@edcanop I was curious about the uniaxial compression test you mentioned. Sorry to cross pollinate, but I am using MFIX-Exa. I ran a uniaxial compression test just as in the paper. The results are slightly different, likely due to Hertz vs LSD. (This is still running so it’s only a partial curve, but still enough to show my confusion.) Then, I coarse grain the particles by a factor of f = d_g / d_p = 4, i.e., f^3 = 64 “particles per grain.” I am scaling the spring constant by factors of f^0 = 1, f^1 = 4, f^2 = 16 and f^3. I expected to see either f^2 give the correct match in this test based on Eq. (28) or f^3 based on Eq. (28) combined with Eq. (35) in your referenced paper. Although, to be honest, I am really not sure how one is supposed to interpret Eq. (35) other than introducing a new factor in front of either the spring constant or, conversely, in front of dashpot coefficient, as in this paper. Anyway… have you done similar uniaxial tests w/ CG LSD DEM? Any insights into why f^1 scaling of k_n seems to be the right fudge factor for this test?
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