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In steel element design, the design ratio under the combined axial force and biaxial bending (PMM ratio) is made by the ÇYTHYE CYTHYE 2016 (GKT & YDKT), AISC 360-16 (ASD & LRFD) or EN 1993-1-1. According to AISC 360-16, axial force and biaxial bending interaction equations are calculated below.
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Laterally unbraced length of the steel element can be reduced by using steel braces.
Steel element cross-section can be increasedenlarged.
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Symbols
Pr: Required axial strength using LRFD or ASD load combinations
Pc: Available axial strength
Mr: Required flexural strength using LRFD or ASD load combinations
Mc: Available flexural strength
x: subscript relating symbol to significant axis bending
y: subscript relating symbol to minor axis bending
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