Compression and Bending Resistance of Steel Members: A Comparative Study on EN 1993-1-1 and AISC 360-22 Provisions

This paper presents a comparative study of provisions in two widely used design standards for structural steel members: the European standard EN 1993-1-1 (Eurocode 3) [9] and the American standard AISC 360-22[10]. The research concentrates on the verification of steel members subjected to combined axial compression and bending -frequently encountered in buildings, bridges, and industrial structures. In the beginning, this paper briefly compares the relations in both standards to identify key similarities and differences in terms of verification formulae, safety factors, and underlying design assumptions. A focus is placed on the influence of member slenderness, as the study considers columns across a range of slenderness ratios to assess how each standard responds to varying levels of slenderness. Furthermore, the main body of the research investigates in detail the resistance predictions of both standards through a structured parametric analysis. The study considers three representative cases of moment diagrams along the bar: uniform bending, linearly varying moment, and opposite end moments, each examined across a range of member slenderness ratios. Results are presented graphically in a structured and sequential manner, to facilitate interpretation and to highlight cases where the two standards yield possible significantly different resistance capacities. The comparative study shows that differences between EN 1993-1-1[9] and AISC 360-22[10] can be noticed in the member and the combination of applied loads.