Automatic assembly of tensegrity chain structures along axes based on NURBS curves

•An automatic design method for large-scale tensegrity chain structures is proposed.•The NURBS curves are utilized to capture the desired structural configurations.•Some elementary units and their shape transformations are introduced for assembly.•Parametric determinations of node coordinates, topology, and prestress are studied.•Design examples demonstrate the validity and superior versatility of this method. Tensegrity chain structures (TCS) are emerging as a promising structural form and have gradually garnered increasing attention across a wide range of applications. However, designing large-scale tensegrity chains, particularly those with complex geometric shapes, remains a challenging endeavor. To address this issue, this study proposes a fully parametric design method, termed the Modular Growth Assembly (MGA), to facilitate the automatic construction of TCS. Leveraging Non-Uniform Rational B-Splines (NURBS) curves, this method can directly capture the desired structural shapes and guide the assembly of numerous elementary tensegrity units into the overall structure along their axes. For assembly, some existing tensegrities are exemplarily introduced to serve as the elementary units, forming an elementary unit library. To adopt to various packing spaces, two transformation techniques are employed to explore different shape transformation patterns. Subsequently, the parametric determinations of nodal coordinates, topology, and prestress for the overall structure are investigated, respectively. A number of fascinating design examples, including both 2D and 3D cases, are then presented to demonstrate the effectiveness of the proposed method. This research will pave the way for the convenient production of customized TCS for diverse applications and might be beneficial to provide a comprehensive optimization framework for such systems.