Page 576 - index

1-ɦɵɫɚɥ. Ɋ=40 ɬ ɤԛɲɿɦɟɧ ɠԛɤɬɟɥɝɟɧ 131-ɫɭɪɟɬɬɟ ɤԧɪɫɟɬɿɥɝɟɧ ɫɵɪɵԕ

ԕɨɫɬɚɜɪɞɚɧ ɠɚɫɚɥԑɚɧ. Ɇɚɬɟɪɢɚɥɞɵԙ ɦԛɦɤɿɧ ɤɟɪɧɟɭɿ >V @ 1600ɤɝ / ɦ2 .

Ԕɨɫɬɚɜɪɞɵԙ ɧԧɦɟɪɿɧ ɬɚԙɞɚɩ ɚɥɭ ɤɟɪɟɤ.

131-ɫɭɪɟɬ

(10.32) ɮɨɪɦɭɥɚɞɚɧ Ⱥɧɟɬ P 40000ɤɝ 25 ɫɦ2 . Ʉɟɫɬɟɞɟɧ ԕɨɫɬɚɜɪɞɵԙ

>V @ 1000ɤɝ ɫɦ2

ɧԧɦɟɪɿɧ ɚɧɵԕɬɚɣɦɵɡ.
Ɇɟɦɥɟɤɟɬɬɿɤ ɫɬɚɧɞɚɪɬ ɛɨɣɵɧɲɚ, ɟԙ ɵԙԑɚɣɥɵ ԕɨɫɬɚɜɪ ʋ18ɚ, ɚɭɞɚɧɵ
Ⱥ=25,4ɫɦ2, ɿ= 2,12ɫɦ. ȿɧɞɿ (10.42) ɮɨɪɦɭɥɚɦɟɧ ɨɪɧɵԕɬɵɥɵԕԕɚ ɟɫɟɩɬɟɣɦɿɡ.

Ɉɥ ԛɲɿɧ ɦɚɣɵɫԕɵɲɬɵԕɬɵ O ɬɚɛɚɦɵɡ, ɹԑɧɢ O P˜" 2 ˜ 200 | 187 .
i 2,12

Ⱥɧɵԕɬɚɦɚɥɚɪɞɚ ɤɟɥɬɿɪɿɥɝɟɧ M f O ɤɟɫɬɟɫɿɧɟɧ ɢɧɬɟɪɩɨɥɹɰɢɹ ɚɪԕɵɥɵ ij

ɲɚɦɚɫɵɧ ɚɧɵԕɬɚɣɦɵɡ:

M 0,216 Ÿ V 40000 7290 !! 1600.
0,216˜ 25,4

Ȼԝɞɚɧ ɤɟɥɟɫɿɞɟɣ ԕɨɪɵɬɵɧɞɵ ɠɚɫɚɣɦɵɡ. ȿɝɟɪ ʋ18 ԕɨɫɬɚɜɪɞɚɧ ɠɚɫɚɥԑɚɧ
ɫɵɪɵԕ ɨɪɧɵԕɬɵɥɵԑɵɧ ɠɨԑɚɥɬɩɚɫɚ, ɨɧɞɚ ɛɟɪɿɥɝɟɧ ɠԛɤɬɿ ɤԧɬɟɪɿɩ ɬԝɪɚ ɚɥɚɪ
ɟɞɿ. Ȼɿɪɚԕ ɫɨԙԑɵ ɟɫɟɩɬɟɭɞɿԙ ɤԧɪɫɟɬɭɿɧɟ ԕɚɪɚԑɚɧɞɚ, ɦԝɧɞɚɣ ɫɵɪɵԕ

ɨɪɧɵԕɬɵɥɵԑɵɧ ɠɨԑɚɥɬɵɩ ɚɥɚɞɵ, ԧɣɬɤɟɧɿ: V !! >V @.

ɀɨԑɚɪɵɞɚ ɤɟɥɬɿɪɿɥɝɟɧ (10.33) ɮɨɪɦɭɥɚɞɚ ɟɤɿ ɛɟɥɝɿɫɿɡ (ij, Ⱥ) ɛɨɥԑɚɧɞɵԕɬɚɧ

ij ɲɚɦɚɫɵɧ ԧɡɿɦɿɡ ɬɚԑɚɣɵɧɞɚɣɦɵɡ (ɤԧɡ ɦԧɥɲɟɪɦɟɧ). Ɇɵɫɚɥɵ, M1 =0,5
ɛɨɥɫɵɧ, ɨɧɞɚ:

Ⱥ P 40000 50 cɦ2 .
0,5 ˜1600
M ˜>V @

Ɇԝɧɞɚɣ ɚɭɞɚɧɵ ɛɚɪ ԕɨɫɬɚɜɪ ɠɨԕ, ɟԙ ɠɚԕɵɧ ɲɚɦɚɫɵ ɛɚɪ ԕɨɫɬɚɜɪɞɵԙ
ɧԧɦɿɪɿ 30ɚ.

Ɉɥ ԛɲɿɧ Ⱥ1=49,9cɦ2, i 2,95 .

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