Проверка местной устойчивости стенкив зоне развития пластических деформаций

В соответствии с п. 7.5 [1] необходимо проверить устойчивость стенки в зоне развития пластических деформаций. Должно выполняться условие:

где коэффициент a определяется по формуле:

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.

27

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,

4

20600

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24

2

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,

1

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150

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×

=

×

=

Условие не выполняется.

Увеличиваем размеры пояса в середине пролета до b_f × t_f = 380×2,8 мм. Тогда:

Проверяем местную устойчивость сжатого пояса при его ширине 380 мм:

.

Условие выполняется. Оставляем сечение пояса в середине пролета b_f × t_f= 380×28 мм.