( ) d S ,
, (15.19)
Bn=Bcosa - d S (a - n ), d S =d S n - , d S, n . , cos a ( n).
, . . , , , , .
B S
. (15.20)
-, - , n= = const
.
():
1 - , 1 2, - , 1 (1 =1 ∙2).
: :
. (15.21)
, , .
. , . (, , .15.11), .
, .
l I ( ), , . , , ,
.
- d x 1 2. , ,
, (15.22)
l d x= dS - , , B d S= d- , .
, I , . .
. I . , ', .15.12 . ( ) ( - ) . : ABC CD .
|
|
d A, , ABC (d A 1) CDA (d A 2), . .
dA |
d A= d A 1 + d A 2. (15.23)
, CD , , d A 2>0. (15.22), I CDA . CD d0 , , d2, . ,
d A 2= I (d0+ d2).(14.24)
, ABC , , d A 1<0.
d0 , , d1 . ,
d A 1=- I (d0+ d1).(15.25)
(15.24) (15.25) (15.22), :
d A = I (d2 - d1),
d2- d1= d¢ - , . ,
d A = I d¢. (15.26)
(14.25), , , :
A = I D, (15.27)
.. - , . (15.27) .