The shift mechanism of Bragg wavelength with stress variation for a fiber grating is investigated in detail. The influence of strain change on reflection and bandpass is theoretically analyzed. By applying stress, the...The shift mechanism of Bragg wavelength with stress variation for a fiber grating is investigated in detail. The influence of strain change on reflection and bandpass is theoretically analyzed. By applying stress, the dynamic single/dual channel filter with tunable fiber Bragg gratings is achieved.展开更多
The reinforcement effect of a reconstruction scheme for a steel factory building was investigated using finite element method and dynamic performance test. The workshop concerned is a portal frame structure with four ...The reinforcement effect of a reconstruction scheme for a steel factory building was investigated using finite element method and dynamic performance test. The workshop concerned is a portal frame structure with four spans and two slope roofs, of which ten columns need cutting for expanding span. The design and reconstruction project of column-cut supported by joist were introduced, which includes column reinforcement, connection rebuilding between brackets and crane beams, and the changing of rigid joint into hinge joint. The construction scheme was put forward in the light of the characteristics of the reinforcement and reconstruction. Spot test of dynamic performance on the workshop and comparison with theoretical analysis results show that the column-cut supported by joist design is effective and the reconstruction project is successful.展开更多
An asymmetric fiber （Fabry-Perot, F-P） interferometric cavity with the good linearity and wide dynamic range was successfully designed based on the optical thin film characteristic matrix theory; by adjusting the ma...An asymmetric fiber （Fabry-Perot, F-P） interferometric cavity with the good linearity and wide dynamic range was successfully designed based on the optical thin film characteristic matrix theory; by adjusting the material of two different thin metallic layers, the asymmetric fiber F-P interferometric cavity was fabricated by depositing the multi-layer thin films on the optical fiber＇s end face. The asymmetric F-P cavity has the extensive potential application. In this paper, the demodulation method for the wavelength shift of the fiber Bragg grating （FBG） sensor based on the F-P cavity is demonstrated, and a theoretical formula is obtained. And the experimental results coincide well with the computational results obtained from the theoretical model.展开更多
文摘The shift mechanism of Bragg wavelength with stress variation for a fiber grating is investigated in detail. The influence of strain change on reflection and bandpass is theoretically analyzed. By applying stress, the dynamic single/dual channel filter with tunable fiber Bragg gratings is achieved.
基金Supported by Program for New Century Excellent Talents in University (No. NCET-06-0228)
文摘The reinforcement effect of a reconstruction scheme for a steel factory building was investigated using finite element method and dynamic performance test. The workshop concerned is a portal frame structure with four spans and two slope roofs, of which ten columns need cutting for expanding span. The design and reconstruction project of column-cut supported by joist were introduced, which includes column reinforcement, connection rebuilding between brackets and crane beams, and the changing of rigid joint into hinge joint. The construction scheme was put forward in the light of the characteristics of the reinforcement and reconstruction. Spot test of dynamic performance on the workshop and comparison with theoretical analysis results show that the column-cut supported by joist design is effective and the reconstruction project is successful.
文摘An asymmetric fiber （Fabry-Perot, F-P） interferometric cavity with the good linearity and wide dynamic range was successfully designed based on the optical thin film characteristic matrix theory; by adjusting the material of two different thin metallic layers, the asymmetric fiber F-P interferometric cavity was fabricated by depositing the multi-layer thin films on the optical fiber＇s end face. The asymmetric F-P cavity has the extensive potential application. In this paper, the demodulation method for the wavelength shift of the fiber Bragg grating （FBG） sensor based on the F-P cavity is demonstrated, and a theoretical formula is obtained. And the experimental results coincide well with the computational results obtained from the theoretical model.
