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65-ɫɭɪɟɬ

ȿɝɟɪ ɞɟ ɯ1 ɠԥɧɟ ɭ1 ɨɫɶɬɟɪi ɨɪɬɚɥɵԕ ɨɫɶɬɟɪ ɛɨɥɫɚ, ɨɧɞɚ Sx1 0 , Sy1 0.
(5.11)
Ȼԝɥ ɤɟɡɞɟ

J x2 J ɨɪɬ c2 ˜ Ⱥ ,
x1

J y2 J ɨɪɬ a2 ˜ Ⱥ,
y1

J x2y2 J ɨɪɬ a ˜ c ˜ Ⱥ .
x1y1

ɉɨɥɹɪɥɵԕ ɢɧɟɪɰɢɹ ɦɨɦɟɧɬɿɧɿԙ (5.7) ɮɨɪɦɭɥɚɫɵɧ ɬԛɪɥɟɧɞɿɪɟɣɿɤ. Ɉɥ ԛɲɿɧ
65-ɫɭɪɟɬɬɟɧ U 2 x 2 y 2 ɦԥɧɿɧ ɫɨɥ ɮɨɪɦɭɥɚԑɚ ԕɨɹɣɵԕ:

³ ³ ³ ³J U U 2dA (x 2 y 2 )dA x 2dA y 2dA J y J x . (5.12)

AA AA

ɀɨԑɚɪɵɞɚԑɵ (5.11) ɮɨɪɦɭɥɚɥɚɪɵɧ ɬɚɥɞɚɣ ɤɟɥɟ, ɦɵɧɚɞɚɣ ԕɨɪɵɬɵɧɞɵ
ɠɚɫɚɣɦɵɡ: ԕɢɦɚɧɵԙ ɤɟɡ ɤɟɥɝɟɧ ɨɫɶɬɟɪiɧɞɟɝi ɢɧɟɪɰɢɹ ɦɨɦɟɧɬɬɟɪi, ɨɧɵԙ
ɨɪɬɚɥɵԕ ɨɫɶɬɟɪiɧɞɟɝi ɢɧɟɪɰɢɹ ɦɨɦɟɧɬɬɟɪiɧɟɧ ɤԧɩ ɛɨɥɚɞɵ.
1-ɟɫɟɩ. Ȼɢiɤɬiɝi h ɤԧɥɞɟɧɟԙi ɜ ɬiɤɬԧɪɬɛԝɪɵɲɬɵԙ ԕɚɛɵɪԑɚɥɚɪɵɧɚ ɩɚɪɚɥɥɟɥɶ
ɨɪɬɚɥɵԕ ɨɫɶɬɟɪiɧɞɟɝi (ɯ1, ɭ1) ɠԥɧɟ ԕɚɛɵɪԑɚɥɚɪɵ ɚɪԕɵɥɵ ԧɬɟɬiɧ ɨɫɶɬɟɪɞɟɝi (ɯ2,
ɭ2) ɢɧɟɪɰɢɹ ɦɨɦɟɧɬɬɟɪiɧ ɬɚɛɭ ɤɟɪɟɤ ɛɨɥɫɵɧ. Ɉɥ ԛɲɿɧ ɯ1 ɨɪɬɚɥɵԕ ɨɫiɧɟɧ ɭ
ԕɚɲɵԕɬɵԕɬɚ, ԕɚɥɵԙɞɵԑɵ dy ɷɥɟɦɟɧɬɚɪ ɬiɥiɦ ɛԧɥiɩ ɚɥɚɦɵɡ (66-ɫɭɪɟɬ).

66-ɫɭɪɟɬ
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