Exercise 2
Givenstructure:2Dconcreteframewithpartialdiscontinuity(twosimmetricprecasted
components with middle pin-jointed connection). Geometry and
loads:according to the sketch Supports:according to the sketch
Column cross section: 30 30 cm; A = 900 cm2; I = 67500 cm4
Beam cross section:20 40 cm; A = 800 cm2; I = 106666 cm4
Material properties:E = 2105 daN/cm2 = 0.2 Distributed load:p = 60
daN/cm Force value:F = 600 daN Element type:BEAM3 Requirements: -
Deformed shape - List of nodal displacements - List of reaction
forces - Axial force, shear force and bending moment diagrams along
the structure New preprocessing commands
Inordertoinsertthepartialdiscontinuity(thehinge)inthemiddleofthegirder,twocoincident
nodes must be defined in that position (7, 8). The displacement
DOFs are restored by coupling the
horizontalandverticaldisplacementofthesetwonodes.TherotationalDOFremain
unconstrained,thusthetwobeamelementsconectedtonodes7and8repectivelymayhave
different rotations (according to applied loads). To couple DOFs
for coincident (or close) nodes, ANSYS provides the following
command: CPINTF, lab, toler lab - degree of freedom label (ux, uy,
uz, rotx, roty, rotz) toler- tolerance for coincidence (defaults to
0.0001) Note: all nodes lying inside a circle (sphere) of radius
toler are coupled along the lab DOFs. To apply distributed loads
along a beam element, ANSYS provides the following command: SFBEAM,
elem, lkey, lab, vali, valj elem - element number or all if applied
after a previous elements selectionlkey - load key defining the
load orientation (see element input data) lab - pres vali- load
value at node i valj- load value at node j Note: if the distributed
load is constant, only the first value (vali) is required.
Preprocessing text file /PREP7 ! ET,1,BEAM3 R,1,900,67500,30
R,2,800,106666,40 MP,EX,1,2E6 MP,NUXY,1,0.2 ! N,1,0,0 N,5,0,400
FILL,1,5 N,6,100,400 N,7,200,400 N,8,200,400 N,9,300,400
N,10,400,400 N,14,400,0 FILL,10,14 ! REAL,1 ! E,1,2 EGEN,4,1,1
E,10,11 EGEN,4,1,5 ! REAL,2 ! E,5,6 E,6,7 E,8,9 E,9,10 ! D,1,ALL,0
D,14,ALL,0 ! CPINTF,UX CPINTF,UY ! ESEL,S,ELEM,,9,12,1
SFBEAM,ALL,1,PRES,60 EALL ! F,5,FX,600 F,10,FX,600 ! SAVE FINISH
Postprocessing The element table assignement for the required
graphical representations (axial force, shear force and bending
moment diagrams) are (for element BEAM3): ITEMCOMP (NODE i)COMP
(NODE j ) AXIAL FORCE SMISC17 SHEAR FORCESMISC28 BENDING
MOMENTSMISC612 Commands sequence for postprocessing (to be typed in
the GUI* command line): /POST1 PLDI,2 PRNS,U,COMP PRRS,F PRRS,M
ETAB,NI,SMISC,1 ETAB,NJ,SMISC,7 ETAB,TI,SMISC,2 ETAB,TJ,SMISC,8
ETAB,MI,SMISC,6 ETAB,MJ,SMISC,12 PLLS,NI,NJ PLLS,TI,TJ PLLS,MI,MJ
PRET,NI,NJ,TI,TJ,MI,MJ * Graphical User Interface
