Integrated design framework for optimizing shape and Damper placement in steel gridshells under seismic loads

This paper introduces a design methodology to enhance the seismic response of gridshells by simultaneously optimizing their shapes and the configuration of viscoelastic dampers. While viscoelastic dampers effectively reduce seismic responses, their impact on gridshell geometry has received limited attention. The proposed framework integrates damper placement into the initial design stage to address this gap, unlike conventional approaches that treat geometry and damper design separately. Leveraging parametric geometric and structural modeling, combined with a genetic algorithm, the framework utilizes a multi-phase fitness function derived from static and dynamic analyses, accounting for damping effects and material and geometric nonlinearities. The findings reveal that, as the number of dampers increases, optimized gridshells tend to adopt more elliptical shapes while achieving substantial reductions in both maximum displacement (exceeding 50 % in some cases) and thrust forces (up to 40 %), with the effect being more pronounced in mid-rise domes. Notably, even configurations with as few as 32 dampers can yield satisfactory seismic performance. Overall, locally symmetric damper layouts are recommended. The proposed methodology underscores the benefit of integrating damper placement with shape optimization during the early design phase, enabling adaptable applications to other structural systems and supporting more informed performance-based design decisions.