Probabilistic assessment of calculation resistance models of composite section with partial shear interaction

Abstract

Istraživani su spregnuti nosači u zgradarstvu s djelomičnom posmičnom vezom. Postupak određivanja točne otpornosti presjeka na savijanje takvih spregnutih nosača iterativan je i dugotrajan. Analizirana su četiri različita proračunska modela otpornosti, različitih autora, koji omogućuju neiterativno određivanje otpornosti ovakvih nosača. Laboratorijski utvrđena otpornost poprečnog presjeka na savijanje uspoređena je s otpornostima dobivenim korištenjem različitih modela, nakon čega su računski modeli probabilistički evaluirani. Rezultat ovakve analize je najpouzdaniji neiterativni proračunski model za određivanje otpornosti na savijanje poprečnih presjeka s djelomičnom posmičnom vezom Nadalje, predlaže se novi proračunski model otpornosti. Predloženi model se temelji na linearnom modelu koji se zatim prilagođava najpouzdanijem neiterativnom proračunskom modelu otpornosti. Koeficijent korekcije određuje se na determinističkoj razini, nakon koje se provodi probabilistička analiza novog modela. Rezultat istraživanja je vrlo jednostavan neiterativni model koji daje razinu pouzdanosti u skladu s ciljanom vrijednosti indeksa pouzdanosti.Composite beams in buildings with partial shear connection have been researched. The procedure of determining the exact resistance of such composite beams in bending with partial shear interaction is iterative and tedious. Four different calculation resistance models of various authors for non-iterative determination of such cross-section resistance have been analysed. Bending resistance of cross-section obtained from laboratory tests is compared with the resistance calculated from different models after which the calculation models are probabilistically evaluated. The result is the most certain non-iterative calculation resistance model of cross-section in bending for a beam with partial shear interaction. Furthermore, a new resistance model is proposed. The proposed model is based on a linear model which is then modified according to the most favourable non-iterative calculation resistance model. Correction coefficient is obtained on a deterministic level, after which probabilistic evaluation of the new model is conducted. The result is a very simple non-iterative model with the reliability levels close to the target value of the reliability index