I want to analyze a rectangular cross section under torsion weekend by a edge crack. I used element of PLANE42 for modelling of cross section, then with help of element of SOLID45, I extruded cross-section along the perpendicular to the surface. but I don't know how to apply a moment to the end of beam.
/prep7
ET,1,plane182
ET,2,solid95
DOF,ROTZ,WARP
MPDE,ALL,1
TBDE,ALL,1
MPTEMP,,,,,,,
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,EX,1,,30e6
MPDATA,PRXY,1,,0.3
*AFUN,DEG
k, , 0, 12.5+SIN(45)/2
k, , COS(45), 12.5-SIN(45)/2
k, , 0, 12.5+SIN(45)/2
k, , 0, 0
k, , 5, 0
k, , 5, 12.5-(5-COS(45))*TAN(45)-SIN(45)/2
k, , 5, 25
k, , 0, 25
L,4,5
L,5,6
L,6,2
L,2,1
L,1,4
L,6,7
L,7,8
L,7,8
L,8,3
L,3,2
/PNUM,LINE,1
/REPLOT
AL,1,2,3,4,5,
AL,6,7,8,9,3,
CSKP,11,0,2,6,7,1,1,
CSYS,0
KSCON,2,1/20,1,6,0,
KESIZE,ALL,5/3
kesize,1,1/3
kesize,3,1/3
kesize,2,1/30
K, ,,,0,
K, ,,,-100,
L, 9, 10
AMESH,ALL
TYPE, 2
EXTOPT,ESIZE,100,0,
FLST,2,2,5,ORDE,2
FITEM,2,1
FITEM,2,-2
VDRAG,P51X, , , , , , 10
/VIEW,1,1,1,1
/ANG,1
/REP,FAST
EPLOT
FLST,2,2,5,ORDE,2
FITEM,2,8
FITEM,2,13
/GO
DA,P51X,ALL,
I have done some studies of solid models of beams under torsion recently to look at the influence of warping on torsional stiffness and had to deal with the issue of correctly applying the boundary conditions. It requires setting up the correct kinematic relations and then simply applying a point torque. Take a look at http://www.ramsay-maunder.co.uk/downloads/warping_article_web.pdf and come back with any questions.
For application of more realist moment I suggest you to look at the article http://www.padtinc.com/blog/wp-content/uploads/oldblog/PADT_TheFocus_19.pdf in the Focus magazine of PADT. They present a simple code which I did not tested now but assume is a good start.
The idea is to build a web of MPC elements which apply the moment along the boundary. I assume there are several macros in the net for this which you may look for.
I have no idea how it may be combined with the edge crack but here is my suggestion. I am not an expert in fracture so hope someone who is may also answer you.
I have done some studies of solid models of beams under torsion recently to look at the influence of warping on torsional stiffness and had to deal with the issue of correctly applying the boundary conditions. It requires setting up the correct kinematic relations and then simply applying a point torque. Take a look at http://www.ramsay-maunder.co.uk/downloads/warping_article_web.pdf and come back with any questions.
The main question here is, is warping of the section at the end allowed or not allowed? How was the torsion applied in reality? if it was applied by a heavy metal jacket or plate or such at the end of the beam, then most likely warping is not allowed, and you should better simulate it by adding such heavy metal jacket/plate at the end of the beam. If the beam is torqued by a simple couple at the end, then you can also do so by putting a couple or equivalent couple, with the ends free to warp.
- Badges
- Science topic