( . 4.5).
. 4.5
(f ) (f )
.
,
|
f |
1,50 1,85 . |
|
|
|
|
|
|
|
f |
|
|
|
4.5 – |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
f /f |
|
|
|
|
|
|
|
|
f |
fy |
|
|
i i |
|
|
0.143 |
0.086 |
1.66 |
|
– |
|
0.151 |
0.053 |
2.85 |
|
– |
|
0.129 |
0.056 |
2.30 |
|
|
|
|
|
|
|
,
:
. …............................................................. 1.18-1.43
. …....................................................... 1.33-1.67
40 15 …................................................... 1.1-1.43
950 0 …................................................... 1.72
1220 0 …............................................... 1.64
,
, ,
, ,
.
,
.
8. .
,
,
, .
.
0,5,
. ,
,
.
« »
,
.
: f =0,1-0,2; f =0,03- 0,15;
,
. 4.8, ,
.
:
|
|
0,1 2 |
|
(4.42) |
f kf 0,07 |
|
|
|
2 |
|
|
2 (1 ) 3 |
|
|
- , ;
kf - , ( . . 4.9).
08
=0,3
.
4.8 –
|
|
f |
f |
|
f |
|
|
|
|
|
|
f |
|
|
|
|
|
1. |
, |
0.143 |
0.086 |
1.66 |
2. |
|
0.130 |
0.053 |
2.85 |
3. |
|
0.129 |
0.036 |
2.30 |
|
|
|
|
|
|
4.9 - ( 4.42)
|
f |
kf |
|
|
|
|
0.086 |
1.55 |
|
0.075 |
1.35 |
|
0.070 |
1.25 |
|
0.058 |
1.0 |
(10% ) |
0.056 |
1,0 |
|
0.053 |
1.0 |
|
0.051 |
0.9 |
|
0.050 |
0.9 |
|
0.048 |
0.9 |
.
,
|
|
k 1 |
|
0,4 |
0,01 Rz |
|
|
0,1 2 |
|
1 |
|
f |
|
|
|
|
|
|
|
0,07 |
|
|
|
(4.42 ) |
|
|
|
|
|
|
|
|
2 |
|
1 0,25 50 0,005 50 |
|
|
|
|
2 (1 ) 3 |
|
|
k – , ;- , %;
Rz – , ;
50 - 50 0 , 2/ .