Hi,everybody. Inspired by the example VM278 in ANSYS help, I'm working on the problem that a beam is located within a cylinder. The beam is modeled by the Pipe288 element, while the cylinder is regarded as a rigid surface and meshed by the Targe170 element. A contact pair is established between the beam and cylinder, using Conta177& Targe170 elements. The boundary condition at the both ends are treated as a pin. In the first step, the gravity and a axial compress force is loaded. Then a rotational displacement is applied at the left end.

However, it seems that the contact does not work, since the contact status and the penetration ara null. The beam deforms largely, and the radial displacement exceeds the extent of the cylinder.

Anybody would offer some help?

The APDL file is attached as follows.

finish

/clear

/PREP7

L=50 ! MODELING PARAMETERS

OD=0.5

WT=(0.5-0.4)/2

!*** SOLID MODEL ***

!-------------------

k,1,L,,

K,2,

K,3,L,,-0.8/2

K,4,,,-0.8/2

L,1,2 ! GEOMETRY OF THE BEAM

L,3,4

AROTAT,2,,,,,,1,2,360,

!*** MATERIAL PROPERTIES FOR STEEL IN NEWTONS AND METERS ***

!----------------------------------------------------------------

MP,EX,1,2.1E11 ! YOUNG'S MODULUS

MP,PRXY,1,0.3 ! POISSON'S RATIO

MP,DENS,1,7800 ! DENSITY

MP,MU,1,0.35 ! COEFFICIENT OF FRICTION

!*** ELEMENT TYPES ***

!---------------------

ET,1,PIPE288 ! 3-D 3-NODE PIPE

ET,2,170 ! 3-D TARGET SEGMENT

ET,3,CONTA177 ! 3-D LINE-TO-SURFACE CONTACT

KEYOPT,3,2,1 ! PENALTY FUNCTION ALGORITHM

KEYOPT,3,3,2 ! TRACTION-BASED CONTACT TYPE

KEYOPT,3,7,1

KEYOPT,3,10,2

!*** SECTION DATA ***

!--------------------

! EXAMPLE SECTION:

SECTYPE,1,PIPE,,PIPE1 ! DEFINE PIPE SECTION

SECDATA,OD,WT,16 ! APPLY MODELING PARAMETERS TO PIPE SECTION

! *** REAL CONSTANTS ***

! ----------------------

R,2,

RMODIF,2,3,-1e10 ! ABSOLUTE VALUE OF PENALTY STIFFNESS

! *** MESHING ***

! ---------------

TYPE,1

MAT,1

SECNUM,1

LESIZE,1,1,

LMESH,1

*GET,dnodemax,node,,num,maxd

/pnum,node,1

asel,s,,,all

TYPE,2

REAL,2

amesh,all

! CONTACT/TARGET

TYPE,3 ! CONTACT TYPE

REAL,2

MAT,1

LSEL,S,,,1

ESLL

ESURF ! PLACE CONTACT ON PIPE ELEMENTS

esel,s,real,,2

ESEL,r,TYPE,,2

ESURF,,REVERSE

/pnum,node,0

ALLSEL,ALL

FINISH

/SOLU

ANTYPE,4

NLGEOM,1

ACEL,,9.8

d,2,UX,,,,,UY,UZ

ddele,2,ux

f,2,fx,5e4

d,1,UX,,,,,UY,UZ

KBC,0

AUTOTS,1

OUTRES,ALL,all

TIME,2

SOLVE

kbc,0

*do,i,1/30,1,1/30

d,2,rotx,6.28*i

timint,on

TIME,2+i

AUTOTS,1

solve

*enddo