## General Mechanical

#### Element Has Zero Length

Subscriber

Dear ANSYS Users:

I am using "beam3" element to solve a 3D beam. I am getting an error message saying that "Element Has Zero Length". I am chaning the element size and node merging. But it did not work. I am also attaching my APDL code. Is there anyone who can help me to solve this problem? Thanks,

!! APDL Code:

fini
/clear
/title, Beam Problem "Exercise # 4.25"
/prep7

!! Make model first
!! Define Keypoints
k,1,0,0
k,2,10*12,0        !! x=10 feet
k,3,10*12,0,5*12    !! x=10 feet, y=0 and z = 5 feet

!! Create Lines
L,1,2    !! L1
L,2,3    !! L2

/pnum,line,1
Lplot

!! element type
et,1,3

!! Real constant
!! Section, W18 x 35 beam

A=10.3     !! in^2
I=510     !! in^4
D=17.7    !! in

r,1,A,I,D

!! material, steel
mp,ex,1,30e6
mp,prxy,1,0.3

!! Make FE model
esize,1        !! Element size = 1 inch

!! Recall Proper ID Numbers
type,1
real,1
mat,1

Lmesh,All
elist

!! BC
dk,1,all,0

fk,3,fy,-1000
fk,3,fx,500
fini
alls

/solu
solve
fini

• Chandra Sekaran
Ansys Employee

BEAM3 is a 2D element (ux,uy,rotz dof) and MUST be in X-Y plane. The above input is in X-Z plane. May be you can switch to X-Y plane or switch the element type to Beam188 or Beam4.

• Mike Rife
Ansys Employee

Beam3 is a 2D beam that should be in the global XY plane only (it has X & Y translation and ROTZ degrees of freedom).  Perhaps you mean to use Beam4 which is a 3D beam element.

Also, why are you using an undocumented element type?

Mike