Dear Lammps users,
I’m shearing my model with displacing the upper block with fix move command, fixed the bottom layer and let middel mobile under nvt.
And I using two method to calculate the stress (press)
(I)
compute stress all stress/atom NULL
compute Supper upper reduce ave c_stress[5]
compute vor all voronoi/atom
compute Sv all reduce ave c_vor[1]
variable stress_atom equal c_Supper/c_Sv/10 #bars to Mpa
(II)
compute Fx upper reduce sum fx
variable Fshear equal (c_Fx/lx*ly)*160217.66208 #ev/A to MPa
The result of (I) is 10 times to (II)
Can anyone tell me where is wrong?
Best wishes,
Jeaha