结合OFDR与Ko位移理论的变形估算研究

Study of deformation estimation combining OFDR and Ko displacement theory

Ko位移理论能够很精准地对结构进行变形重构,为了将这一理论应用到实际工程中,选用光频域反射(OFDR)分布式光纤传感器作为测量工具,设计了基于等强度梁的变形估算实验方案。实验在等强度梁上分六级加载,用百分表测得4个测点在每级荷载下的真实挠度值,并根据每级所测应变值进行挠度的变形重构,最后将2种方法所得到的挠度值进行对比。实验结果表明:光纤的应变系数为0.71666,变形重构挠度值与真实挠度值之间的最大误差为0.586 mm,符合实验预期。

The Ko displacement theory can reconstruct the structure accurately.In order to apply this theory to the practical engineering,the optical frequency-domain reflection(OFDR)distributed fiber sensor is used as the measuring tool,and an experimental scheme of deformation estimation based on equal strength beam is designed.The experiment is divided into six stages of loading on the beam of equal strength,and the true deflection values of four measuring points under each stage load are measured by dial gauge.The deformation reconstruction of deflection is carried out according to the strain value measured at each stage.Finally,the deflection values obtained by the two methods are compared.The experimental results show that the strain coefficient of the fiber is 0.71666,the maximum error between the deflection value of deformation reconstruction and the true deflection is 0.586 mm,which is in line with the experimental expectation.