基于光纤光栅技术的半刚性基层力学响应测试分析

依托104国道改建项目，开展了光纤光栅传感器在半刚性基层动静态力学响应测试中的应用研究。通过测试静载和动载作用下半刚性基层底拉应变，分析静载作用下轴重对半刚性基层底拉应变的影响，以及动载作用下车速对半刚性基层底拉应变的影响。研究表明，静载作用下半刚性基层底拉应变与荷载大小呈正比，且随荷载值增加拉应变增长率不断减小，当荷载较小时，基层承受大部分荷载，层底拉应变实测值大于理论值，随荷载的增加，实测值逐渐趋近理论值，即受力情况逐渐趋于结构整体受力；动载作用下，半刚性基层底拉应变与荷载大小呈正比，与车辆车速呈反比。测试结果表明光纤光栅传感器与半刚性基层协同变形良好，能较好地用于半刚性基层应变场的测试，应用前景广阔。

Experiments and Analysis on the Mechanical Response of the Semi-rigid Substrate Using Fiber Bragg Grating Sensing Technology

Relying on the NO.104 National Road renovation project,one application research which is using Fiber Bragg Grating(FBG)sensor to test the static and dynamic mechanical response of the semi-rigid substrate is carried out. By testing layer bottom’s tensile strain of the semi-rigid substrate under static and dynamic load effect,analy?sis the tensile strain on the impact of both static axle load and vehicle speed of dynamic load. The research indi?cates,the tensile strain of the semi-rigid substrate which is under static load effect is proportional to the value of the load,and the tensile strain growth rate is decreasing with the increasing load value. When the load is small,the mea?sured value of tensile strain is greater than the theoretical value,because the substrate bears majority load;with the load increasing,the measured value is gradually approaching the theoretical value,that means the pavement struc?ture resists load as a whole. Under the dynamic load effect,the tensile strain of the semi-rigid substrate is propor?tional to the value of the load and is inversely proportional to the vehicle speed. The test results show that Fiber Bragg Grating sensor has good coordination deformation with semi-rigid substrate,therefore,it can be better used to test the semi-rigid substrate strain and has broad application prospects.