- ( ) . - . . - , - , , .
p = ISn | , | (2.2.1) | ||
n | m | |||
− . |
- , .
F 2
F 1 | |||
B | B | ||
pm | F | pm | |
F 4 | |||
. 2.2.1 | |||
1 2 3 4 I, | |||
B (. 2.2.1). F 2 F 4 | (. 2.2.1, ), | ||
2 3 4 1, : | |||
F 2= F 4= IB sin(90 α) = IB cosα. | (2.2.2) |
- . . 2.2.1, , -
. F 1 F 3, - 1 2 3 4, :
F 1= F 3= IBd. | (2.2.3) |
, l.
, , F 1 F 3:
= F 1 l = F 3 l, | (2.2.4) |
l = c sin α . | |
(2.2.3) (2.2.4), : | |
= IdcB sinα. | (2.2.5) |
dc = S IS = m , α pm B, (2.2.5) :
M = pm B sinα. | (2.2.6) |
(2.2.6) : | |
M = pm × B. | (2.2.7) |
(2.2.7) . , , :
B = | M max | = | M max | . | (2.2.8) | |
p | IS | |||||
m |
, m B (. .
= sin 0 = 0).
d α,
δ A = Md α = pm B sin α d α. | (2.2.9) |
|
|
d α -, . -, , - :
δ = − d . | (2.2.10) |
α = π/2, α α π / 2. :
π 2 | π 2 | π 2 | |
= − ∫ δ A = − ∫ Md α = − ∫ | pm B sinα d α= − pm B cosα | ||
α | α | α | (2.2.11) |
= − pm ⋅ B.
(2.2.11) .