Structural topology optimization of bridge girders in cable supported bridges

This work applies a ultra large scale topology optimization method to study the optimal structure of bridge girders in cable supported bridges. The current classic orthotropic box girder designs are limited in further development and optimization, and suffer from substantial fatigue issues. A great disadvantage of the orthotropic girder is the loads being carried one direction at a time, thus creating stress hot spots and fatigue problems. Hence, a new design concept has the potential to solve many of the limitations in the current state-of-the-art. We present a design method based on ultra large scale topology optimization. The highly detailed structures and fine mesh-discretization permitted by ultra large scale topology optimization reveal new design features and previously unseen effects. The results demonstrate the potential of generating completely different design solutions for bridge girders in cable supported bridges, which differ significantly from the classic orthotropic box girders. The overall goal of the presented work is to identify new and innovative, but at the same time constructible and economically reasonable, solutions to be implemented into the design of future cable supported bridges.