Asymmetric thin-walled open sections such as angles are used widely in trusses and transmission towers. Such members have relatively low torsional and bending stiffnesses and are connected eccentrically. The paper derives the element geometric stiffness matrix for angle and tee beam-columns. The total potential energy of a general thin-walled beam-column is formulated, incorporating member geometrical nonlinearity. The validity and accuracy of the proposed finite element formulations are demonstrated on a number of buckling problems, including flexural-torsional buckling of narrow rectangular beams and cantilevers, tee beams under moment gradient and angle beam-columns. In all cases, results obtained are in good agreement with the closed form or independent numerical solutions. Results obtained for angle beam-columns demonstrated clearly the influence of the geometry updates on the buckling load and the load-deformation curves. The proposed approach may be extended to analyze three dimensional behavior of space frames comprising angle type sections.
|Title of host publication||Research Report Series - University of Queensland, Department of Civil Engineering|
|Publication status||Published - 1 Jan 1986|
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