Analiza potrebne togosti prečnih ojačitev pri polnostenskih nosilcih : diplomska naloga

Stenko, Rok (author), Korelc, Jože (mentor), Sinur, Franc (co-mentor)

V diplomski nalogi smo obravnavali obnašanje polnostenskih nosilcev. Polnostenski nosilci so sestavljeni iz kompaktnih pasnic in vitke stojine, ki je običajno ojačena z vzdolžnimi in prečnimi ojačitvami. Osredotočili smo se na iskanje potrebne togosti prečne ojačitve, ki mora nuditi ustrezno podporo pločevini. V prvem delu diplomske naloge so predstavljena pravila za dimenzioniranje polnostenskih nosilcev, ki jih navaja standard EN-1993-1-5, v nadaljevanju pa sledijo rezultati numeričnih simulacij, ki so bili izvedeni v programu Abaqus, s katerimi smo želeli pokazati primernost izrazov za določitev togosti. V primeru vzdolžno ojačene in neojačene pločevine v čistem tlaku, smo za izračun potrebne togosti izhajali iz izrazov, ki jih predlaga standard EN-1993-1-5. Izkazalo se je, da pogoj pomika ni vedno izpolnjen, zato smo predlagali nov način določitve ustrezne togosti prečne ojačitve, s katerim smo dobili zadovoljive rezultate. Pri vzdolžno ojačeni pločevini v čistem strigu smo za izračun prečne ojačitve uporabili enačbe, ki so bile razvite za neojačene pločevine v čistem strigu. Te enačbe so se izkazale kot ustrezne tudi za primer ojačene pločevine.

• Language: Slovenian
• Keywords: gradbeništvo, diplomska naloga, UNI, jeklene konstrukcije, polnostenski nosilci, izbočenje pločevin, vitke pločevine, nepopolnosti, togost, vzdolžne ojačitve, čisti tlak, strig
• Work type: Undergraduate thesis
• Typology: 2.11 - Undergraduate Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [R. Stenko]
• Year: 2014
• Number of pages: XVI, 97 str.
• PID: 20.500.12556/RUL-32264
• UDC: 624.072.2(043.2)
• COBISS.SI-ID: 6664033
• Publication date in RUL: 10.07.2015

Secondary language

• Language: English
• Title: Stiffness requirements for transverse stiffeners in plate girders

Abstract

This thesis deals with the behavior of plated girders, composed of compact flanges and slender webs, which are usually stiffened with longitudinal and transversal stiffeners. The main goal was to analyze transversal stiffeners, which have to provide a rigid support for the base plate. The first part of the thesis overviews the design rules for plate girders, which are included in the standard EN 1993-1-5. Numerical results from the finite element analysis are shown in the second part. Numerical simulations were performed to confirm or disprove the existing equation for the evaluation of stiffness. For longitudinally stiffened and unstiffened plates in compression the expressions from standard EN-1993-1-5 were used. It was shown, that the deflection criterion is not satisfied in all cases. A new design rule, which ensure the proper stiffness of the transversal stiffeners, was suggested. For longitudinally stiffened plates in shear solutions developed for unstiffened plates in shear were used. These equations yield a good approximation.

• Keywords: steel structures, plate girders, plate buckling, slender plates, type of imperfection, stiffness, longitudinal stiffeners, transverse stiffeners, direct stresses, shear