Flexural Strength of Laterally Unsupported Angle Beams

Abstract

This chapter discusses that in nuclear power industry, angles are extensively used as beams to support pipes. In latticed towers, angles are subjected to axial forces and bending moments. Thus, it is necessary to be able to accurately determine the bending strength of angle members for use in their design as beams and beam-columns. This chapter experimentally determines the strength of laterally unsupported angle beams and assesses the magnitude of conservatism, if any, in the 1993 edition of the American Institute of Steel Construction's “Specification for Load and Resistance Factor Design of Single-Angle Members.” The chapter presents the results of tests on eight laterally unsupported angle beams ranging in size from 75 x 75 x 9 to 150 x 90 x 9 mm. The maximum compressive and tensile strains at the tips of the legs for all the specimens far exceeded the yield strains. It discusses the evaluation of the interaction equation for bending about both of the principal axes based on the assumption of the development of the plastic moment of resistance yielded results, which are in agreement with the tests. Specification for Load and Resistance Factor Design of Single-Angle Members was highly conservative regarding the bending strength of laterally unsupported angle beams.