Study of Fiber Optic Sensing Monitoring on Ultra-High Performance Concrete Considering Shear-lag Correction

The strain transfer correction model is proposed for the surface-adhesive tubular fiber sensor on Ultra-High Performance Concrete (UHPC). The adhesive layer shear stress is assumed to be quadratically distributed and displacement averaging method is used, and the effect of internal shear stress in the structural body is also considered, so that the corrective model proposed in this paper has an error of no more than 1% in the numerical calculations and finite element simulation results. The tensile test experiments were completed on the UHPC, and the strain transfer coefficients are 0.919, 0.911, and 0.913, with an average value of 0.914, which was more consistent with the theoretical result of 0.95, with an error of 3.79%. The linearity of fiber sensor in the three repeated experiments is good, the repeatability error is small, the R<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> is above 0.99, and the hysteresis error is 3.33%.