(, .) t ( ) . . θ θ . . . , , , θ θ (. 6.1). θ θ . .
.6.1
t . . . . ., . . . . , I..:
I2. = I2t + I2at (6.1)
Iat - , It .
, t t, . :
i2t Rnp t = C m θ (6.2)
Rnp , , m .
, .. , :
i2t ρ (1+ αθ) dt = s lγco (1+ β θ)d θ (6.3)
it ..
ρ (1+ αθ) - θ,
co (1+ β θ) - θ, . / .
ρ co 0
α β ρ c
s l , 3; γ . , /3
, :
dt = d θ (6.4)
= γ
t θ θ , :
d θ (6.5)
it , (). .6.2. .∞
.6.2 .
.6.2 , .. t .. t, ..
|
|
. = dt
() .. I2∞ t . , ODEF. t t .. t =f (λ) (.6.3), λ = I / I∞. :
t (6.6)
.6.3
, .. it 6.6:
t.. (6.7)
t.. , .. , .. t.
.. : it =√2 Io -t/Ta (6.8)
Io ( 5.9) .. 0. :
t. = λ2, (6.9)
λ = Io/
t = t + t.
6.5 θ. , θ =0. . .. θ. :
θ = θ + (θ - θ) I2 / I2 (6.10)
θ
θ
I
I
θ . θ ( +40). ( 6.4) . t = + t. θ . θ θ. .
.6.4 .
, ( ), θ , , . , θ .
( ) θ . , θ = 300.
, , , , .
( ..)
|
|
I 2 ¥ t < (I 2 t) .,
I ¥ - ..; t ..;
(I 2 t) . ( ).
,,
i F, (.6.5). W , F .
dW = Fdx (6.11)
- .
6.11 .
. 6.5 .
W L i :
(6.12)
F = (6.13)
L1 L2 i 1 i2 W :
W = L1 i21 + L2 i22 + i1 i2 (6.14)
, (L1= const; L2= const) :
F = i1 i2 (6.15)
() , , .
= 2 l (ln - 1)10-7 (6.16)
dM /dx = dM/da = (2l / a) 10-7 (6.17)
F = (2i1i2 l / a) 10-7 (6.18)
.
, , . . , , .. σ. ≤ σ
σ. :
) ;
) ;
) ;
) .
:
σ. = (1.06 i 2 L2/ a h2 b) * 10 -10, (6.19.)
,
σ. = (1.33 i 2 L2/ a h2 b) * 10 -10, (6.20)
.6.6 .
:.
σ. = (1.06 i 2 L2/ a h b2) * 10 -10, (6.21)
, ,
σ. = (1.33 i 2 L2/ a h b2) * 10 -10, (6.22)
i - ;
- , , = 6...7
L - , , L = 60 ;
h- , ;
- , ;
- , , .6.7
. 6.6
. 6.7 .
.. . () .
. :
i . . < i . .;
:
It . < It ,
i . . .. , ; i . . .. ; It .. ( ); It , - .
|
|
.
1. , ?
2. , ?
3. ?
4. ?
5. ?
6. ?