Practical nonlinear analysis of steel–concrete composite frames using fiber–hinge method

A fiber–hinge beam–column element considering geometric and material nonlinearities is proposed for modeling steel–concrete composite structures. The second-order effects are taken into account in deriving the formulation of the element by the use of the stability functions. To simulate the inelastic behavior based on the concentrated plasticity approximation, the proposed element is divided into two end fiber–hinge segments and an interior elastic segment. The static condensation method is applied so that the element comprising of three segments is treated as one general element with twelve degrees of freedom. The mid-length cross-section of the end fiber segment is divided into many fibers of which the uniaxial material stress–strain relationship is monitored during analysis process. The proposed procedure is verified for accuracy and efficiency through comparisons to the results obtained by the ABAQUS structural analysis program and established results available from the literature and tests through a variety of numerical examples. The proposed procedure proves to be a reliable and efficient tool for daily use in engineering design of steel and steel–concrete composite structures.

► A fiber–hinge method is proposed for geometric and material nonlinear analysis of steel–concrete composite structures.
► The second-order effects are considered by using the stability functions and the material nonlinearity is simulated by the proposed fiber–hinge method.
► The proposed procedure proves to be a reliable and efficient tool for daily use in engineering design of steel and steel–concrete composite structures.