Hi everyone,
I was using LIGGGHTS_PFM for a while, and after that, I realized that using LIGGGHTS-WITH-BONDS, based on Potyondy and Cundall's paper, is better for my simulations. I used the same model for an uniaxial compression test, which had no errors in LIGGGHTS_PFM, as input in LIGGGHTS-WITH-BONDS, but it cannot correctly calculate the average stress and strain. Despite the fact that those commands were original LIGGGHTS' commands, not specified only in PFM, can someone help me with this matter? I will attach the parts of the code that LIGGGHTS-WITH-BONDS cannot recognize.
#computing average stress
compute peratom all stress/atom
variable vol atom (4.0/3.0)*PI*radius^3
compute sumvol all reduce sum v_vol
compute sumsigma all reduce sum c_peratom[3]
variable avgstress equal c_sumsigma/c_sumvol
# Storing the z-coordinates of the top wall's mesh nodes every timestep
variable top equal f_top[9]
#calculating the strain based on the displacement of the top plate
variable d equal '0.1657 - f_top[9]'
variable initial_length equal 0.08601
variable strain equal '(v_d) / v_initial_length'
#outputting the data
fix printStress all print 100 "Time: ${time} Strain: ${strain}" file output_avg_stress_strain.txt title "# Average Stress Over Time"