The architectural potential of tensegrity structures is proven. Yet, paradoxically, very few real construction projects have been built around the world. The main reasons are complex construction processes, lack of design and optimization guidelines, and excessive self-weight due to the prestress needed to guarantee stiffness and dynamic behavior. Hence, optimizing the stiffness and self-weight is a key aspect when designing a tensegrity footbridge. Previous research has demonstrated the validity of a design and optimization methodology, based on morphological indicators, that identifies geometry with a maximum stiffness and/or a minimum self-weight for a family of structures. In this paper, that methodology is applied to footbridges composed of tensegrity modules comprising simplex, quadruplex, pentaplex, and hexaplex types. A comparison of the stiffest and lightest structures is provided, a practical case study is developed, and the relevance and feasibility of such tensegrity footbridges are discussed. As a result, the study provides advice on optimum footbridge topologies with the following characteristics: excellent stiffness and dynamic behavior; efficient structures composed of simplex modules; and self-weight that is still rather high but similar to that of bended structures, although with potential to be reduced thanks to optimization of the prestress scenario.

This research investigates the robotic assembly of timber structures connected by wood–wood connections. As the digitization of the timber construction sector progresses, digital tools, such as industrial robotic arms and Computer Numerical Control machines, are becoming increasingly accessible. The new-found ease with which wood can be processed stimulates a renewed interest in traditional joinery, where pieces are simply interlocked instead of being connected by additional metallic parts. Previous research established a computational workflow for the robotic assembly of timber plate structures connected by wood–wood connections. This paper focuses on determining the physical conditions that allow inserting through-tenon joints with a robot. The main challenge lies in minimizing the clearance between the tenon and the mortise in order to keep the connections as tight as possible. An experimental protocol has, therefore, been developed to quantitatively assess the performance of the insertion according to different geometric parameters. Robotic insertion tests have been carried out on over 50 samples of 39 mm Laminated Veneer Lumber. Results showed the interest of tapering the joint with a 5 degrees angle, in addition to introducing an offset of 0.05 mm, to minimize friction forces during the insertion. This configuration was confirmed by successfully assembling a 2,50 m long box girder with the same parameters.

This article presents a design methodology based on a stiffness and volume optimization algorithm for three-dimensional nonlinear hyperstatic and pre-stressed structures composed of elements only subjected to axial forces, with a special emphasis on tensegrity structures. The algorithm is based on dimensionless numbers called morphological indicators that allow finding, within a given family of structures, the geometry related to a maximum stiffness or a minimum volume of materials or the best ratio between stiffness and volume. The algorithm takes into account the buckling of the struts and different materials for cables and struts. This article first demonstrates the optimization algorithm and then gives numerical confirmations and examples.