Biaxial bending with axial force of reinforced, composite and repaired concrete sections of arbitrary shape by fiber model and computer graphics

A new method is proposed for the study of the failure mechanism of reinforced concrete sections of arbitrary shape in biaxial bending with axial force. The procedure is an alternative fiber model which employs computer graphics as a computational tool for the integration of normal stresses over the section area. In addition to the cases of classic reinforced concrete sections with longitudinal reinforcement steel bars, the method is extended to sections of reinforced concrete structural members repaired by jackets as well as to members with composite steel-concrete sections. Such a computational tool satisfies the needs of nonlinear analysis of reinforced concrete structures as well as the needs of the daily design practice. The method does not include any iterative procedure within its steps and thus it does not have the disadvantage of possible nonconvergence. On the other hand, it is fast and gives accurate results. Four representative numerical applications of the method are presented for the clarification of its validity and advantages.

[1]  Cheng‐Tzu Thomas Wsu.  Biaxially Loaded L‐shaped Reinforced Concrete Columns , 1985 .

[2]  S. F. Chen,et al.  DESIGN OF BIAXIALLY LOADED SHORT COMPOSITE COLUMNS OF ARBITRARY SECTION , 2001 .

[3]  S. Chan,et al.  Biaxial bending design of arbitrarily shaped reinforced concrete column , 1993 .

[4]  Cheng-Tzu Thomas Hsu,et al.  Behavior of Biaxially Loaded Concrete-Encased Composite Columns , 1997 .

[5]  Gregory G. Deierlein,et al.  Nonlinear Analysis of Mixed Steel-Concrete Frames. II: Implementation and Verification , 2001 .

[6]  Y. F. Dafalias.  A Model for Soil Behavior under Monotonic and Cyclic Loading Conditions , 1979 .

[7]  Michael N. Fardis,et al.  Bounding Surface Model for Cyclic Biaxial Bending of RC Sections , 1991 .

[8]  Egor P. Popov,et al.  A model of nonlinearly hardening materials for complex loading , 1975 .

[9]  Cheng-Tzu Thomas Hsu,et al.  Biaxially Loaded Concrete-Encased Composite Columns: Design Equation , 1997 .

[10]  Soliman I. Al‐Noury,et al.  Closure to “Behavior and Design of Reinforced and Composite Concrete Sections” by Soliman I. Al‐Noury and Wai F. Chen (June, 1982) , 1983 .

[11]  Luciano Rosati,et al.  Ultimate strength analysis of reinforced concrete sections subject to axial force and biaxial bending , 1998 .

[12]  Michael N. Fardis,et al.  Monotonic and Cyclic Constitutive Law for Concrete , 1983 .

[13]  L. N. Ramamurthy,et al.  L‐Shaped Column Design for Biaxial Eccentricity , 1983 .

[14]  J. Dario Aristizabal-Ochoa,et al.  Biaxial Interaction Diagrams for Short RC Columns of Any Cross Section , 1999 .

[15]  Stephen Wolfram,et al.  The Mathematica book (4th edition) , 1999 .

[16]  Cheng-Tzu Thomas Hsu,et al.  T-SHAPED REINFORCED CONCRETE MEMBERS UNDER BIAXIAL BENDING AND AXIAL COMPRESSION , 1989 .

[17]  Andreas J. Kappos,et al.  Earthquake-resistant concrete structures , 1996 .

[18]  Michael N. Fardis,et al.  A cyclic multiaxial model for concrete , 1986, Computational Mechanics.

[19]  Stephen Wolfram,et al.  The Mathematica Book , 1996 .