Structural behaviour of an asymptotic curtain wall stiffened with lamella couplings

Abstract

Asymptotic structures are a novel construction system that allows fabrication from straight and flat lamellas, that are bent and twisted into the design shape. The challenge of this strategy is to design sufficiently slender profiles for deformation while maintaining structural stability in the curved state. This paper investigates a strategy to reinforce two parallel lamella members through timber couplings to improve their structural performance. The structural behaviour of the reinforced structure is investigated experimentally and numerically, and compared to the original design. The structural principle of coupling reinforcement is investigated for a double-lamella member under axial force, shear force, bending moment, and torsion. Results show that the structural stiffness and the load-bearing capacity of the asymptotic curtain wall under point load and wind load increase significantly if coupled. This effect can further be improved, by increasing the material stiffness, parallel offset, and the number of coupling blocks. Moreover, using a continuous coupling between the two lamellas to form a steel-timber-steel sandwich member can stiffen the asymptotic curtain wall structure by 436% under wind load, in comparison with 76% using two discrete timber couplings for each member.