Plate Element Modeling of Steel Angle Members

Abstract

Angle members in steel lattice towers are currently individually designed by approximate formulas that take into account geometric and material properties, as well as conditions of eccentricity and restraint at end joints. Full‐scale tests of towers show that current design formulas are not always appropriate and that failures often involve a group of members (subassembly) rather than individual members. An alternate is proposed herein to full‐scale testing for determining the ultimate strength of angle members or subassemblies. It proposes to model angle members by nonlinear plate elements located in the legs of the angles. Such a detailed modeling allows for the occurrence of local buckling, lateral‐torsional buckling, eccentricity of connections, localized plasticity, etc., A plate element appropriate for modeling steel angles is discussed in detail, and several examples are presented to demonstrate the usefulness of the concept.