, . . . . 16 . 16 .
20 . :
α2 = φ1 + φ3 = 14 + 3416 ' = 4816 ',
φ3 = arctg (1,42/2,084) = 3416 ';
k α = 0,72; = 0,848.
20 :
T 1 = 0,5 cdk α = 0,5×15×2,0×0,72 = 10,8 ;
T 2 = 2,5 d 2 = 2,5×22×0,818 = 8,48 .
D 2/2 = 13,92/2 = 6,96 < T 2 = 8,48 .
5 , 70 . .
n = 2/ T = 13,9/1 = 13,9 .
16 , 4 2 .
50 ´ 3 , , :
F = (50 - 1×21)3 = 87 2;
2/(2 F ) = 13,92×103/(2×87) = 80 < Ry γ/γ n = 245×0,9/0,95 = 232 .
A = 82 . 1 2 (1,293 + 0,128)/(1,913 + 0,141) = 0,692, Δ = 82×0,692 = 57 , l /314 < l /300.
. 39.
2. 18 , 3 (. 40).
2- 3- . -III. 150 , . . . -3 . 1 II-25-80.
. 39.
. 40.
) ; )
25
. | , | . | , | ||
-192,7 | +182,45 | ||||
-51,25 | |||||
-127,1 | +53,3 |
h 0 = 2,96 , l /6. 1:3
|
|
α = 1825 '; sin α = 0,3162; cos α = 0,9487.
g 1 = 0,467 /2,
g 1 = g 1/cos α = 0,467/0,948 = 0,49 /2 .
g = (g 1 + P )/[1000/(K l) - 1] = (0,467 + 1,5)/[1000/(4×17,8) - 1] ≈ 0,15 /2.
IV 1 2 P = 1,5 /2; g / P = (0,467 + 0,15)/1,5 = 0,41 1,6.
1 :
q = (g 1 + g + P )3 = (0,49 + 0,15 + 1,5)3 = 6,42 /;
q = [(g 1 + g ) n 1 + P n ]3 = [(0,49 + 0,15)1,1 + 1,5×1,6]3 = 9,31 /.
. 25.
A = B = q l /2 = 9,31×17,8/2 = 82,86 .
b = 15 h = 3 ´ 15 = 45 , , , . , . .
M = q l 2cos2 α/8 = 9,31×5,872×0,94872/8 = 36,1 ×.
F = bh = 150×450 = 6,75×104 2;
W = bh 2/6 = 150×4502/6 = 5,06×106 3;
R = R = R = 15 m /γ n = 15×0,9/0,95 = 14,2 ;
2- . 3- - 10,4 :
λ0 = l 0/ r = 587/(0,289×45) = 45;
λ = μλ0 = 1,18×45 = 53,
= = 1,18 II-25-80, (12);
K = 1,4/(δ b ) = 1,4/(1,2×15) = 0,08;
φ = A /λ2 = 3000/532 = 1,06;
ξ = 1 - N /(φ R F ) = 1 - 192,7×103/(1,06×14,2×6,75×104) = 0,81;
M = M /ξ = 36,1/0,81 = 44,6 ×;
W = WK ω = 5,06×106×0,85 = 4,3×106 3.
(28) II-25-80
N / F + M / W = 192,7×103/6,75×104 + 44,6×106/4,3×106 = 13,4 < R = 14,2 .
3- h = 30 b = 15 .
F = 150×300 = 4,5×104 2;
Mq = q l 2cos2 α/8 = 9,31×3512×0,9482/8 = 12,9 ×;
M = Ne = 127,1×0,0375 = 4,77 ×;
Mx = 8,6 × , , , 1,97 :
F = 150×300 = 4,5×104 2; W = 150×3002/6 = 2,25×106 3;
λ0 = l 0/ r = 351/(0,289×30) = 40,5; λ = μλ0 = 1,17×40,5 = 47,4;
|
|
μ II-25-80, (12)
φ = 3000/47,42 = 1,34;
ξ = 1 - N /(φ R F ) = 1 - 127,1×103/(1,34×10,4×4,5×104) = 0,797;
N / F + Mx /(ξ WK ω) = 127,1×103/4,5×104 + 8,6×106/(0,797×2,25×106×0,85) = 8,46 < R = 10,4 .
, 1/200 l .
12 58 . S = 10δ = 120 . ( II-25-80, . 5.29):
T = 0,75 b = 0,75×15 = 11,25 .
(45)
n = 1,2 MS /(ξ I T) + kN / T = 1,2×36,1×106×4/(0,81×3×450×11,25×103) + 0,2×192,7×103/11,25×103 = 17,2 .,
= 0,4 l / S = 0,4×5870/120 = 19 > 17,2 .
k = 0,2 .
n = 12 . .
-III .
F = N γ n / R = 182,45×103×0,95/375 = 463 2,
25 , F = 491 > 463 2.
. 579 2, 32 640 2.
-III.
545 2, 2 20 628 2.
3- 150 ´ 150 :
l 0 = 382, , rx = ry = 0,289 h = 4,35 ,
λ = l / rx = 382/4,35 = 88, φ = A /λ2 = 3000/882 = 0,386.
:
N = 51,25 ; F = 1502 = 2,25×104 2;
N /(φ F ) = 51,25×103/(2,25×104×0,386) = 5,9 < R = 10,4 .
σ = N / F = 51,25×103/2,25×104 = 2,2 < R α = 6,3 α = 43.
-III , 135 2; 14 154 2. 18 .
(. 41, )
, ,
F = N / R α = 182,45×103/12,6 = 1,45×104 2,
R α - 2- α = 1826 ' m γ n, (2) II-25-80.
150 , h = 1,45×104/150 = 97 ; h = 250 , F = 150×250 = 3,75×104 2.
1 2 :
q = N / F = 182,45×103/3,75×104 = 4,86 /2;
1
M = ql 2/12 = 4,86(150 + 10×2/2)2/12 = 9,74×103 ×;
W = M γ n /(Ry γ) = 9740×0,95/(245×0,95) = 39,8 2.
Ry - 3.
18 , W = 1×182/6 = 54 2 > 39,8 3.
|
|
8 . 10 , 10 .
F = A γ n /(m R α) = 82,85×103×0,95/(0,9×3,2) = 2,74×104 2,
R α - α = 90 - 1816 ' = 7134 '. a = F / b = 2,74×104/150 = 182 , a = 200 .
. 41.
) ; ) ; ) ; 1 - 20 ; 2 - 28 ; 3, 4 - 150 ´ 110 ´ 10; 5 - 125 ´ 80 ´ 10; 6 - ; 7 - 250 ´ 190 ´ 18; 8 - 250 ´ 110 ´ 10; 9 - ; 10, 11 - 16 ; 12 - 70 ´ 150 ´ 930; 13 - 14 ; 14 - 110 ´ 110 ´ 10; 15 - 125 ´ 80 ´ 10; 16 - ; 17 - 36 ; 18 - 16 ; 19 - 310 ´ 100 ´ 18; 20 - 25
(. . 41, )
F = N γ n /(m R α) = 53,3×103×0,95/(0,9×3,2) = 1,76×104 2,
3 140 ´ 140 , 1,94×104 2. 10 .
(. . 41, )
, , 3. 125 ´ 80 ´ 10 , - 310 ´ 100 ´ 18 . , 36 .
6.37. , , 1/6 1/8.
; 1/12 - 1/15 .
, . 1.
6.38. -II-25-80, . 6.25 6.27.
6.39. , , .
:
) , ; (, , );
) .
6.40. , , .
30 .
1/4 l , .
6.41. :
|
|
) (f < 1/3 l);
() ;
, () ;
, () , ( II-6-74, . 5, . 2), ;
) (f ≥ 1/3 l) - () ;
, () II-6-74 ;
.
6.42. - , .
6.43. , ; II-25-80, . 6.25 6.27.
1. .
. 42.
; 1, 5 ´ 5 ; 240 ´ 1344
, l = 60 , f = 11 > l /6 6 , (. 42). III .
1,5 ´ 6 , . .
, 24 , . , .