Could not locate a fix/property storing value(s) using rolling_friction epsd3

Submitted by oranjesr on Sun, 04/19/2020 - 05:59

Hi, everyone
when I use the rolling_friction epsd3 for my simulation, I got the following error:

ERROR: Could not locate a fix/property storing value(s) for rollingStiffness as requested by rolling_model epsd3. (../modify_liggghts.cpp:411)

The epsd3 model request the definiton of rollingStiffness, but it is calculated as k_r = coeffRollingStiffness*k_n*rmu*rmu*reff*reff in the liggghts doc.

Any suggestion what I missed in my script.

# Material properties required for granular pair styles

fix m1 all property/global youngsModulus peratomtype 3.e10 3.e9
fix m2 all property/global poissonsRatio peratomtype 0.3 0.3
fix m3 all property/global coefficientRestitution peratomtypepair 2 0.8 0.8 0.8 0.8
fix m4 all property/global coefficientFriction peratomtypepair 2 0.8 0 0 0
fix m5 all property/global coefficientRollingFriction peratomtypepair 2 0.3 0 0 0
fix m6 all property/global coefficientRollingViscousDamping peratomtypepair 2 0.8 0 0 0
fix m7 all property/global coeffRollingStiffness scalar 3

# pair style
pair_style gran model hertz tangential history rolling_friction epsd3 # Hertzian without cohesion
pair_coeff * *

Best wishes!
Han

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oranjesr | Mon, 04/20/2020 - 12:40

Solved
I found out that there is some typo in doc for epsd3, it should be RollingStiffness(Rdeclared in global_properties.cpp as scalar) rather than coeffRollingStiffness(delcares as matrix） .