Measurement of flow-induced vibrations using a fiber Bragg grating sensor

摘要

Abstract: A fiber-optic bragg grating sensor for flow-induced vibration measurement is described. The sensor is based on monitoring shift in the Bragg wavelength of a fiber Bragg grating. the fiber Bragg grating, when bonded onto a structure, can measure local axial strain variation of the structure. The strain can be related to the structural bending displacement. Experiments were conducted to measure the flow-induced vibration of a cylinder in a crossflow. The measurement results in terms of then natural frequency of the fluid-structure system and the vortex shedding frequency are consistent with the result obtained from a laser vibrometer. Fiber Bragg grating sensors have potential applications in the study of fluid-structure interactions of cylinder arrays in a crossflow. !11