Quantitative Detection of Contact Force Chains in a Model Particle Assembly Using Digital RGB Photoelastic Measurements

This paper explains a newly developed technique for identifying particles belonging to the contact force chains in a model particle assembly. This was accomplished through digital image analysis of the color images obtained from photoelastic measurements. Descriptive statistics for RGB color intensities of pixels in a central square region inside the particle were digitally measured to determine the particle force, as opposed to the traditional method of counting fringe orders. The relationships between the descriptive statistics of the RGB color intensities and the applied forces were analyzed. The developed image analysis technique was applied to digital photoelastic images of an assembly of stacked particles. This technique could embed the numeric data of the particle forces in the digital photoelastic images which provide comprehensive information for a quantitative analysis of the progressive evolution of the soil arching phenomena in a particulate media.