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6




(, .) 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

() .. I2t . , 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. ?

 





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