基于光纤光栅的螺纹钢标准试件拉伸应变分析与测量

Analyses and measurement of stretch strain based on fiber Bragg grating

利用光纤光栅作为传感元件,对螺纹钢标准拉伸试验试件的拉伸应变特性进行了分析与测量,采用电阻应变片作为对比测量,并与理论值进行了比较。测量结果FBG2的应变测量灵敏度为15.647 με/kN非常接近理论期望值15.680 με/kN,而电阻应变片的应变测量灵敏度仅为14.162 με/kN:同时,利用光纤光栅测量钢筋试件弹性模量,其中FBG2测得弹性模量为2.03×105MPa与标准测量值一致。结果表明,作为测量应变的常用仪器,光纤光栅比电阻应变片具有更强的实用性。

Using the sensitive characteristic of fiber grating, the standard thread steel bar has been measured in our experiments. The data measured by FBG and resistance strain chip are compared with their theoretical values. The measured strain sensitivity of FBG2 is 15.647 με/kN approaching to the theoretical value 15.680 με/kN, and the strain sensitivity of resistance strain chip is only 14.162 με/kN. Moreover, an applied method to measure the elasticity modulus of material by FBG is proposed. Measured value of FBG2 is 2.03× 105MPa equal to the standard value of elasticity modulus of material. The results indicate that the measurement of fiber grating is more effective and exact compared with the resistance strain chip as a strain measurement instrument.