Parametric CAD/CAM toolchain for adaptive bamboo joints: Digital fabrication and experimental validation for rural structures

Abstract

Bamboo is a renewable and abundant material, but its geometric variability (diameter, ovality, taper, wall thickness) complicates the development of standardized connections for structural applications. This paper presents a parametric CAD/CAM toolchain, implemented in Rhino/Grasshopper, that generates adaptive steel joints for bamboo culms of varying sizes and connection angles. The system encodes geometric constraints and structural rules, particularly the orientation of steel plates according to section properties, producing fabrication-ready outputs (DXF and assembly guides) suitable for manual or CNC manufacturing. A prototype joint was fabricated and tested in a cantilever bending experiment with a 3-m bamboo member. Results demonstrated a linear load–deflection response up to 39.2 N, with failure at 49 N due to bamboo splitting. The implemented orientation rules improved bending resistance by a factor of ≈50×, confirming the role of simple codified decisions in enhancing performance. The contribution aligns with ICITS themes on software systems (D), systems modeling (C), and decision support (G), illustrating how digital fabrication can translate computational design into practical, low-cost technologies for sustainable rural construction.