简易桥式起重机的力学结构是一种简支梁, 研制了一种行车模型, 主要包括工字梁及一个可吊挂重物的滑块。光纤Bragg光栅沿工字梁的轴向均匀粘贴于行车主梁的下表面, 测点分别位于离主梁的1/4、1/2和3/4等三个位置。在测量中, 通过吊挂重物对主梁产生挠度, 从而导致粘贴其下表面的光纤Bragg光栅产生波长移位。载荷试验表明, 在主梁中心进行加载和卸载时, 位于3个测点的光纤Bragg光栅的波长移位-挠度灵敏度分别为259 pm/mm, 440.5 pm/mm, 270.5 pm/mm。该方法可实现对行车的实时测量, 还能避免人为误差。

Because the mechanical structure of simple bridge crane is a simply supported beam, a crane model is developed with an I-beam, a slider, and a hanging weight. Three fiber Bragg gratings are mounted on the bottom surface of main beam along the axis of I-beam, where the measuring points are located at the three positions of 1/4, 1/2, and 3/4 length of main beam. In the measurement, the deflection of main beam is induced by hanging weights, which causes the wavelength shift of fiber Bragg grating mounted on the bottom surface of main beam. The Loading experiment indicates that the load sensitivities of three measuring gratings are respectively 259 pm/mm, 440.5 pm/mm, and 270.5 pm/mm. This method can not only offer an on-line monitor for crane, but also avoids artificial errors.