8.6. Double helical dislocations
1
To create double dislocation helices,
Step 1:
Use the tool in subdirectory tools/Bcc to creat an BCC crystal sample:
bcc_reg.lmp, use the shell script in subdirectory tool/Helical_surface to create the mesh files of two helical surfaces:mesh0.datandmesh1.dat;
Step 2:
Open terminal, run the following command:
1CryDisGen para_file bcc_reg.lmp
Parameter file
Content of the para_file:
1#lines starting with '#' are comments
2#crystal region
3Region
4-x 1 -1 0 # lattice orientation along x-axis
5-y 1 1 -2 # lattice orientation along y-axis
6-z 1 1 1 # lattice orientation along z-axis
7-lat 2.867 # lattice constant of Fe
8-pbc 1 1 1 # boundary condition flags along x/y/z-axes: '1' for periodic, '0'for non-periodic
9
10nHelix 2 # total number of helices
11Helix # lable for dislocation helix section
12-bvh 1 1 1 # orientation of Burgers vector for the helix
13-bsh 1/2 # scalar coefficient of Burgers vector, e.g., 1/2 in 1/2<110>
14-f mesh0.dat # mesh data file of the helical surface
15
16Helix
17-bvh 1 1 1
18-bsh 1/2
19-f mesh1.dat
20
21#dislocation
22 nLoop 2 # number of dislocaiton loops
23 Loop # label for dislocation section
24 -bv 1 1 1 # orientation of Burgers vector
25 -bs -1/2 # scalar coefficient of Burgers vector, e.g., 1/2 in [110]/2
26 -dnorm 1 -1 0 # normal direction of dislocation plane
27 -dc 0 25 0 # center of dislocation loop
28 -dr 25 # half of the edge length of a square loop
29 -lx 1 1 -2 # local x-axis on slip plane
30 -ly 1 1 1 # local y-axis on slip plane
31 -ndisl 4 2.7 # number of segments of in the square loop and a scaling factor
32
33 Loop
34 -bv 1 1 1
35 -bs 1/2
36 -dnorm 1 -1 0
37 -dc 0 -25 0
38 -dr 25
39 -lx 1 1 -2
40 -ly 1 1 1
41 -ndisl 4 2.7