Objectives One-way periodic stiffened plates are widely used in ship structures, and their vibro-acoustic characteristics provide a theoretical reference for the analysis and optimization of the sound and vibration characteristics of stiffened plates.
Methods Considering the force and torque of the stiffeners to the plate, along with the coupling effect between the fluid acoustic medium and the plate, a structural dynamic model of infinite one-dimensional and two-dimensional periodically stiffened plates is established. The spatial domain is transformed into a space wave number domain using the Fourier transforms method. The vibration equation of the stiffened structure is deduced using the constructor, Poisson's formula and periodic function. The analytical solution of the motion equations of typical periodic stiffened plates is obtained and calculated under a time-harmonic point force or harmonic excitation. Combined with the stationary phase method, the far field radiated sound pressure can be obtained. The influence of the torque of the stiffener, excitation types, excitation locations, plate thickness, periodicity spacing and parameters of stiffeners on the sound radiation characteristics of three different models of periodic stiffened plates are numerically quantified.
Results The torque of the stiffener has a lesser effect on structural vibration characteristics. The influence of the stiffener parameters on the phonon crystal band gap can be used to attenuate the vibration at certain peak frequencies. The excitation load on the strong structural components can effectively weaken the vibration. The periodicity spacing and parameters of the stiffeners have obvious effects on structural vibration characteristics.
Conclusion The underwater acoustic vibration characteristics of reinforced plate structures can be effectively optimized by the reasonable setting of the excitation types and parameters of the stiffeners.
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