Research into using a fiber Bragg grating sensor group for three-dimensional in situ stress measurement

Abstract. The observation and estimation of the deep crustal stress state is a key difficult problem for in situ measurement. Using borehole wall strain gauge based on overcoring stress-relieving method one main methods In this paper, strain-sensing array fiber Bragg grating (FBG) designed by using structure classical hollow inclusion cell, its layout scheme studied. According to scheme, inversion algorithm hole deduced. Following this, triaxial loading unloading experiment platform built, calibration FBG sensor designed. Finally, Abaqus finite element software used simulate measurement process relief. values each direction before after are extracted, equation carry out inversion. comparison results proved that group feasible reliable. quasi-distributed module paper can invert three-dimensional measuring strain, which places theoretical experimental foundation development application an gauge. It makes up deficiency existing resistance gauge, provides direct accurate observations measurement, has important practical value technology.