# moving and rotation in fixe command!

I want to make a tool rotate about the z axis and move in x direction. But the tool is just move in x direction and fluctuate about the z axis. Can anyone solve it for me? thanks!
my program:

# Friction stir welding of copper C11000

clear
dimension 3
boundary p s p
units metal
atom_style atomic

# Create geometry

lattice fcc 3.615
region box block 0 63 0 16 0 20
create_box 1 box

mass 1 63.54

# atom regions

region ma cone z 8 8 4 6 2.7 5.7

# create atoms

create_atoms 1 region ma

# EAM potentials

pair_style eam
pair_coeff 1 1 Cu_u3.eam

# define groups

group tool region ma

# initial velocities

velocity tool create 300 482748 mom yes rot yes

# computes

compute eng all pe/atom
compute eatoms all reduce sum c_eng

# fixes

fix 1 tool rigid single

# Run

timestep 0.005
thermo 100
thermo_style custom step pe pxx pyy pzz c_eatoms
dump 1 all xyz 20 dump.xyz
variable V equal 8.0
variable y equal vdisplace(0.0,\$V)
fix 2 tool move rotate 8.0 8.0 2.7 0.0 0.0 1.0 1
fix 3 tool move variable NULL v_y NULL NULL v_V NULL

run 1600

I don’t think you can use fix move on the same set of atoms

twice, e.g. to get rotation and translation. You’d have to write
a fancier variable that did both motions in one fix move command.

This is b/c the way fix move works it puts each atom in the position
that fix move command specifies. So the 2nd one will simply
override the first.

Steve

You might want to try using fix move rotate to rotate your group tool,
and then use velocity set to move the group in the x direction.

Ray

Dear Sir!
I still haven’t solved for making a tool rotate about the z axis and move in y direction. Otherwise, I can make a tool rotate and move about the y direction. The code as the following:

clear
dimension 3
boundary p s p
units metal
atom_style atomic

# Create geometry

lattice fcc 3.615
region box block 0 63 0 16 0 20
create_box 1 box

mass 1 63.54

# atom regions

region ma cone z 8 8 4 6 2.7 5.7

# create atoms

create_atoms 1 region ma

# EAM potentials

pair_style eam
pair_coeff 1 1 Cu_u3.eam

# define groups

group tool region ma

# initial velocities

velocity tool create 300 482748 mom yes rot yes

# computes

compute eng all pe/atom
compute eatoms all reduce sum c_eng

# fixes

fix 1 tool rigid single

# Run

timestep 0.005
thermo 100
thermo_style custom step pe pxx pyy pzz c_eatoms
dump 1 all xyz 20 dump.xyz
variable V equal 8.0
variable dy equal vdisplace(0.0,\$V)
fix 3 tool move rotate 8.0 8.0 2.7 0.0 1.0 0.0 1
fix 4 tool move variable NULL v_dy NULL NULL v_V NULL
run 1600
Please you help me to solve for making a tool rotate about the z direction and move in y direction!

Thanks!

Vào ngày 12:55 Thứ Ba, 5 tháng 11 2013, long tranngocbaolong <tranngocbaolong822008@…4656…25…> đã viết:

I want to make a tool rotate about the z axis and move in x direction. But the tool is just move in x direction and fluctuate about the z axis. Can anyone solve it for me? thanks!
my program:

# Friction stir welding of copper C11000

clear
dimension 3
boundary p s p
units metal
atom_style atomic

# Create geometry

lattice fcc 3.615
region box block 0 63 0 16 0 20
create_box 1 box

mass 1 63.54

# atom regions

region ma cone z 8 8 4 6 2.7 5.7

# create atoms

create_atoms 1 region ma

# EAM potentials

pair_style eam
pair_coeff 1 1 Cu_u3.eam

# define groups

group tool region ma

# initial velocities

velocity tool create 300 482748 mom yes rot yes

# computes

compute eng all pe/atom
compute eatoms all reduce sum c_eng

# fixes

fix 1 tool rigid single

# Run

timestep 0.005
thermo 100
thermo_style custom step pe pxx pyy pzz c_eatoms
dump 1 all xyz 20 dump.xyz
variable V equal 8.0
variable y equal vdisplace(0.0,\$V)
fix 2 tool move rotate 8.0 8.0 2.7 0.0 0.0 1.0 1
fix 3 tool move variable NULL v_y NULL NULL v_V NULL

run 1600

I think I answered this Q before. You cannot apply fix move
twice to the same atoms.

Steve