Study On The Mechanical Properties Of Plexiglass By Laser Wavenumber Scanning Interferometry

The chemical name of the plexiglass material is polymethyl methacrylate,which is a polymer compound material with good elasticity,transparency,and weather resistance.It is widely used in medical,construction,aerospace,machinery and other fields.Considering that organic glass has defects such as pores and cracks due to process parameters during preparation or external factors in actual use.Therefore,it is of great significance to test the mechanical properties of plexiglass in tensile,porosity,and fracture.There are many methods for detecting plexiglass.The laser wave number scanning interferometry technique based on Michelson interferometer used in this paper determines the mechanical properties of plexiglass by analyzing the tensile displacement field distribution of the tangent plane before and after loading.The loading method uses a precision mechanical testing machine as a standard,which further improves the reliability and accuracy of the experimental results.It is verified that the laser wavenumber scanning interference technology as a non-contact optical detection method provides a new method for the detection method in the field of organic glass.This thesis first cuts into the research background of organic glass,analyzes the necessity of mechanical properties analysis of organic glass,and the research history and research results of laser wavenumber scanning interferometry technology as non-destructive non-contact optical detection.The theoretical basis of laser wavenumber scanning interferometry is introduced,including wavenumber scanning principle,wavenumber calculation method,random sampling Fourier transform,calculation method of off-plane and tangential displacement fields,and system performance parameters.Then on the basis of theory,the mechanical design of the measurement system was improved,and the design of the optical path system,the selection of system hardware components,the calibration of the camera,the operating steps of the mechanical testing machine,and the design concept of the mechanical loading device were analyzed.Finally,combined with the theory and hardware system,the experimental methods and experimental operating procedures for the mechanical property testing of plexiglass are given.Based on this,the experimental results of non-defective plexiglass and pore-containing plexiglass are analyzed.The distribution diagram of the tensile displacement field of the tangent plane of the glass is compared with the experimental measurement results and the data of the mechanical testing machine.From the experimental results,it can be seen that the tensile displacement field distribution of the plexiglass under the load of a mechanical testi ng machine is basically consistent with the actual stress condition of the material,showing the result that the displacement changes linearly with the load.And the experimental results of the measurement system and the load data of the mechanical testing machine basically agree within the error range.The comparative analysis of the experimental results shows the feasibility of laser wavenumber scanning interferometry as a high-precision full-field non-contact optical detection method.The measurement system has high signal-to-noise ratio,detection speed and reliability.It is proved that laser wavenumber scanning interference technology has better potential value and development prospect in the field of plexiglass detection.