Generalized response spectrum analysis based computational morphogenesis for metal gridshells with buckling-restrained braces subjected to seismic loading. (15th January 2023)

• Record Type: Journal Article
• Authors: Terazawa, Yuki; Niimi, Atsuya; Nair, Deepshikha; Takeuchi, Toru
• Is Part Of: Computers & structures. Volume 275(2023)
• Publication Date: 2023-01-15
• Subjects: Structural morphogenesis -- Parametric design -- Shape optimization -- Gridshell -- Buckling-restrained brace -- Response spectrum analysis; Structural engineering -- Data processing -- Periodicals; Electronic data processing -- Structures, Theory of -- Periodicals; 624.171
• DOI: 10.1016/j.compstruc.2022.106914
• Languages: English
• ISSNs: 0045-7949

Abstract

Highlights: A generalized response spectrum analysis based computational morphogenesis method is presented. The method directly considers dynamic response and response reduction effect by dampers. Developing a plugin having visual programming function for Rhinoceros + Grasshopper. An example application of the method to metal grid shell roofs with supporting structures in high seismic zones. The form-found models are validated by buckling analysis and nonlinear response history analysis. Abstract: Structural morphogenesis is widely used as a parametric tool to find an optimal structural shape of shell structures for a prescribed objective function and a given design load. However, the current optimization methods are limited to finding a geometry under only a specific static load like the dead load or an equivalent static seismic load for predefined geometrical shapes, and so can not be applied to free-form gridshells. This poses a challenge to achieving an efficient free-form shell structure in high seismic hazard areas. This paper aims to resolve this by presenting a computational morphogenesis method to obtain form-found shell structures by considering the dynamic seismic loads and the response reduction effects of seismic energy-dissipating devices using generalized response spectrum analysis. The method was applied to optimize the buckling-restrained brace layouts on target spherical metal gridshell structures with different diameter-to-height ratios. The resulting form-found structures had an efficient roof geometry, along with an efficient damper layout (to prevent member buckling and the dropout of finishing materials). Dampers were found to be more efficient if placed in the (relatively heavy) supporting structure instead of the roof, and a flattened but locally bulged roof shape proved to be the most efficient in mitigating the seismic response. The generalized response spectrum analysis significantly reduced the computation time while evaluating the displacement response with sufficient practical accuracy, although it slightly underestimates the acceleration response if compared to the conventional nonlinear response history analysis results.