Elasto-plastic large deformation analysis of PR steel frames for LRFD

Abstract An efficient second-order finite element-based method is presented here considering geometric and material nonlinear behavior of steel frames with nonlinear flexible connections and local plasticity effects. The assumed stress method is used to derive the governing equations which satisfy joint equilibrium and displacement compatibility conditions. An explicit form of the tangent stiffness matrix of the structure is obtained that makes the proposed method extremely efficient in nonlinear analysis. In deriving governing equations for large deformation, each element is characterized as a beam-column which undergoes arbitrary large rigid displacement but small relative displacement. The behavior of flexible connections is represented by an exponential function. In solving the nonlinear equations, the Newton-Raphson method with arc-length control is used in tracing the post-buckling behavior. Several numerical examples are given to demonstrate the robustness, accuracy and efficiency of the proposed method.

[1]  Eric M. Lui,et al.  Effects of connection flexibility and panel zone deformation on the behavior of plane steel frames , 1985 .

[2]  F. W. Williams,et al.  AN APPROACH TO THE NON-LINEAR BEHAVIOUR OF THE MEMBERS OF A RIGID JOINTED PLANE FRAMEWORK WITH FINITE DEFLECTIONS , 1964 .

[3]  U. Hindenlang,et al.  Finite element analysis of two- and three-dimensional elasto-plastic frames—the natural approach☆ , 1982 .

[4]  M. John Frye,et al.  Analysis of Flexibly Connected Steel Frames , 1975 .

[5]  Aris Phillips,et al.  Plastic Analysis of Structures , 1959 .

[6]  M. Crisfield.  An arc‐length method including line searches and accelerations , 1983 .

[7]  Aslam Kassimali.  Large Deformation Analysis of Elasticplastic Frames , 1983 .

[8]  Graham H. Powell,et al.  Theory of Nonlinear Elastic Structures , 1969 .

[9]  S. Atluri,et al.  Large-deformation, elasto-plastic analysis of frames under nonconservative loading, using explicitly derived tangent stiffnesses based on assumed stresses , 1987 .

[10]  K. Bathe,et al.  Large displacement analysis of three‐dimensional beam structures , 1979 .

[11]  Y. Ueda,et al.  The plastic node method: A new method of plastic analysis , 1982 .

[12]  H. Saunders,et al.  Finite element procedures in engineering analysis , 1982 .

[13]  Satya N. Atluri,et al.  A simplified finite element method for large deformation, post‐buckling analyses of large frame structures, using explicitly derived tangent stiffness matrices , 1986 .