ix = 0,43×h, iy = 0,24×b (h , b ). ( yy) y y , . 12.
:
x x le f, x = m × lk = 1 × 1080 = 1080 ,
y y le f, y = m × lk / 2 = 1× 1080/2 = 540 .
. 12.
. l = 45.
:
. 72* [3] j = 0,873.
1. :
2. :
i = lef, x / l = 1080/45 = 24 ;
i, y = lef, y / l = 540/45 = 12;
3. [1, . 8.1]: h = i, / a1 = 24/0,43 = 56 ;
4. : b = i, y / a2 = 12/ 0,24 = 50 .
hw = 560 , ( 82-70*), - 500 (. 13).
:
tw= hw /48,5 = 56/48.5 = 1.15 .
tw = 12
: A, = (A 2 × × tw) / 2 = (90.2 2 × 22.8 × 1.2) / 2 = 17.74 2.
. 13.
: tf = A, / bf = 17.74 / 50 = 0,35
(. 7.23*):
:
( 82-70*) 500´18 . h = hw + 2tf = 56 + 2×1,8 = 59.6 .
1. : A = 2 × bf× tf + hw× tw = 2 × 50 × 1,8 + 56 × 1.2 = 247.2 2;
2. : red = 2 × bf × tf + 2 × c× tw = 2 ×50 ×1,8 +2 ×22.8 × 1.2 = 234.72 3. :
x x:
y y:
4. :
5.:
l = lef,x /ix = 1080/26 = 41.5;
ly = lef, y /iy = 540/12.3 = 44
ly = 44 j = 0,875:
3.2.
- , . - . (. 14).
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. 14.
245 Ry= 240 (. 51*[3]).
:
N = 2×Qmax × 1,01 = 2 × 936 × 1,01 = 1890 .
, m = 1.
l = 1080 (. . 3.1).
: lx = ly = m × l = 1 × 1080 = 1080 .