, , N = 50 ; f p = 0,45;
= P × Fy = 10×1,4 = 14 .
(E)
E = , (8)
h = 1,85 - , ;
B0 = 4,12 - , ;
la - ; j = 30, d = 30, la = 0,27.
, Ea = 1,8× ×4,12×0,27 = 3,44 c.
Ep
Ep = P hBla,
= 3 ( , ).
, Ep = 10×1,85×3,0×0,27 = 15 .
(E )
E = , (9)
l - j = 30, d = 30, l = 0,27.
E = 1,8× ×4,125,67 = 72 .
n 1, n 2, n 3 II-.11-62.
,
n 1 + n 2 = 0,9×68,6 + 0,8×10,5 = 70,1 .
.. .
P = (10)
- , .
= 68,6 + 10,5 + 14,0 = 93,1 .
(F ) :
F =
(W )
W =
(l)
,
- ,
(11)
x p - (F), , ; x p = 1,9 . . 46).
= 50×2,08 + 15,0×0,93-14,0×1,9 = 91,4 .;
0,25 D = 1,30 .
l r , .
, , . 0,25 (D) , .
Pmax = /2 < 1,2 R = 1,2×20,0 = 24 /2,
PN = /2 < R = 20 /2.
, Pmax £1,2 R P £ R , .. .
|
|
2