: |
: 1) : U = 10 []. 10 I = 1,24 ; 2) = 60 [ ]; 3) b x b = 60x60 L = 2 , L 0 = 0,7 . , , . b x h = 40 4 , ; 3) ( 100 ; 3); 4) , R = 0,8 . , . 10 1 . 500 R = 0,5 . R R , : 1/ R = (1 / R ) - (1/ R ). : 1/ R = (1 / 0,5)- (1/ 0,8); , :: R == 1,33 . r r : r = r × k ; r = r × k ; r = 100 [×] - (f); k × k - . 3 k = 2 0,8 k = 1,4 23 0,50,8 . : - : r = r × k = 100 × 2 = 200 [ × ]; - : r = r × k = 100 × 1,4 = 140 [ × ].
. 11.7. .
L0 >0,5 L
L > d
d
11.7 -
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d = d = 0,95 × b.
b - .
b =0,06 [ ]:
d = 0,95 × b = 0,95 × 0,06 = 0,057 [ ],
:
. [ ]
. . = 4 [ ] L = 2 [ ]: ( / L) = (4 / 2) = 2.
, : k = 0,66 ( 60 ( / L) = (4 / 2) = 2). n :
n = [ R / (k × R )];
R - [ ].
n :
n = [ R / (k × R )] = [ 50,5 / (0,66 × 1,33)] = 57,5;
; - , n = 58.
, , b x h = 40 x 4 , . : k = 0,28 ( 60 ( / L) = (4 / 2) = 2.
:
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11.8.
L L |
H
11.8 -
D = 4 . 60, , , L = 58 × 4 = 232 .
L = 232 .:
.
:
. [ ]
k = 0,58, 60 ( / L) = (4 / 2) = 2:
n = [ R / (k × R )] = [ 50,5 / (0,58 × 1,64)] = 53,1;
58 , .
, , ; U U j 3. j 3. , , , , , , . .
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, 0,8 1, 0 0,8 1, 0 , 6 . , , (58 54).
b x h = 40 x 4 . S [ 2 ] :
,
I = 1,24 [ ] - ;
t = 1,25 [ ] - ;
= 74 , .
::
. [ 2 ]
S = b x h = 40 x 4 = 160 [ 2 ] > 18,7 [ 2 ] .
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