en Structure-Concrete Structure- Concrete Research Paper Research Paper <p align="left"><i><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2">A comparison between design codes i.e. ACI and AISC-LRFD in evaluation of flexural strength of concrete filled steel tubular</font></font></font></i></p> <p align="left"><i><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2">columns (CFTs) is examined. For this purpose an analytical study on the response of CFTs under axial-flexural loading is carried</font></font></font></i></p> <p align="left"><i><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2">using three-dimensional finite elements with elasto-plastic model for concrete with cracking and crushing capability and elastoplastic</font></font></font></i></p> <p align="left"><i><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2">kinematic hardening model for steel. The accuracy of the model is verified against previous test results. The nonlinear</font></font></font></i></p> <p align="left"><i><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2">modeling of CFT columns shows that the minimum thickness that recommended by ACI and AISC-LRFD to prevent local buckling</font></font></font></i></p> <p align="left"><i><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2">before the steel shell yielding for CFT columns could be decreased. The comparison of analytical results and codes indicates that</font></font></font></i></p> <p align="left"><i><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2">the accuracy of ACI method in estimation of axial-flexural strength of CFT columns is more appropriate than AISC-LRFD. The</font></font></font></i></p> <p align="left"><i><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2">ACI lateral strength of CFTs is located on upper bond of the AISC-LRFD’s provisions. AISC-LRFD estimates the lateral strength</font></font></font></i></p> <p align="left"><i><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2">conservatively but ACI in some ranges such as in short columns or under high axial load levels computes lateral strength in nonconservative</font></font></font></i></p> <p align="left"><i><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2">manner. Supplementary provisions for post local buckling strength of CFT columns should be incorporated in high</font></font></font></i></p> <p><i><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2"><font color="#231f20" face="TimesNewRomanPS-ItalicMT" size="2">seismic region. This effect would be pronounced for column with high aspect ratio and short columns.</font></font></font></i></p> Code, Concrete, Steel, Finite element modeling, Composite member, Confinement 280 290 http://ijce.iust.ac.ir/browse.php?a_code=A-10-283-1&slc_lang=en&sid=1 B. Beheshti-Aval beheshti@kntu.ac.ir 180031947532846009794 180031947532846009794 Yes Associate Professor, Civil Engineering Faculty, K.N.Toosi University of Technology, Tehran, Iran