Analyzing a Non-Compact Beam Undergoing Elastic Lateral Torsional Buckling per LRFD and ASD

June 8, 2017 Abdul Siraj, P.E.

In this post, I will discuss the fifth example in our steel design course covering the analysis and design of beam members. The goal of this steel design example is to analyze a non-compact beam undergoing elastic lateral torsional buckling per LRFD and ASD. We are using the 13th edition of the AISC Steel Construction Manual.


The problem statement states,


A W14 x 99 simply supported beam with a span length of 50′ is laterally supported at its ends and experiences the following loads:


DL = 500 lbs/ft

LL = 1000 lbs/ft

Fy = 50 ksi


Is the beam adequate for the given conditions per LRFD and ASD.