In order to solve the problem of insufficient anti-eccentric load capacity of the pressure sensor in cable force monitoring,a combined pressure ring based on fiber Bragg grating is designed,and the strain transfer rate between the bonded fiber Bragg grating sen-sor and the substrate is theoretically analyzed.According to the cable force monitoring range,the design requirements are put forward for the elastic modulus,diameter,and quantity of bearing pillars of the combined fiber Bragg grating pressure ring and the pretension stress of fiber Bragg grating self-sensing rod.The cable force is monitored by recovering the pretension strain of eight quasi-distributed fiber Bragg grating sensors to eliminate the influence of eccentric load on the measurement results.The cyclic loading test of the combined fiber Bragg grating pressure ring is carried out by using the pressure testing machine.The results show that the combined fiber Bragg grating pressure ring can effectively monitor the load,its monitoring sensitivity is about 2.298 2×10-4 nm/kN,linearity error≤0.821%,hysteresis error≤0.382%,repeatability error≤3.758%,and total accuracy≤3.867%.The combined fiber Bragg grating pressure ring is used to monitor the cable tension of a bridge in real time,and it is mutually verified with the reading method of the oil pressure gauge and frequency method.Through analysis,it is found that the cable tension monitored by the fiber Bragg grating pressure ring and frequency method is similar,and the error is within 3.4%.The combined fiber Bragg grating pressure ring uses the subarea bearing and the recovery of pretension strain to realize compression monitoring,eliminate the measurement error caused by eccentric load bending,improve the monitoring accuracy,change the self-sensing rod pre-tension stress and the number of load-bearing pillars to achieve cable force monitoring of multiple specifi-cations of cables,and reduce the project monitoring cost.
关键词
索力监测/光纤光栅传感器/组合式压力环/抗偏载/应变传递率
Key words
cable force monitoring/fiber bragg grating sensor/combined pressure ring/anti-eccentric load/strain transmissibility
维普
万方数据