Computational Techniques for Novel Design of Long-Span Bridges Considering Aeroelastic Phenomena

Abstract

Optimization techniques have demonstrated their capability to obtain economic and sustainable designs while meeting the performance and safety requirements in a number of engineering disciplines. In the bridge engineering field, the increasing main span length of superlong span bridges makes the wind-resistant design a top priority. However, it has been traditionally conducted following heuristic rules based on experimental analyses. Alternatively, the last advances in CFD and metamodeling techniques enables the development of optimization frameworks. The right conception of the aerostructural optimization problem is crucial to achieve noticeable reductions in the required amount of material and comprehensive safe designs. This paper reports the last advances in the authors' line of research that pursues the definition of a numerical methodology for the full aerostructural optimization of long-span bridges considering shape and size design variables. The capabilities of the method are presented, and the necessity of considering uncertainty in the process is discussed.

Sequential aero‐structural optimization method for efficient bridge design

“…The space coherence is modeled through the Davenport model assuming 𝐶 ux = 10, 𝐶 uz = 10, 𝐶 wx = 6.5, and 𝐶 wz = 3. The aerodynamic and aeroelastic parameters are obtained using the aerodynamic surrogate, as reported in Cid Montoya et al (2020). The RMS of lateral, vertical, and torsional buffeting-induced accelerations at 171 buffeting RP uniformly distributed along the deck are used to define the aeroelastic design constraints.…”

“…where 𝐶 𝐷 , 𝐶 𝐿 , and 𝐶 𝑀 are the steady-state drag, lift, and pitching moment coefficients, respectively, and 𝐶 ′ 𝐷 , 𝐶 ′ 𝐿 , and 𝐶 ′ 𝑀 are their slopes at a wind angle of attack 𝛼 = 0 • . This information is used to estimate the fluid-structure interaction parameters (Zhu et al, 2008), namely, the flutter derivatives and admittance functions, following the procedure described and validated through wind tunnel tests for streamlined decks in Cid Montoya et al (2020). The limitations and advantages of this approach were discussed in the references above, as well as alternative modeling approaches.…”

Refined Time‐Domain Buffeting Analysis of a Long‐Span Suspension Bridge in Mountainous Urban Terrain

“…Computational Fluid Dynamics (CFD) approaches are conducted to determine how the flow fields are changed by the subsidiary structures that influence the buffeting responses. is can provide insight into fluid mechanisms [40] and guide the structural designs in wind-engineering to a better level [45]. e details of the CFD simulation can be found in a previous work conducted by the author [46], where the accuracy of the simulation is validated by comparing the numerical aerostatic forces and experimental ones.…”