Present-day large mobile objects such as the ships are equipped with a large number of different devices and systems whose mutual angular position must be known to a high degree of accuracy. Owing to static and dynamic deformations of the object, the angular position of peripheral apparatus such as optical systems, radar antennas , etc. may differ essentially from that of central devices. For removing the effects of angular deformation, suitable measurement methods should be studied. The problem of evaluation for angular deformation measurement particularly is becoming urgent for large-sized vehicles such as big ships, spacecrafts, etc. Fiber Bragg Grating (FBG) sensors can be used to measure many different parameters including strain, temperature, pressure, displacement, electrical field etc. With the major advantages which is attributed to wavelength-encoded information given by the Bragg grating, deformation measurement system based on FBG is briefly introduced. As strain measured by FBG sensor can be obtained, an angular deformation measurement method using strain information is proposed. Strain response modality model is deduced based on finite element method (FEM). Based on strain response modality model, experiment strain modality analysis is done and strain response calculation model can be set up. Then transformation between strain information and angle deformation is deduced, and the results comparison between using strain response analysis method and using ANSYS analysis method for simple ship deck structure under different loads is made. The simulation results show that angular deformation measurement method using strain response analysis is suitable to meet the measurement requirement.

Date Published: 31 December 2008
PDF: 6 pages
Proc. SPIE 7130, Fourth International Symposium on Precision Mechanical Measurements, 71300C (31 December 2008); doi: 10.1117/12.819548

Published in SPIE Proceedings Vol. 7130:
Fourth International Symposium on Precision Mechanical Measurements
Yetai Fei; Kuang-Chao Fan; Rongsheng Lu, Editor(s)