Development and assessment of a spherical cap timber gridshell with compound beam sections

Elastic gridshells are an efficient family of structures. However, stability issues arise when they are employed at large scale. When stacking subsequently bent elements in superposed layers and mechanically coupling them together, a compound beam section is achieved that can provide sufficient cross-sectional capacity and structural stability to overcome these issues. The structural behaviour of such systems is highly non-linear with discrete force transfer, rendering the numerical modelling and analysis difficult. Existing strategies have proven accurate with negligible computational errors. However, these approaches are often cumbersome, and a more straightforward approach is required especially at the early design stages. This paper follows the approach of modelling the individual lamellas and coupling them with spring elements with analytically evaluated spring stiffnesses. A structural test was performed on a spherical cap timber gridshell with compound beam sections, serving as a benchmark for the evaluation of two numerical models: one including all lamellas and one including only the continuous lamellas. The geometrical concepts that formed the basis for the design developments, the realization of the prototype as well as the structural and numerical results are presented in the paper. ... mehrFinally, the results are discussed and evaluated against findings from other reference assessments.