Abstract: The length of box-type girder of bridge crane is much greater than the height and width. It is difficult to obtain a solution or a clear and periodic topology configuration using conventional algorithm. In order to obtain a periodic structure which is easy to manufacture, periodic topology optimization is applied to the lightweight design of bridge crane’s girder. The optimization domain of girder is divided into some sub-domains and the relation between sub-domains and optimization domain is structured. The mathematical model of girder for periodic topology optimization is built, in which mean compliance is taken as objective function under volume constraint condition. Periodic topology optimization of girder is researched under the strength and static rigidity criterion. Results show that periodic holes are appeared in sub-domains during optimization process. Until periodic topology optimization is over, a similar trussed topology configuration is obtained. Even when the number of sub-domains is different, periodic topology configuration which has a good consistency and manufacturability is achieved. A feasible approach is proposed aiming at lightweight design for bridge crane.

Key words: box-type girder, bridge crane, periodicity, topology optimization