Transcript 비선형 거동 - com.ne.kr

CHAPTER 8
Workshop Session
- Hexagonal Steel Plate -
Written by Changhyun, SON
Chapter 8. Workshop Session - 1
Description

An overdesigned steel plate under
tension loading of 50 MPa needs
to be optimized for minimum
40
weight subject to a maximum von
Mises stress limit of 150 MPa. You
are allowed to vary the thickness
t1 and fillet radius fil.

fil
t1
100
Properties:

Thickness = 10 mm

E = 2.07e5 MPa

n = 0.3
Written by Changhyun, SON
Chapter 8. Workshop Session - 2
HEXPLATE.INP
! GEOMETRY (in mm)
!----------------*afun,deg
! Degree units for trig. functions
inrad=200*cos(30)-20
! Inner radius
t1=30
! Thickness
fil=10
! Fillet radius
/prep7
!
Create the three bounding annuli
cyl4,-200,,inrad,-30,inrad+t1,30
cyl4,200*cos(60),200*sin(60),inrad,-90,inrad+t1,-150
cyl4,200*cos(60),200*sin(-60),inrad,90,inrad+t1,150
aplot
aadd,all
adele,all
! Delete area, keep lines
lplot
!
Fillets on inner slot
lsel,,radius,,inrad+t1
Written by Changhyun, SON
! Select inner arcs
Chapter 8. Workshop Session - 3
l1 = lsnext(0)
line numbers
l2 = lsnext(l1)
l3 = lsnext(l2)
lfillet,l1,l2,fil
lfillet,l2,l3,fil
lfillet,l3,l1,fil
lsel,all
lplot
! Keep only symmetric portion
wprot,,90
lsbw,all
wprot,,,60
lsbw,all
csys,1
lsel,u,loc,y,0,60
ldele,all,,,1
lsel,all
ksll
ksel,inve
kdele,all
unnecessary keypoints
ksel,all
Written by Changhyun, SON
! Get their
! Fillets
! Delete
Chapter 8. Workshop Session - 4
! Create missing lines and combine
csys,0
ksel,,loc,y,0
lstr,kpnext(0),kpnext(kpnext(0)) !
ksel,all
csys,1
ksel,,loc,y,60
lstr,kpnext(0),kpnext(kpnext(0)) !
ksel,all
csys,0
lsel,,loc,x,100
lcomb,all
! Add
lsel,all
! Create the area
al,all
aplot
Written by Changhyun, SON
right edge lines
Bottom symmetry edge
60-deg. symm. edge
lines at the right edge
Chapter 8. Workshop Session - 5
! MESHING
! ------et,1,82,,,3
r,1,10
mp,ex,1,2.07e5
mp,nuxy,1,0.3
smrt,3
amesh,all
eplot
finish
! LOADING
! ------/solu
csys,1
lsel,u,loc,y,1,59
dl,all,,symm
csys,0
lsel,,loc,x,100
sfl,all,pres,-50
lsel,all
Written by Changhyun, SON
!
!
!
!
Plane stress with thickness
Thickness
Young's modulus of steel, MPa
Poisson's ratio
! Symmetry b.c.
! Pressure load (MPa)
Chapter 8. Workshop Session - 6
! SOLUTION
! -------eqslv,pcg
solve
! POSTPROCESSING
! -------------/post1
plnsol,s,eqv
/dscale,,off
/expand,6,polar,half,,60
/replot
/expand
! Equivalent stress contours
! Displacement scaling off
! Symmetry expansion
! Retrieve maximum equivalent stress and volume
nsort,s,eqv
*get,smax,sort,,max
! smax = max. equivalent stress
etable,evol,volu
ssum
*get,vtot,ssum,,item,evol
! vtot = total volume
finish
Written by Changhyun, SON
Chapter 8. Workshop Session - 7
Results of the Initial Step
Written by Changhyun, SON
Chapter 8. Workshop Session - 8
HEXPLATE_OPT.INP
anfile='hexplate'
anext='inp'
! ENTER OPT AND IDENTIFY ANALYSIS FILE
/opt
opanl,anfile,anext
! IDENTIFY OPTIMIZATION
opvar,t1,dv,20.5,40
opvar,fil,dv,5,15
opvar,smax,sv,,150
opvar,vtot,obj,,,1
VARIABLES
! DVs: Thickness
!
Fillet radius
! SV: Maximum equivalent stress
! OBJ: Total volume, tolerance = 1.0
! RUN THE OPTIMIZATION
opkeep,on
optype,subp
opsave,anfile,opt0
opexe
! Save best design
! Subproblem approximation method
! Save the current opt database
! REVIEW RESULTS
oplist,all,,,1
plvaropt,t1,fil
plvaropt,smax
plvaropt,vtot
finish
!
!
!
!
Written by Changhyun, SON
List all design sets
DVs t1 & fil vs. set number
SV smax vs. set number
OBJ vtot vs. set number
Chapter 8. Workshop Session - 9
Design Sets
Written by Changhyun, SON
Chapter 8. Workshop Session - 10
Optimized Model & Analysis Results
Written by Changhyun, SON
Chapter 8. Workshop Session - 11
Exploring the Design Domain
Description

Run a Gradient
and Sweep study
of the hexagonal
steel plate from
earlier workshop
40
fil
t1
100
exercises.
Written by Changhyun, SON
Chapter 8. Workshop Session - 12
Exploring the Design Domain
Hexagonal Steel Plate
1. Enter ANSYS (or clear the database) and change the jobname to hex2.
2. Resume the best database file from the optimization run, hexplate.bdb.
3. Enter the optimizer and resume the optimization database file,
hexplate.opt1.
4. Run the Gradient Tool with the best design as the reference point and
check the sensitivity of the design to DVs t1 and fil.
Which DV has more effect on the design?
5. Repeat Step 3.
6. Run the Sweep Tool with 3 sweeps per DV using the best design as the
reference point. Now find the global sensitivity of the design.
7. If time permits, run the sweep tool again, this time with 4 or 5 sweeps
per DV. Is there any difference in the global sensitivity curves?
Written by Changhyun, SON
Chapter 8. Workshop Session - 13