Ïðîâåðêà óñòîé÷èâîñòè ýëåìåíòîâ ñòàëüíûõ êîíñòðóêöèé ïî Eurocode 3
Ïðîâåðêè óñòîé÷èâîñòè ýëåìåíòîâ ñòàëüíûõ êîíñòðóêöèé ïî Eurocode 3 âûïîëíÿþòñÿ ñîãëàñíî ðàçäåëó 6.3 EN 1993-1-1:2005/AC:2009.
Êðèâûå ïîòåðè óñòîé÷èâîñòè äëÿ ñæàòûõ ýëåìåíòîâ ïîñòîÿííîãî ïîïåðå÷íîãî ñå÷åíèÿ ïðèíèìàþòñÿ ñîãëàñíî òàáë. 6.2.
Çíà÷åíèå ãèáêîñòè äëÿ ïðîâåðêè èçãèáíî-êðóòèëüíîé ôîðìû ïîòåðè óñòîé÷èâîñòè ñæàòîãî ýëåìåíòà îïðåäåëÿåòñÿ ñîãëàñíî ïîäðàçäåëó 6.3.1.4.
Êîýôôèöèåíòû âçàèìîäåéñòâèÿ â ôîðìóëàõ, îïèñûâàþùèõ ñîâìåñòíîå äåéñòâèå èçãèáà è îñåâîãî ñæàòèÿ, íàõîäÿòñÿ ñîãëàñíî ïðèëîæåíèÿ B.
Êðèâàÿ ïîòåðè óñòîé÷èâîñòè ïðè ïëîñêîé ôîðìå èçãèáà îïðåäåëÿåòñÿ â îáùåì ñëó÷àå â ñîîòâåòñòâèè ñ ðàçäåëîì 6.3.2.3.
Êîýôôèöèåíòû Ñ1, Ñ3, ó÷èòûâàþùèå óñëîâèÿ çàêðåïëåíèÿ, è êîýôôèöèåíò Ñ2, ó÷èòûâàþùèé íàëè÷èå è âèä âíåøíåé íàãðóçêè íà ýëåìåíò, ïðè íàõîæäåíèè êðèòè÷åñêîãî ìîìåíòà ïîòåðè óñòîé÷èâîñòè ïî èçãèáíî-êðóòèëüíîé ôîðìå (ïîòåðÿ ïëîñêîé ôîðìû èçãèáà) ýëåìåíòà ìîíîñèììåòðè÷íîãî ñå÷åíèÿ, èçãèáàåìîãî â ïëîñêîñòè ñèììåòðèè Mcr, îïðåäåëÿþòñÿ èç òàáë. B1 è B2 Design Manual For Structural Stainless Steel – Third Edition, 18 April 2006, Euro Inox and The Steel Construction Institute è òàáë. 4.2 NCCI: Mono-symmetrical uniform members under bending and axial compression SN030a-EN-EU.
Äëÿ îïðåäåëåíèÿ óñëîâíîé ãèáêîñòè ïðè èçãèáíî-êðóòèëüíîé ôîðìå ïîòåðè óñòîé÷èâîñòè âû÷èñëÿåòñÿ óïðóãèé êðèòè÷åñêèé ìîìåíò îáùåé ïîòåðè óñòîé÷èâîñòè Mcr. Ïîñêîëüêó Eurocode 3 íå ïðåäîñòàâëÿåò íèêàêèõ ôîðìóë èëè ïðàâèë ïî ðàñ÷åòó Mcr, óïîìèíàÿ òîëüêî ÷òî ðàñ÷åò äîëæåí áàçèðîâàòüñÿ íà õàðàêòåðèñòèêàõ ïîïåðå÷íîãî ñå÷åíèÿ áðóòòî è ó÷èòûâàòü óñëîâèÿ çàãðóæåíèÿ, ðàñïðåäåëåíèå ìîìåíòà è áîêîâîå ðàñêðåïëåíèå ï. 6.3.2.2 (2), òî îïðåäåëåíèå êðèòè÷åñêîãî ìîìåíòà îñíîâûâàåòñÿ íà ñëåäóþùèõ èñòî÷íèêàõ NMono-symmetrical uniform members under bendiCCI: Elastic critical moment for lateral torsional buckling SN003a-EN-EU è NCCI: Mono-symmetrical uniform members under bending and axial compression SN030a-EN-EU, Design Manual For Structural Stainless Steel – Third Edition, 18 April 2006, Euro Inox and The Steel Construction Institute.