We demonstrate a distributed two-dimensional(2D)strain-sensing system in optical frequency domain reflectometry(OFDR)with an Archimedean spiral arrangement of the sensing fiber.The Archimedean spiral describes a simpl...We demonstrate a distributed two-dimensional(2D)strain-sensing system in optical frequency domain reflectometry(OFDR)with an Archimedean spiral arrangement of the sensing fiber.The Archimedean spiral describes a simple relationship between the radial radius and polar angle,such that each circle(the polar angle from0 to 2π)can sense the 2D strain in all directions.The strain between two adjacent circles can also be easily obtained because an Archimedean spiral facilitates sensing of every angle covering the full 2D range.Based on the mathematical relation of Archimedean spirals,we deduce the relationship between the one-dimensional position of the sensing fiber and 2D distribution in polar coordinates.The results of the experiment show that an Archimedean spiral arrangement system can achieve 2D strain sensing with different strain load angles.展开更多
The radiation fields of the Archimedean spiral antenna are derived by approximating the spiral with a series of semicircles. The computational formulae for calculating the radiation fields of the airborne spiral anten...The radiation fields of the Archimedean spiral antenna are derived by approximating the spiral with a series of semicircles. The computational formulae for calculating the radiation fields of the airborne spiral antennas are developed by using geometrical theory of diffraction (GTD). The calculated results are in good agreement with the experimental ones.展开更多
基金supported in part by the National Natural Science Foundation of China(Grant Nos.61505138,61635008,61475114,61735011)in part by the Tianjin Science and Technology Support Plan Program Funding(Grant No.16JCQNJC01800)+2 种基金in part by the China Postdoctoral Science Foundation(Grant Nos.2015M580199,2016T90205)in part by the National Instrumentation Program(Grant No.2013YQ030915)in part by the National Key Research and Development Program(Grant No.2016YFC0100500)
文摘We demonstrate a distributed two-dimensional(2D)strain-sensing system in optical frequency domain reflectometry(OFDR)with an Archimedean spiral arrangement of the sensing fiber.The Archimedean spiral describes a simple relationship between the radial radius and polar angle,such that each circle(the polar angle from0 to 2π)can sense the 2D strain in all directions.The strain between two adjacent circles can also be easily obtained because an Archimedean spiral facilitates sensing of every angle covering the full 2D range.Based on the mathematical relation of Archimedean spirals,we deduce the relationship between the one-dimensional position of the sensing fiber and 2D distribution in polar coordinates.The results of the experiment show that an Archimedean spiral arrangement system can achieve 2D strain sensing with different strain load angles.
文摘The radiation fields of the Archimedean spiral antenna are derived by approximating the spiral with a series of semicircles. The computational formulae for calculating the radiation fields of the airborne spiral antennas are developed by using geometrical theory of diffraction (GTD). The calculated results are in good agreement with the experimental ones.
