Centriškai gniuždomų spragotųjų strypų pastovumas pagal STR ir EC3

Abstract

Straipsnyje pateikta plieninių spragotinio skerspjūvio kolonų laikomųjų galių, apskaičiuotų vadovaujantis Lietuvoje galiojančių plieninių konstrukcijų projektavimo normų STR 2.05.08:2005 ir Eurokodo 3 nuostatomis, lyginamoji analizė. Skaičiavimai buvo atliekami vienodomis pradinėmis sąlygomis, tik naudoti skirtingi skaičiavimo metodai. Kai kuriais atvejais gautieji rezultatai yra labai prieštaringi ir reikalingi išsamesnės analizės ar eksperimentinių tyrimų.

In the second case – column slenderness makes ly = lz/2. When slenderness is lz ≤ 100, the axially loaded column calculated according to the STR method has similar results compared to the Eurocode 3 method (Fig. 10). The most dangerous according to STR is the stability of the entire column round the z-z axis (Fig. 8), whereas in accordance with Eurocode 3 it appears to be the stability of one chord round the y-y axis (Fig. 9). In such a case, the stability condition of the axially loaded column according to Eurocode 3 has more reserve only when slenderness is lz > 100 (Fig. 10). Therefore, calculation according to Eurocode 3 is less safe if compared to the STR method. The main reason is that Eurocode 3 does not require checking the entire column stability round the z-z axis. Hence, for calculating slender columns according to Eurocode 3, some cases (lz > 100) are not very safe, which was also noticed in the numerical investigations provided by other authors Kalochairetis (2011). In some cases, results are controversial, and therefore it is necessary to perform additional analysis or experimental investigation.