, , .
: 1, - , 30...36 .
, ( ) 1,2 3, .
282.
³ 282 1, 2, 3 :
- l1 13,2 ; l2 6,2 ;
- ;
- 10,0 .
- ;
- ;
- ;
- ;
- n=30 ;
- ;
- ;
- 璺 ;
- 27772-88: 275; 275; (, , ) - 255; 15.
³ (.1).
l1 =13200 (.1,).
.1.
; ;
. l2 =6200 . =0,6...1,6 l1 n . l1 =13,2 n =11, = l1 /n=13,2/10=1,32 (. .1,).
璺 .
, 璺 .
.
璺
275 Ry=270 Ryu=275 Ryn=380 (. 51* [1], ). Rs=0,58Ry =0,58×270=156,5 .
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275 Ry=270 Run=275 (. 51* [1], Rs=0,58Ry=0,58×270=156,5 . . 52* [1] Run=346 R=346 .
3.3.
( 8240-89) ( 8239-89) 245.
: , .
. .51*[1] 255 Ry=240 .
. 255, Ry=245 Run=370 (. 51* [1] ), Rp=336 (. 51*[1]) Run=370 .
Rs=0,58Ry=0,58×245=142,1 .
. , 20 .
255 Ry=245 (.51* [1]).
15 R=8,5 .
3.4. 璺
. , 20 4.6.
( ) =13,2 , =30 =30 , n0= =150.
. 63 [1] =2,06×105 n = 0,3 1=/(1-n2)= 2,06×105 / (1-0,32)=2,26×105 .
:
t=16 .
6...14 , 1 . , .
t=0,016 , g=9,81/2, r=7,85 /3.
:
S0=t×g×r=0,016×9,81×7,85=1,232 /2;
:
S= S0 =1,232 . 1=1,232 /2;
=1 .
:
q1=(P + S)×a=(30+1,232)×1,32= 41,226 /.
:
q1=(Pngfp+Sngfs)×a=(30×1,2+1,232×1,05)×1,32= 49,228 /.
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Q, M .2.
:
:
41,226×6,22/8=198,09 ×;
:
49,228×6,22/8=236,54 ×;
Q = q1×l2/2=49,228×6,2/2= 152,607 .
.
. 2 Q, M
:
W0 = M/Ry=23654/27= 876,0 3.
I 40 :
Wx=953 c3, =19062 4, S=545 3, h=40 , bf=15,5 , tf=1,3 , tw=0,83 , =72,7 2.
:
: f = bf×tf = 1,5×1,3 = 20,15 2;
: w = A-2Af = 72,7 - 2×20,15 = 32,4 2.
Af/Aw = 20,15/32,4 = 0,622.
. 66 [1] Af/Aw= 0,622 = 1,102. t = 0, = 1 = 1,1.
:
s = /(1×Wx) = 23654/(1,102×953) = 22,523/2 = 225,23<Rygc = 270;
:
:
t = Q/[tw(h-2tf)] = 152,607/[0,83×(40-2×1,3)] = 4,916/2 = 49,16 <Rsgc = 156,5 ;
( ):
t= 1,5Q/[tw(h-2tf1)] = 1,5×152,607/[0,83×(40 2 × 1,3 - 2)] = 7,79/2 = 77,9 < Rsgc=156,5 ;
1 = 2 , ;
:
.
(. 3,).
6.1.
F, qconst, .
:
F = q1×l2 = 41,22×6,2 = 255,6 ;
:
F = q1×l2 = 49,228×6,2 = 305,21 .
qconst, n=3 / gf=1,05.
(. 3, ):
:
198,57 /;
:
236,68/,
n=10 , (..1,).
Q . 3, .
:
:
198,57×13,22/8=4324,85 ×;
. 3. Q () ().
:
236,68×13,22/8=5154,89×.
:
Q = q× l1 = 236,68×13,2/2 = 1562,1 .
6.2. ϳ
275, : Ry=270 , Rs=156,5 , R=346 .
.
:
W0 = M/(Ry×gc) = 515489/(27×1) = 19092 3.
, I 60 ( 8239-89) Wx=2560 3 < W0=190992 3, (. 3, ).
:
; h=1350 .
|
|
:
tw1=7+3×h=7+3×1,35=11,05 .
:
131,45; hopt=140 .
:
:
tw, min = 1,5×Q/(hw×Rs×gc) = 1,5×1562,1/(133×15,65×1) = 1,13 ,
hw=0,95×h=0,95×140= 133 .
, :
0,722 .
tw=14 .
̳ fu/l=1/400:
120,96 .
h=140 .
:
0 = 0,5×Woh = 0,5·19092·140 = 1336440 4.
hw = 0,95×h = 0,95×140 = 133,5, :
:
f = I0 - Iw = 1336440 - 274474 = 1061966 4.
hf = 0,97·h = 0,97·140 = 135,8 , :
f = 2 ·If /hf2 = 2·1061966/135,82 = 115,85 2.
bf=(1/31/5)·h=(1/31/5)·140= 46,728 .
bf=380 . :
tf = Af/bf = 115,85/38 = 3,05 .
tf = 32 .
: tf/tw = 32/14 = 2,28 < 3,0.
:
52,576 .
6.3.
(. 3, ):
:
= tw·hw3/12 + 2·bf·tf3/12 + 2·bf·tf·hf2/4 = 1,4·133,63/12 +2·38·3,23/12+ 2·38·3,2·136,82/4 = 141638,84,
hw = h-2·tf = 140-2·3,2 = 133,6 ;
hf = h-tf = 140-3,2 = 136,8 .
: Wx = 2·Ix/h = 2·1416238,8/140 = 120231,98 3 > W0 = 19092,8 3.
: 25,48 /2 = 254,8 < Ryγc=270 .
6.4.
(.4). =l1/6=13200/6=2200 =2200 .
:
:
1 = q·c·(l1-c)/2 = 236,68·2,2·(13,2-2,2)/2 = 2863,8 ·;
:
Q1 = q·(0,5·l1-c) = 236,68·(0,5·13,2-2,2) = 1041,39 .
:
:
W1 = M1/(Ry·γc) = 286380/(27·1) = 10606,67 3;
:
1 = 0,5·W1·h = 0,5·10606,67 ·140 = 742466,9 4;
:
Af1=2·(I1 - )/hf2 = 2·(742466,9 1,4.133,63/12)/136,82 = 49,62 2;
:
bf1=Af1/tf=49,62/3,2= 15,51 .
.4. .
, :
bf1>20, bf1>h/10=140/10=14 bf1>0,5·bf=0,5·38=19 , bf1=260 .
. 5.
6.5.
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Q=1515,8 . :
τ = 1,5Q/(tw · hw) = 1,5 · 1562,1 / (1,4·133,6) = 12,53/2 = 125,3 < Rsγc= 156,5 .