关键词: 梯形结构, 大应变, 有限元分析, 光纤光栅

Abstract:

Aiming at the ‘flexible beam' type, ‘unit load method' was firstly employed to deduce the large strain transfer model of the trapezoidal frame. The model expression was clear and understandable. The finite element model of the trapezoidal frame was established in ANSYS, and the simulation results are in accordance with the deduced transfer model. A large strain sensor specimen based on the trapezoidal frame with a mounted fiber Bragg grating was home made. In experiments, the specimen's large strain was supplied by the motorized translation stage, and the fiber Bragg grating's wavelengths were interrogated by the manual optical inspector(MOI) instrument. The experimental results show an agreement with the theoretical analysis. And the spiecimen has a strain measuring range of -16%~33.3%, with the linearity less than 1%, the repeatability less than 1% and the hysterisis error less than 0.9%.

Key words: trapezoidal frame;large-strain sensing, finite element analysis;fiber Bragg grating