Analiza ponašanja aksijalno pritisnutih spregnutih štapova pri ekspolatacionom i graničnom opterećenju

Abstract

Predmet istraživanja u ovom radu je eksperimentalno – teorijsko modelska analiza ponašanja centrično pritisnutih stubova spregnutog preseka. Modeli su formirani od AB stubova kvadratnog poprečnog preseka ojačanih na tri načina. U prvom slučaju upotrebljene su čelične cevi. AB stubovi su postavljeni unutar cevi dok je međuprostor popunjavan etonskim mešavinama tri različita kvaliteta. Druga metoda ojačavanja obuhvatala je izradu omotača od betona i čeličnih ugaonika međusobno mestimično spojenih veznim limovima čime je formiran "kavez" oko AB stuba. Razmak veznih limova variran je u dva slučaja. Treća metoda ojačavanja obuhvatala je pritezanje poprečno postavljenih visokovrednih zavrtnjeva. Variran je broj zavrtnjeva, odnosno njihov međusobni razmak. Numerička analiza ponašanja stubova izvršena je MKE metodom. Izvršeno je poređenje rezultata računskog modela i rezultata eksperimentalnog ispitivanja i dat je predlog za proračun nosivosti preseka/modela za sve analizirane uzorke.

The topic of research in this dissertation is experimental-theoretical model analysis of behavior of axially compressed composite section columns. Models are formed from RC squared cross section columns strengthened in three ways. In first case steel pipes were used. RC columns were placed inside the pipe while free space was filled with three different quality concrete. Second method of strengthening included making of concrete jacket and using steel angles connected to each other by connecting plates forming steel cage around RC column. Space between connecting plates were varied in two cases. Third method of strengthening included tightening of the cross placed prestressed bolts. Number of bolts and their spaces were varied. Numerical analysis of the behavior of columns was carried by FEM method. Comparison of the numerical and experimental results was conducted and numerical model for calculating cross section/member capacity was proposed for all analyzed specimens.