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

Why such warning is reported in the Output file: 

   **WARNING- THE AXIAL COMPRESSIVE STRESS EXCEEDS THE EULER STRESS FOR MEMBER X
EQN. AISC H1-1 CANNOT BE CHECKED PROPERLY.

Why this leads to the huge utilization ratios?

Some members may fail for equation AISC H1-1 as the actual axial compressive stress exceeds the Euler stress. These values of actual compressive stress (fa) and Euler stress (Fez and Fey) corresponding to failing members can be viewed in the output by defining a design parameter called TRACK followed with a value 2 in the input file.

As per the  AISC equation H1-1, You will find that there are 2 terms in the denominator, called

(1-fa/Fey)

and

(1-fa/Fez)

If the value of fa equals or exceeds Fey or Fez (Euler stresses), the respective terms become zero or negative, which is not a desirable event. In such a situation, STAAD replaces that negative number and reports the ratio with a significant number and also gives a warning

   **WARNING- THE AXIAL COMPRESSIVE STRESS EXCEEDS THE EULER STRESS FOR MEMBER X
EQN. AISC H1-1 CANNOT BE CHECKED PROPERLY.

To remedy the problem, You need to use a larger cross section so that "fa" becomes smaller, or use one with a smaller KL/r value so that Fey and/or Fez become larger.