Computationally Generated Charts for Critical Local Buckling Stress of L-,T-, and Cruciform-Section Columns

When performing hand calculations for critical local buckling stresses, charts are commonly used to determine the coefficient in the governing equation. Historically, these values have been calculated using moment-distribution methods supplemented by energy methods, often through manual means. This paper discusses the computational implementation of moment-distribution methods, significantly reducing the need for energy methods due to increased computing power. Considerations for ensuring that assumptions fall within appropriate ranges for accurate moment-distribution calculations are discussed. The accuracy of the computational approach is validated by comparing computed values in regions where energy methods were traditionally used against historical data for Z-stringers. Charts for determining critical local buckling stresses of columns with L-, T-, and cruciform cross-sections are presented. The application of moment-distribution methods to these geometries is detailed, and the computed results are validated against finite element simulations performed in Abaqus.