Optimization of geometrical parameters for periodical structures applied to floating raft systems by genetic algorithms

•The power transmissibility of a floating raft system was investigated.•Stop bands of periodic structures were utilized to decrease power flow.•A practical design approach for optimization of periodic structures was developed.•A genetic algorithm and the transfer matrix method were utilized.

This paper presented a theoretical study of the vibration control of a floating raft system using periodic structures. The band gap properties of the periodic structures, the power flow and the power transmissibility of the floating raft system were investigated by using the transfer matrix method. To minimize the power flow through periodic structures in a floating raft system, the geometrical parameters of the periodic structures were optimized by using a genetic algorithm. The numerical results demonstrated that the optimum periodic structure can provide broader stop band regions. The stop band regions of the optimum periodic structure contained all the harmonic frequencies of the force excitation in the floating raft system. The numerical results validated that the proposed optimization approach is sufficiently capable for the design of periodic structures. The proposed optimization approach has potential use for the development of vibration and shock isolation systems such as floating raft systems.