ankushaggarwal2
Aerospace
- May 22, 2007
- 26
Hello,
I want to model a helical circular cylinder(I hope I am clear) with continuum elements. There is, lets say a cut in the cross section which should always face the axis of the helix.
I tried it by making an area as required and (VDRAG)dragging it along a helical line (which is locus of the centre of circle), but the cut does not rotate along axis.
(I am attaching at the end the command file for this, which has some other things too, but you can just run it and see the final mesh I am getting by VDRAG, in which the Z axis is the axis of the helix and I am modelling half of the pitch, and at the the other end the cut is not facing the axis but is away from it)
I also tried by VEXT but it just joines the keylpoints by straight lines and is a total failure.
If somebody can help me in how should I model it, I will be very obliged.
Thank you very much.
!!!!!THE COMMDANDS I USED FOR MODELLING BY VDRAG
/prep7
!!!!Radius of the strand
R=0.81
!!!!Pitch of the strand
P=45
!!!!Number of points to define the spline
N=200
K,1,2/sqrt(3)*R,0,0
!K,1,1.1547*R,0,0
csys,1
KGEN,N,1,,,0,360/2/(N-1),P/2/(N-1)
KSEL,all
BSPLIN,all
KSEL,U,KP,,1,
KSEL,U,KP,,N
KDEL,all
allsel,all
numcmp,all
LPLOT
KGEN,N,2,,,0,360/2/(N-1),P/2/(N-1)
KSEL,S,KP,,2,1+N,1
BSPLIN,all
KSEL,U,KP,,2,
KSEL,U,KP,,1+N
KDEL,all
allsel,all
numcmp,all
LPLOT
NUMCMP,all
/view,0,0,1,P/2/3.14
KWPLAN,,1
CSWPLA,11,1,1,1,
csys,11
K,1000,0,0,0,
K,2000,R,0,0,
K,3000,R,140,0,
K,4000,R,160,0,
K,5000,R/3,140,0
K,6000,R/3,160,0
K,7000,R,180,0
!LARC,start,end,centre,radius
LARC,2000,3000,1000,R,
LARC,3000,4000,1000,R
LARC,4000,7000,1000,R
LARC,5000,6000,1000,R/3
!!straight line
LSTR,1000,5000
LSTR,5000,3000
LSTR,1000,6000
LSTR,6000,4000
LSTR,1000,2000
LSTR,1000,7000
AL,4,8,6,10
AL,3,11,7,8
AL,6,7,9
ET,1,mesh200,7
amesh,all
CSWPLA,12,0,1,1,
csys,12
arsym,y,all
nummrg,all
allsel,all
asel,all
cm,area1,area
csys,1
allsel,all
ET,2,SOLID95
TYPE,2
LESIZE,1,,,10
LESIZE,2,,,20
VDRAG,all,,,,,,1
EPLOT
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I want to model a helical circular cylinder(I hope I am clear) with continuum elements. There is, lets say a cut in the cross section which should always face the axis of the helix.
I tried it by making an area as required and (VDRAG)dragging it along a helical line (which is locus of the centre of circle), but the cut does not rotate along axis.
(I am attaching at the end the command file for this, which has some other things too, but you can just run it and see the final mesh I am getting by VDRAG, in which the Z axis is the axis of the helix and I am modelling half of the pitch, and at the the other end the cut is not facing the axis but is away from it)
I also tried by VEXT but it just joines the keylpoints by straight lines and is a total failure.
If somebody can help me in how should I model it, I will be very obliged.
Thank you very much.
!!!!!THE COMMDANDS I USED FOR MODELLING BY VDRAG
/prep7
!!!!Radius of the strand
R=0.81
!!!!Pitch of the strand
P=45
!!!!Number of points to define the spline
N=200
K,1,2/sqrt(3)*R,0,0
!K,1,1.1547*R,0,0
csys,1
KGEN,N,1,,,0,360/2/(N-1),P/2/(N-1)
KSEL,all
BSPLIN,all
KSEL,U,KP,,1,
KSEL,U,KP,,N
KDEL,all
allsel,all
numcmp,all
LPLOT
KGEN,N,2,,,0,360/2/(N-1),P/2/(N-1)
KSEL,S,KP,,2,1+N,1
BSPLIN,all
KSEL,U,KP,,2,
KSEL,U,KP,,1+N
KDEL,all
allsel,all
numcmp,all
LPLOT
NUMCMP,all
/view,0,0,1,P/2/3.14
KWPLAN,,1
CSWPLA,11,1,1,1,
csys,11
K,1000,0,0,0,
K,2000,R,0,0,
K,3000,R,140,0,
K,4000,R,160,0,
K,5000,R/3,140,0
K,6000,R/3,160,0
K,7000,R,180,0
!LARC,start,end,centre,radius
LARC,2000,3000,1000,R,
LARC,3000,4000,1000,R
LARC,4000,7000,1000,R
LARC,5000,6000,1000,R/3
!!straight line
LSTR,1000,5000
LSTR,5000,3000
LSTR,1000,6000
LSTR,6000,4000
LSTR,1000,2000
LSTR,1000,7000
AL,4,8,6,10
AL,3,11,7,8
AL,6,7,9
ET,1,mesh200,7
amesh,all
CSWPLA,12,0,1,1,
csys,12
arsym,y,all
nummrg,all
allsel,all
asel,all
cm,area1,area
csys,1
allsel,all
ET,2,SOLID95
TYPE,2
LESIZE,1,,,10
LESIZE,2,,,20
VDRAG,all,,,,,,1
EPLOT
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!