FEM- Farsi
Transcript of FEM- Farsi
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1-1 .
n. 1-1 n n n.n .
1-1
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n. .""
. :.
1-2 . . .
. . . .
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2-1 . 1-3. F2F1 ". .))1()2."
1-3 .X :)1-1(F2=K(u1-u2) :)1-2(F1+F2=0 :)1-3 (F1= -K(u1-u2)
))1-1()3-1 :)1-4(
=
2
1
2
1
u
u
kk
kk
F
F
F1F2 F1eF2e. :
)1-5(
=
2
1
2
1
u
u
kk
kk
F
Fe
:)1-6] (u[
e]K[=
e]F[
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]]u1-6 ]e]F ]e]K ( .) .
.1-4. . :
)1-7(
EA
PL=
:)1-8(
K
Fx=F=kx
1-4
)1-9(KL
AE
:)1-10([ ]
L
AE
L
AEL
AE
L
AE
K
=
:
1-5
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1-6 1-6: . :
K13=13:-k4K12=12:-k1-k2:
+
++
++
4334
323121
421421
KKKK
KKKKKK
KKKKK
3 .33 . .
: 1000A.1-7 .((E=200e7 Pa
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1-7
: . . . . . :A
1-8
:i
ii
L
EAk =
Ki ..]66]k :
]] [K]=[F[ 2345 ))16F:.F
1-9
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.
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.-A2-i .3-1 " --." . .
.
- - .. . . . .1-11
1-11Courant1943 (
...) . ""Finite ElementClough1960 . "" " ."
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: .:
0=== xzyzzz .
1-12
: :.zx=zy= zz=0 .
.)1-12()(5-1 ))Xi,Yii.1-13 ))ui,vi)(Fxi,Fyii. ..
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1-13 . . ]]k :
)1-13([ ]
=
3
3
2
2
1
1
66
3
3
2
2
1
1
vu
v
u
v
u
K
F
F
F
F
F
F
xij
y
x
y
x
y
x
:
]][[][ kF =
:.)1-14(
++=
++=
yxyxv
yxyxu
654
321
),(
),(
12,.... ())xi,yiiui,vi.i) :
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)1-15(
=
6
5
4
3
2
1
33
33
22
22
11
11
3
3
2
2
1
1
1000
0001
1000
00011000
0001
yx
yx
yx
yxyx
yx
v
u
v
uv
u
]: ] [ ] [ ] 166616 = A
.]]A)1-16([ ] [ ] [ ] 16
1
66 = A
(14-1u(x,y)v(x,y]] . :)( 2321 =++
=
= yx
xx
ux
6354 )( =++=
=
= yx
yy
vy
)()( 654321 yx
xyx
yx
v
y
uy
+++++
=
+
=
53 +=xy
xy
y
x
:
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)1-17(
=
6
5
4
3
2
1
010100
100000
000010
xy
y
x
:)1-18([ ] [ ] [ ] 166313 = C
:1-16]])1-19([ ] [ ] [ ] [ ] 16
1
666313 = AC :]]
)1-20([ ] [ ] [ ] 1666363 = ACB
:
EE
yxx
=
E
v
E
xy
y
=
xy
xy
xyEG
)1(2 +
==
:
)1-21(
+
=
xy
y
x
xy
y
x
E
vEE
vE
v
E
)1(200
01
01
:
)1-22(
=
xy
y
x
xy
y
x
E
2
100
01
01
1
:
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]][[][ D= D .))Stiffness . :
)1-23([ ] [ ] [ ] [ ] 166333 = CD ))0=z :EEE
zyxx
=
EEE
zyxy
+=
0=z
xy
xy
xyEG
)1(2 +
==
:
)1-24(
+
=
xy
y
x
xy
y
xE
)1(2
2100
011
01
1
)21)(1(
)1(
:133313 ][][][ = D . . "". . Fi
W :.
)1-25 (i
vol
n
i
iextvol FWdW ===
=1int
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)1-26([ ] [ ] [ ]{ [ ]}[ ][ ][ ] == BDB TT :
=
)1-27( dvol .dvol:
)28-1(
)1-28(t
yx
yx
yx
Vol
33
22
11
1
1
1
2
1=
t . :)1-29 ()](][[][][ VolBDBK
T= . - :)1-30(]][][[][ BD= ][]][[ BDH :=
][][][ = H
6-1 . :0=
+
+
ZYX
xzxyxx
0=
+
+
ZYX
yzyyyx
vol
eT dvolBDB }]{]][[][[
y
x
y
x
y
x
F
F
F
F
FF
3
3
2
2
1
1
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0
2 =
+
+
ZYX
zzyxx
-- . . . . . -...- . .
7-10
2
2
=++ cdx
dub
dx
udR2
. . (FiniteDifference) . .
~)0(u.~)x(u c
dx
udb
dx
uda ++
~~
2
2
:.)(
~~
2
2
xRcdx
udb
dx
uda =++
"(R(x )")Residual term )(~ xuu(x). :)(~ xu .(R(x .. ~)()1(1 += xxxu . ~)()1(1 += xxxu
.1)12(1221
~~
2
2
)( +=+=+= xxdx
ud
dx
udx
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.(R(x n])])1,0. R(x):
R(xi)=0 i=1,2,,n
1:2
2
=+udx
ud)0()1(1 uu == . ~)(.: xu
1~~
2
2
)( += udx
udR x
. . n .Collection Method.~u
~)( xu dxxR .)( :
=+1
0
0]1)12([ dxx
][ 0)( 102 =+ xxx
022 =
2
1=
:)1(
2
11~ )( += xu x
= 0)( dxxR :....)1()1(1)(
~ 22
2
1 +++= xxxxxu ,..., 21 .
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. ~)( xu 12 ,,..., n. 12 ,,..., wwwn i:
0)(~
= dxuW xb
a i
win n 12 ,,..., n . iw . ))Galerkin . i iw . x )1(1)(~)1( +== xxuxxw ~)()1()1(1 221 xxxxxu ++= :
)1(1
xxw =)1(22
xxw = :)1(1)(~ += xxxu
)1(1 = xxw
=1
00)( dxxWR
01)12()1(
1
0=+ dxxx :
8
5=
:)1(
8
51)(~ += xxxu
:101)( = xxU .%6/15%5/12
1-7-1 . :1-31.
)1-31(0)( )()()( =+
xxx qcdx
dua
dx
du
:
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)(@,)0( 0)(0 Lxqdx
duauu x ===
1-14
(Q.)(q)a(u)
EA K
0((
128
4
D
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V 2):)1-1
1-31 )( . ))1-1 .1-14 .
1-7-2 i~1-31iu . -n][0,L .- ejueju . ~eu :)1-32()(
1x
m
j
eju
e
j
e u =
=
.ej xBxA. :)1-33( =+
0)](~([
~
)( dxxguCdx
uda
dx
dw
xx
x
x
B
A
~u u .)(w u~uu . :
~u . .
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)1-34(udx
dvv
dx
du
dx
uvd+=
)(
:)1-35(dxdudx
dwa
dx
dua
dx
dw
dx
duwa
dx
d/)()( =
uwu :.1
)1-36(= dxdxdu
adx
dW
x
x
A
B)]([
+=+ dxdxdu
dx
dwa
dx
duwadx
dx
du
dx
dwadx
dx
duwa B
A
B
A
B
A
B
A
x
x
x
x
x
x
x
x ][)(
:))1-37dx
dx
duaw
dx
duawdxwqcwu
dx
du
dx
dwa
AABB
B
Axxxx
x
x
+= )()( )()(
dx
dua
. w
dx.du
a Q.Q:)(
)(2dx
duaQ
e = dx
duaQ
e =1
((Free Body Diagram Qi ( Qi .) :.(-
.)uX.- ( 2 0axa122xa .ai
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ui- ( .)ui :
)1-38(bxaue +=
e
x
ee
x
e uuuuBA
21 , == :Abxau e +=1
)1-39(B
ebxau +=2
=
b
a
x
x
u
u
B
A
e
e
1
1
2
1
:ue)1-40(
e
AB
Ae
AB
Beeeew
e uxx
xxu
xx
xxuuxu 212211 )(
+=+=
AB
B
xx
xx
AB
A
xx
xx
))shape Function. .)(xeu ~u .
n )2)n )(w :)1-41()()( xx
e
ii =
.in :n +
==
ej
ej
n
j
eeej
n
j
ej
eeie
jdx
da QxdxqxuC
dx
du
n
e
x
xB
A )(]))(()1
111
1([ 1
...
)42-1(ej
e
j
n
j
e
n
e
n
e
j
e
n
e
jn
e
j
e
nx
x Qdxqxej
Cdx
du
dx
da xuBA )(])(()([0
1
=
+=
:1-42 ==
ne
i
e
i
e
j
e
ij niQFuk ),...,2,1(0
+= dxCdxddxdaK ejeie
i
e
ix
x
e
ijB
A)(
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)1-43(= dxqF eixxei BA e
ijK
e
iF :
)1-44(
+
=
e
n
e
e
e
n
e
e
e
n
e
e
nnn Q
Q
Q
F
F
F
u
u
u
KK
K
KK
2
1
2
1
2
1
1
21
1212
.........
...
]]F ]]QK . .KKij :
:-1
1
1
+= een uu
(e .)e)(-2
.)(:Q0:Q0.{01 0Qeen QQ =+
eeen Uuu == +11 :
=
+
+
+
E
EE
EEE
u
u
u
KK
KKK
KKK
KKK
K
.
.
.
2
1
2221
1211
1
32
3
11
2
22
2
21
2
12
2
11
1
22
2
21
1
12
1
11
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)45-1(
++
+
+
++
EE
EE
Q
QQQQ
Q
f
ff
ffff
f
2
3
1
2
2
2
1
1
2
1
1
2
1
1
2
3
1
2
2
2
1
1
2
1
1
...
...
))Assembled Model Equations . ij K .1-7-3
0)( =+ kCudx
dua
dx
d
:q
dr
dTkr
dr
d
r 2)2(
1=
)46-1(
00 )(@ TRT = , 0)0(@2 =
dr
dtkr
1-2 .350.00
346.09
334.38
314.84
287.50252.34
209.38
158.59
100.00
352.63
347.42
335.27
315.48
287.95252.65
209.56
158.68
100.00
358.73
348.31
337.90
313.59
289.29249.70
210.12
155.06
100.00
377.78
356.24
335.11
315.28
249.44254.83
197.22
148.61
100.00
433.33
391.67
350.00
308.33
266.67225.00
183.33
141.67
100.00
R
S
0
0,1250.250
0.3750.500
6.625
0.750
0.875
0.000 .))1-2
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))Shape Function8-1 . ))Local Coordinate Variables . . ANSYS.
.1-8-1 .)15-1(
1-15 .71[].1-15 . .)(xu (u(x . )(. . (u(x (u(x . )(. . n )(xu
(u(x n-1 . .n-1 . .
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1-8-2 . . 715-1 .71 . - . . .
1-8-3 ~u 1~u1 2~u2 :1x2x
)1-47(2
12
2
1
12
1 ~~)( uxx
xxu
xx
xxxu
+
=
1-16:L2L1
L
xx
xx
xxxL
=
= 2
12
21 )(
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)1-48(
L
xx
xx
xxxL 1
12
12 )(
=
=
:2211 ~)(~)(~ uxLuxLu += 1-17 L2L1. .
1-17
1-8-4:(L1(x)L2(x
1)( 11 = xL 0)( 11 =xL0)( 11 = xL 1)( 22 =xL L1 L21 .2
: ) 21 xxx
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dxdxxdL
dx
xdL.
)(.
)( 21 dxxLxL )()( 21
. . Local Coordinate System x1. :x2-x1
1-18
)1-49(
,
12
12 0)(,1)(xx
xxx
===
.1-49 .
1-19:
)1-50()1(2
1)(1 =L , )1(
2
1)(2 +=L :
)1-51()()( 2211 LxLxx += :. == 2
1)()(
2
1
2
1
dd
dxLdxxL
3
1])1([
24
1)1(
4
1 11
32 == + d :)1-52( = 3
1)(
2
2 dxxL :])-]1,1(
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)1-53( == 8
1)()(
2
1)()(
2121 dLLdxxLxL
61)1( 2 = d
.
: dxu x)(2.:)()()( 2211 xLuxLuxu +=
uu2,u1 : +=++=+ dxLudxLLuuLuLudxLuLu
2
1
2
12121
2
2
2
2
2
1
2
1
2
2211 =][)2( ++=++=+ ][3
1
6
12
3
12 21
2
2
2
121
2
2312
12121
2
2
2
2 uuuuuuuudxLLuuLu
.21-8-6 2 u :2
)1-54(2210)(
~ xaxaaxu ++=21 xxx .u ~)( xu . . x :
)1-55(2321
~ xxu ++=
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)1-56(
==
==
==
3
~
2
~
1
~
1
2
1
0
uu
uu
uu
x
x
x
:)1-57(
++=
++=
=
3213
2
2212
11
)2
1(
2
1
u
u
u
:)1-58(
332211 )()()(~ uxQuxQuxQu ++= :
)1-59()
11)(
1
21()(1
xxxQ
=
)1
1(1
4)(2
xxxQ
=
)11
2(
1)(3
=
xxxQ
:)1-60(
=
===
1,0'11
1',2
1'3,20
)(1xNodeat
xxNodeatxQ
)1-61(
=
xNodeat
NodeatxQ
1
3,10)(2
)1-62(
= 31
2,10)(3
Nodeat
NodeatxQ
)1-63(10 x1)()()( 321 =++ xQxQxQ )1-16(. :
)1-64()1)(1()(2 +=Q
)1(2
)(1 =
Q
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)1(
2)(3
+=Q
:1-20Q2Q3Q1332211 )()()(
~ uQuQuQu ++=
1-20
7-8-1 .Qi
2. :.)1(
2)(1 =
Q
)(1.1iQi Q )23(0=1=))1= Q1.)1-66(= )()()(1 GFQ
)(1 Q1=.:)1-67(1)( = F )(1 Q0=.:)1-68( =)(G
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n n .2Q1. )(1 Q . )(F)(G.2)1-69()1()(1 = KxQ 11==)(1K Q:
2
1=K
))1-70)1(
2
1)(1 = Q .
.4"":
1-21)(2: Q
)()()()()(2 IHGKFQ =1)1()(01 +=== F )(F === )(0)( 0 GG
2
1)(0)(
2
1 ===
HH
1)(0)( 1 === II
12
12 )(=
=Q:
1)1)(1)(2
1
)(( 21=+
=K
3
81)
2
1)(
2
3)(1)(
2
1(
==
KK
:
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)1)(1)(
2
1(
3
8)(2 +=Q