Experimental study on vibration characteristics of fluid-solid coupling cantilever thin aluminum plate

Abstract

Compared with the general environment, the modal characteristics of structures under fluid-solid coupling will show great differences. Reasonable experimental methods can provide reliable conclusion support for fluid-solid coupling research. In order to explore the modal characteristics of structures under the action of fluids, the interference and finite element numerical calculation methods are used to study the dry and wet modal characteristics of the cantilever aluminum plate under fluid-solid coupling. According to the amplitude fluctuation resonance discrimination method, the resonant frequency and mode of the cantilever aluminum plate under different working conditions are obtained accurately. Experiments show that the effect of the fluid will greatly reduce the natural frequency of the structure and have little effect on the vibration mode. With the gradual increase of the fluid-solid coupling interface, the natural frequency drop rate and the amplitude at the gas-liquid interface remain consistent, and slightly ahead of the amplitude characteristics. At the same time, for each mode with the same characteristics, the frequency decreasing trend is linear, such as the first few pure bending vibration modes, and the first few bending and twisting combined vibration modes contain first-order twisting vibration. The experimental results and the finite element numerical results are in good agreement, which shows that the electronic speckle method is a good test method for studying fluid-solid coupling modes. Most importantly, the experimental conclusion has reliable reference value for practical engineering applications.