The Study On Photo-elaticity Method Test For Granular Matter In Linear Light Field

The utilization of photoelastic experiment method to study granular stress in granular systems has the great advantage of gaining in-system load distribution without disturbing the system.In this paper,the method of using photoelasticity method to study the interaction force of granular in granular system has been studied.In view of the lack of research on non-circular particle samples using linear polarization field in the research status,this paper designs an experimental study of the elliptical particle samples in the linear polarization field performance.In the process of setting up the experiment,the experimental accuracy was improved by introducing a LED light and introducing dichroic filter.By comparing the RGB image mode with the green channel image mode,the green channel image mode with higher data sensitivity is selected as the data analysis basis and the experimental procedure is finally established.PMMA(Polymethylmethacrylate)was finally selected as the material for the preparation of experimental particles by comparing different materials under linear polarization.By means of the fringe behavior of the PMMA material in the linear polarization field,we introduce the analytical method of the local average light intensity.By means of Taylor expansion,the relationship between the load and the light intensity in a linear polarization field has a relationship of sin~2 theta Simplify and use the quadratic polynomial function to fit the relationship between the local mean intensity near a load point and the load on this load point.By comparing the experimental results of three different types of contact points and three groups of different loading directions,the quadratic function of the average local light intensity and the applied load in the linear polarization field of the elliptical particles is given by a comprehensive average of three experiments formula.The contact area method was introduced and the relationship between the stress of the particle sample near the contact point and the local average intensity was obtained.