大型宽频带水下振动台流固耦合动力学特性的研究

为建立水下振动环境试验系统，对大型宽频带水下振动台中运动部件的流固耦合动力学特性进行了研究.根据水下振动台运动部件大尺寸和宽频带工作的要求，提出了运动部件结构的设计原则，进而建立其在水域中的模型及流固耦合有限元方程，由此计算分析了运动部件的两个重要模态振型及频率--台面弯曲振动振型和运动部件轴向振动振型，并与空气中的计算结果进行了比较，结果表明，流固耦合使得运动部件这两个模态频率降低；进一步的实验研究表明，计算分析结果是正确的,流固耦合使得运动部件等效阻尼变大.本研究结果为研制水下振动台系统的动态设计技术和测试分析技术提供了重要的依据.

Study on fluid-solid coupling dynamic characteristics of large wide-frequency-range underwater vibration tables

Dynamic characteristics of large wide-frequency-range vibration tables were studied in order to set up the underwater vibration testing environment system, the fluid-solid coupling dynamic. Due to the requirement of large dimension and wide-frequency-range of moving parts in the underwater vibration tables, the design principles of moving parts were applied. Then the model of the moving parts in the water and its fluid-solid finite element equation were built. Two important modals and their corresponding frequencies of the model in the water and air were separately ealculated-flexural vibration modal and axial vibration modal. The calculating results showed that the modal frequencies in the water are lower than those in the air. Moreover, the experimental results proved the above conclusions obtained by calculation. In the meantime, the experimental results also present the fact that the moving parts in the water have higher equivalent damping than in the air. The study will supply important clues for dynamic design and measurement of underwater vibration tables.