Start with the load path.
The screen divides a concentric axial load by the gross rectangular area. It helps expose the basic load-to-area relationship before a more complete member model is opened.
Allowable stress needs a basis.
An entered allowable average stress is not universal. It should be traceable to the material, design code, load combination, project brief, and limit state being considered.
What still needs judgement
- Slenderness, buckling, imperfections, second-order effects, eccentricity, and biaxial bending.
- Reinforcement, confinement, connections, end restraints, durability, fire, and detailing.
- Material-specific resistance factors and national or project-specific design parameters.