRIMO (Printing Robot for Infrastructure and Mobile Operations), a WPI Major Qualifying Project that created a compact mobile robot capable of continuously 3D-printing cement while traversing and building atop previously printed layers. The extrusion system includes a screw-based positive displacement pump and a modular multi-nozzle distribution mechanism. Experimental validation with a full-scale prototype demonstrates successful deposition of consecutive cement layers, confirming the feasibility of scalable, height-agnostic construction from a mobile platform. However, the tests followed a trial and error method, instead of being connected to simulation. While PRIMO did print layers that it could drive over once dry, the precision and quality of the layers could be improved, ideally without having to run a full scale print to test any changes. To further our research on how PRIMO can improve its printing quality and consistency, this paper uses FLOW-3D CFD to simulate material deposition under different feasible printing parameters to determine what works best for PRIMO’s specific use case. This could help enable results that establish a foundation for future autonomous, multi-robot swarms aimed at rapid, decentralized construction in remote, off-grid, or extraterrestrial environments, offering a lightweight alternative to traditional gantry and robotic arm systems.
Advisor: Professor Mohammad Mahdi Agheli Hajiabadi
Committee: Professor Vincent Aloi, Professor Jessica Rosewitz