Design, material, and structural aspects of friction-based spatial structures: the case of a “minimal making grammar”

Through a combination of simulations and physical prototypes this paper explores the design, material, and structural aspects of digitally fabricated friction-based spatial structures. We define digitally fabricated friction-based spatial structures as three-dimensional structures composed of modular components assembled without fasteners, nails, or glue, designed and fabricated employing computational design and digital manufacturing methods. In this paper, we focus on a case study of a production system for such structures which adapts traditional mortise-tenon techniques to computational design and flat-cut manufacturing methods, and which has been shown to display manufacturing simplicity, design flexibility, and structural integrity [7, 8]. To study its material and structural aspects in greater depth, this paper reports on three simulation-based studies: (1) an experimental method for testing compressive strength, (2) an assessment of the maximum moment effect on beam-column parts of a twelve-piece joint assembly using spring connectors, (3) optimization of the element profile. To understand real-world behavior and limitations, Instron machine tests are conducted for each simulation. These revealed that identical elements exhibited different failure patterns depending on their position, reflecting the mechanics of traditional mortise-and-tenon joints. Based on these findings, the optimized elements for spatial-scale lightweight structures were evaluated for the system’s manufacturing feasibility, providing a potential foundation for practical applications.