An analytical method in a quasi-static fiber grating sensing system under transverse uniform press is proposed based on genetic algorithm The effect of population size, generations, crossover ratio and mutation ratio ...An analytical method in a quasi-static fiber grating sensing system under transverse uniform press is proposed based on genetic algorithm The effect of population size, generations, crossover ratio and mutation ratio to genetic algorithm, and the optimization parameters of genetic algorithm were given. The relevant experimental system is constructed. The simulation and experiments show that the analytical method proposed can be applied to analyze the reflective spectra of the quasistatic FBG sensing system at transverse uniform press, the strain measurement with high-precision of 0.91% can be realized展开更多
We present a new calorimetric method for measuring alternative current(AC)losses of high-temperature superconducting(HTS)tapes by optical fiber Bragg grating(FBG),which is particularly well suited for the AC loss meas...We present a new calorimetric method for measuring alternative current(AC)losses of high-temperature superconducting(HTS)tapes by optical fiber Bragg grating(FBG),which is particularly well suited for the AC loss measurement of Re BCO wires,so-called the second generation(2G)HTS wires.Compared with conventional calorimetric methods,the suggested method is both free of electromagnetic disturbance,magnetic field,and fast as well as simple.Self-field AC losses are measured by the optical FBG method and the conventional lock-in-amplifier(LIA)technique,respectively.The results show that the measured AC loss is in good agreement with those measured by the electric method,thus the presented calorimetric method would be available for measuring the AC loss of 2G wire and is expected to be generalized for the measurement of AC loss or thermal performances of HTS bulk.展开更多
When a structure material is damaged by impact events, the reliability and lifetime of the material will be severely af- fected. So impact location is considered as the prime approach for structural health and damage ...When a structure material is damaged by impact events, the reliability and lifetime of the material will be severely af- fected. So impact location is considered as the prime approach for structural health and damage monitoring. In this study, a novel fiber Bragg grating （FBG） impact location system based on broadband light source is designed, aiming at the shortcoming of existing location systems based on FBG. An improved localization algorithm based on the time difference of arrival （TDoA） is proposed for impact location. According to this algorithm, the impact position can be accurately predicted without wave velocity. Impact planar location experiments are carried out for verification of the FBG impact location system and algorithm on a 400 mmx400 mmx3 mm aluminum alloy plate. The resulted locating error shows high precision and good stability of the proposed system.展开更多
文摘An analytical method in a quasi-static fiber grating sensing system under transverse uniform press is proposed based on genetic algorithm The effect of population size, generations, crossover ratio and mutation ratio to genetic algorithm, and the optimization parameters of genetic algorithm were given. The relevant experimental system is constructed. The simulation and experiments show that the analytical method proposed can be applied to analyze the reflective spectra of the quasistatic FBG sensing system at transverse uniform press, the strain measurement with high-precision of 0.91% can be realized
基金supported by the National Natural Science Foundation of China(Grant No.51477053)the Beijing Education Commissions(Grant No.GJ2013009)
文摘We present a new calorimetric method for measuring alternative current(AC)losses of high-temperature superconducting(HTS)tapes by optical fiber Bragg grating(FBG),which is particularly well suited for the AC loss measurement of Re BCO wires,so-called the second generation(2G)HTS wires.Compared with conventional calorimetric methods,the suggested method is both free of electromagnetic disturbance,magnetic field,and fast as well as simple.Self-field AC losses are measured by the optical FBG method and the conventional lock-in-amplifier(LIA)technique,respectively.The results show that the measured AC loss is in good agreement with those measured by the electric method,thus the presented calorimetric method would be available for measuring the AC loss of 2G wire and is expected to be generalized for the measurement of AC loss or thermal performances of HTS bulk.
基金supported by the National Natural Science Foundation of China(Nos.61503218,61403233,61573226 and 61473176)the Excellent Young and Middle-Aged Scientist Award Grant of Shandong Province of China(No.BS2013DX018)the Natural Science Foundation of Shandong Province for Outstanding Young Talents(No.ZR2015JL021)
文摘When a structure material is damaged by impact events, the reliability and lifetime of the material will be severely af- fected. So impact location is considered as the prime approach for structural health and damage monitoring. In this study, a novel fiber Bragg grating （FBG） impact location system based on broadband light source is designed, aiming at the shortcoming of existing location systems based on FBG. An improved localization algorithm based on the time difference of arrival （TDoA） is proposed for impact location. According to this algorithm, the impact position can be accurately predicted without wave velocity. Impact planar location experiments are carried out for verification of the FBG impact location system and algorithm on a 400 mmx400 mmx3 mm aluminum alloy plate. The resulted locating error shows high precision and good stability of the proposed system.
