## General Mechanical

#### Do loop for moving pressure load

• HollyFart
Subscriber

Hello,

I'm trying to implement a moving pressure load with a circle shaped area, which is moving along the Y direction via do loop.

The pressure value is uniform and located within a circle shaped area.

The moving direction is the Y axis. It should start at the global CS (0,0,0) and heads towards the positive Y axis.

The load isn't moving, I don't have a clue why.

The script is posted below due to size restrictions in the post.

Best regards,

HF

• peteroznewman
Subscriber

ANSYS staff are not permitted to open attachments.

```total_time = 10                                  ! Total simulation time in seconds
time_steps = 100                                 ! Total amount of steps
time_inc = total_time/time_steps                 ! Time increment in seconds
V_p = 0.01                                       ! m/s Load velocity
PV = 1E07                                        ! Pa  Load value
nsub,time_steps

*do,I,1,time_steps,1
time=I*time_inc
Y_Local=V_p*time
wpcs,-1,0                   ! WP @ GLOBAL ORIGIN
wpof,,Y_Local            ! OFFSET WP ALONG ITS Y AXIS (i.e. provide current position of center of circle along Y axis)
cswp,11,1                   ! DEFINE Cylindrical COORDINATE SYSTEM @ WP ORIGIN
esel,s,ename,,154       ! Select SURF154 elements
sfed,all,,pres               ! Delete old pressures if any
nsle                             ! Select nodes attached to selected SURF elements
csys,0                         ! Set CSYS back to global
esln,r                          ! Select SURF elements attached to the nodes within the circle
sfe,all,,pres,,PV          ! Apply pressure based on your calculation at the said time.
allsel,all
outres,all,all

*if,I,EQ,1,THEN
/prep7                                 ! Enter into /prep7 as ET and ESURF are valid only in /PREP7
et,100,154                          ! Create a new element type for SURF154
cmsel,s,surface1                ! Select nodes on a face via Face named selection
type,100                             ! Set the element type as 100
esurf                                   ! Create surface effect elements on the selected nodes
allsel,all                              ! Select everything back
/solu

time=I*time_inc
Y_Local=V_p*time

wpcs,-1,0                         ! WP @ GLOBAL ORIGIN
wpof,,Y_Local                 ! OFFSET WP ALONG ITS Y AXIS (i.e. provide current position of center of circle along Y axis)
cswp,11,1                       ! DEFINE Cylindrical COORDINATE SYSTEM @ WP ORIGIN
esel,s,ename,,154         ! Select SURF154 elements
sfed,all,,pres                  ! Delete old pressures if any
nsle                                ! Select nodes attached to selected SURF elements
csys,0                            ! Set CSYS back to global
esln,r                             ! Select SURF elements attached to the nodes within the circle
sfe,all,,pres,,PV             ! Apply pressure based on your calculation at the said time.
allsel,all
outres,all,all

*else
time=I*time_inc
Y_Local=V_p*time

wpcs,-1,0                            ! WP @ GLOBAL ORIGIN
wpof,,Y_Local                     ! OFFSET WP ALONG ITS Y AXIS (i.e. provide current position of center of circle along Y axis)
cswp,11,1                           ! DEFINE Cylindrical COORDINATE SYSTEM @ WP ORIGIN
esel,s,ename,,154             ! Select SURF154 elements
sfed,all,,pres                      ! Delete old pressures if any
nsle                                   ! Select nodes attached to selected SURF elements
csys,0                               ! Set CSYS back to global
esln,r                               ! Select SURF elements attached to the nodes within the circle
sfe,all,,pres,,PV               ! Apply pressure based on your calculation at the said time.
allsel,all
outres,all,all
*endif

*enddo```
• peteroznewman
Subscriber

• HollyFart
Subscriber

This is the model sketch

• HollyFart
Subscriber

And the used script:

```total_time = 10                                  ! Total simulation time in seconds
time_steps = 100                                 ! Total amount of steps
time_inc = total_time/time_steps                 ! Time increment in seconds
V_p = 0.01                                       ! m/s Load velocity
PV = 1E07                                        ! Pa  Load value
nsub,time_steps

*do,I,1,time_steps,1
time=I*time_inc
Y_Local=V_p*time
wpcs,-1,0                   ! WP @ GLOBAL ORIGIN
wpof,,Y_Local               ! OFFSET WP ALONG ITS Y AXIS (i.e. provide current position of center of circle along Y axis)
cswp,11,1                   ! DEFINE Cylindrical COORDINATE SYSTEM @ WP ORIGIN
esel,s,ename,,154           ! Select SURF154 elements
sfed,all,,pres              ! Delete old pressures if any
nsle                        ! Select nodes attached to selected SURF elements
csys,0                      ! Set CSYS back to global
esln,r                      ! Select SURF elements attached to the nodes within the circle
sfe,all,,pres,,PV           ! Apply pressure based on your calculation at the said time.
allsel,all
outres,all,all

*if,I,EQ,1,THEN
/prep7                                 ! Enter into /prep7 as ET and ESURF are valid only in /PREP7
et,100,154                             ! Create a new element type for SURF154
cmsel,s,surface1                       ! Select nodes on a face via Face named selection
type,100                               ! Set the element type as 100
esurf                                  ! Create surface effect elements on the selected nodes
allsel,all                             ! Select everything back
/solu

time=I*time_inc
Y_Local=V_p*time

wpcs,-1,0                         ! WP @ GLOBAL ORIGIN
wpof,,Y_Local                     ! OFFSET WP ALONG ITS Y AXIS (i.e. provide current position of center of circle along Y axis)
cswp,11,1                         ! DEFINE Cylindrical COORDINATE SYSTEM @ WP ORIGIN
esel,s,ename,,154                 ! Select SURF154 elements
sfed,all,,pres                    ! Delete old pressures if any
nsle                              ! Select nodes attached to selected SURF elements
csys,0                            ! Set CSYS back to global
esln,r                            ! Select SURF elements attached to the nodes within the circle
sfe,all,,pres,,PV                 ! Apply pressure based on your calculation at the said time.
allsel,all
outres,all,all

*else
time=I*time_inc
Y_Local=V_p*time

wpcs,-1,0                            ! WP @ GLOBAL ORIGIN
wpof,,Y_Local                        ! OFFSET WP ALONG ITS Y AXIS (i.e. provide current position of center of circle along Y axis)
cswp,11,1                            ! DEFINE Cylindrical COORDINATE SYSTEM @ WP ORIGIN
esel,s,ename,,154                    ! Select SURF154 elements
sfed,all,,pres                       ! Delete old pressures if any
nsle                                 ! Select nodes attached to selected SURF elements