Need for the coupling of beam and shell co-rotation

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  • Last Post 17 May 2018
manu87 posted this 28 April 2018

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

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maurya posted this 28 April 2018

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://studentcommunity.ansys.com/thread/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 posted this 17 May 2018

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 posted this 17 May 2018

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

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