Flexible thin manufactures (sheets) are used in numerous engineering applications. In their manufacturing processes, the sheets are subjected to a fluid flow, and external disturbances can induce vibrations. The vibrations cause severe damage to the sheets. Therefore, an in-depth understanding of the vibration characteristics and excitation mechanism of a sheet in a fluid flow is essential. In this study, the vibration characteristics and excitation mechanism of a sheet under a harmonic forced excitation are investigated by both theoretical calculations and experiments. In the experiments, a harmonic displacement excitation is inputted at the leading edge of a sheet in a wind-tunnel by an exciter using the slider–crank mechanism. In the theoretical analysis, the sheet is modeled as a cantilevered beam, and the fluid force acting on the sheet surface is calculated using three-dimensional theory. The frequency response of the sheet in a uniform flow is investigated with changing the flow velocities and forcing frequencies inputted to the sheet. Finally, the work done by the fluid force acting on the sheet under the harmonic excitation is determined, and the excitation mechanism is discussed.

It is found that the flow velocity considerably affects the sheet response. As the flow velocity increases, the amplitude of the second peak of the response becomes larger than that of the first peak. Moreover, the vibration mode of the second peak of the response transforms into a traveling-wave-type mode due to the modal coupling caused by the fluid force.

柔性薄制品（片材）用于众多工程应用中。在它们的制造过程中，片材经受流体流动，并且外部干扰会引起振动。振动会严重损坏纸张。因此，深入理解流体中的片材的振动特性和激发机理是必不可少的。在这项研究中，通过理论计算和实验研究了板在谐波强制激励下的振动特性和激励机理。在实验中，由激振器使用滑块-曲柄机构将谐波位移激励输入到风洞中板的前端。在理论分析中，板材被模拟为悬臂梁，利用三维理论计算作用在板材表面的流体力。通过改变流速并强迫输入到薄片的频率来研究薄片在均匀流动中的频率响应。最后，确定了在谐波激励下作用在薄板上的流体力所完成的功，并讨论了激励机理。

发现流速显着影响纸张响应。随着流速的增加，响应的第二个峰值的幅度变得大于第一个峰值的幅度。此外，由于流体力引起的模态耦合，响应的第二峰值的振动模式转变为行波型模式。