Abstract: The design of structural dynamic performance is inevitable in the design and manufacturing process of complicated equipment. A topology and free size collaborative optimization method considering the dynamic response is proposed for the design requirements of the complicated shipborne antenna pedestal structure. A topology optimization model with the maximum weighted frequency as the objective function is established, and the stress amplitude of the structure under harmonic excitation is considered as the design constraint. The sensitivity information of the objective function and the constraint function with respect to the design variables is derived. Take the antenna pedestal structure as an example, the topology-freesize collaborative optimization design is carried out for the hybrid model of solid and shell. The topology optimization results determine the internal structural configuration, and the free size optimization results determine the approximate thickness distribution of the shell. When considering manufacturability, precise size design is carried out. Subsequently, the optimization model was remodeled and checked. The proposed method can effectively spare repeated iterations in the design process to improve efficiency. The design results show that the proposed collaborative optimization method significantly improves the first three orders of natural frequencies of the structure and greatly reduce the maximum stress amplitude, displacement amplitude of the structure under the most severe operating conditions, and achieve a better structural design of the antenna pedestal.

Key words: topology optimization, free size optimization, dynamic response, weighted frequency, antenna pedestal