Most of the reinforced concrete systems are monolithic. During construction,
concrete from the bottom of the deepest beam to the top of slab, is placed at
once. Therefore the slab serves as the top flange of the beams. Such a beam is
referred to as T-beam. In a floor system made of T-beams, the compressive
stress is a maximum over the web, dropping between the webs. The
distribution of compressive stress on the flange depends on the relative
dimensions of the cross section, span length, support and loading conditions.
For simplification, the varying distribution of compressive stress can be
replaced by an equivalent uniform distribution. This gives us an effective
flange width, which is smaller than the real flange width. In various codes
there are recommendations for effective flange width formulas. But these
formulas are expressed only in terms of span length or flange and web
thicknesses and ignore the other important variables. In this thesis, three-dimensional finite element analysis has been carried out on
continuous T-beams under different loading conditions to assess the effective
flange width based on displacement criterion. The formulation is based on a
combination of the elementary bending theory and the finite element method,
accommodating partial interaction in between. The beam spacing, beam span
length, total depth of the beam, the web and the flange thicknesses are
considered as independent variables. Depending on the type of loading, the
numerical value of the moment of inertia of the transformed beam crosssection
and hence the effective flange width are calculated. The input data and
the finite element displacement results are then used in a nonlinear regression
analysis and two explicit design formulas for effective flange width have been
derived. Comparisons are made between the proposed formulas and the ACI,
Eurocode, TS-500 and BS-8110 code recommendations.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12612180/index.pdf |
| Date | 01 July 2010 |
| Creators | Kucukarslan, Sertac |
| Contributors | Utku, Mehmet |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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