LẬP TRÌNH TÍNH TOÁN HÌNH THỨC TRONG PHƯƠNG PHÁP PHẦN TỬ HỮU HẠN GIẢI MỘT SỐ BÀI TOÁN CƠ HỌC MÔI TRƯỜNG LIÊN TỤC
NGUYỄN ĐÌNH HIỂN
Trang nhan đề
Mục lục
Mở đầu
Chương_1: Một số ký hiệu, định nghĩa và các khái niệm cơ bản.
Chương_2: Tổng quan về các tính toán hình thức.
Chương_3: Một biểu diễn của phương pháp phần tử hữu hạn cho tính toán hình thức.
Chương_4: Phần tử hữu hạn trong toán học tính toán hình thức để giải bài toán cơ học.
Chương_5: Áp dụng lập trình tính toán hình thức vào một số bài toán cơ học
Chương_6: Kết luận.
Các kết quả của luận văn đã được công bố
Tài liệu tham khảo
Phụ lục_1: Sơ đồ tính bài toán khuyếch tán khí
Phụ lục_2: Bài toán tấm vật liệu đàn nhớt
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79
Chuang5 :
AP DT)NGL!P TRINH TINH TOAN HINH THDe
VAo MOT SOBAI TOAN CO HOC
5.1Bili tmin 1: Tinh toaDhlnhthucchobili toaDbienkhuye'chtankhi thai
theomohlnhbachi~u.
Bflitminbien truy~nva khue'chtankhithai (xem[35],[361):
TImrpE C2(0) thoa :
C(p &p &p ocp (Olcp /::~<:J: 01rp- +u-+v-+w-+a-rn-I[ -+---;- -v-= f~ ~ ~ ~ 't" r ~J ~ ~JIA ax: 0' oz ax:- (1'- 0::;- trang Q x (O,T)
* £)i~uki<$nbien'
* Di~uki<$nd§u .
. Dangbie'nphan .
Voicaekhonggianham:
v={V/E D( 0) : V/If =o} H =~1.2(01 va v = ~HJ(Q)
uiy V/Ev, nhan phudngtrlnhtrenvdi u. richphantrenQ , r6i apdl:111geongthti'c
GreentaduQc: r~dO+a(rp,fjI)=ffV/dOn Q
trangd6 : f(&p orp c<oJ fa(rp,If/) = u--:::-+v- +\I" ;.. V/dO +(J rplf/dO +
Q ex 0' (- Q
f,/ o(poV/ co' forp olf/ f+J-l [--:::-:::- +--=-:-dO +\" ~ -:::- dO +vfJ rpV/dr 0
Q .ex ax: ('. n oz oz f"
Tadide'nphatbi~ubie'nphaneuabairoan:
Chofer) EL1(O,T,V ), rim rp(t)EL1(O.T.:O)n L"(O.T,H) vdi rpoEH, thoa :
rp=0 tren f x (O,T)
&p,
tren fox(O,T)=fJrpoz
orp
tren fh x (O,T)-=0Oz
rp(G) = rpo trong Q
80
(d:;t),1f/);.IX,.+a(tp(t),If/)= (f(t),If/)vXVI,"dlf/E V
<p(G)= tpO
Roi r<,lemi~nxaedinhva xa'pxi trenm6iph~ntll'([36])tadi thudu<;1eh<$phuong
trlnhd<,lis6 xaedinheaegia tri cpt<,licaedi€m nut:
.
J1ct>+Kct>=F
e=1 <"=1
lie
va F =I '(,IFJ.. . F
e=1
M M
tron!!d6 . _VI ="'\'T.'m1.: l\.="'\'T'k.T~ ~, " ~ e "
m, = fN'NdQ, e
0,
va k =k +k +k +k +ke e, e, <", e, e,
ke2= a fN' N dQe
0,
k" =lN' N[(U,,)(~)+(v"t;)+(w,,{~)]dQ,
k., ; PQ{(~n~)+(ZHZ)]dQ,
k" = v1[(~n ~)]dQ, ke,=v/3fN' N drOer",
va F: =fN' N dQe
0,
caematr~nTeehilacaematr~ndinhvi (l~prap),khongdn phaixaedinh.Cae
richphantrend~udu<;1ctinhtrencaeph~ntll'th1,icQt:, Khi tinhroantrenmay,ta
chuy€nd6ichocaeph~ntll'quyehie'uOr.(tuonglingvoiph~ntll'th1,ic).Ne'ucae
ph~ntll'th1,icla ph~ntll'kh6i Sailm~t,ph~ntll'quychie'ue6d<,lng:
ChQneosa xa'p Xl :
!
-l'-l'l~ -l..l.l: '.II , 1 ,. . '. ,.,
I ~---:-----
-1.-1.-1 ' I
8-n-i-_u_",
I
,I.'.-1.-1
p=(1 ~ 11 ~ ~1l 11c; ~C; ~11c;)
(C6 th€ thayd6i d~dangtrongchuangtrinh)
Ma tr~nJacobi cuaphepbie'nd6i nay:
'~1.1.-1
"
£)~t : Q= J-I
ex cy e=- -
e; c; 13;
ex cy c=J=I -
CTJ CTJ cry
ox dy c=- -
ct; at; ot;
81
(o~)ox
B\, = Il/ O~V)oy
(~)
(~)
B,=I(~:)
(~~)
va v =((UII) (VII) (WJ )
Khi d6 ta c6 :
me= fN'.\ [dct(J)1dO,.
n,
k, = fN' X VQB:Idet(J)ldO,.
n,
k" =a J N' Vi det(J)1dO,.
Q,
k",+k",= fBe'Q'DQB" Idet(J)1dO,.
0,
k'r = vfJ IN'.V J, d~d'7
fll'
troll (1 do .b
[
Jl 0 0
]
D= 0 Jl 0
0 0 v
(
0'0= 0=Ov)
2 O=m: &:C:-
)
2
[,nry rym:)
2
J, = 11 01;dry- 02;oOry T 02;dry - o~cry + ot: dry- 02;dry
Xu dl:lilgthu vi~n(Package)FEMI ta c6 th~tie'nhanhroanb(>caetinhroanly
thuye'td trend~di de'nke'tquacu6iclingla caematr?n me, ke ' Ce , Fe dd<;lng
chuy~nd6i qua ngon ngu so truy~nthong(Fortran) ( 1t?P tin tren ilia) :
>eq:=Diff(phi,t )+11*Diff(phi,x )+v*Diff(ph i,y)+w*Diff(phi,z)+sigma*phi-
mu*(Diff(p hi,x$2)+Diff(phi,y$2))-nu *Diff(p hi,z$2)=f;
"a"~,
(
'3
)
la\ '0\
13q:= l~ It 1+u -.; 1>.+V l;:",1» +W i. -:::-IP)+ G 1> - ~Lut) .jX v.,Y \ az
-v
(
~q,I=j
az2 .J
(
"
J(
'-"
lJ
a<::. a<::.
ax 2 1>+ 0-,2 1>/
>ini:=
philgamma[1]]=0,Di.ff(phi[gamma[2J],::.)=beta*phi,Diff(plzi[gamma[3]],z)=0);
ini :=:; =0, ~ 1> = ~1>,~ 1> =0
"f az"ll az "II
'1 (2 (3
82
>read'FEM1.m' :
>with(FEMI) :
>ep:=bienphan(eq,ini);
j
'
j
'
;=1 'a a " a "
8P= r~t1Jdo.+ (u(ax(P)+ v (~ 1Jj + w (IE (P)) lV do. + (5J 1J lV do.
+~f(a: ~)(a:'")+( ~~)dO +-i f(~~)(~\If )a'O + v ~fh aT 2~
J1' ltfdo.
> P:.=[1,xi,eta,zeta,xi*eta,eta*zeta,xi*zeta,xi*eta*zetaJ;
P:= [1,';,lJ,~,';lJ,lJ~,~';,';lJ~]
>matran(ep, P , Lagrange.,8) ;
m[e],k[e]luutrendia-->MMvaKK
Ch£ngh~n,ffiQtdo~ncuat~ptinKK ( chuamatr~nKe) cod~ngd ngonngu
Fortran):
tl =dy**2
t3=dx**2
t4=nuy*tl*t3
t6=dz**2
t7=muy*t3*t6
t9=muy*t1*t6
tl0 =tl *t6
t12= tl0*u8*dx
t13= t3*tl
KK(1,l) = -(t35+t64)*t66*t70/864
KK(1,2) = (t72+t73)*t66*t70/864
KK(1,3) = (t77+t78)*t66*t70/864
KK( 1,4)= -(t82+t83)*t66*t70/864
KK(1,5) = -(t87+t88)*t66*t70/864
KK( 1,6)= (t92+t93)*t66*t70/864
KK(1,7) = (t97+t98)*t66*t70/864
KK( 1,8)= -(tl02+tl03)*t66*t70/864
KKr2,J) = -(tl07+tl08)*t66*t70/864
83
KK(2,2)=(tl12+tl13)*t66*t70/864
KK(2,3)=(tl17+tl18)*t66*t70/864
KK(2,4)=-(t122+t123)*t66*t70/864
KK(2,5)=-(t127+t128)*t66*t70/86
MQtvi d1,lC1,lth€: tinhto<lnchomi~nkh6nggiannhusau:(moi buckla 1m)
M6 hinhtfnhbaitoankhuyechtan khf1000nut
49
10
E
0-
il
0-x
E
H)
~ lmx9=9m
I
-/
il-
I
I
1
4011
-" 403:;z::::
405 407
/./ //
410
4Q
x ..
10
500
Ngu6nt<;1inut455.Ngu6nca'pkhi thaivaom6itruong(trongffi~tph~ng401-500)
Haitruongh<;p:
1./Kh6ngcogi6
2.1C6giGffiQtchieutheophuongx \"~nt6c:O.2n1Js;O..+mJs:O.6m/s
'/
-I
,
:1, /
./ /
/ ./ / / / /
/ / / /
I
10 t
y /
/ / v
/ 1/ v
)(IV
v (
V
V
'1n I)() 7n lnn
",-
SV THAY 001 GIA TR!HAM <pTHEa THOI GIAN - va V N TOC GIG
Boc tu do 10 291 - Nut so: 453
Bvac thol ion W=O w=0.2 w=0.4 w=0.6 24 5.55207 12.5541 19.6337 25.30451
1 5:57E-D1 5.57E-D1 5.57E-D1 5.57E-D1 25 5.609416 12.9021 20.2132125.88121
2 1.06372 1.13216 1.19896 1.26577 26 5.6615 13.2337 20.7564 26.3
3 1.525419 1.72139 1.9155142.11240 27 5.708796 13-.5491 21.2639 26.8337
4 1.945823 2.31994 2.69537 3.08037 28 5.751738 13.8489121.7365727.2153
5 2.32859 2.92382 3.5279 4.15258 29 5.79072 14.133422.1751 27.53821
6 2.677058 3.52946 4.403241 5.311481 30 5.826102 14.403122.5807 27.80604
7 2.994271 4.13371 5.311 6.53951
8 3.283004 4.73377 6.24412 7.81942'1 ...........
9 3.5457885.3272247.1925179.134641
I
10 3.784931 5.91193 8.149124 1O.4693
11 4.002538 6.48606 9.10697 11.80897 141 6.164285118.312 25.3834726.2734
1
12 4.200527 7.04807 10.0597 13,1398 142 6.164283 18.312 25.3835 26.27347:
13 4,380647 7.596641 11,0018414.4497 143 6.164281 18.312 25.3835
1
26.27352,
144
i
14 4.544493 8.130674 11.9282115.72781 6.16428 18.3123 25.3835 26.273
15 4.693519 8.649287 12.8344 16.9644 145 6.164279 18.3123325.3836326.2735.
I
16 4.829048 9.15177 13.7168 18.15154 146 6.164277 18.3122 25.383 26.273621
17 4.95229 9.637604 14.5721 19.28224 147 6.164276 18.3122 25.3836 26.2736
18 5.064343 10.1063 15.397720.35107 148 6.164275 18.312L 25.383726.2736
19 5.166212 10.5578 16.1912 21.35377 149 6.164274 18.3121 25.3837 26.2736
20 5.258809 10.9918716.9511422.2872 150 6.164273 18.3121 25.3837426.2736
21 5.342968 11.4084 17.676 23.1496
22 5.419447 11.8075 18.365123.939
23 5.488938 12.189419.0177424,6578
100
Me;hinhtfnhbai toan khuyech
tan khf3600nut
3030
57
1mx29=29m
3035
1800
TRlJONG HQP 1:MAT 1201-1800CHUA NGUON THAI
vAo I\t'IOITRl.IC1NGT~INOT1480
BAITOANEX..t:1CGIAivd! cAc TRLeJNGH.?P:
1.KhOngc6 gi6
2 .C6 gl6phUongX.v<)nt6c :O.Amjs
1800
NGU6N - 1485 - 1487
T~NG HQP2:~ T 1201-1800CHUA4 NGLON THAI
vAo MOlTRlfJNG T~IcAe NOr 1425-1427-1485-1487
BAtToAN Dl..1OCGlJ\I ~I TRI.JO>JG!-pp KHCNG cO Gl6
E
to
"
~
E
107
Nhanxetvake'tluanchob~iiloan1:
Vdi cacchudngtrinhtinhloanhinhthuctrenmaytinh(l~ptrinhSymbolic)
c6the'chophepgiai cacbaj loanr!t phuct~p,cacdi6uki~nyell cftucao(Cl , C 2
...)vavdidQchinhxaccaomad d6khongthe'chQncacphftntitddngianduQc(vi
d~v~tli~ucomposite,cdhQcphahuy...).
Tit cacthu'vi~nchuyend1;lng(Packages)c6the'ti€n tI!dQnghoal~ptrInh
(t~omangu6nchocacchu'dngtrinhgiaisO').
K€t quabaiLoanthayd6ithencaevi tringu6n,v~nt6cgi6.va otnhtinh
nh~nth!y hoanloanhQply. C6 the'mdrQngvi dl;lthanhffiQttht!cnghi<%mtrenmay
tlnh.
108
5.2Hilitoan2: Phudngphapphftntii'hUllh~nghHbai toaDbien
? .,
vai v~tli~lldaDnhat-danghuang-dangnhi~t
5.2.1./TiDhcha"tcdhoct6D2QUatcuabaitmiDdaDnhot:
Quilllijt llng xii ailnnh6'tclla vijtreind~tatrell caccdsdsall:[8l[25]
. Tiend§ :giatritlicthaicliatensorlingsuatphI,!thu()cv2wroanbQlichsubien
thienclia tensorbienJ~lng.
. Tien d§ bQnhdtatd~n:slfphu[huQcCULlgiLltri tlic thaicuabien sC;thlinhat
VaGgiLltri CULl biensO'thlihai lmngthaigiantniacdayGl((jCxacdinhnhamOt
hamtrQngluQng,hamnayd~il11baaslfph~lthuQcgiiimlien tucvaocaeslfki~n
trangquakhli k~tuthaidi~mLiangxettrdv€ truac.Tien denay th~hi~nrhea
df
c:;Id(C;ik,(f))
dt
khi t, >t2>0bi~uthlicsau:
d(C;lki(r))
'=1, 1=1.
. Nguyen 19dQcl~plac dl;lng.
. &(t) lahamlientl;lctheothoigian.
Phuongtdnhcobandn thietd~gi~iibairoanlingsuat-biend~ngtlfatInhtuyen
tinhcho\.~th~batd~nghuangl3.baphuongtdnhcanbang:
a(5 if + F, = 0
ax
J
(5.2.1)
trangd6 Fr la cacthanhph~ncliJ 'ector llfc kh<5i,sau quanh~chuy~nvi biend,:lllg
I ~
l(Oll;,OU,(t)= -; --:-
Gij ,; ax ax;- "
(5.2.2)
clingvaisauquanh~lingsuatbiend:;mg
oc ~
(j if = fC ijkl (t - r, Xi) CE:kl d r
0 ar
(5.2.3a)
trangd6 giathietcachamling su{,biend~ngtri~tlieu khi bienthai gian t<D.
TrangtruanghQpv~tdn d6ngchar.d~nghuangC""I(t) chiph~thuQct.
Cijkl(t) : la modulh6iph~c(relaxationfunction).
109
00
(J = fe (t ) O£k!ij ijk! - r ~ d r
0 OT
(5.2.3b)
Vie'tlC;li(5.2.3) rhea trong truongh<;1pd~nghuang:
"'
f ( )0£ (T) f oGier)(Jij(t)=5ijAt-r ~ dr+2JJL(t-r) : dT
0 OT 0 or
(5.2.4)
hayvie't lC;li(5.2'-+)rhea modun E(t)va "(I)
"'
f" E(t - r) ( )
dt- r)
)}0";;(1)= ( v( -)) £,,(r+ "){ )c5ii£kk(r ir0 1+ I-, 1-..;.lt-r
(5.2.5)
trangd6:
va
.E(t)
,u(t)=2(1+v(t))
E(t).v(t)
;.(t) = (1+v(t)XI- 2v(t))
(5.2.6)
(5.2.7)
Di;lngkhaccuaquailh~Ung su:1t-bie'ndq.ng:
YO
E:ij = fSijk! (t - r) Cc: k! dr
0 cr
(5.2.8)
Clingnhuhamh6iphl,lcvahamchaych~mS ijk! (t) d~ctrungchocactinhchatco
hQCcua v~tli~u.Vai truongh<;1pd~nghuangtac6 dC;lngt6ngquatcuatensorhC;lng
4d~nghuang:
(jk/(t)=~[c;(t)-C (t)~~5k/+~[~(t)K5;k5j1+c;CjJj ..;. (5.2.9)
B~t(5.2.9) VaG(5.2.3) ta thudu<;1c:
:c , oe
Sij = fC1 (t - ")~ dr
0 o.
(5.2.10)
00 ~
(]' kk = fC 2 (t - :,)c~,dr
0 c:'
(5.2.11)
trangd6:
1
Sf;=OJ, -::, I5kk0;
.J
i tensor l~ch ling suat) (5.2.12)
110
1
eij =G ij - ""3G kk 5'1 (tensorlc%chbie'nd~ng).
(5.2.13)
! vatac6 h~thlicchaych;%mgiii'abiend~ngva lingsuattu'dngling:
X
f ( )
as
eij = J1 t - r --Ldr
0 or
(5.2.14)
YO
fJ ( )
oakk
Gkk = 2 t - r ---;::-dr
0 or
(5.2.15)
Trangd6:
~(t),~(t): hamh6i pht,lcvahamchaych;%mtu'dnglingvai tr~ngtheljbiend~ng
tru'Qt.
C2(t),J2(t):hamh6i pht,lcva,hamchaych;%mtu'dngling vai tr~ngthaibiend~ngthti
tich.
A.pphepbie'nd6i Laplacevao(5.2.10),(5.2.11),(5.2.14),(5.2.15):
S =sC] eI) I)
e =sJ
]
S
I) 1J (5.2.17)
0k =S~&kk
Gkk= sJ2 Gkk
Tu'dngtVnhu'ly thuyetdanhbi.caehamh6i pht,lcd£nghu'angkhi truQtthucintily
vagiannd th~rich:
J1(t)=~c](t) ; k(t)=XC2(r1 (5.2.18)
So sanhyai (5.2.17)tathayrang:Khi thaymodundanhbi bangphepbiend6ide
hamhbi pht,lctu'dngling trongde h~thliccualy thuye'tdanh6i tase thuduQcly
thuyetdannhat.
Ta c6cac bie'nd6i Laplacecua:
ModunYoung
111
~(s)= 3~'C2(s) = 9170l.kW
~+2C2(s) j.l(s)+3kW
(5.2.19)
h~soPoisson:
;;w- ~- ~ - 3fG)- 2;0)
- s(~+ 2~) - ~u (.I')+ 3k(s)]
(5.2.20)
vaHamh6ipht,lc:
m=~[c2(.I')-~] =k (.I')- y;P (.I') (5.2.21)
Vdi v~trandannhdtthaythe(5.2.2)(5.2.4)vao(5.2.1)tathuduQc:
."'
f
-
( )
au, i (r) oo
f
~ ,
( ) ( )
ell k ki (r )
pt-rl dr+ At-;j.lt-r . dT+F=O
0 aT 0 aT
(5.2.22)
rheonguyen19dQcl~placdt,lngtac6th€ matacacchuy~nvi,biend~ng,vaung
sU<ltnhusail:
Ui(Xi,t)= uiO(xJ.u(t)
E ij (.\: i , t )=E ~ (xJ. u(t)
(j ij (xi , t )=(J" ~ (xi ). F (t)
(5.2.23)
f)~c6th€ tachbienduoid~ngt6ngquatnhutrenhc$soPoissondannhotphaila
hangsotht;tc[45].f)i~unayc6th€ th<1yratll'phuongtrlnhdin b~lllgclingnhudi~u
kic$ntuongthich.
f)~tIIi (xi ,t) tll'(5.2.23)vao(5.2.22)vad~t~=0 tathayrangphuongtrlnhdin
bangchi thoamankhi: A(t) -"- ,LL(t) =K)J(r ) trangd6:K=hangso
A.pdt,lngcachc$thlic (5.2.20)va (5.2.21)vaodangthuctrenta timduQc:
v (5)=~
5
nghlala ( )
J v '\
V t =L- ! - =v =canst<s (5.2.24)
5.2.2.1V~motphuongphapghHbai toaDdfmMot tm-entinhd~ngnhiet:
5.2.2.1.1Ngllyenlj tztdngIlng:[25]
Theonguyen19tuongling,nghiemcuabairoanbiendallnhotruyentinhc6 th€ thu
duQctll'nghi~mcuabAiroanbi~ndanh6i.trangd6cachangsodanh6iduQcthay
112
b~ngcactm1ntlthampht,lthuQcthaigian(modunchungling Stittho~chamchay
ch~m).
Dl,l'atrennguyen19tuongling, taapphepbie'nd6i Laplacetheobie'nthaigian
thl,l'ct~0 vaocacphuongtdnhcanb~ng,h~thlicCauchybi~uthiquailh~chuy~n
vi- bie'nd~ng,dinhlu~tHooket6ngquatvacacdi€u kit$nbien.
ClCphuongtrinhthuduQcchliahamJnh cilaphepbiend6iLaplacehoanloan
tu'dngtt,tv€ m~tlOanhqcvai caephuongtdnhcua19rhuye'tGanhM ruye'ntinh.TJ
n6ieacphuongtdnhnaymorabairoanGanh6i ke'thQp.
D~thuduQcnghi~mcuabai lOanbiendan-nhattaphaiapphepbiend6i Laplace
nguQcvaonghi~mcuabai loandanh6i ke'thQP.
5.2.2.2/Phat biill biLiloan biendiLnnhottllytn tinh:
Phuongtdnheobanc~nthietd~giai bai loan ling SU<lt-bie'nd~ngtt,tatInhtuyen
tinhehov~tth~btt d£nghuanglabaphuongtrlnhcanb~ng:
C(J"if F. =0-+ I
cx)
xem (5.2.1)
rrangd6 F; la caethanhph~ncuavectorIt,tekh6i,Sailquailh~ehuy~nvi biend~ng
- ]
(
aui aui )E. -- -+-
). 2 ax. ax.I I
xem (5.2.2)
clingvai sau quailh~lingStittbiend~ng
cY:!
J ( )
a[; k!
iJ ij = C ijk! t - 7:,x! _8
d7:
0 7:
xem (5.2.3a)
Di€u ki~nbiendannhat:
/I. =U. ,X E fI' " \5.2.25)
G ;1/=T;.x; EfT \5.2.26)
rrangd6 l1j: eosinehihuangcuavectorphapdonvi huangrangoaicuam~tbienf.
Theo[9]h~thlie(5.2.3a)e6th~viet:- -
cr =Cijk/&k/ (5.2.27)
113
ijk/ =P .Cijk/ (5.2.28)
..anhcila bie'nthaigianthvct quaphepbie'nd6i Laplace.
ijk: la anhcila ~jk quaphepbiend6i Laplace.
.2.2.3./Bizi toandizllhiJi ktt h{lp:
uabiend6i LaplacetathuduQcbai roanuanh6i ke'thQptit(5.2.1).(5.2.2):
cau+FI=O
ax)
(5.2.29)
~=~
[
au
.
; + aui I
lj } a a I- X i XI )
(5.2 .30)
Vabie'nd6i eae di~uki<$nbien:
- -
UI=Vi tren C (5.2.31)
O".dn=Lx ErriJ J I I (5.2.32)
Trangd6gia thie'trangcac m~tbienkh6ngph1,lthuQcthaigian( ehuy~nvi be).
Phuongtrinh(5.2.29).(5.2.30),(5.2.31),(5.2.32)clingvoi quailh<$ung sua't-bien
d<;1ng(5.2.27),(5.2.28)la Svtu'angduanghlnhthuGvoibairoandanh6itrenmi~n
hinh Qcgi6ngnhau.chilltaGd1,lngchuy~nvi ui =ui(Xj'p) .lve m~tr, =r,(x;,p)
val1,1'ckh6i F;=F;(x .p), tagQid6la bairoandanh6ikefhQp.
Khibienkh6nggian\-abie'nthaigiane6th~bi~udi€n banghamphanly bien:
U; =u;o(XjP?V), F; =F;°(..JF;I/(t), ... (5.2.33)
[hIsvphanb6kh6nggiancilachuy~nvi vaIvctaGd1,lngtrongbairoandanh6iket
hQpgi6ngnhu'bai roanaan-nhotg6c.Theo (5.2.24)ai~ukiend~tachbie'nnhutren
la: v(t) =const
114
5.2.3.Giai bai toaDta'mchii nhiit. vat lieu daDnhot b~ngphu'dDgphap giai tich.
(TAMCH~UTAl PHAN BO VUONG GOC VOl MA.T PHANG GIU A TAM.)
Vi€t l(,1icaephuongtrlnh(5.2.29),(5.2.30),(5.2.31)chobai loanta-mmong
hlnhchITnh~tb~d~yh chili lionvoi h,tcphanb6 q(x,y):
°j-L., --,""
//0 //- .
b//I T /',/
/ /-1 / /."." I ./ /' / I"' / ./
/ , I
I
/(
./ T -'-
1\/16hTnngiGi bai toan tam kfchthL16ca x b
u' I
/
/ xa
-~-------
So do bieu dien each tfnhu'rhea Zva C(
NhaDxet (XemhlDh) : Chuy~ndichu',v' t(,1idi~mtrenlOpsongsongva each
m~tgiITamQtkhoangz , t(,1ithaidi~mt -do51,1'u6ncongta-mt(,10ra- co d(,1ng:
?
u'=-z sin(a(r))::::-zrg(a(t))=-z o-waxel
(5.2.34)
?
v'=-2sin(a(t))::::- ::tg(a(t))=-z o-w
Oyot
, OW
Laplace(u ) =- zp-::;-,ox
-
ow
Laplace(v')=-zPa;:
115
Tlinh~nxettrenke'th<;ip(5.230)chota:
a,- ",,- ,--w - o-w - a-w
E:tr=-zp ;- , fi,"V=-::p :;- , fin =-zp-
. o."c" oy" oxay
(5.2.35)
Tll (5.2.28)chota:
- "-E
I (o:~' 0";'\(Jxx=-p :;-::~ +v~ I
1- v- \ 0- ~v- )
(5.2.36)
- "- I
(
o"~' 01~
]
(J =-p E-z -+v-
XI' I-v" m': ax"
~=-p"E
- I
(
02~\,\
xv -7 I. I
_-I
+V axm'!
Vie'tl:;1i(5.2.29)chobai roanta'm(lingsua'tph~ngsuyrQng)[IJ taco:
a~ or", o~~+~+~=O
Ox av oz (5.2.37)
ar", aCT\1 a~
~ + '-'--+~ =0
Ox 01' oz
arx. oil~ oa--- 0~+--'-+--=- =
Ox Oy oz
f)ua(5.2.37)VflO(5.2.36)chota:
a I '"' ~"- ",1-, I 0'x= 2-E 0 cwo W I 2-E-= p -z- -+- =P -7-L1 W
az I-v" ax ex2 ay") I-V2 -ax I
(5.2.38)
8",= ,- I 0 82; 02~' ,- 1 0
--'- =p' E :;-Z_. --;- +---;- = P' E --;- z - ~I).V
oZ 1- v- or or ay') I-v- Oy
Tichphan(5.2.38)rheaz:
- ,- I Z1 a -
,.-=p"E ---~,W+Ip (X,1')
'- I-y- 2 ax . .. (5.2.39)
- ,- I Z1 a -
r,==P" E , -~~I w+ If/(x,y)
. 1- y- 2 oy
117
1 - 1 h3 a -
Q,=-p- E I-v212 axLl1W
=> -8 -QI =-D-:::-~,wox
- 1 h3 a A -;1 --0,
0 =-p- E~ 12~'-2 1- V uy
=>
-8 -
Q2=-D 0' ~IW
T d' D
1
E
1 h3
(
.
I' d
A' kh' A'
rang 0: =- p- 1- V2 12 gQI a Q cling tn,1 I lion) (5.2.47)
Phu'dngtrinh(5.2.46)c6 d<;ing:
(
~4- 4- --4-\
- a wow c w - -
D --:! +2 ~ 2 1 +~
J
=DI1/11 H' =0
ax ox CJy- c~v
(5.2.48)
Phu'dngtrinhtrenIa phu'dngt:rinhSophie-Germaintrangbairoandanh6ichophep
xacdinhdQvangcuabairoandanh6ike'th<;1p.
TImnghi~mphu'dngtrinh(5.2.46)voi caedi~'uki~nbien
(ta'mc6d<;inghlnhchi1'nh~t0:$x:$ a va 0.::::y:$ b):
}--
0
' a-W 0 ' . 0 ,w= va - = VOlx= vax=a
ax2
(5.2.49)
-
0 ' a2; 0 ,. 0 , b
w= va 0'2 = VOly= vay=
sadl;1ngphu'dngphapNavie- (dungchu6ilu<;1nggiackep):
f)i~uki~nbien(5.2.49)serheane'utabi~uthide)vangquachu6iFourier:
x '"
- ~ '" ' milX . mrv
W =L L- amll SIn - SIn ---::.-
111=111=' a b
(5.2.50)
Takhaitri~nhamrai trQngq(x,y)thanhchu6iFourier:
00 '"
q(x,y)=~~ q sin m1lX . I1tryLL 11111 SIn-
m=ilI=i a b
trangdo theo[1]gia tri gm'n' Ii:
4 a b "
ff ( )
' m ilX . 11m' .dqm'II'= - q x,y SIn-SIn ~cl..:r: y
ab 00 a b
(5,2.51)
vanghi~mcuabairoanIa:
L
118
W- - ~~ q11l1l 0 mm 0 n7r)l- ~L..J sm-sm-
11/:1//:1 ..-
(
m~ n~
J
2 a b
JT:D -+-
a2 b~
(5.2.52)
Trrtullghdp q(x,V) =qf)=cons!:
4QoUf
h
f 0 mm 0 nJrY dxd 16qoqlllll== - Sln-Sln- y==.,-ab 0 0 a b If-mn
(5.2.53)
- 16Qo 'f- f' 1 . mTCX. nm'
11'=---=- L L SIn-SIn---'-ir"D -,. -' ( ~ ~
J
~ a b
/1/-1.0.0..//-1.0.5 m, n
mnl- T -
\. a~ b"
(5.2.54)
Ta chi e~ntinh ~khiffi, n lanhungs61e.Vdi taingoaiphanb6d~u,ffi~t
giuakhiu6nphaid6i xling,caes6h~ngffi,n chaotudnglingydi de)yangkhong
d6ixungnenchungphaib~ngkhong.
Thea nguyen19tudnglingchungtase thuduQcloi giai cuabai tmindan
nhOttuloi giai cuabai tmindanh6ik€t hQpb~ngphepbiend6i LaplacenguQc.
w=Laplace-'6~)
11'=Laplace -I r
16qo
: Jr6 D
I
I
"
I
'"
I'" I 0 111TCX 0 n:ry
(
' ,
J
"Sin-Sin - b/1/:1.3.5...//:1.3.5 111- n
,
- a
mn -+-
a~ b"
(5.2.55)
voi(5.2.47)chu 9r~ng:
(
1
J
1
(
12(1- v2)
] (
1
J
12(1- v2)
Laplace-I = ==Laplace- - , ==Laplace-I ---= ---:-
D p2 EhJ p~E h-
D~t:
WI ==Lanlace -J! ~
)r , p2 E
(5.2.56)
f
!
,,
-i12CI-\o:)16Qo f' ~ 1 . !l1TCX,.n:ry11'0_
I
'
13 6 L L. ( ' , \ ~ Sin sin b1 If -'- -,- - - am-l.o.J...//-L.J ,In }/
)m11\--'--. . a"- . b~\ \
(5.2.57)
119
taco: W=WIWO (5.2.58)
Vidu: Gia SItvq.fli~udilll Ilhflt !nOfa Ilhztsan:
v=canst..
(
1
J
1 --'71
E =Eo 1- 2e 2
(5.2.59)
Giiiibai loan(theo(5.2.58»:
E=Laplace(E)=E{ ~- 2(P~~)]
'7'
WI=Laplace -I
(
~
J
- 2e-2 coshTJ!
,- - "
p-E -Eo
Nghi~mcuabailoandannhot(theov~tli~u(5.2.59)):
w=
(
2e-f cosh~t
J
~r12(1~V')16Qo
- Eo l 11' Jr6
x
L
x
L I . 111m:. 111rV]
(
1112 n=
)
2 sm~smb I
mn ,--+~ )a- b-
m=U.5...//=U.5,..
(_'E- \
f
'
W=I2e 2 coshTJl I 12(1- v-) 16q0
~ 2) E h3 .".6
/ l 0 '"
~ ~ 1 . mm . "1ZY 1
'-' L. ,sm-sm- i
I " I " ( ' '
J
- a b '
In= .0.)...11=.0.0 111- 11- ,
mill - + - j
~a2 b2 )
W=WTJWE (5.2.60)
trongdo:
(
_'7t t
JW1/= 2e .::cosh ~
(5.2.61)
12(l-~':)I6qo ~ ~ 1 . mm . mry
W =1 ~ ~ Sin-Sin-
E E /1: ,76 -' -' .
(
2 2
J
2 a b
0 1n-1.~.5...II-I.~.) m 11
mil - +-
al b2
(5.2.62)
120
2
1.8 \\
\,
\.
'\
\\
\\
\
\.
'\
"",",,-,.
1.6
1.4
1.2
""""",
-""'..,.,
.~ -'-
'- '--' ~-
1
i:J 2 4 6 8 10
(
- "t t
JD6 chicuahambien&;mgnh6tw" = 2e 2 cosh ~ ' v6i: 17=0.5
5.2.4.Giai bili tmindiln-nhot tllye'ntinh binS!phu'dngphapphftntti'hull hall:
Qua vi d~trentathefynghit$mrimduQcla nghit$mcila b~lito£lntefmph~ng.
Trangthl;tcte',s6cacbairoancdhc,cod~ngnghit$mgiiiirich,Ia reftit. Cachgiii
trenkh6ngnhungkh6ngmarQngchonhi~ubairoanmaconkh6ngth~l~ptrinh
hinhthuc. (j daychungt6i xin giai thit$uffiQtphu'dngphapgiii khat6ngquatcho
nhi~ubai roandannhat,d~nghu'ang,d~ngnhi~tb~ngcachl~ptrinhph~ntd'huu
h'.lnke'thQpnguyenly tu'dngung.
Tatimchuy~n\'i theod~ngham:
u(t) =Uo . u"(t) (5.2.63)
Bie'nd6i Laplace:
u(p) =Uo . u,,(p)
f;:-;.~. dV =J~t . f v . dV + f;'f rdf
r I' r
(5.2.64)
(5.2.65)
Trangdo:
(j"t =[~11, (j :.::, (]' 33, (j 12, (j 23' (j 13] (5.2.66)
121
~t= [~11' {;22 ,{;33 ' {;12,{;23 , {;13] (5.2.67)
-
(J=C'{; xem (5.2.27)
C=p.C xem (5.2.28)
C=Laplace (C)
c= E(t}C(1+v)(1-21')1 (xemchtidng1-19 thuye'tdanh6i) (5.2.68)
Quanh~bie'nd£!.ngva chuySnvi (xemchtidng1):
-
[;=Du (D tmlntU'vi phan trongcong thuc Cauchy) (5.2.69)
Apd~ngphtidngphap ph~ntU'hUll h£!.n,ta xet xa'pXl tren m()tphan tU'e ba'tky, tli'
(5.2.64)ta suy ra chuySn vi Ue(t) tren ph~ntU'1a:
ldt)= UOe.ul] (t) bie'nd6iLaplace====> Ue(p) =uoe.ul](p) (5.2.70)
!u'u9ding:
. UOe: 1achuy~nvi trenph~ntU',vala thanhph~nchIph~thuQcbie'nkhong
gian.khongph~thuQcbie'nthaigian.Daychinhla thanhph~nchuy~nvi
danh6icuaph~ntU'.
. UlJ(t): lahamchuy~nvi theathaigian,vala thanhph~nkh6ngph~thuQc
bie'nkhonggian.Daychinhla thanhph~nchuy~nvi nhdtcuav~tran.
GQi:
. Ue(t)1achuy~nvi t£!.inutcuaph~ntU'e t£!.ithaidi~mt.Anh cuano quabie'n
d6iLaplacela U,(p).
. UOela gia tri chuyenvi danh6it£!.inutcuaph~ntU'e t£!.ithaidi~mt.
. Se(t) : la hamxapXlchuySnvi quagia tq chuySnvi nut- trenph~ntU' e.
Tll(5.2.70),(5.2.69),(5.2.27)suyra :
ue(p)=Se. Ue(p) = Se . UOe. Ul7(p) (5.2.71)
122
fie= Due = DS eUOeU'l (5.2.72)
(Je=C . fie=CDSeUOeU'l (5.2.73)
Vie'tl<;iinguyen19congao chobai lOandaTIh6i ke'thQp,vdi nela sophftntli'cua
bailoan [4]:
n,
L F;U~eS;D1C{DSeUoeu'ldV=
e=\ v~
ne - - n, - -
=L fll"U~eS:~.dV+L fU"U~eS:/fdr
e=1I'e e=l fe
(5.2.74)
D~t: R =DS" "
Va: la vectorchuy€n vi loanh~- la matr~nh~ng.
~:Matr~ndinhvicuaphftntli'e lIenloanh~.
tasuyra : UOe= I;Uo
TU(5.2.74)ta co:
n
IfUTJU~I:'R~C'R):UouTJdV=IF:U~T/S~/vdV +:tfuTJU~Te'S;frdr (5.2.75)
,=1V, e=!V,. e=1r,
Nh?nxet rang: u,?' U~co th€ duara ngoai da'utich phan va da'ut6ng VI chung
khongph\!thuQcto<;idQkhonggian.Ta khli'cacthanhphftntuongling a2 ve':
nc ~ - n, - n, -
L. fTe{R~C'ReTeUoll"dV= :L fTelS;lvdV + I fT/S;frdf
e=!Ve e=1Ve e=1r,
(5.2.76)
Bie'nd6i Laplace nguQc(5.2.76), chti9r~ngchico C{,u'?'Iv, Ir lachilabie'np:
(kyhi~uLaplace -I (I) 1abie'nd6i1ap1acenguQchamcuahamf)
tT:[lR;(LaPlacdc'.uJ'jR,dr- T,Uo=
123
11. II.
=I fT/S;J;,dV+ ! fT/S;frdr
e=1,'" e=1f"
(5.2.77)
Ky hit%u:
Ke= fR~(Laplace-l(Ct.;;))RedVlamatr~ndQclingphgnnY.
v,
(5.2.78)
11"
K="T1.K .1'L c e e (5.2.79)
e=l
11. 11.
F=! fTetS~f,;dV+ I fT/S~ffdr
e=ll', e=1f,.
(5.2.80)
tadi denbi~uthlicsail:
K .U 0 =F (5.2.81)
Giaiht%phu'dngtrlnhdi.;lituyentrentatimdu'QcVa la cacchuy~nvi daTIh6i ti.;licac
nut.Do do:nghit%mdaTInhdtla :
u(t) =Ua ,ulJ(t) (5.2.82)
£)~timham IITJ (t) tahillyden giathietValanghit%mdaTIh6i,tZfdosuyralil ma
trQnKphil;lil matrijll hlillgdolva;t.Daychinhlamatr~ndQclingdanh6i.£)i~u
naycho ta ht%thuc sail :
(Laplace-l(Ct.uJ) phailamatr~nhangs6d6ivdit,nghlala: (5.2.83)
-
)
A
(e' .u, = p trongdoA : lamatr~nhangs6d6iydip ,pia anhcua t qua
bie'nd6i Laplace.
124
Xetmothiii toaDenth~:
z 9 xO.4m=3.6m
61
/ / 51" .'<:,;.
// 31'
'\ "" \ \ '\
~+Q~ ;~~\ \~"-~, y
(~.'
A ~ ~, , K
MO HINH GIAI BAI TOAN TAM
70 x
~
\ \\". >(~" M~,TKHA,O
\ \ "" SAT\,~.
\ \
\\
10
Tamday: O.O3m
VatlieuEo=2xlOE8KN/m2
TOitrQngq=-lOKn/m2
Trztdnghdv 1:
(
I
J
1 --'If
E(t)= Eo 1- ie 2 (giong vi dl,ltren) (5.2.84))
Til (5.2.68)vadi~uki~n(5.2.24)tasuyra :
C E(t) rt- (l+v)(l-2v)~ vdiv=canst (5.2.85)
rhea(5.2.28)thl
Ct =[p . Laplace (E(t ))] [(l+V)(\-2V)C: ] (5.2.86)
X6th~thuc: Laplace-I ((if.u,J
vdinh~nxet:matr~nKe(trong(5.2.78))phaiIii matr~ndoeun2daDh6iphftn
tll',tatha'yr~ng:
Laplace-I ((if.Laplace(U7(p)))=
(
- . -
))~ 1 C'
=[Laplace-lp.£lp)'u)p 'J(1-vXl-2v) I
(5.2.87)
125
thi:
[Laplace-l(p.E(P). up(P»)J=Eo
Laplace-l{Et.Laplace{UT/(P»))=Eo (I+VXI-2V) c;
(5.2.88)DeU
(5.2.89)
BaychinhIa matr~nCot,la matr~ndanh6iv~tli~u.Tit dotha'ydudedingK
TITbi€u thuc(5.2.88)tafundu'<Jchambitn d(;lngnhot:
up (1)=1+e-l1t (5.2.90)
Vanghi~mcuabai loanla:
u(t)=Uo(1+e-l1/)
Trongd6UoIakttquacua(5.2.81), d6lacaechuy€nvi dotinhcha'tdaDh6iv~t
li~uvalachuy€nvi t(;licaenut.
E(I)=E.(l- ~e-",)00TH!E(t)THEOTHill GIAN,vUicaeh? sd TJ
E(t)=y.Eo
1.1
2 4 6 8 10 12 14 16
Thai giant
11= 1.0
11=0.7
11=0.5
11=0.2
0.9
0.8
0.1
0.6
0.5
0
126
V6 thjbiend~ngnhdtWTJ(t) , theothoigianva h~8611
E(t)=E.(l- ~e-~'")
w =1+e-111
11
V~tli~uco tinhchiftOOdt:
Ham Wll (1)It!:
W,/t)
2 3 .. 5 6 7 8 9 10 1 1
Thoi giant
11=0.2
11=0.5
11=0.7
11=1.0
KET QuA BAI TOAN(tru'itnghf/p1): TINH TAM, v~T LItU DANNHOT
BANGPHUONGPHAP PTHH
00 tillchuyenviZtheotholg/ont
NUT
ODOE-t{)O
31 33 34 35 36 37 38 40
~ -5.00E-D6>
~'"
1i -1.00E-D4
-1.60E-D4 ------------------
t=10
t=8
t=
t=4
t=2
t=0
MAT CAT GIUATAM QUAcAc NUT31-40-
2.15
1.95
1.75
1.55
1.35
1 .1 5
0.95
0
O.ooE+OO
~ -5.~>
c:.
i -l.t1OE-O4u
-1.5OE-Gt
o.aEtOO
~
c.>-
~
-l.~
127
H~s6nMt eta=0.2( Xems6li~uph&nph~l~c)
DoltIichuyenviZIheoIhoigtanI
NUT
31 4034 35 36 37
t= 10
t= 8
t= 6
t= 4
t= 2
t= 0
M~T CAT GIUA TAM QUA'CAC NUT 31-40-
H~s6OOoteta=0.5( Xems6li~uph&nph~l~c)
Dolfi c:I1u\8IwZIMIoIx8 gemt
NUl"
31 4)34 35 36 37
t=10
t= 8
t= 6
t= 4
t= 2
t= 0
M~TCAT GIUATAM QUA'CACNUT31-40-
H~s6OOoteta=1.0(Xems6li~uph&nph~l~c)
128
( ) (
1 -1-111\
TnilI1lghdp2: ViiI Ji?uc6: E" =Eo 1+2:e 2 )
DO TIQ E(t) THEO THOI GIAN, YcHcaeh~S611
E(t) =Y x Eo
1.6
1.5
1.4
1.3
1.2
1.1
0.9
0 2 3 4 5 6 7 8 9 10 11
11=0.2
11=0.5
11=0.7
=1.0
D6tbjbitn dfngnhdtW"(I). theothaigianvaht;sf)11
1 (171)
HamW17(t)Ui:wl1(t)=l-3"e3
WJt)
1.05
0.95
0.9
0.85
0.8
0.75
0.7
0.85
0 2 3 4 5 7
11=1.0
11=0.7
11=0.5
=0.2
--,
I
12 13 14 15 16
. Thoigiant
9 10 11
Thoi giant
129
K ."" , K A A" ,
KETQUA BAI TOAN (trli<tnghejp2): TINHTAM, V~TL~UDANNHOT
BANG PHUONG PnAP PTHH
Do tIll elu,yoll vlZ thoo thol gmll I
NUT
O.OOE.OO,
.,.00E-OS3:
36 3731 34 35 30
N -2.00E-OS
-s
~ -3 OOE-O5
} .. -4.00E-Q5
-S_OOE-OS
-b_OOE-OS -,--.~-~-----
t=O
t= 2
t= 4
t= 6
t= 8
t= 10
MAT CAT GIUA TAM QUA CAC NUT 31-40-
He.s6nhoteta=0.2(Xerns6lie,uph~nph~l~c)
DothichuyenviZtheothoigiant
O.OOE+OO
-J.Q()8)5
N -2.00E-05
~ -3.00E-05.
?; -4.00E-05r.
u -5.00E-05
-5.OOE-05
-7_OOE-OS~-_._------_._-------- ---- ---------
t=O
t= 2
t= 4
t= 6
t= 8
t= 10
MAT CAT GIUA TAM QUA CAC NUT 31-40-
He.s6nhoteta=0.5(Xerns6lie.uph~nph~l~c)
130
Do IhI c:hIyen 111Z Iheo thai ~ t
NUT
0.00800
-1.OIE-OS
N -2.0IE-ffi
"> -3.0IE-ffii
~ -4.OIE-OS.&:;
u -6.OIE-OS
~.OIE-ffi
-7.0IE-ffi
1=0
t= 2
t= 4
t= 6
t= 8
t= 10
M~T CAT GIUA TAM QUA CAC NUT 31-40-
H~s6nhdteta=1.0( Xems6li~uph~nph~l~c)
5.2.5.Nhanxetvak6t loin CUBvi do2:
Phu'dngphapph~ntithii'uh~nchobaitoaDdaDnhd~diinghu'dng,diingnhi~t
giuptagiii du'<Jebaitoantu'dngd6it6ngquat.Co theapd~ngchocaebailoan
mQtchi€u,haichi€u,bachi€u.Bi€u ki~nlit: h~s6Poissoncuav~tli~ugii thittla
hAngs6deapd~ngphanly bitn.
QualiJi giii tren,vi~exaedjnhbienthde u,.(t)di du'<Jcl~ptrlnhtinhtoaD
hinhthue,ph~thuQcvitohamE~)t6ngquatcuav~tli~udaDnhdt.
B6i vdi caenghi~mdaBh6i Do, t1mb~ngphu'dngphapph~ntithii'uh~n,ta
d1icogiii thu~tl~ptrlnh[4],[6],[31].
Trongvi d~e~the()tren,tathiy hamehuylnvi u,.(t),trongliJi giii giii tich
vaph~n1eualiJi giii b~ngphu'dngphapph~ntithii'uh~n,la nhu'nhau.
131
~
Tinh tminbaitmincohQcngftunhienb~ngphuong
phapphftntll'hUllh~nngftunhien.
5.3.Bai tmin 3:
5.3.1/.Phuong phapph~ntit hUllh~nngftunhien [21]:
TrangCo HQc,cacbai roanv€ ngaunhienthuanglien quaildenmQth~phuong
tdnhvi phantuyentinhvoi cach~sO'ngaunhien.Cac h~so'nayd~ctrungchocac
tinheha'tcuah~, coth~hi~ulacaebienngaunhien,hayehinhxachonlacacqua
trinhngaunhienvoi mQtCalltrucxacsuatnaodo.V€ m~ttminhQc, bairoanc6
d~ng:
Au=f (5.3.1.1)
trangd6Ala mQtroantuviphantuyentinhngaunhien, ula phanungngaulimen,
f lakichdQngngaunhien
MQtI;' thuyetroanhQcdftduQcxay dlfngchotruanghQp(5.3.1.1)c6d?ng
Ita(cach~sO'ngaunhiencuaroantuA duQcgia thiet1acaequatdnh<5ntrang
[29]),Wigiaila mQtquatdnhMarkovmaphanb6xacsuathoaphuongtdnh
Fakker-Planck- mQtphuongtdnhd?ohamriengnoichungkhangconghi~mgiai
tich.
Tuongtlfphuongphapph~ntuhUllh?n (pp.pthh)ti€n dinh,trangd6 cacham
so'duQcbi~udi~nbdimQt?Prair?ccacthamsO'g<5mgiatfihamvad?ohamcua
not?icacdi~mnut,trangtruanghQpngaunhien,mQtquatrinhngaunhiencling
du'Qcbi~udi~nbdi mQtt?PGemduQccacbienngaunhiennhamrai r?c hoaqua
trinh.V€ m~tungd1,mg,matacacquatdnhngaunhientheoeachnay co th~thu
du'QcIDQtbi~uthucph~ntuhUllh?ncuabai roanV?tI;'.
5.3.1.1Biiu di~llquatrzllhllgiiunhienvakhaitriill Karhzmell-Loeve
MQtrongnhungketquaquailtrQngnhatcuaI;' thuyetquatrinhngaunhienla vi~e
bi~udi~nph6cuacacquatrlnhngaunhien:
OJ(x,e)= fg(x)d,LL(e) (5.3.1.2)
132
COJOJ (XI ,X~) = fg(x, )g(x~)(d/11(8)d.u~(8») (5.3.1.3)
Fongd6 co(x,8)la mQtquatrlnhng~unhienva CCOCO(XI,X::)la hamhi~pphuong
i (covariance)cuan6,g(x)la mQthamti~ndinh.va d~(8) la mQtdQdong~u
hientn!cgiaoxacdinhtrenmQtcr-tniongcacbienc6ng~unhien.
M!)tbiiu diinphilkhacla kIwitriin Karhlllien-Loevesaltday,ifdom!)tqua
'inkngdunhienm(x,B) cothi khaitriin theocacs6'h(PlgcllaIll!)tt{jphtfpdtlll
'l'(lCcacbitnngdllnhien tr~'cgiao.dov{jyco thi xelllllhlt Lal1l!)triJi rt:J-clla qua
'nhngdullhien.
Qi OJ(x) la ky vQngcuaco(x,8)va, khid6 :
OJ(x,B) =OJ(x) +f ;,,(B).[i: f,,(x)
. ,,=0
(5.3.1.4)
Itrongd6 Anvafn(x)lagiatqriengvavectoriengcuanhanC(x,,x::)nghlala
nghi~mcuaphuongtrlnhrichphan:
fC(XpX2)/,,(x)dYI =).,111,,(X2)
D
(5.3.1.5)
Dlami~nxacdinhcuax, va {~n(8)}lacacbienng~unhienrhoa:
= 0 va = Onm (5.3.1.6)
TtldngtV'nhuco sdroanhQccuapp.pthhti~ndinh.Devijverva Kittler ([22])da:chI
fatinhcha'tsai s6cV'cti~uva tinhcha'tduynha'teuakhaitri€n Karhunen- Loeve
rheah~tQadQsuyrQnglacaevectoriengcuaOx, , X2) trong (5.3.1.5).
5.3.1.2.Giiii slfphztdngmnh richphiin (5.3.1.5)
Vi~capdl:111gkhai tri€n Karhunen-Loevetrongpp.pthhph\,!thuQcVaGpt. richphan
(5.3.1.5)(la mQtphuongtrlnhFredholmthuftnnharlo(;li2.Devijver. Kittler ([22]),
vaGhanemR.G., SpanosP.D. ([40])da:chIra nghi~mgiai richtrongffiQts6 d<:1ng
d~cbi~tcuahamm~tdQph6cuaquatrlnhng~unhien.d daychungtoixU'd\,!ng
pp.Galerkind€ timnghi~mb~ngs6.CacvectoriengduQcrimquad.c hamxa'pXl
hiCx)
133
fk (x) =
N
L di(k>hi(x)
i=1
(5.3.1.7)
oisais6tu'ongling dovi<$cxffP xiia :
~d;"'[IC(X"x,Jh;(X,Jdx, - ""h,(X,J]& N = (5.3.1.8)
~sais6benhfft,tu'dngdu'ongvaivi<$csais6naytn!cgiaovaikhonggianxffpXl:
f:N, hi (x» =0 , i =1,..., N (5.3.1.9)
ongd6 (.,.) chItichvohu'ang:
fd/*>
[
f
[
fc(xl,X2)h;(X2)dX2
]
h/XI)dXI -A" fh;(X)h/X)dX
]
=0
,=1 D D D
(5.3.1.10)
f)~t: Cij= f fC(XI'X2)h;(X2)dx2hj(x,)dxl
DD
(5.3.1.11)
Bij = fhi(x)hj(x)dx
D
Dij =dij va Aij =<5ij Ai
khid6«5.3.10)trdthanh:
CD=ABD (5.3.1.12)
trong.doC=(Cij), B=(Bij),D=(Di)lacaematr~ntu«5.3.11).Tanh~ndu'Qc
(5.3.12)labaitoangiatririengd(;1.is6blnhthu'ong.
5.3.1.3.Caedathuehiin lol}-Il(Chaos):
GQi {~ih=l,oola t~pcaebiSnngfiunhienGausstnfcgiaova gQi rp la t~p
h<jpcacdathuctrong{~i}i=l,00b~ckhongquap, va trt!cgiaovai r p-l. Khi d6rp
du<jcgQila t~ph<;Jpcacda thach6nlo(lnb~cp. Kakutani(xem[40])dii chIrar~ng
ffiQihamngfiunhien( blnhphu'ongkhatich) d~ucoth€ biSudi€n quacacdathuc
h6nlo(;1.n:
'" '" i,
Ji (e) =a0r0 + ~ a; r1(;; (e» + ~ ~ aii r 2(;; (e),; i (e»L.., IlL.., L.., 12 , ,
;,=1 i,=1;,=1
'" i, i,
+ L L L ai,i,i) r3(~il (O)'~i, (O)'~i) (0»
i, =1. i, =I i)=1
134
~ i, iz i)
+L L L L ailiZi)i~ r (~i,(O)'~iZ(O)'~i)(O)'~i~(0))
i)=1 iZ=1 i)=1 i~=1
+ (5.3.1.13)
Dotinhtn!cgiaovaGausscuacacbienng~unhien~i , cacdathlicrpcoth€ tinh
du'Qc[40],(cactinhtoancoth~tienhanhtu'angtvquatrlnhtrvcgiaoboaGramm-
SmithtrongB,!i s6tuyentinh) :
r II
L (-IY L Il ~ik<Il~iI)nchan
r=1I ;r(i"...,i.) k=1 l=r+1
r (j::'.,-,~. )=' rchullP ':>', 'n I r II
L (-Iy-I L Il ~ik<Il~iI)nle
r=1I ;r(i"...,i.) k=1 l=r+1
rchull
(5.3.1.14)
chungt6i dil l~ptrlnhsymbolictrenmaytinhkhi tinhtoancacdathlicnay( xem
giaithu~tchuang4) :
r .=1
O'
r 1(~i):=~i
r
(
l'- J<.
)
'=J<. J<. -0
2 ';>, , ':0. ' ':0, ':0. ,.
z1 z2 z1 z2 z1z2
r
(
J<. J<. "
)
'=J<.J<. "_J<.o -" 0 -I< 0
3 ':0. ,':0, ,~, ' ':0. ':o.~. ':0. .. ~, .. 1". ..
z1 z2 z3 z1 z2 z3 z1 z2z3 z2 z1z3 z3 z1z2
.. , . . . . . ,
3
r3:=~1 -3~1
2
~1 ~2- ~2
2
~1 ~3- ~3
~12~3- ~4
2
~1~2 - ~1
.. . . . . . . .
Tadanhs61,!ithlitvtrong((5.3.13)d~thu~nti~nchocachviet:
135
00
/-i(B) = L a;¥Ij[{q(B)}]
;=\
(5.3.1.15)
5.3.1.4Xii d{lngcac da th,lC h{jn lo{lntrongphltdngphap philn tit hllil h{ln
ngdll nhien
Co nhi~ucachxaydvngm6hlnhphc1ntii'hUllh<;lngftunhien( xii'd\mgpp.
perturbation,khaitriSnNeuman,...[12]va[40]), songd daychungt6ixii'd\mgcac
dathuchanlo<;lnVInhi~ubiSuthucvah~s6cothStinhtoanqual~ptrlnhsymbolic.
Bai toan(5.3.1.1)co thSvi€t du'oid<;lng:
[ L(x) +II(x,B)] u(x,B)=j(x,B) (5.3.1.16)
trongdoL la toantii'vi phanti~ndinh,ilIa toantii'vi phancocach~s6la cacqua
trlnhngftunhientrungblnhkh6ng.Kh6nglamgiamtinht6ngquattacothSxem
Il(x,B)=a(x,fJ)R(x) trongdoR lamQtoantii'ti~ndinh.KhaitriSnKarhunen-
Loevechoa(x,fJ)tadu'QC:
AI
[L(x)+ L: ~lIall(x)R(x)] u(x,B) = j(x,e)
11=1
(5.3.1.17)
KhaitriSnKarhunen-Loevechou(x,fJ)taco :
/,
u(x,B) = L: ej X j(B)bj(x)
j=1
(5.3.1.18)
Sud\mgdathuchanlo<;lnchobi€n ngftunhienXj(8)(dllngdath,lCh{jnlo{lntt..irdi
rlJchoam/)tqllatrinh ngdllnhien) :
p
lj(e) =. L: Xj()1fI j[{~II(e)}]
;=1
(5.3.1.19)
Thay (5.3.19) VaG (5.3.18) ta du'QC:
u(x,e) =
p
L: 1fI;[{~r}]d;(x)
;=0
(5.3.1.20)
f trongdo:
I
I M P
[L(x)+ ~';"a,,(x)R(x)] 'f, 'I'Ag.}]dj(x) = f(x,O)
di (x) =}; xP} ej bj(X). Bay gio (5.3.17)trd thanh :
(5.3.1.21)
136
Loi giai u(x,8)sexacdinhduQcn€u bi€t dj (x).B~ngpp.phfinti'thuuh£:lnti~ndinh,
xtp Xl di(x) theocaehamcdsci gk(x) , k =1,..., N, N la s6b~ctl!docuah~ :
N
di(x) =I dki gk(X)
k=I
(5.3.1.22)
Thay(5.3.1.22)vao(5.3.1.21)taduQc:
p N
[
M
]I ~~dkj [\f/j[{qJ]] L(X)gk(x) +t;qi(8)\f/){qr}]ai(X)R(x)gk(X) = l(x,8) (5.3.1.23)
Nhanhaiv€ cua(5.3.1.23)voi gh(x) r6ilty tichphantrenmi~nxacdinhtaduQc:
P N
[
M
]~t;dtg[VlJ {~r}]]I L(X)gk(x)gh(x)dx+~~i(e)VlJ {~r}]lai(x)R(x)gk(x)gh(x)dx
= ff(x,8)gh(X)dx , h =1,...,N
D
(5.3.1.24)
D~t :
Lkh =fL(X)gk (X)gh(x)dx
D
Rikh = fai(x)R(x)gk(X)gf1(x)dx
/)
va 1;, = ff(x)gh(X)dx
I)
(5.3.1.25)
Khi d6(5.3.1.24)trCithanh :
P N
[
!vi
]~B VIj[{~r}]Lkh +-8 ~i(e)VI j[{~r}]Rikh dkh
h = 1, ... , N
= Ih (5.3.1.26)
Nhanhaiv€ (5.3.1.24)voi \Pm[{~r}], lty kyvQnghaiv€ valu'uy r~ng:
= 0m
tanh~nduQC:
N p]V M
I L kh dk/ll +I I dkj I Rikl C ij/ll
k=l j=O k=1 i=1
=
<Ih , VI /II [{~r }])
h =1,.. .,N
m=l,...,M
(5.3.1.27).
trongd6 : Cijm= , hay:
[G+R]d=h (5.3.1.28)
trongd6 :
137
Gmj = J mj L ,
M
Rn!i=LCijm Rj
i=1
va hm=
Phu'dngtrinh (5.3.1.28)1ftmQth~phu'dngtrinh d<;1is6bInh thl.long,tim dl.l<;1ccae dki,
duavao(5.3.1.24)va(5.3.1.22)taxacdinhduQcth€ hi~ncuau(x).
5.3.2.Ghii bili tminkhuye'chtankhithaibachi~utheoroohinhngfiunhien.
Baitoanbientricuast!khuye'chtankhong ian3chi~u:(xem[35],[36]):
,TimrpEC2(Q) thoa:
I orp orp orp orp
(
02rp 02rp
J
02rp
Of +u & +v 0; +w & +arp-fl &2 + 0;2 -D &2 =1 trong .ox(O,T)
f)i~uki~nbien: rp=0 tren Tx (O,T) "
orp
a;=fJrp on I;)x (O,T) (5.3.2.1)
Giatri d~u
orp=0
&
<;0(0)=<;00
on Ih x (O,T)
In .0. -
Q famQtkho'itrl;lco bienfa 00: b~m(ittrl;lT,ddyT{)(z=O),dlnhlh(z=h).
cp(x,y,z,t)famgtdQkhfthaigayra batngu6nf(x,y,z,t)va ~=(u,v,w)fa vgntoegio,
wii u,v,wfahamcua x,y,z,t.
51!t6nt~ivaduynhfftcuaWigiaicuabaitoan(5.3.2.1)dii(duQcchungminh
trong[35],[36])
~
Xemdingv~nt6cgio v =(u,v,w)vahamngu6n j(x,y,z,t) 1aquatrlnhng~unhien,
vadodom~tde>rp(x,y,z,t)ciingtrllangngdunhien.
D~ngbie'nphancuabaitoan(5.3.2.1) nhusau:(xem[36])
fZdo.+a«;O,If/)= fllf/do.Q n
trangdo: f(
orp orp orp
J fa(rp,lf/)= U& +v .rit+W& If/do.+a rplf/do.+n vy n
138
f(orpOljl orpJ forpOljl f+j.1 -- +;;I, do.+D - :-1. do.+D/3 rpljldfo0 Ox Ox l/'y 0 & UL. f"
Roir'.lcmiSn xac dinh va xa'pXl tren tungph~ntli' :
rp(x,y,z,t,B) = Ne(x,y,z) <De(t,B)
<De(t, B) = T: <D(t,B)
chungtathuduQch~phuongtrlnhmanghi~mla gia tri cua rpt'.linutcuacacph~n
tli':
.
M<D(t,B)+K<D(t,B)=F(t,B) (5.3.2.2)
voi:
/Ie
M =L T;,ImeT;,
e=1
/Ie
K = L T;,IkeT;,
e=]
/Ie
va F = "" T,I F,L < <
e=1
(5.3.2.3)
me = fNI N dQe
0,
and k, = k, + k, + k" + k" + k,< " <2 ., .. <r
k" = J N' [U(X,y,z,! '/1{ '.:)+v(x,y,Z,!Ii{:) +w(x,y,z,!,Ii{ '.:) ]dQ,
ke2= (J fNI N dQe
0, k" =p)[(~n~)+(~)t~)]dQ,
k" ~ vl[('.:')'( '.:') ]dQ, , k., ~ DfJ,[N' N dro, ' F, ~jN'j(x,y,z,/)dQ.
~ -
Khi v =(u,v,w)va j(x,y,z,t) la quatrlnhngaunhien,chungtachIchuyde'nma
tr~nke,vaF. GQiV lacuongdQcuav~nt6cgiG:V=II~" va aI, a2,a3lagoc
~ ,
giuav va cactn,lctQadQx, y, z , IanluQttaco:
u=vcas(a] ) v =V cas( a2) w =Vcas(a3)
(Cacgoc a] , a2,a3co thSxemla quatrlnhng~unhien,nophanb6gi6ngnhau
rheacachuangchinh)
V la truongng~unhien.
KhaitriSnKarhunen-Loevechoquatrlnhnayvachohamngu6nj(x,y,z,t) :
139
,iii
V(x,y,z,t,B)=V(x,y,z,t)+Ic;k (B)~Ak(t)fk(x,y,z,t)
k=1
M
f(x,y,z,t,B) =f(x,y,z,t) +I c;k(B)~j3k(t)gk (X,y,z,t)
hI
trongdofk lavectori{~ngtu'onglingvoitririengAk'tu'ongtl!chogkvaak,khido
chunglanghit%mcuaphu'ongtrinhrichphan:
f C(X"Xl )In (Xl )dXt = An In (Xl)
12
vaiXj=(Xj'Yi'Zj) Vachungtaco th~stYdl,mgthutl,lCGalerkinchoWi giai 56. Vi
V?ymatr?n ke,va Feco d~ng:
k" ~ 1N'V (x,y,z,t) [ cos(a,{~)+cos(a,{:) +COS(a3{'.:') ]dQ,
+I;k(B) ffi:fk(X,y,z,t)NI
[cOS(al{eN) +cOS(a2)(
av
) +COS(a3)(
av
)]
dOe
k=1 no ex 0' &
M
Fe= fN1](x,y,z,t)dOe +Ic;k (B) fN1 fi{gk(x,y,z,t)dOe
n, k=1 no
Phuongtrlnh(5.3.2.2)tro thanh:
. M M
M~(t,B)+K,~(t,e)+L;kKY) ~(t,e)=~ +L;kF2(k)
k=1 k=1
(5.3.2.4)
. lie
vai: M nhu'trong(5.3.2.3)va K, =Ir.1fer..
. pI
ke= ke,+ ke2+keJ+ke. +kef ' trong do :
Eo, ~1N'V (X,y,z,t)[ cos(a,J( ::)+cos(a,>(:)+cos(a,)(~) ]dQo
lie
K(k) ="Tlj( T2 L eee
e=1
k. =IF.f,(x,y,z,I)N'[cos(a,{-:) +cos(a,{:) +cos(a,{~) ]dQ,
140
/Ie
F;=L r:1F'"I voi Fe = fNI ](x,y,z,t)dQe
e=1 fl.
/Ie
va F;(k)=L r:1 F',,2 vOi Fe2 = fNI -J7i;gk(x,y,z,t) dQe
e=1 fl.
Giai phu'dngtrinh (5.3.2.4),chungtaco nghi<%mcua <D(t)
Trang tru'onghQpham ngu6n Ia ti€n dinh , phu'dngtrlnh (5.3.2.2)co d,;l.llg(h<%s6 ()
duQclo(;lira chobi~uthucddngian):
. M
M<D(t)+K, <D(t)+L qkK?) <D(t)=F(t)
k=l
(5.3.2.5)
Bie'nd6i Fouriercuaphu'dngtrinh(5.3.2.5):
[iWM+K, +t;,K~" ] Cw)= FCw)
hayla mQtd(;lngkhac:
[H(W) +~~Kj')](W)~F(w)
(5.3.2.6)
voi: H(OJ)=iOJM+K, lamatr~nti€n dinh.
Phudngtrinh(5.3.2.6)co th~vie'tla:
[I +~~R!"](UJ) ~ P(UJ)
trongdo: Rik)=H(OJ)-' KY> va P(m)=H(m)-'F(OJ)
Dodoph6cua <D(t)co d(;lng:
[
M
]
-1
[
M
]
-H
S(OJ)= I +~qkRY> Spp(OJ)I +~qkRik>
(Chi s6H th~hi<%nbie'nd6i Hermite)
ho~cla sudl;lngkhaitri~nNeumanncholoantungu'Qc, taco:
00 00
S(CU)=LL(-I)i+)[qkRjk)f Spp(cu)[qkRjk)Y
i=\ )=1
L
141
5.3.3.AP dQngtInhtminchobili tminv~HrAnbie'nd~ngvOiv~tli~ucocae
thams6ngftunhH~n:
B~ngeachxU'dvngkhaitri~nKarhunen-Loeved~hlnhthanhmahlnhchophu'dng
phapphffntU'hUllhC].nngfiunhien,chophepl~ptrlnhtinhroanhlnhthlic(1~ptrlnh
kyhi<%u,symbolicprogramming)chohffuh€t cacbi~uthlictru'ockhichuy~nd6icho
cacHnhroans6truy~nth6ng.
Taxetcacbairoank€t ca'ucocacthams6ngftunhien,ch~nghC].n0 dayta-xetcac
v~thi codQcL£ngfamQtdqifu(1ngngtiunhien.Moduldanh6icuav~tli<%ud 'Qcgia
thi€t,ch~nghC].n,lamQtquatrlnhngfiunhienGauss-3chi~uvoikyvQngE vaham
hi<%pphu'dngsai(covariancefunction)C(Xj,X2).Tu'dngtl,l'nhu'phffntru'oc,tac6th~
giathi€t hamkichdQngla ti~ndinhhoi.icngfiunhien,tuynhiend~ddngiancho
eachvi€t sauday,tahayxemkichdQngla ti~ndinh.Ta apdvngphu'dngphapphffn
tithullhC].ngfiunhienchocacbai roanyoi dC].nghlnhhQcba'tky.
GiasU'mQtta'mQ, du'QCchiathanhN phffntU'hUllhC].n.Th€ nangbi€n dC].ngdanh6i
V cuam6iphffntU'De codC].ng:
ve=~ fa-T(X)£'(X)dQe
fl,
(5.3.3.1)
trongd6 a(X) va £'(X) la cacvectorlingsua'tva bi€n d,:lllg, X ky hi<%uthaycho
(x,y,z).
i./Voibairoandanh6ituy€ntinhtacocacquailh<%giualingsua'tvabi€n dC].ng:
a = De(£,- G,,)+ a"
aT = (ax ay az Txy Ty=Tzx) va £'T =(£' x £'y £'= rxy ryz rzx)
De=Ee(X,B)Re (5.3.3.2)
142
1 C) C1
1 C)
1-1/ I 1
Re = re
(1+,lie )(1- 2,lie) C2
C2
C2
,lie
c=-
) 1 - ,lie
1- 2,lie
C2 = 2 (1- ,lie)
:ongdo Re IamQtmatr~nti€n dinh, f.1eIah~s6Poissoncuarheintii'e, va
;;ex,B)la moduldanh6icuarheintii'e.
i./Voi baitminlingStittph~ngtaco:
a r = (a x a y T xy ) va & T =(&x & y rxy)
C2
Re=C1IC2
(I-C2)
2
1
C1=1- ,lie2 C2 = ,lie
ii./ Voi baitoanbi€n dangph~ngtacocaehethlictu'ongtu':
1- /I
C = re
I (1+,liJ (1- 2,liJ
,lie
C2 = 1- ,lie
IXii'dl:mgphuongphaprheintii'huuhl;ln(ti€n dinh) voi hamnQisuyif , vector.
chuy€nvi u(X, B) co th€ bi€u di€n quacaechuy€n vi nut If( B) :
u(X,B)=if(X) if( B) (5.3.3.3)
quailh~giuabi€n dl;lngva chuy€n vi : &(X, B) =S u(X,B)
trangdo S lamQt(matr~n)toantii'viphan, . (5.3.3.3)trothanh :
&(X,B) = Be U(B) (5.3.3.4)
trongdo Be=Sif .
Thay(5.3.3.3),(5.3.3.4)vao (5.3.3.1)tadu'<Jc:
143
V e = ~ VeT fE (X , B)BeT R eBe do. eVe
Qe
vadodo :
1 N
v =-2: VeT fE(X,B)BeTReBedo.eVe
2 e=1 Qe
(5.3.3.5)
Quanh~giii'avectorchuy6nvi diaphuongif vavectorchuy6nvi loancl,lcU
thongquaphepbie'nd6i :
if =LeU
vavi the'tavie'tl(;li (5.3.3_.5)dudid(;lng:
1 TV=-U KU
2
trongdo
N
K =L Le1'Ke Le
e=1
Ke = ~ fE(X ,B)Be T ReBe do.e
Qe
(5.3.3.6)
Bu'ocke'tie'ptaphai giai bai loangiatri riengtuonglingvoi nhanhi~pphuongsai
di;lng(5.3.1.7).Vdi ffiQts6nhand~cbi~t,dffco ffiQts61Oigiai giai tich. Trang
tru'onghQpt6ngquat (5.3.1.7)cod(;lng:
N
AnIn (X, y) = I fc(x, y ;u, v) In (u, v) dO e
e=1ne
(5.3.3.7)
Xudl,lngnQisuy : In (X, y) = Heine
(5.3).7) trdthanh :
N
Anln(x,y)=I fC(x,y;u,v)HedOe Ine
e=1ne
(5.3.3.8)
(5.3.3.8) cod(;lngla ffiQtbai loangia tri riengd(;lis6 t6ngquatnhu (5.3.1.14).
Khaitri6nKarhunen-Loeved6ivdiffioduldanh6i,vathayvaobi6uthucthe'nang
bie'nd(;lngdaTIh6i (5.3.3.5)taduQC:
144
1 m
V =- uTI C;k(e)K k u
2 k=1
(5.3.3.9)
HiygiOtatinhC6ngcualIfcldchdQng:
n
W=L fUeT(X,e)j(X)dOe
e=10,
n
=uTI reTfHe Tj (X) dOe=U TF
e=1 0,
(5.3.3.10)
)0sanh (5.3.3.9)va (5.3.3.10), tadi de'nphudngtrinh:
m
( I !;k(e)K k ) U = F
. k =I
(5.3.3.11)
giltirataduQccacth€ hi~ncua U tudngtlfnhuml;1ctruac.
5.3.4.Vi d\lghlimQthili toaDHIm
X6tmQtUlmmongc6cacdi~uki~pbienphilhQP.Giltsli'moduldanh6icuata'mla
mQtquatrinhng~unhienGausshaichi~uyaigiatritrungblnhE vahamhi~p
hudngsai C(x" X2) dffbie't,Ilfc ngoaila ti~ndinh(ne'uIlfc ngoaila ng~unhien
clingkh6nggaykh6khangl).
Chiata'mthanhN ph§n tli'tli giac,m6iph§ntli'c6 8 b~ctlfdo.NangluQngbie'n
d'.lngve cuam6iph§n tli'Aec6 d(;lng:
ve =.!.-fcrT(x)E(x)dAe,
2 AC
(5.3.4.1)
Vectorcr(x)va E(X)bi€u di~nlingsua'tvabie'nd(;lng,Iahamrheaxtrongm6iph§n
tu:
crT=rcr cr 't ]t x, ", "1"2 (5.3.4.2)
ET = [E",E"2Y""'2] (5-;3.4.3)
trongd6 cr"iIa ling sua'theohuangdQCXiva 8",la bie'nd(;lngdQCrheaclinghuang.
Giltsli'lingxli'cuav~tli~uIa tuye'ntinh,lingsua'tduQcbi€u di~nquabie'nd(;lngnhu
Gu:
145
cr=DeE (5.3.4.4)
:rongd6 De la matr~ndaDh6i,
E>6ivai bai loanling Stittph~ng,Dedu<Jchobdi :
trongd6 pematr~nti~ndinh, ~ela ht%s6Poissonva Ee(x,8)la moduldaDh6i.
Vectorchuy€nvi u(x,8)mieutelchuy€nvi theochi~udQcvangangt~idi€m btt ky
trongm6iphftntU'du<Jcxtp Xlquachuy€nvi nutcuaphftntU'duaid~ng:
u(x,8)=He(I"I2)Ue(8), (5.3..4.6)
trongd6 He(I" I2)la matr~nnQisoycuaphftntU',Ue(8) la vectorchuy€n vi nut
(ngaunhien), IIva I21atQadQdiaphuongga:ntIeDphftntU'.D6i vaiphftntU'chIT
nh~t:
(XI - Xlc)
II = ,
Ixl
(X) - x)J[- - -
2-~ x,
(5.3.4.7)
trongd6 Ix;la oQdai c~nhcuaphftntU'chITnh~tdQctheohuangthli i Ih , vaXic latQa
dQdQCtn;lcmahuangcuag6cthtpnhttd bell trai cuaphftntU'.Ma tr~nnQisoy
He(II' [2) c6 d(~lllg:
[
N} 0 N 2 0 N3 0 N 4 0
]He(I"I2) = 0 NI 0 N2 0 N3 0 N4
(5.3.4.8)
I
trongd6
N} =I} (1- I2) ,N2 =I2 (1- II), N 3=III2,N 4=(1- II )(1- I2) (5.3.4.9)
Thay(5.3.4.5)vao(5.3.4.1)tadu<Jc:
Ve=.!.fEe(x,ekT(x,e)pec:(x,e)dAe
2 A<
(5.3.4.10)
Quanht%giuabie'nd~ngvachuy€nvi,theochi~udQcvatheochi~ungangc6d~ng:
1 e 0
De=Ee(x,8)I
1 0 1=Ee(x,8)Pe, (5.3.4.5)1 2 e-e (1-e)0 0
2
146
(5.3.4.11)
Khi d6 (5.3.4.11)duQcvi6t l~id~ng:
s(x,e)=BeUe (5.3.4.12)
Thay(5.3.4.12)VaGl~i(5.3.4.10)tac6 :
1 I
V =~UeT.f fE(rprz,e)BeT(rprz)peBe(r"rdr IdrldrzUe0 0
(5.3.4.14)
trongd6 IJeIta dinhthlicJacobiancuabi6nd6imQtphfintii'ba'tky (e)VaGphfintii'
thamchi6u([18]),tichphanduQcth1!chi<$ntrenphfintii'thamchi6u, tu d6nang
lu'Qngbi6nd~ngt6ngcQngV c6d~ng:
1 N ] (
V=- IUeT ffE(rl,rz,e)BeT(r(,rz)peBe(r],rz~JeldrldrzU
2 e=' 00
(5.3.4.15)
Sii'd\mgmatr~ndint vi ce voi vectorchuy€n vi toanh<$:
u"=,eeu (5.3.4.16)
Khid6nangluQngt6ngcQngcuah<$duQcvi6tduoid~ng:
v=.!..uTKU
2
(5.3.4.17)
trongd6
. N
; K =IeeT Keee
: e=1
L
(5.3.4.18)
a 0-
ax,
s(x,e)=I 0 lu(x,e)
axz
a a- -
axz ax(
voi
-
(-1 +rz) 0 (1+rz) 0 rz 0 _2 0
I Ix, I Ix,x, x,
Be=1 0 (-l+r]) 0 r( 0 r, 0 (1- r() I (5.3.4.13)
Ix I Ix Ix2 x, 2 2
(- 1+r() (-1+rz) r( (1+;z) r( rz 1-rl rz- - -
I Ix, I I I Ix I IX2 X2 x, X2 I X2 x,
147
C6 th€ dungnhi~uky thu~tHipnip d€ tinh(5.3.4.18)makhongc§n sttd\lngma
tr~ndinhvi c".
Tu'ongt1,!'trongcactinhtoantru'ocday,bu'ocke'tie'pla taphaigiai bai toangia t~i
riengtu'onglingvoi nhanhi~pphu'ongsai :
A"/,,(Xl'Yl) = fC(x] 'Yl ;X2'Y2 )/" (X2'Y2)dx,dYI
A
(5.3.4.19)
Tren m6iph§nttt A", phu'ongtrinh(5.3.4.19)trdthanh :
N
A"/,,(X,,y,)= I fC(XPYI;X2'Y2)/',(X2'Y2)dA"
"=1A'
(5.3.4.20)
xa'p Xl qua gia tri t(;linut:
/" (x,y) =H" (r],r2)/,," (5.3.4'.21)
trongd6 H"(rl,r2)lamatr~nnQisuytheocacthanhph§ncuatQadQdiaphu'ongr,
varz, /,,"lavectorcacgiatqt(;linut(ham§n)lingvoiph§nttt(e).d dayc6th€
chQnd(;lngnQisuysongtuye'ntinhtrenph§nttt tli giacb6ndi€m nut.Khi d6,ma
r tr~nH"h,r2) c6 d(;lng: .
I
H"(rprz)=~[(l-rIXl-rz) (1+r,Xl-r2) (l+r,Xl+rz) (l-r,Xl+rz)]
(5.3.4.22)
Thay(5.3.4.21)vabie'nd6i tutQadQtoanC\lCsangtQadQdiaphu'ong,(5.3.4.20)trd
thanh
N
A"/,,(x,y,)=I fc(x, ,Y, ;Xz'Y2)H"(r\,r2~J"ldA"/',"
"=1A'
(5.3.4.23)
trongd6IJ"lla Jacobiancuabie'nd6itQadQ.Sais6tu'onglingtn,tcgiaovoicac
hamnQisuytu'ongt1,1'm\lc(1.2)ph§n 1., tu(5.3.4.23)tathudu'Qc:
CD=ABD (5.3.4.24)
trongd6 cQtthlij cuaD la vectoriengthlij tinhdu'Qct(;licacdi€m nUtva
A.. =8..11..
I) I) I (5.3.4.25)
Matr~nC va D thudu'Qcb~ngcachHipnipcacmatr~nCefva Bef :
148
Cef = f fC(XpYI;X2'Y2)HeT(r"r2)Hf(r"r2)dAedAf,
AcAf
(5.3.4.26)
Bef = fC(XpYI;X2'Y2)HeT(r"r2)Hf(r"r2)dAe,
Ac
(5.3.4.27)
(j day (xpYI)va (rpr2)bi€u diSnh~tQadQtO~lllC1;1Cvah~tQadQdiaphu'dngcua
ffiQtdi€m trongAe. Vi~cHipnip matr~nthvcra conhi€u cach,tu'dngtv nhu'trong
PP.Phfintii'hUllh~nti€n dinh,tie"nhanhnhu'(4.26)va(4.27)lamQtphu'dngpharo
Khaitri€n Karhunen-Loevechomo~uldaTIh6ir6ithe"vaophu'dngtdnh(5.3.4.15),
bie"nd6i phu'dngtdnh(5.3.4.17)chota:
V =!UTt~k (8)K(k)U
2 k=1
(5.3.4.28)
CongcuaIvcngoaila:
N
V' =:LSueT(x,8)f(x)dA e,
e=A'
M
=UT:L CeTfHeT(x)f(x)dA e=UTf
k=1 Ac
(5.3.4.29)
(jday
N
f =:LCeTfHe(x)f(x)dAe.
e=1 Ac
(5.3.4.30)
Cvcti€u hoat6ngthe"nang (V - V') chota :
[K(O)+~~k(8)K(k)JU =f
(5.3.4.31)
Tu'dngtl!m1;1c1.,U co th€ cocackhaitri€n :
p
U =:LCi\VJ{~I}]'
k=1
cac Cj du'Qctinhquah~phu'dngtrinhd~is6 :
[~K"l ~ viA{.;,}]f>, j =l...P.
149
. 0
...0. 5
-O~1
..().15
.0.2
-0.26
..o~3
0
0
Bi6nchpageiiati'mtheokYvQng95%
5.3.5.K6t I~n coobaitoaD3:
Sitd'1ngkhaitrin Karhunen-Loevevadatlntchanlo~nde'xAydt1ngmQtmohinh
chophu'dngphapphin tithii'llh~nnglunhiensedttthu~nti~nchocaebaitoaDcd
hQCnglunhientrongkhimQtvaiphudngpbapmophong86choquatrinhngftu
nhienIari'tkh6.
f)~cbi~t,chungtoinhinm~nhrAng,hiDhEtcacoongth1.1'ctrongphu'dngphapnay
c6the'tinhtoaDhinhthactrenmaytinhtrttdckhichuye'nsangcacngonngfi'tinh
L toaDs6truy~nth6ng.