缆索内置光纤光栅应变传感器研究

Research on optical fiber grating strain sensor implanted in cable

针对缆索局部埋植传感器测试索力的特殊要求,特制光纤光栅应变传感器,传感器封装保证光纤光栅植入缆索的成活率,减敏结构设计保证缆索索力测试的大应力监测要求。针对应变传感器与钢丝的2种连接方式,即传统的结构胶连接和特制的抱箍机械连接方式进行了张拉性能测试。由标定的传感器力敏系数可知,在钢丝产生5 000×10-6的应变变化下,光纤光栅实际中心波长变化不超过2 900 pm,达到了减敏效果,传感器可以满足大索力长期测试要求。

Aimed at the special demand on the cable locally integrated with the sensor for cable force monitoring, the specific fiber grating strain sensor was designed. The sensor encapsulation assured the survival rates of fiber grating implanted in the cable. The sensor desensitization guaranteed the need of big stress monitoring. Two connected ways between the steel wire and the sensor were researched,which was using the glue and the designed hoop. The two connection ways were tested for the single steel wire tension performance test. From the calibrated force-sensitive coefficients, the practical central wavelength variations of the fiber grating changed within 2 900 pln when the steel wire strain changed 5 000 ~ 10-6. The results showed that the sensor design reached the desensitization effect and could meet the need of long-term cable force monitoring.