Stability of cold-formed members

A finite element method capable of predicting the buckling capacity of arbitrarily shaped thin-walled structural members under any general load and boundary conditions is presented. A rectangular thin plate element with 30 degrees of freedom is used. The linear and geometric stiffness matrices for this element are derived explicitly using symbolic manipulation, thereby eliminating the need for the expensive process of numerical integration. Further, the explicit form of the stiffness matrices makes it easier to interpret the physical significance of the various stiffness terms. For sections composed of rigid flanges and flexible web, a lower-order plate element is used in combination with a general beam-column element to form a super element for predicting distortional buckling modes. Formex formulation is used for the automatic generation of the data necessary for the analysis. Numerical examples of thin-walled structural members involving local, distortional and flexural-torsional buckling modes are presented to demonstrate the accuracy, efficiency and versatility of the method.

[1]  L. K. Seah,et al.  Lateral-torsional buckling of channel beams , 1990 .

[2]  Kenneth M. Will,et al.  Beam Buckling by Finite Element Procedure , 1974 .

[3]  M. N. Akhtar,et al.  Interactive and local buckling of thin-walled members , 1991 .

[4]  Mahen Mahendran,et al.  Elastic buckling analysis of ideal thin-walled structures under combined loading using a finite strip method , 1986 .

[5]  Faris Albermani,et al.  Stability of thin-walled members having arbitrary flange shape and flexible web , 1992 .

[6]  Sritawat Kitipornchai,et al.  Geometric nonlinear analysis of asymmetric thin-walled beam-columns , 1987 .

[7]  Faris Albermani,et al.  Nonlinear Analysis of Thin‐Walled Structures Using Least Element/Member , 1990 .

[8]  van Gm Gerard Erp,et al.  The spline finite‐strip method in the buckling analyses of thin‐walled structures , 1990 .

[9]  R. D. Wood,et al.  GEOMETRICALLY NONLINEAR FINITE ELEMENT ANALYSIS OF BEAMS, FRAMES, ARCHES AND AXISYMMETRIC SHELLS , 1977 .

[10]  R. J. Plank,et al.  Buckling under combined loading of thin, flat‐walled structures by a complex finite strip method , 1974 .

[11]  Gregory J. Hancock,et al.  A nonlinear elastic spline finite strip analysis for thin-walled sections , 1991 .

[12]  T. M. Roberts,et al.  Lateral, local and distortional buckling of I-beams , 1983 .

[13]  Hoshyar Nooshin.  Formex configuration processing in structural engineering , 1984 .

[14]  Faris Albermani,et al.  Closure of "Finite Element Method for Buckling Analysis of Plate Structures" , 1993 .

[15]  R. Richard Avent,et al.  Elastic Stability of Polygon Folded Plate Columns , 1976 .