Current Mechanical Engineering Student studying at University of Rochester. Meanwhile, working as an undergraduate research focusing on photo elastic material and its properties. The purpose of my research is deriving the same function equation for circular and triangular grains. To achieve this goal, I initially reproduced the experiment done by Daniels et al. By capturing the image of photoelastic disk under load, I can calibrate an important optical property of the material. Afterward, with an unknown load applied on the same disk, the load can be calculated reversely.Furthermore, I started exploring the properties in triangular material. By using finite element method purposed by Bower, I obtained the value for principal stresses at the material surface. However, this created a significant error since the edge of the triangular grain has a large deformation, which make the calculated stress become inaccurate. In this case, with the discussion with the professor, we change our approach. We stepped back to the circular disk and currently, I am trying to fit a polynomial function that relate the number of fringes to the applied load.