, , . , .3.1, :
. (3.1)
dF ( ). , - . 3.
1, y1 2,2 (.3.2). 1 2 b, 1 2 . F 1 1, S x1 S y1. S x2 S y2
:
x 2 = x 1 a, y 2 = y 1 - b (3.2)
:
,
,
(3.3)
, , F . (3.3). b , . , , bF S 1, S 2 2 .
, , . , 1 :
, , , (3.4)
. , , . , . , , .
:
(3.5)
.
x . 4. , dF. , , , .
. , 1 1. 2 2, :
(3.6)
(3.6) (3.2), :
|
|
,
, (3.7)
(3.7), (3.1), :
(3.8)
x (.3.3), S = S y = 0 :
(3.9)
, ( - ) , . (3.9) , ( =0 b= 0). , , 2 F b 2 F , .
. , , 1 III 2, 2 (.3.4), , , II IV , .
, . , v, (J u J v J uv ), a (.3.5). dF , ,v :
(3.10)
u v:
,
,
(3.11)
3.11 (3.10). : ,
,
, (3.5), :
(3.12)
3.12, :
(3.13)
, a .
,
,
ρ (.3.1). ,
, (3.14)
Jp -
. (3.15)
a J u J v , . a, , . J u (3.12) a , : . (3.16)
J uv a , (3.12).
, , , . , . . .
. (3.12) :
,
, ,
(3.16) a.
:
, - . , , , (. .3.6).
|
|
:
Jx = bh 3/12, Jy = hb 3/12,
h, b - .
.
.3.7 . .3.8. y, , . , (.3.9) (.3.10). b, h t :
b / h / t = 100 / 10 / 1.
, .3.9 x,y. :
Jx = bh3/12 (b-2t)(h-2t)3/12 =
= 100 ×103/12 98 × 83/12 = 8.333 4.181 = 4.152 4
Jy = hb3/12 (h-2t)(b-2t)3/12 =
=10 ×1003/128 × 983/12 = 833.333-627.461 = 205.872 4
J xy = 0, ,
.
. , , , (.3.10), U V .
UV :
y = Arc tg (H / L ),
L , - (). y = 30. .
J v :
J u = 4.152 × cos230 - 0 + 205.872 × sin230 =
= 3.114 + 51.468 = 54.582 4
.
J u / Jx = 54.582 / 4.152 = 13,1
, : , :
P V = P Y × os y. = 0,87 P Y.
, J v , , . , .
U (.3.10).