Learning Forum

[manu87]

Hi,everyone. Here I try to couple a beam end with a cylinder(meshed with shell181), and rotate them along the longitudial axis, shown as the following picture. The end node of the beam is applied an axial compression and be rotated. The coupling between the beam and cylinder is made by the internal multipoint constraint(MPC), But, as the uncompatible freedems between beam(ux uy uz rotx roty rotz) and shell element(ux uy uz rotx roty rotz,but the freedom of rotz is fictitious) ,the cylinder cannot be rotated.So how can I make it? thanks

[maurya]

Hello Manu

                     Beam is always a line element and cylinder as you mention is surface( thats why shell181 element) .

You can provide contact easily.

Attache archive file(https://forum.ansys.com/forums/topic/saving-sharing-of-working-project-files-in-wbpz-format/) to understand the problem.

mention the version of ansys.

You used the word "rotate them"  both bodies are having torque/moment ?.

regards

Deepak

 

[manu87]

Hi manurya. Thank you for you reply. Sorry for the trouble resulting from the information I missed. As shown in the picture, the assembly is rotated only by the end of the beam.. However, due to the uncompatible freedems between beam(ux uy uz rotx roty rotz) and shell element(ux uy uz rotx roty rotz,but the freedom of rotz is fictitious), the rotional freedom is always zero when a rotational speed is applied on the end node of the beam. Do you have any idea on handling this problem?

Regards

manu

[sk_cheah]

I'm guessing the problem is with your MPC184 with KEYOPT(1)=0 (default) has only translation DOF. Here's my take with CERIG. 

Kind regards,
Jason

 

! Twists Cylinder made of Shells

/prep7

et,1,181        ! shell181

et,2,4          ! beam4 (old)

mp,ex,1,210e3

mp,nuxy,1,0.3

r,1,0.01

r,2,100,40,40



! geometry and mesh

r = 20

L = 100

tol = 0.0001



csys, 1

k, 1, r, 0

k, 2, r, 120

k, 3, r, 240

k, 4, r, 360

k, 5, r, 0, L

l, 1, 2

l, 2, 3

l, 3, 4

l, 1, 5

adrag, 1, 2,3,,,, 4

csys, 0



mat,1    ! shells

type,1

real,1

mshkey,1

aesize, all, 6

alls

amesh,all



type, 2  ! beams at ends

real, 2

*get,nmax,node,0,num,max

n,nmax+1,0,0,0

n,nmax+2,0,0,-L

n,nmax+3,0,0,L

n,nmax+4,0,0,2*L

e,nmax+1, nmax+2

e,nmax+3, nmax+4



! connects using cerig

alls

nsel,s,loc,z,0-tol,0+tol

cerig, nmax+1, all, all

nsel,s,loc,z,L-tol,L+tol

cerig, nmax+3, all, all



!! Boundary Condition and solve

/solu

alls

antype, static

d,nmax+2,all,0

d,nmax+4,rotz, 0.01

solve

/post1
set,last
plnsol,rot,z