DYNAMIC AND STRUCTURAL OPTIMIZATION OF THE TOWERS’S CENTRAL CORES BRACING FOR TARGETED DESIGN AND UPGRADED SEISMIC RESPONSE

This study introduces a parametric preliminary design of central core bracing tailored for towers and tall buildings dominated by dynamic flexural vibrations and handled by accidental and serviceability deflections. In such slender systems, the determination of the core thickness is of critical importance to structural engineers, as it formally validates the pre-project stage and, subsequently, enables proper structural detailing outcomes in accordance with seismic regulations and technical standards. This issue is a real challenge, as it typically entails an unlimited number of attempted iterations and enormous computational time to converge towards the optimal values of the structural load-bearing elements. To address this problem, we introduce a streamlined methodological approach, structured as a practical guideline, aimed at defining an optimal variation of the thickness profile and facilitating accurate structural sizing. This dynamic and structural optimization is governed by the max-min formulation of the natural frequency eigenvalue. For this, two strategic zones, depending on the height of the tower, were delineated. Additionally, the construction material usage quantity constraint is imposed to ensure its optimal consumption, thereby establishing a bridge between structural design maturity and the ambitions for increasing profits and resource savings. The principal advantage of this mechanical and mathematical resolution lies in its simplicity and practicality, allowing rapid and efficient hand-use calculations. The present paper is crowned by an illustrative case study designed to evaluate the tangible benefits achieved through the dynamic modal analysis.