Applies To
	Product(s):	STAAD.Pro
	Version(s):	All
	Environment:	N/A
	Area:	Design
	Subarea:	American Steel Design
	Original Author:	Bentley Technical Support Group

In the context of design, what is meant by the term Ratio?

In steel design, the Pass/Fail status of a member is determined according to various conditions. According to most design codes, the member has to be checked for failure against axial compression and axial tension, slenderness, compressive & tensile stresses caused by axial compressive force + bending moments, failure caused by shear stresses, etc. For each of these conditions, determination of whether the member is safe or unsafe is done by checking whether the actual values due to the loading exceed or are less than the allowable values. The amount by which the member is stressed for each of these conditions is quantified in the form of the Ratio. For example, take the case of equation H1-1 of Section H of the AISC-89 specifications. The number obtained by computing the left hand side of that equation is the Ratio corresponding to that equation.