利用光纤曲率传感器测量轴向应变

为了实现对轴向线应变的测量,建立了光纤曲率传感器的轴向线应变测量系统。对系统中传感器的布置方式、敏感区的位置优化和测量系统的数学模型等进行了研究。根据光纤曲率传感器只对曲率变化敏感的特性,将传感器绕成圆弧形布置在被测物体的表面,并保持传感器敏感区表面与被测物体表面垂直;对传感器上的点在轴向力作用下的移动轨迹进行了分析,建立了轴向线应变与传感器曲率之间的数学模型;在上述数学模型的基础上,对传感器敏感区的位置进行了优化。最后,对聚氨脂橡胶块在电子万能实验机上进行压缩,使其产生轴向线应变,利用上述的测量系统对聚氨脂橡胶块的轴向线应变进行了测量实验。实验结果表明,本文系统的应变测量精度为0.002 8应变单位。

Axial strain measurement based on curvature fiber optic sensor

In order to realize the axial strain measurement,an axial strain measurement sys tem based on curvature fiber optic sensor is established and its algorithms,such as the layou t of the sensor,and the position optimization of sensitive zone,and the mathemat ical model of measuring system are investigated.Firstly, based on the characteristic that the curvature fiber optic sensor is only sensit ive to the curvature changing,the curvature fiber optic sensor including a circular arc is arranged on the surface of object and make sure that the sensitive zone is perpendicular to the surface of object.The moving paths of po ints on fiber optic sensor under axial loading are analyzed and the mathematical model is set up between axial st rain and curvature changing of fiber optic sensor.Then,based on the above mathematical model,the position op timization of sensitive zone is done.Finally,polyurethane rubber block is compressed on electronic all-powerf ul experiment machine and makes it undergo an axial deformation.The proposed measuring system is used to measur e the axial strain of polyurethane rubber block.Experimental results indicate that the maximum strain deviation is 0.0028,which shows the validity of the measuri ng system.