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Electrical and Computer Engineering Commons

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Full-Text Articles in Electrical and Computer Engineering

Fringe Visibility Enhanced Extrinsic Fabry-Perot Interferometer Using A Graded Index Fiber Collimator, Yinan Zhang, Yanjun Li, Tao Wei, Xinwei Lan, Ying Huang, Genda Chen, Hai Xiao May 2010

Fringe Visibility Enhanced Extrinsic Fabry-Perot Interferometer Using A Graded Index Fiber Collimator, Yinan Zhang, Yanjun Li, Tao Wei, Xinwei Lan, Ying Huang, Genda Chen, Hai Xiao

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

We report a fringe visibility-enhanced extrinsic Fabry-Perot interferometer (EFPI) by fusion splicing a quarter-pitch length of a graded-index fiber (GIF) to the lead-in single mode fiber (SMF). The performance of the GIF collimator is theoretically analyzed using a ray matrix model and experimentally verified through beam divergence angle measurements. The fringe visibility of the GIF-collimated EFPI is measured as a function of the cavity length and compared with that of a regular SMF-EFPI. At the cavity length of 500 μm, the fringe visibility of the GIF-EFPI is 0.8, while that of the SMF-EFPI is only 0.2. The visibility-enhanced GIF-EFPI may …


Design, Construction And Load Testing Of The Bridge On Arnault Branch, Washington County, Missouri Using Innovative Technologies, Dongming Yan, Genda Chen, Nestore Galati, Sahra Sedigh Feb 2010

Design, Construction And Load Testing Of The Bridge On Arnault Branch, Washington County, Missouri Using Innovative Technologies, Dongming Yan, Genda Chen, Nestore Galati, Sahra Sedigh

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The superstructure and instrumentation designs of a three-span bridge are presented in this report. The three spans include a precast box-girder bridge, a precast deck on steel girder and a precast deck on concrete girder. They were designed to compare the performance of various bridge decks reinforced with fiber reinforced polymers (FRP) through field instrumentations. A wireless monitoring system was designed to facilitate the collection of field data after the completion of bridge construction. The collected data will allow the study of FRP bars and stay-in-place FRP grid systems.


Crack Detectability And Durability Of Coaxial Cable Sensors In Reinforced Concrete Bridge Applications, Genda Chen, Ryan D. Mcdaniel, Michael A. Brower, David Pommerenke Jan 2010

Crack Detectability And Durability Of Coaxial Cable Sensors In Reinforced Concrete Bridge Applications, Genda Chen, Ryan D. Mcdaniel, Michael A. Brower, David Pommerenke

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The working mechanism and the measurement principle of topology-based crack sensors made of coaxial cables are briefly reviewed. The sensitivity, spatial resolution, and ruggedness of two coaxial cable sensors, respectively made of rubber and Teflon dielectric materials, were compared and validated with laboratory testing of a 4/5-scale, T-shaped, reinforced concrete beam-column specimen. Two Teflon sensors were installed on one of the solid decks of a three-span continuous highway bridge to investigate their durability and measurement repeatability. Laboratory tests indicated that both types of sensors have high sensitivity, but the Teflon sensor has a higher spatial resolution and a negligible spillover …