Single Angle Geometric Axis Flexural Compactness Criteria: Horizontal Leg Tension

Abstract

Currently, designers experience difficulty when trying to gauge the flexural ductility of a given single angle member due to the lack of single angle flexural compactness criteria in the American steel building specification. In fact, many designers may believe that single angle beams are incapable of developing their full cross-sectional plastic capacity due to this omission in the specification. As a result, few engineers are willing to exploit the advantages associated with employing plastic analysis and design methodologies to proportion single angle members. The research reported herein applies experimentally verified, nonlinear finite-element modeling techniques to the study of geometric axis flexural ductility for the flexural sense, where the horizontal leg of the angle cross section is in tension. It is shown that compactness criteria must be given in terms of both cross-sectional plate slenderness as well as beam slenderness. It is further observed that the grade of steel plays an important role in affecting compactness. Based on the results of the present study, a design equation is proposed as a means for predicting equal leg, single angle compactness for this flexural orientation. The equation has been developed so as to lend itself to everyday use by the designer.