Dear lammps developer,
Recently, I wanted to do a simulation of the rolling process of polycrystalline Fe at room temperature, but I still couldn’t solve the problem that the atomic system temperature is more than 100000 k after I wrote the in file,The contents of the in file of my rolling process simulation are as follows:
##定义变量##
variable a equal 1.0 ##定义原子模型截断半径
variable T_start equal 300
variable T_end equal 300
##模拟环境初始化##
units metal
atom_style atomic
boundary s p s
neighbor ${a} bin
neigh_modify delay 0 every 1 check yes
##工件和轧辊的组合原子模型
read_data Fe-C.data(2)
###对刚性滚子和被压工件进行划分区域
region rollera cylinder y 140.04 -69.016 69.984 EDGE EDGE units box
region rollerb cylinder y 140.04 62.996 14.004 EDGE EDGE units box
region rollerc cylinder y 349.992 61.484 14.004 EDGE EDGE units box
region rollerd cylinder y 349.992 -67.504 69.984 EDGE EDGE units box
region gongjian block 0 100 0 66.7 0 50 units box
##对刚性棍子和被压工件进行分组
group rollera region rollera
group rollerb region rollerb
group rollerc region rollerc
group rollerd region rollerd
group gongjian region gongjian
##定义轧辊和工件之间的相互作用势##
pair_style hybrid eam/fs morse 4.5
pair_coeff * * eam/fs Fe_Earth_core.eam.fs Fe NULL
pair_coeff 1 2 morse 0.72140 1.59380 2.49010 4.0
pair_coeff 2 2 morse 0.38540 1.27180 2.81780 4.0
##对各组尽心固定
#fix rollera rollera setforce 0.0 0.0 0.0
#fix rollerb rollerb setforce 0.0 0.0 0.0
#fix rollerc rollerc setforce 0.0 0.0 0.0
#fix rollerd rollerd setforce 0.0 0.0 0.0
compute myTemp gongjian temp/partial 0 0 1 # 在计算温度的时候不考虑x轴，y轴的速度
#compute myTemp gongjian temp/com
#输出原子热力学信息和位置
thermo 100
thermo_style custom step lx ly lz press pxx pyy pzz pe c_myTemp temp vol dt time
dump 1 all custom 200 Fe-C.xyz id type x y z
##thermo_modify temp myTemp
##在NVE系综下对轧辊和工件的组合模型进行保温500ps
fix 2 all nvt temp {T_start} {T_end} 0.05
fix_modify 2 temp myTemp # 将控温对象改为temp2
##对各组尽心固定
#fix rollera rollera setforce 0.0 0.0 0.0
#fix rollerb rollerb setforce 0.0 0.0 0.0
#fix rollerc rollerc setforce 0.0 0.0 0.0
#fix rollerd rollerd setforce 0.0 0.0 0.0
##对刚体组的速度进行固定
velocity rollera set 0.0 0.0 0.0
velocity rollerb set 0.0 0.0 0.0
velocity rollerc set 0.0 0.0 0.0
velocity rollerd set 0.0 0.0 0.0
##让刚体进行旋转
fix 3 rollera move rotate 140.04 0.0 -69.016 0 1 0 1 units box
fix 4 rollerb move rotate 140.04 0.0 62.996 0 -1 0 1 units box
fix 5 rollerc move rotate 349.992 0.0 61.484 0 -1 0 1 units box
fix 6 rollerd move rotate 349.992 0.0 -67.504 0 1 0 1 units box
##fix 7 gongjian move linear 6.0 0 0 units box
velocity gongjian set 6.0 NULL NULL sum yes units box
##设置运行时间
timestep 0.002
run 50000
###输出原子模型
write_data Fe-C.data(3)
I still don’t know how to solve this problem?
Xue bao shuai