Development Of The Experimental Apparatus Of Young's Modulus Measuring Based On Fiber-optic Sensors

Young's modulus, as one of the basic mechanical parameters that represent the properties of solid materials, is one of the bases for material selection in engineering design. It can be said that the measurement of Young's modulus is of great significance in scientific research and engineering design. Young's modulus measurement experiment is a relatively comprehensive experiment, many schools put the young's modulus measurement experiment as a physical experiment course will do experiment, is to students to master the relevant knowledge and skills.At present, there are many kinds of experimental instruments for measuring Young's modulus. These instruments are based on different principles, and they have different characteristics for different measuring conditions.Based on the optical fiber displacement sensor system as the research object, the author has developed the young's modulus measuring instrument based on reflective optical fiber displacement sensor, a new method is given by using the measurement of wire micro deformation of the optical fiber displacement sensor. The main contents of this paper include: (1)In this paper, the basic concept of Young's modulus is introduced briefly, and the main classification and measuring method of Young's modulus tester are discussed.(2)This paper introduces the basic theory of optical fiber sensors, introduces the reflective optical fiber displacement sensor structure, working principle and its characteristics, and studies the main components of the optical fiber displacement sensor system, including the classification and characteristics of the light source of the fiber optic sensor system, the basic working principle, classification and characteristics of the photoelectric detector.(3) According to the actual experimental system conditions, the device of the optical fiber sensor system is selected and analyzed. The driving circuit of the light source and the signal amplifying circuit of the photoelectric detector are also studied.According to the experimental requirements, the function, characteristics and communication interface circuit of the master chip are analyzed and studied.(4) The software of the upper computer and the lower computer of the experimental instrument is studied. The functions of data conversion and transmission of the slave computer and the data processing and display functions of the host computer are realized by software design.(5) The experimental platform for measuring Young's modulus is built, and the micro elongation of the wire is measured,and the experimental data are obtained. The young's modulus of the wire is obtained by processing the upper computer.The feasibility of the scheme is verified by testing the experimental instrument and analyzing the experimental results. The newly developed device has less adjustment steps and convenient operation. It can make the students learn the knowledge of the optical fiber displacement sensor while measuring Young's modulus.