NGHIEN CUU THIET KE SUON TANG CUONG ONDINH CHO DAMTHEPTIET DIEN C H Q I
CANH RONG (HFB)
Pham Van Hoi Huynh Minh Son
ABSTRACT The article presents results of the researching on solution of stiffen- ers design to Increase the stability ofAustrallan technology HFB. The authors calculated distorslonal buckling moment and designing bending moment of stiffners HFB In comparison to non-stiffeners HFB to clarify advantages of the
stiffeners forming to Increase the stability as well as the bear- ing capacity of HFB. On the other hand, the designing of stiffners Is also calculated according to local buckling condition due to shears or due to reactions at supports as well as conditions for guarantee- ing the buckling for self-stiffners.
The researching results give reasonable factors for designing stiffners such as: Form, type of connection to HFB, dimensions, density, distance and strength of stiffners.
PGS. TS Pham Van Hoi TrUcmg Dai hoc Xay diAig
Th.S Huynh Minh Sofn TrifofngOai hoc Oa Ning
1. Dat van de
Dam thep tiet dien chd I eanh rdng theo cdng nghe Uc (Hollow Flange Beam - viet tat la HFB) la loai tiet dien mdi, hinh dang die biet chd I, ddi xdng kep theo hai true x-x va y-y, gdm hai cinh rdng tam giie lien ke't han vdi b i n bung. Do ed nhieu Uu viet ve trpng lUpng, khi ning chiu t i i trpng va tinh edng nghe nen dam HFB dugc nhieu nude quan tam nghien cdu v i trien khai dng dung hieu q u i nhU: Uc, My, Anh, New/zea- land... Khi ning chju t i i trpng eua d i m HFB chiu i n h hudng rat Idn bdi cic dieu kien dn djnh tdng the va dn djnh cue bp. Vin de d i t ra l i ed the sd dpng sUdn tang eUdng de ning cao khi ning dn djnh tdng the va cue bd cho d i m HFB? Nghien edu tinh t o i n sudn ra sao de dat hieu q u i tdt nha't m i khdng phat sinh nhdng b i t cap lim d i m ning ne, tdn thep va edng ehe tao.
2. SU can thiet cau tao siidn tang cUcrng on dinh cho dam HFB
2.1. Moi quan he giCta bai toan on dinh & bai todn ben
Dim HFB ed hai dang mat dn djnh tong the: Sp oan ben do udn xoan va sp oan van [4].
Kha nang chiu mdmen cua dam HFB phu thudc vao k h i ning chju mdmen danh nghia ve ben (M^);
khi ning chju mdmen danh nghTa ve oan van (M^^) v i kha nang chiu mdmen danh nghTa ve oan udn- xoan (MJ.
Mdmen thiet ke eua dam HFB:
M;=min(4),M^;ct)^M^,;4),MJ De dinh gia mdc dp i n h hudng cua dn djnh tdng the de'n k h i nang chju t i i ta tinh: Ty sd M^JM^^^ the hien mdc dd chenh lech gida khi ning chju oan van va chju oan udn xoan. Ty sd (M^VM^) the hien mdc dp chenh lech gida kha nang chju oan so vdi k h i ning chiu mdmen ve ben. Trong dd cic g i i trj cua khi nang chiu mdmen ve ben (M ); ve dn djnh oan udn xoan {MJ v i dn dinh oan van ben (Mbd) tinh theo AS/
NSZ4600 [4].
Khao sat 09 sd hieu dam HFB djnh hinh eua Uc ke't q u i eho thiy:
Ty sd {MJMJ={69,3^^90,^3)%.
Sp chenh lech gida mdmen tdi han dan hdi oan van v i oan udn xoan (M^^«M^J se dan de'n ling phi vi k h i ning chju tai trpng eua dam HFB bj han ehe bdi dieu kien dn djnh oan van. Mat khic ty sd [M^^'Z M) = (15,79^81,12)%. Chdng td sU mat dn dinh oan van da lam han che rat nhieu khi ning chiu mdmen eua dam HFB. Sd hieu dam cing Idn, inh hudng eua oan van cang nhieu. inh hudng cua oan udn-xoan la ding ke song khdng cd y nghTa quye't dinh.
Tuy nhien, khi dam l i m viee ddc lip van can cd bien p h i p g i i m chieu dai tinh t o i n L^ de tang k h i ning chju oan udn-xoan. Khi dd chenh lech gida khi nang chiu oan udn-xoan va chiu oan van se cang Idn hon do dd, cang phai tinh toan giii p h i p tang eudng ehdng oan van.
64 ^E^nifVn^l . 11.2009
Bing 1 .Ty le MJM^^ va M^/M^ (%) cua dam 45090HFB38 Chieu dai tinh t o i n Le(m)
« f i r a 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 1 10 1 11 1 12
Ms 1 6 1 1 6 1 1 6 1 1 6 1 1 6 1 1 6 1 1 6 1 1 6 1 1 6 1 1 6 1 1 6 1 1 6 1 Mbo 1 6 1 14444 12123 3853 7809 6436 5480
m 12270 1 7 3 i l 6631 1 7 4762 4157 WM/Mbo 75,74 7528 7334 6791 71,55 7198 75,85 Mb1tbeooffl»M) 14580 12333 10911 1 7 1 5793 4932
\ k \ k m w ] 11043 3786 8001 6022 5028 4285 3741 M i M t W 11043 3786 8001 i 2 5028 4285 3741
n m 6817 6041 4339 3717 31,04 X,45 2103
4774 4231 3739 3448 3157 1 6 3322 1 2 2366 2842 7722 7851 8086 8603 3001 4237 3808 3413 3103 2841 3318 2 1 2765 2670 2557 3318 2 1 2765 2670 2557 2048 1845 1707 16,48 15,73 Bing 2. Qng suit tdi han d i n hdi (f^^) phu thudc sd lupng sudn
So luoiig
S I l O l l (11,)
n,=0 n,=2 n,=3
Chieu dai tinh toan Le(m)
-•-n:
- • - 1 1 :
- * - n :
^ n :
=f,
=1
=2
— >
4 5 6 7 Chieu d i i tinh t o i n L Jm) Bing 3. Qng suit tdi han (f^^) php thudc dang sudn
So liieii (lain H F B 45090HFB38 40090HFB38 35090HPB38 30090HFB38 30090HFB33 30090HFB28 25090HFB28 25090HFB23 20090HFB23
Dang (1) 1914 1772 2481 2962 3065 3089 3757 4048 5058
Fii^ s'liiit toi luiii (tail lioi oiiii van (<laN Daiig C)
1918 1777 2484 2966 3069 3091 3759 4050 5060
Dang (3) 1919 1778 2486 2968 3072 3093 3761 4052 5061
Dang (41 1923 1782 2491 2972 3076 3097 3764 4056 5064
[ Dang (51 1924 1784 2493 2974 3078 3098 3768 4059 5066
D.in2 (6) 1926 1786 2495 2976 3081 3101 3769 4061 5069
m^)
Dang (") 1929 1789 2498 2979 3083 3104 3771 4064 5072
Dang (8) 1930 1791 2490 2991 3084 3106 3774 4067 5075
2.2. Tdc dung sUdn tdng cudng Khio sat dam 250HFB28. Chpn SO dd dam chiu t i i trpng t i p trung d nhjp d i u thda nham kiem che cinh tren (chju keo), de bung va cinh dudi (chiu nen) van theo phuong ngang)
phu hpp vdi md hinh oan van. Ke't q u i nhan thiy: Sd lupng sudn (n^) cing Idn thi dng suit tdi han dan hdi (f^^) cang t i n g (xem Bing 2 va do thj). Trong dd (f^^) cd the tinh theo quy tac php lue D cua AS/NSZ4600
[4] hoac tinh bang chuong trinh NASTRAN theo phUOng phip PTHH [2]. Chdng td sudn ed t i e dung l i m tang ding ke kha nang chiu oan van.
Khio sit toan bd 09 sd hieu dam HFB cdng eho ket q u i nhu tren. Sp khie biet die trung cua d i m HFB la sUdn t i n g cUdng khdng chi cd t i c dung lam t i n g k h i ning dn dinh cue bd nhu d i m thdng dung m i cdn cd t i c dung lam t i n g dn djnh tdng the oan van, qua dd tang kha nang chiu t i i eua dam.
Dieu niy cd the giii thieh dpa tren dang m i t dn dinh oan van cua dam HFB: Sudn gia eUdng da han che ehuyen vi eua cinh v i sp oan van eua b i n bung do dd lam tang g i i trj dng suit tdi han d i n hdi.
Gii trj dng suit tdi han dan hdi oan van (f^^) khi bd tri sUdn d mdt phia hay hai phia eua b i n bung ed su chenh lech ding ke do dd can tie'p tue nghien edu cie thdng sd eua sudn. Viee thie't ke thdng sd eua sudn c i n dupe nghien cdu dUdi nhieu gdc dd de dat hieu q u i cao nhi't: VUa phii t i n g cUdng k h i nang chiu oan van, vda tang k h i ning chju oan cue bd do lpc cat hoac do phin lpc tai gdi tUa. Chpn eie thdng sd khio sit gdm:
- Hinh dang sUdn: Sudn dang ban hay sUdn tiet dien rdng hinh chd nhit (RHS).
- Cach bd tri sUdn: Bd tri mdt phia hay c i hai phia bung dam.
- Cich lien ke't sudn vao d i m : Sudn h i n vdi bpng; han vdi eanh dam hoac han vdi ea bung va eanh
- Khoing cich sUdn (a) hay m i t dp sudn (a/d) (d: chieu eao bung dam).
- Kieh thudc sUdn (chieu rdng sudn bs va be day sUdn t^): Be rdng sudn chpn theo cau tao de truyen lpc deu nen lay bang dp vuon eua cinh b^ = (B-t)/2. Do dd dai lUpng can xet la be d i y sUdn (ts)
- Cudng dp thep sUdn (f 3): f ^ = {250^600)Mpa.
3. Nghien cufu chpn cac thong so cua sudn tang cUdng
3.7 Nghien citu chgn hinh dgng sadn va cdch lien ket vdi dam
^ B t l B I l B l , 11.2009 65
So d d tinh khdng ddi. Cie trUdng hpp k h i o s i t n h u sau:
- Dang 1: Sudn don dang b i n (bd tri mdt phia), han vdi c i n h va bung;
- Dang 2: Sudn ddi dang b i n (bd t r i hai phia), han vdi bung;
- Dang 3: Sudn ddi dang b i n (bd t r i hai phia), h i n vdi c i n h ;
- Dang 4: Sudn ddi dang b i n (bd t r i hai phia), han vdi eanh va bung;
- Dang 5: SUdn tiet dien rdng (RHS) (bd t r i mdt phia), hai dau han vdi c i n h va bung;
- Dang 6: SUdn tiet dien rdng (RHS) (bd t r i hai phia), hai dau h i n vdi bung;
- Dang 7: Sudn tiet dien rdng (RHS) (bd t r i hai phia), hai dau han vdi c i n h ;
- Dang 8: Sudn tiet dien rdng (RHS) (bd tri hai phia), hai dau han vdi c i n h va bung;
Ket q u i xem B i n g 3 nhan t h i y : Dang (8) eho (f^^) Idn nhi't song khdng qua trdi so vdi dang (4) nen khdng chpn vi tdn nhieu t h e p sUdn va dudng h i n . Dang (7) ed (f^^) Idn hon dang (6) v i nhd hon dang (8) mdt it song nang ne, t d n thep va dudng han vda tdn edng gia edng eat v i t hai dau thanh nen khdng chpn. Dang (3) ed (f^^) Idn hon dang (2) v i nhd hon dang (4) khdng nhieu song xet de'n dieu kien dn djnh sUdn nen khdng chpn. Chpn Dang (4) theo d d sudn tang eUdng dang b i n , bd tri ddi xdng hai phia bung dam v i lien ke't han vdi ea c i n h v i bpng (Hinh 2).
3.2. Nghien cCtu chgn mat do sudn va khodng cdch sUdn
Chpn mat d p sUdn (a/d) de t i n h de'n i n h hUdng cua chieu cao bpng ddi vdi sUoan van. So d d t i n h khdng doi. Ket qua nghien cdu cho thay:
Mat d p sudn (m^=a/d) cang nhd thi dng s u i t tdi han dan hdi (f^^) c i n g t i n g (xem B i n g 4 va d d thj). Tuy nhien, q u i nhieu sUdn se t d n t h e m edng & lam dam nang ne.
Xet ve dieu kien oan cue bd, khi lpc cat Idn ddi hdi sd d u n g dam sd hieu Idn tuy nhien (d/t) Idn khdng ed Ipi chju oan cue bd nen can bd t r i sudn vdi k h o i n g c i c h tdi thieu de
Bang 4. Qng s u i t tdi han (f ) phu thudc mat d p sUdn A l ^ t <16 s'ltoii
i n , = a <I 0 1 2 3
N l i i p (lain L (in) 2 i n
6169 10880 10460 9945
3 i n 4444 7 000 6800 6425
-iin 3694 5200 5040 4798
5 m 3177 4 1 4 0 4020 3862 1
6 i n 2782 3480 3380 3246
" i n 2444 3000 2900 2831
8 i n 2194 2600 2540 2387
9 m 2000 2360 2267 2185
c
1(0->
c
•1(0 o
c ro-
CD
c
11000 10000 9000 8000 7000 6000 5000 4000 3000 2000
• \
\ v *
^ . ''
\
\
\
i
V
I 3 4
1.-!/"^
~ - i
5 6
fej
7 £ ! 9 ^ ^ ^•in:.=':'
• iii:,=l
•in:-2
• iii:.=3
Chieu d i i t i n h t o i n Le(m)
„ 18000 E 2 16000
ro 3 14000
4 - '
g 12000 O 10000
^ 8000
• 5 6000 Ol
£ 4000 ,ro 2000
r-
ifln
H
I Mbd Mflltiecoawjon-m) I ii^teoaMan)
|lilinlHI;etti' I^IVtils
4 5 6 7 8 9 10 11 12 C h i e u d a i t i n h t o i n Le(m)
Hinh 1. Bieu do kha nang chiu momen cua dam 45090HFB38
.b.
Dam HFB CO saon tang cuang dang ban
b. Si/dn rong RHS
6 6 B ^ I ^ E I l K i l ^ l . 1 1 . 2 0 0 9
Bing 5. Chpn mat dp sUdn (a/d) v i khoing cich sUdn (a) HFB
45090HBF38 40090HBF38 35090HBF38 30090HBF38 30090HBF33 30090HBF28 25090HBF28 25090HBF23 20090HBF23
1 d
37 32 27 22 21,9 21.8 16,8 16.8 11,8
! dA 97.37 84.21 71,05 57,89 66,36 77,86 60 73,04
51,3
(a/d)1 0,555 1 1 1,348
1 1 1,204
1 2,621
(e/d)2 0,895 1.231 3432 + 00 + 00 1,644
+ 00 2,458
+ 0 0
(e/d)3 3 3 3 3 3 3 3 3 3
(syd)4 1 7.13 9,533 13,39 20,168 15,349 11,152 18,778 12,67 25,683
a/d chon 0,555 <= a/d <= 0,895
1 <= a/d <= 1,231 1 <= a/d <= 3
1,348<=a/d<=3 1 1 <= a/d <= 3
1 <= a/d <= 1,644 1,204<=a/d<=3 1 <= a/d <= 2,458 2,621 < = a / d < = 3
a chon 2 0 , 5 4 < = a < = 3 3 1 2
3 2 < = a < = 3 9 , 4 1 2 7 < = a < = 8 1 2 9 . 6 5 < = a < = 6 6 21,9 < = a < = 65,7 21.8 <= a <= 35,85 2 0 , 2 2 < = a < = 5 0 4 16,8<=a<=41,29 30,93 < = a < = 35,4
Bing 6. Chpn sd lUpng sUdn theo nhjp d i m L
So liirii (lain H F B
45090HFB38 40090HFB38 35090HFB38 30090HEB38 30090HFB33 30090HEB28 25090HFB28 25090HFB23 20090HFB23
S o Iitoiio .siidii toi Hiieii clio ilain H F B theo idiip (lain L(in)
l i n 2 2 1 1 1 2 1 2 2
2 m 4 4 2 2 2 4 2 4 4
3 m 6 6 3 3 3 6 3 6 6
4in 8 8 4 4 4 8 4 8 8
5 m 10 10 5 5 5 10
5 10 10
6 m 12 12 6 6 6 12
6 12 12
"m 14 14 7 7 7 14 7 14 14
$in 16 16 8 8 8 16 8 16 16
9in 18 18 9 9 9 18 9 18 18
lOin 20 20 10 10 10 20 10 20 20
1 1 m 22 22 11 11 11 22 11 22 22
1 2 m 24 24 12 12 12 36 12 24 24
<^chon
33,33cm 33,33cm 50,00cm 50,00cm 50,00cm 33,33cm 50,00cm 33,33cm 33,33m
Bing 7. Qng suit tdi han (f ) phu thudc be day sUdn (t)
C l i i e u fliiy sucrift t, ( i i u n )
3 m m 5 m m 3 m m 1 0 m m
Chieu dii tinh toin L^im)
2 i n 9 1 1 8 9 1 5 3 9196 9216
3 i n 5793 5820 5928 5993
4 m 4 2 9 4 4 3 3 0 4 3 7 9 4 3 9 5
5 m 3420 3468 3492 3503
6 i n 2880 2 9 4 3 2980 3000
" i n 2500 2556 2580 2640
S i n 2240 2306 2322 2362
9 i n 2000 2 0 4 8 2072 2112
iOOOO o
• ^ cjf.f.r C
1
> • = - • - ' '
O
XL ^'^^•^.'
3 , r . r , r , C31
-•^
k
5 4 5 O 7 5 9
tE
Chieu dai tinh toan L =(m)
bung khdng bj oan khi dam cdn lam viee dan hdi.
Dieu kien de sp oan cue bd (neu ed) chi xiy ra ngoai mien d i n hdi theo AS/NSZ4600 [4]:
^ ^ E i ^ < d / t < 1 , 4 1 5 7 E k , / f ^ hay
0,5(d/t)2 f/E < k^ < (d/t)2 f/E.
Thay f = 450l\/lpa v i £=200000 Mpa ta dupe:
0,001125(d/t)= < k < ,00225 (d/t)^
Xet a/d > 1: k = 5 , 3 4 H 4,00
" ( a / d /
Thay vio:
0,001125(d/t)^<k 4,00
= 5,34H
Suy ra:
( a / d /
< 0 , 0 0 2 2 5 ( d / t ) '
0,00225.| - I -5,34 - < —< a
^ d
0,001125.
- X e t a / d < l : k „ = 4 + Thay vao ta dupe:
0,001125(d/t)'<k„
-5,34 5,34
„ 5,34
= 4 + r- ( a / d / Suy ra:
< 0 , 0 0 2 2 5 ( d / t ) '
5,34 0,00225, - 4
a
< —<
d 5,34
0,001125.
- Mat khae, theo AS/NSZ 4600, mat dp sUdn chju cat phii t h o i :
a r260Y .
- < va<3,0 d [d/tj
Gpi (a/d),; (a/d)^; (a/djj; (a/d)^
l i cie g i i trj can dUdi v i c i n tren eua eae bieu thdc tren, tinh t o i n dupe pham vi mat dp sudn (a/d) va khoing cich sUdn (a) cho 09 sd hieu dam tren Bing 5. Dpa vao mat dp sudn (a/d) theo dieu kien chiu eat va chpn thien ve g i i tri nhd de ed Ipi nha't ve mat dn djnh tdng the oan van, ta chpn dUpc khoang
^ E ^ n i n ^ l .11.2009 67
c i c h sUdn (a ^ ) l i n luot l i 33cm v i
^ c h p n '
50 em de b d t n c i c sUdn deu nhau trong pham vi m d t met d i i ddi vdi 09 sd hieu d i m va tinh t o i n dupe sd lupng sUdn tdi thieu dng vdi mdi nhjp dam L(m) n h u t r e n Bang 6.
3.3. Nghien ciiu chgn beddysUdn K h i o s i t anh hUdng eua be day sudn (t^) de'n dng s u i t tdi han d i n hdi (fj. Cie d u d n g do thi dng vdi c i c g i i tri (t^) g i n n h u trung nhau ehdng t d anh hUdng eua be d i y sUdn de'n sUoan van la khdng d i n g ke. Do d d xem xet theo dieu kien dn dinh cue b d cua sUdn theo AS/
NSZ4600, dien tich sUdn p h i i t h o i : A > A , =
' 1 - k ,
6fn-^
Vkstd-
1,53Ek
(3)
neu ks>0,8 AS 2.7.1 (4) Ol = f / f . Chon thep sudn ed f =
T y ys • "^ ys
250Mpa;ii) = l,8
k^^: He sd phu thudc loai sUdn:
D i m HFB ed sUdn ddi ddi xdng k =1,0
5t
k^: He sd oan do eat
Mat khic, sudn p h i i d i m b i o dn djnh cue bd theo AS/NSZ 4600:
^ < 0 , 3 7 7 E 7 ^
Tiet dien eua sudn p h i i du dp tUa edng de chia b i n bung t h i n h cae d va l i m gdi eho eae d b i n bung. Td c i c dieu kien tren, vdi mat dp sUdn (a/d) da chpn theo k h o i n g c i c h sudn a la 33cm va 50em, tinh dupe be day sUdn t^, va t^^ t d d d chpn dupe be day sUdn eho mdi sd hieu dam HFB: t = max(t ,;t J . Kiem tra dieu kien (b/t^) neu khdng t h o i man thi tang be d i y sudn (t^); neu t h o i man t h d n g b i o ket qua kiem tra dn dinh sUdn l i "OK". Neu ehon
B i n g 8. Chpn ( t ) theo dieu kien dn djnh cue b d sudn
sn
1
2 3 4 5 6
]
j 8
1 9
HFB df
mmm mi
40090HBF33 35090HBF33 30090HBF38 30090HBF33 30090HBF28
8(21
?1,05 5],89 66,36 ]],86 250iHBF28 M 25090HBF23 20090HBF23
im
51,3
aid fe bs As
3 0,41 (31 11,4 1,15 0,9
2,55 0,9 3 0,8 3 0,95 1,49 0,9
3 08 2,05 1 0,9
3 0,8
4,31 0,13
431 431
4,34 4,36 4,36
1,24 2,32
053
0,45
1,3
4,39 0,38 4,39 0,]5
tsl ts2 ts(mm) ^emfra
13,22 4,12 1322 0^
0,85 4,12 4,12 OK 1,44 4,12 4,12 OK 2,69
0,61 0,52
149
0,44 0,86
4,12 4,12 OK 4,14 4,14 OK 4,1] 417 OK 4,1] 4,1] OK 4,19 4,19 OK 4,19 4,19 OK
B i n g 9. Be d i y sUdn (t^) php thudc cUdng dp t h e p sUdn ( ^
HFB 2500 3000 3500 4000 4500 5000 5500 6000
45090HBF38 13,22 1102 40090HBF38
35090HBF38 30090HBF38 30090HBF33 30090HBF28 25090HBF28 25090HBF23 20090HBF23
4 1 2 4 1 2 4 1 2 414 4 1 7 4 1 7 4 1 9 4 19
451 451 451 4 54 4,56 4 5 6 4,59 4 59
9.45 4 8 7 4 87 4,87 4 9 4 93 4 93 496 4,96
8 2 6 521 521 5.21 5 2 4 5,27 5 27
5 3 5.3
7,35 6,61 5,53
5,53 553 5 56 5 59 5.59_
5.62 5,62
5 82 5 82 5,82 586 5,89 5,89 5.93^
l 9 3 611 611 6.11 6,11 6,14 6,18 6,18 6.21
6ir
638 6,38
6,42 6 45 6.45 6.49 6 49
>^ I Bieu d d quan he be d i y sUdn (ts) (mm) '.^-^ v i dng s u i t c h i y cua thep sudn (fys) (daN/em^)
_ © ,
l/l
. 1111.111: \\
2500 3000 3500 4000 4500 5000 5500 6000 Qng s u i t c h i y cua thep sUdn (f y,) (daN/em^)14 12 10 08 06 04
°2 |25(W23
° I
be day (t^) t i t c i eie dam deu theo eudng dp thep sudn f ^ = 250Mpa thi ddi vdi d i m 45090HFB38 se ed b e d a y sUdn t^= 13.5mm q u i Idn va chenh lech vdi t h e p dam do do c i n tiep tuc nghien cdu anh hUdng eua cudng dp thep sUdn (f ) de'n be d i y sudn (t^)
3.4. Nghien cdu chgn thep sUdn Thay ddi dng s u i t c h i y thep
sudn: f ^ = {250^600)Mpa; tinh dugc dien tich sUdn (A^) v i be day sudn (t^). Dpa v i o d d thi Bang 9 n h i n thay: Odi vdi d i m Idn n h i t 45090HFB38, khi ( f j t i n g thi be day sudn (t^) g i i m . Cie d i m cdn lai thi khi ( y t i n g thi (t^) khdng g i i m m i lai t i n g . Oieu n i y do (t) bj ehi phdi bdi dieu kien dn djnh cue bp khi (b ) khdng ddi. Oe tiet kiem t h e p sUdn 6 8 g r o i i j g i . l • 11.2009
Bing 10. Mdc dp tang k h i nang chju oan cue bd do eat
So
liieii
(lam HFB
45090HFB38 40090HFB38 35090HFB38 30090HFB38 30090HFB33 30090HFB28 25090HFB28 25090HFB23 20090HFB23
Car thong so ciia .siioii tang riioiig (la rlion
(It
97.37 84,21 71,05 57.89 66.36 77.86 60.00 73.04 51.30
Mat (16
.SIIOII
(a-d)
2,70 1,03 1,85 2,27 2,28 2,29 2,97 2,02 2,97
K l i o a i i g rarli SIIOII (a)
(cm)
33 33 50 50 50 33 50 33 33
Ty Ir tang kha nang f liin cat (laiili iiglua (Oo) ve oan riir bo
the0 klioaiig rarli snoii (a) 33
(cm)
50 (cm)
^^^^^m^
^^^^^^^^^1
122,53 111,45115,32
110,38 107,01 10S,94
^ ^ ^ • u ^ t ^ ^ ^ H
^ ^ 1 0 9 ! 2 8 ^ T l | ^ ^ ^ ^ ^ ^ B
^ 1 0 4 . 1 4
^^^^^^^^H
T 230
=. 2o0 .,= 24':'
3 ->-)(, 4* ^'- •
I 20r.
••«' ISO
"' lo('
I'' 140 m \
\ \ • 1
\
\ ,
\ 1
\
• \ ,
1 1
—-I
^
•(%) Mod
•{%) Mbd
I Nliip L (in) 4 5 0 7
Hinh 3. Do thj ty le tang kha nang chiu momen can van
va giim bdt trpng lupng sUdn, chpn thep sudn cd dng suit chiy f = 450Mpa v i t^=7,5mm eho dam Idn nhi't 45090HFB38 v i f^= 450Mpa;
t^= 6mm cho eie d i m cdn lai.
3.5. Kiem tra sUdn theo AS/
NSZ4600
Theo dieu kien ben: N*< (b N
~ c s
N^: Khi ning chju nen danh nghia ve ben N = f A,.(A,: Dien
- * s ys s l ^ sl •
tich sudn chju nen)
Theo dieu kien dn dinh: N'< 6 N
" c c
N^: Khi nang chju lpc danh nghia eua sUdn ve dn dinh. N = fnsA,.
cs s2
A^^: Dien tich sUdn v i mdt phan b i n bung quy Udc tinh theo AS
f^^: Qng suit tdi han cua sudn Tai gdi tpa d i u d i m : N = min
(Ns,;N„).
Tai gdi tpa gida dam: N^=min (Ns2;Nc2)- Thay ddi fy^=(250^600)Mpa, d i m Idn nhi't 4090HFB38 cd (N,) giim it; cic d i m cdn lai neu ed (N^) tang khi (f ) tang. Cie dam ed (N^) it chenh lech ehdng td k h i ning chju phin luc khdng phu thudc nhieu vaosd hieu dam.
4. Danh gia hieu qua cua dam hfb CO sUdn tang cUdrng
Nhu d i trinh b i y d mue 1 v i 2; sudn t i n g eUdng dUpc thie't ke nham tang k h i ning dn djnh tdng the oan van v i k h i ning dn djnh cue bd do lUe eat hoac do phin lpc gdi tpa.Tuy nhien, viec eau tao sudn
ed the phit sinh ehi phi vat lieu v i edng ehe tao, do dd tie'p tue nghien edu dinh g i i hieu q u i dam HFB ed sUdn tang eudng.
4.7. Mu'c do tdng khd ndng chiu oan cue bg cua bdn bung khi chiu cdt
Mile dp t i n g phu thudc m i t dp sudn (a/d). Mat dd sUdn (a/d) cang thua, khoing cich sudn (a) cang t i n g , thi ty le t i n g k h i ning chiu oan cpc bd do lpc eat (V^) cang giim. Khi ed sUdn t i n g cUdng, tinh t o i n dupc k h i ning chju oan cue bd do luc cat t i n g len tU (104^142)%
(xem Bing 10).
4.2. Mute do tdng khd ndng chiu oan cue bg ep dap cCia bdn bung do phdn lUc goi
Khi ed sUdn (cd f = 250 Mpa), de tai d i tinh t o i n dupe k h i nang chju ep d i p danh nghTa tai gdi tpa d i u t i n g (222-:-656)% v i gdi tpa gida ting(19U536)%.
4.3. Mifc do tdng khd ndng chiu oan van
Khi sd dung sUdn vdi cic thdng sd d i chpn eho d i m 25090HFB28 trong pham vi L=(l-^12)m, tinh t o i n dupc ty le tang k h i nang chju mdmen danh nghia oan van (M^^^)
=(112,19^121,04) % so vdi d i m HFB khdng sUdn. Tren Tren do thj Hinh 3 nhin thiy: Nhjp (L) cang Idn, mdmen tdi han d i n hdi (M^^^) cang giim tuy nhien [MJ giim it hon.
Oudng do thj ty le tang (M^^) nam tren do thj (M^^^) ehdng td mdc dp tang (M^^) Idn hon (MJ.
4.4. Mite do tdng momen thiet ke Trong pham vi nhjp L=(l-=-12)m, tinh t o i n dUpc dam 25090HFB28 ed sudn ed mdmen thiet ke [M^]
t i n g t d (112,19^121,04)% so vdi d i m khdng sUdn. Nhd ed sudn tang eudng, vdi eung nhip va tai trpng, ta cd the sd dung sd hieu dam nhd hon do dd tiet kiem thep hon so vdi d i m khdng sUdn.
5. Kit luan
1. Anh hudng cua sp oan van den k h i ning chiu t i i cua d i m HFB la r i t Idn. SUchenh lech k h i Idn gida mdmen tdi han dan hdi oan van va oan udn xoan (M ^<<M ) se dan den
od o
B i B n i i a i ,11.2009 69
THONG TIN TIEU
C H U A Nling phi vi khdng t i n dung het k h i nang lim viee eua tiet dien. Do dd, thie't ke sudn ting cUdng dn djnh cho dam HFB la r i t c i n thie't de ting khi nang dn djnh oan van va sdc chju tii eho dam.
2. Kien nghi giii p h i p sUdn ting eUdng dn dinh eho dam HFB vdi eic thdng sd da dupe tinh toan hpp ly nhU sau: Sudn dang b i n ; bd tri d hai phia bung d i m ; han vdi cinh v i bung;
khoing cich sudn 33em va 50em; be day sUdn t^=7,5mm,cudng dp thep sUdn f ^=450Mpa ddi vdi dim 45090HFB38 va t^=4,5mm,eUdng dp thep sudn f =250Mpa ddi vdi eae dim cdn lai. Nhd dd dem lai hieu qui dang ke khdng ehi lam tang khi nang dn dinh tdng the oan van ma cdn lam tang khi nang dn djnh cue bp do lpc eat hoac do phan lpc gdi tpa cda dam HFB.
3. Khi ciu tao sUdn gia cUdng, mdmen tdi han din hdi oan van (M^^) va mdmen udn thiet ke (M^") tang len ding ke; do do khi ning chju tai trpng v i dn djnh tdng the eua dam HFB dupe tang len. Khi dung sUdn cho phep sd dung sd hieu dam nhd hon so vdi dam khdng sUdn nen tiet kiem thep hon. Tuy cd tang them edng ehe tao va tdn vit lieu sUdn va lien ket song giii phip eau tao sUdn theo cic dieu kien dn djnh tdng the va cue bd ddng thdi dim bio dn djnh eua ban thin sudn la sU cai tie'n cin thie't de ning cao
hieu qua dng dung dam HFB. •
^
TAI UEU THAM KHAO
1. Huynh IVlinh Son, Pham Van Hpi - Nghien ciiu ap dung dam thep canh rong HFB theo cong nghe Uc - Ky yeu Hoi thao khoa hpc Quoc gia "Ket cau thep trong Xay di/ng"-Ha Npi 12/2004.
2. Huynh IVlinh San - Tinh toan dam thep canh rong djnh hinh theo cong nghe Uc - Tap chi Khoa hpc va Cong nghe fiai hpc Da Nang so'2(31 )-03/2004.
3. Huynh Minh San - Nghien ctiu sif lam viec va ufng dung dam thep canh rong - Luan van thac sy ky thuat - Dai hpc Xay di/ng - 2005.
4. Doan Dinh Kien - Thiet ke ket cau thep thanh mong tao hinh ngupi-NXB Xay dung-2005.
5. Australian/New/Zealand Standard (1996) Cold- formed Steel Structures, AS/NSZ 4600-1996.
6. Dempsey.R.I - Hollow/ Flange Beam IVIember Design Manual - PalmerTubeTechnologies-1993.
TiEU CHUAN: OAC TRI/N6 NANG LI/0NG CUA CONG TRINH - TINH TOAN SUf DUNG NANG LUGfNG TRONG
K H O N GGIAN LAM MAT"
Tiet kiem va sd dung nang lupng hieu qui la chien lupc cua toan the gidi, vi vay Viet Nam cung dang tich cUc thuc hien chuOng trinh nay nh^m dap dng nhu cau sddung nang lupng ngay mpt cao hon cua nen kinh te qudc dan, ddng thdi bao ve tdt mdl trUdng, khai thic hpp ly cac ngudn tai nguyen nang lupng, thdc hien phit trien kinh te - xa hpi ben vufng. Mat khic, trong nginh Xay dung cung dang thuc hien ddng bd hoa he thdng tieu chuan, quy chua'n theo EuroCode va ISO de dap dng qua trtnh hpi nhap, do do viec chuyen djeh ISO 13790
"Energy Performance of Building - Calculation of energy use for space heating and cooling" la thiet thuc.
Ngay 31/7/2009, Hpi ddng KHCN chuyen nganh Vien da nghiem thu dU thao Tieu chuan vdi mpt sd npi dung chinh sau:
-Thuat ngOva djnh nghTa;
- Ky hieu - Net chinh cua quy trinh tinh toin;
- Xic djnh bien va vung - Nhu eau nang lupng cdng trinh cho sUdi am va lam mat khdng gian;
- Truyen nhiet truyen dan - Truyen nhiet bdi thdng gid - Nhiet toi ben trong - Nhiet toa bdc xa ben trong - Cac thdng sd dpng - Oieu kien ben trong - Sd dung NL cho sUdi am va lam mat.
- Bao cao.
Va cac phu luc kem theo:
-I- Oudng dan tieu chua'n tham chieu;
+ Tinh toan da vung vdi chdng lan nhiet gida cac vung;
+ Phuong trinh day du cua phuong phip theo gid don gian;
-I- Cdng thdc thay the cho phuong phap thay the cho phuong phip theo thing;
+ Truyen nhiet va toa nhiet bdc xa cua cic bd phan dac biet;
-I- Dd lieu khi hau lien quan;
+ Phuong phap don giin va dd lieu dau vao tieu chui'n;
-I- Op chinh xae eua phuong phip;
+ Giii thich v i ngudn gdc cua he sd sd dung theo thing va theo mua;
+ Vi dp thpe hinh; phuong phap theo gid giin dOn v i phuong phap theo thing;
-I-So do quy trinh tinh.
Dp thao TC dugc hoin thanh tren co sd chuyen djeh trung thanh TC gdc vdi mdt sd dieu chinh trong bd tri van bin de phu hpp vdi quy djnh hien hanh. Thuyet minh cua duthao tieu chua'n dap dng yeu cau.
70 S E i n i l f f l l . 11.2009
