Research on deformation field reconstruction of elastic thin plate based on fiber Bragg grating strain monitoring

Abstract

In this paper, a new deformation measurement method based on fiber bragg grating strain monitoring is proposed. Aiming the four-sided fixed elastic thin plate structure, an algorithm for reconstructing deformation field based on fiber bragg grating strain monitoring is proposed. The mechanical model of elastic thin plate was established. According to the degree of deformation, it can be divided into small deflection deformation and large deflection deformation. The relationship between surface strain and curvature of a thin plate was deduced. On this basis, a curvature iteration method was proposed to reconstruct the deformation field of thin plates. Aiming at the non-linear problem of large deflection deformation, a subsidence correction algorithm based on curvature iteration method was proposed. The experimental platform for strain monitoring of thin plate and several different loading conditions was established. Based on the discrete point strain data obtained by fiber bragg grating strain monitoring, the strain field is reconstructed to obtain detailed strain information. Based on the curvature iteration method and strain information, the deformation curves of thin plates under different loads are obtained. The experimental results show that the average error of reconstruction of the elastic thin plate structure is 6%, and the reconstructed results can accurately reflect the deformation surface of elastic thin plate. It also provides a basis for the study of deformation field reconstruction under complex constraints.