NGHIEN ClTU DONG LU^C HOC CUA HE CAN TRUC - PHAO NOI
PGS. TS. NGUYEN VAN VINH ThS. NGUYEN HUU TRI Bg mdn Mdy xdy dung - Xep d&
Khoa Ca khi
Tru&ng Dgi hpc Giao thdng Van tdi
Tdm tdt: Bdi bdo trinh bdy tdm tdt nhirng kit qua nghiin cihi ddng luc hgc eua edn true dgt trin hi cdn true - phao ndi khi ldm viic hi ty day xuong Idng sdng. Ket qud ciru thu dugc cd thi su dung Idm tdi lieu tham khao cd ich de phuc vu cho viic thiit ki, chi tgo hi ndv trong thuc ti.
Summary: The paper summarizes the dynamics research results of the floating crane when the bottom of the floating crane is located on the bottom of river bed. The obtained research results can be used as useful reference materials to design and manufacture of this floating crane in practice.
I. DAT VAN DE
Hien nay d khu vuc ddng bang Nam Bd, de thirc hien cdng tac xep dd hang hda, nao vet kenh rach, phuc vu viec thi cdng cau, xay dung cac cdng trinh thiiy... tren dja hinh sdng ngdi, kenh rach chang chjt, ngudi ta thudng sir dung can true bd dat tren mdt phao ndi. He nay dugc ggi la he can true - phao ndi. He can true - phao ndi trong mdt sd trudng hgp khi lam viec do mirc nirdc thiiy trieu thap nen ty day phao xudng Idng sdng. Can true dat tren phao (thudng la sa lan) lam viec nlur d tren can. Liic nay can phai tinh toan can true theo quan diem ddng luc hgc de tinh hen ket giua phao va can true nham dam bao an toan.
Bai bao nay trinh bay nhung ket qua tinh toan ddng luc hgc ciia he can true - phao ndi trong trudng hgp dac biet khi lam viec nhirng thudng xay ra trong thuc te nhu da neu d tren.
II.NOI DUNG
2.1. Cau tao va nguyen iy hoat dong ciia mot he can true - phao ndi a. c i u tao: Ciu tao ciia he dugc the hien tren hinhl.
b. Nguyen ly boat ddng; Sir boat ddng ciia he thdng qua can true dat tren phao.
Khi lam viec. cac bd may nang - ha hang, bd may thay ddi tam vdi, bd may quay ... ciia can true boat ddng. Ngudi lai se dieu khien cac bd may nay de thao tac cac cdng viec ciia can true.
r^p chi KHOA HQC GIAO THONG VAN TAI So 29 - 03/2010 141
Nd cd thi boc dd lv iheo mgi hudng nhd bd may quay ciia can true.
Hinh 1. Hi edn true - phao ndi dang ngo vet kinh muong bdng gdu ngogm 2.2. Nghien ciru dong luc hoc ciia he can true - phao noi
Trong qua trinh lam viec ciia cin true dat tren he cin true - phao ndi, nhieu trudng hgp do nude thuy trilu nit, muc nude thip nen he phao ndi (sa lan) liic nay ty xuong Idng sdng va nhu viiy cd the sir dung nhung gia thilt sau day dl xay dung md hinh ddng luc hgc (DLH).
2.2.1. Xdy dung mo hinh dong luc hgc a. Cdc gia thiet
- Phao noi (sa lan) ty day xudng Idng sdng, gia thiet ve ca che tiep xuc de len ldp bim nhao cd nude ciia day phao va day sdng phing, sa lan cd vat lieu va ket cau dii cirng de cd the coi can true dirng tren nin cung tuyet ddi (cin true dugc lien ket cimg vdi sa lan va trang trudng hgp nay bd qua bien dang cua sa lan).
- Day cap hang cd do cirng la Si va he sd dap tat dao ddng la K, nd dugc coi nhu Id xo cd the CO dan dugc.
- Xet din do cirng ciia cap can la S: va he sd dap tat dao dgng la K2 •'••••'.. • ,, - Bd qua bien dang ciia ket cau thep can triic.
- Coi vat nang chi dao ddng trong mat phang ciia he can true - phao ndi (mat phang thang dirng chira can va toa quay).
142 Tap chi KHOA HOC GIAO THONG VAN TAI So 29 - Q3/2010
- Vat nang va cum mdc cau dugc quy dan ve khdi lugng m2,
- Hang dugc nang len khi cd do triing cap ban dau 5 hoac khdng cd do trimg cap (hang treo trong khdng gian),
- Tai trgng gid tac dung theo hudng bat lgi cho can true.
- Bd qua khdi lugng ma sat cua puly trong he thdng palang. Chua xet din biln dang cua cac phan tir trong co- cau nang ha hang.
- Khdi lugng ciia can dugc quy dan ve giu'a can bang mdt khdi lugng tap trung m3.
b. Mo hinh dgng luc hgc
- Dat md binh tinh toan vao he toa do tuyet ddi OXY vdi cac toa do suy rgng tuang irng vdi cac phan tir chuyen ddng nhu sau;
Hinh 2. Md hinh ddng lire hgc cua hi edn true - phao ndi q, - Gdc quay ciia true ddng ca, ca cdu ndng hg hdng, rad:
<•/: - Do dich chuyin cua hdng theo phuong cua cdp ndng hdng, m:
q, - Gdc ldc cua edp hdng quanh dinh cdn, rad;
q,i - Gdc quay cua tang ndng hdng, rad:
6 I - Mdmen qudn tinh quy ddn cua rolo ddng ca vd khdp ndi Iritc:
M(q,) - Duong dgc tinh ngodi cua ddng ca ca cdu ndng hg hdng:
Ml - Mdmen phanh cua ca cdu ndng hg hdng:
il - Tl so truyin cua hop gidm toe trong ca cdu ndng hg hdng:
i: - Bdi sudt cdp (so nhdnh cdp Ireo) cua edp hdng:
S:, K: - Tuong img Id do cimg vd hi sd ddp tdt dao ddng cua cdp hdng:
L,. - Chiiu ddi cua cdn cua cdn true:
D - Dirdng kinh cua lang cuon cap thuoc ca cdu ndng hg hdng:
f „ - Tai trgng gid tdc dung vdo cdn true quy ddn vi diem G;
c/v - Chuyin vi gdc eua cdn (gdc ldc cua cdn xung quanh khdp O);
ip„ - Gdc nghiing cua tdm cdn so vdi phuong ngang:
fg - Chiiu ddi cdp hdng:
Xo-}'„ - Tog do han ddu cua diim O.
2.2.2. Thih lap phuong trinh chuyen dom',
D I thilt lap phuong trinh chuyen ddng.chimg tdi sii- dung phuong trinh Lagrange loai II cd
Pap chi K H O A H Q C G I A O T H O N G V A N TAI S o 2 9 - 0 3 / 2 0 1 0
143
dang nhu sau:
A ( ^ ) _ l I . ^ . ^ = Q , ( i = l,2,3,.„n)
d t • ~
aq, ^^' d'q., ^q^ ^ ,.^^., ,
Trong do i la so bac tu do ciia he . ,• .. :> M- a, Xet trudng hgp nang hang cd do triing cap ban dau 5 . ' Qua trinh nang hang xay ra theo ba pha sau day:
Pha I: Cho ddng ca bit diu boat ddng, tang bit diu cudn cap, do trimg cap 5 ^ 0 (bat dau cap cang),
Pha II; Tang tilp tuc cuon cap, luc cang cap cd gia trj tang dan Fc = 0 tang den gia trj lire cang tmh p
ct
Pha III- Tang tilp tuc cudn cap, khi p > "^M luc nay hang thuc sir nang len khdi mat dat
'2
va tilp tuc dugc nang len cao.
Trudng hgp nay md hinh ddng lire hgc cd 4 bac tu do.
Phuang trinh chuyin ddng ciia ca cau d pha 1 nhu sau:
• ••
M(q,) = e,q,
Pha II: He cd 2 bac tir do q,, q4;
Sau khi tiln hanh cac dao ham cin thilt theo phuong trinh Lagrange loai II (chi tiet xm xem d tai lieu tham khao [2]).
Bilu dien phuong trinh chuyen dgng dudi dang ma tran chimg ta cd:
Mq-^Kq-i-Sq = f Chii y: pha thir II kit thiic khi:
niTg
Pha III; Pha III bit diu khi p ^']^,hax\g di len thuc sir. He cd 4 bac tu do: q,, q2, q.i, qj
'2
Sau khi tiln hanh cac dao ham cin thilt theo phirong trinh Lagi-ange loai II (chi tilt xin xem a tai lieu tham khao [2]),
Bieu dien phuong trinh chuyin ddng dudi dang ma tran, chiing ta cd dang sau:
M q + Kj q" + Kjq q^ + K,, q+ Sq = f
144 Tap chi KHOA HQC GIAO THONG V^N TAI So 29 - 03/2010
Trong dd cac ma tran cu the nhu sau:
Mq =
e,
m.
-mX^A
m 2 ( f Q - q 2 ) '
mX^(fQ-q,)B
-m,L^A
m2Lc(fo-q2)B
( m , + — ) L , 4
K , q ^ - m : ( f , - q j
- m X , ( f , , - q , ) A
-m,L,B
-mX^(fQ-q2)A
K 2 q q 3
-2m,(f,-,-q2) -2m,L^B
K,q
i.-K,R-
- i : ' K , R
-i,-K,R
h%
•
••
qi
••
q2
q"
••
q4
(q,)'
( q , ) '
(i)'
( q 4 ) '
q'q*
q*q'
q'q*
q'q'
qi
q' q*
ql
. ap chi KHOA HQC GIAO THONG VAN TAI So 29 - 03/2010 145
Sq
i , - S , R '
-i.-S,R
- i 2 ' S , R i,%
qi
q:
q j
q4
f =
M(q;) + i/S,RX
- i , ^ S | ? ^ - m , g c o s q 3
- m , g ( f Q - q 2 ) s i n q 3
-S,L^-[cos((p„ - q,)sin((p„ - q 4 ) -sin((p„ - q , ) c o s ( p „ ] + m,gL^. cos((p„
m , , g ^ c o s ( ( p ^ , - q j ) - K X , ' s i n ' ( ( p „ - q 4 ) q ;
- q 4 ) +
Luc cang cap d pha III xac djnh nhu sau:
F, =^^^ + K,Al,+S,Al,;F,=^M + K,i,(Rq:-q;) + S,i,(Rq,-q,-^)
2.3. Giai phuong trinh chuyen dong 2.3.1. Sir do khoi thuiit todn
Chimg tdi da tien hanh giai phuang trinh chuyen ddng d tren trong ca 3 pha vdi cac sd lieu cu the nhu sau;
He sd mdmen ddng ca: A = 15,35;B= 1630; 9, =1,1414 k g . m ' Bdi suat cap: i2 = 6
Gia tdc trgng trudng: g = 9.81; (m/s")
Ban kinh quy din: R = 0.0000174 m; J ' 1=0,02 m;
Chilu dai tir dinh can tdi hang nang: fQ = 35 (m) Chilu dai can; Lc= 30 (m)
Gdc nghieng ciia can: (po= 0.874 (rad) Khdi lugng hang nang: in2 = 4900(kg) Khoi lugng can: in, = 4500 (kg)
Do cirng ciia cap hang: Si = 801090 (N/in)
He so dap tit dao ddng ciia cap hang: Ki = 4800 (Ns/m) Do cung cap cin: 82= 1701090 (N/m)
He sd dap tat dao ddng ciia cap can: K2= 1600 (Ns/m)
146 Tap chi KHOA HQC GIAO THONG VAN TAI So 29 - 03/2010
t/3 . O W
-re O
22
o
C/)
5
4
—f
; — 1 ^
s a t i a i i i i iffliii^ iiii
I
"3
j
. 9P Chi KHOA HQC GIAO THONG.VAN TAI So 29 - 03/2010 147
2.4. Cac kit ^ii.i ihu dirffc sau khi chay chuong trinh
Cac kit qua thu dugc khi trgng lugng hang nang la 4,9 tin (day la trgng lugng hang ma chung tdi da tien hanh thuc nghiem vdi nd) dugc the hien tren cac dd thj sau:
iWVvVw-...x,....-.-:..-^ -'^- -'-^ —_
. 1 0 *
' • • . - " " '
a) Gia tdc - van tdc - chuyin vl gdc cua dgng ca (qj)
b) Gia tdc - van tdc - chuyen vi cua hdng theo phuang ciia cdp hdng (qi)
A r- /, ,. „ ,
f!\:\l\!\l '••/'•.A':.rK'-\..'-\/\-^y
! r, :\ h. .-.
UlMA/'AAArv\/vvx..^^v/v.-
V V '•'l\:\i\ ! \ / \ A A/V\/^./^'•V,••-./^.-.
' A/V\A/VV v\A/\A/v'./v^-.^---'
' !' W
lyyvwvwvvx/vv.^.
c) Gia tdc - van tdc - chuyen vi gdc ctia cdp hdng xung quanh dinh cdn (q^J
d) Gia tdc - van tdc - chuyen vi gdc ldc cua cdn xung quanh khdp (qJ
e) Luc cdng tren cdp hdng
Hinh 4. Cdc kit qud tinh lodn trong trudng hgp Q = 4,9 tdn
Nhan xet:
- Cac dd thj cd dang diing nhu ly thuyet
- Luc tac ddng len day cap tang nhanh den gia trj 7000kG trong khoang t = 0,3s sau dd dao ddng dieu hoa giam dan ve gia trj luc cang tTnh va dn djnh d t = 10s.
De kiem chung do tin cay va tinh dimg dan ciia md hinh dgng lire hgc, chuno tdi da tiln hanh do dac thuc nghiem tren he can true - phao ndi vao thang 1 1 nam 2009 tai khu vuc dong
148 Tap chi KHOA HQC GIAO THONG VAN TAI So 29 - 03/2010
bang Nam Bd [I]. Cac ket qua thu dugc bang tinh toan ly thuylt theo md hinh ddng luc hgc d tren da dugc so sanh \di kit qua thuc nghiem [2] va cd thi thiy, md hinh tinh toan da cd do chinh xac dat yeu cau. tin cay.
III. KET LUAN
Tir nhung ket qua nghien ciru ly thuylt va thuc nghiem thu dugc cd thi thiy ,ind hinh ddng lire a tren hoan toan cd the sir dung de tinh toan lire cang ddng trong cap hang cua cin true dat tren phao ndi, khi lam viec phao ty day xuong Idng sdng.
Cac ket qua thu dugc cd the su dung lam tai lieu tham khao cd ich cho viec chi tao he nay ngoai thuc te.
till lieu tham khao
[1], PGS. TS. Nguyin Vdn Vinh. ThS. Nguyin Hmt Chi. Ks. Nguyin Nggc Trung. Nghien cii-u thuc nghiem xac djnh luc cang dong trong cap hang cua cin true tren he cin true - phao n6i. Tap chi khoa hoc GTVT s6 27 thang 09/2009.
[2). ThS. Nguyin Huu. Chi. Nghien cuu xac dinh luc cang dong trong cap hang cua cin true treu he cin true - phao noi khi lam viec tren song nude d6ng bing Nam Bo. Dk tai NCKH cua NCS nam 2009.
MS:T2009 - CK l9.Tru-dn" Dai hoc GTVT*
KHAO SAT VA DANH GIA ...
(Tiip theo trang NO) - Phirong phap giao hdi nghjch thich hgp khi cac diem tren md tru dat dugc may hoac dilm bd tri da dugc xac djnh sa bd bang cac phuong phap khac. hoac dimg de kilm tra, nghiem thu tirng phan toa do lim md tru cau.
III. K I T LUAN
Khi bd tri tam md. tru can bang may TDDT nen bd tri so- bd bang may cd do chinh xac tu- do gdc tir 3" tro- len. Neu cd 2 may thi bd tri bang phuo-ng phap giao hdi gdc - canh, Trong truirng hgp chi cd 1 may thi bd tri so- bd bang phuong phap tga do cue va bd tri chinh xac bing plurong phap giao hgi nghjcb cd tinb cac yeu td hoan nguyen.
Tai liiu tliain khau
11 ], Cau Vii cong (2000), ueu chuan thi cong va nghiem thu. 22TCN266.
[2]. Tran Dac Sir va nnk (2004). Nghien cuu khai thae Toan dac Dien tir phuc vu khao sat thi^t ke va xay thing ciing uinh giao thong. De tai cap bo ma so B2002-35-30*
