THE VALUE OF E FOR MEMBER NNN DOES NOT SEEM RIGHT. What does this mean?
The steel design output for several members is accompanied by the following warning message :
WARNING : THE VALUE OF E FOR MEMBER 21 DOES NOT SEEM RIGHT.
WARNING : THE VALUE OF E FOR MEMBER 22 DOES NOT SEEM RIGHT.
WARNING : THE VALUE OF E FOR MEMBER 23 DOES NOT SEEM RIGHT.
During steel design, there is a check for ensuring that the Modulus of Elasticity (E) specified for the member is within the range that is normal for steel. This is because, E is a crucial term that appears in many equations for calculating section capacities and the program wants you to know if the value appears to be abnormal.
In STAAD, you specify E either explicitly under the CONSTANTS command block or through the DEFINE MATERIAL block, as in the examples below.
Example 1 :
UNIT KIP INCHCONSTANTSE 29000 ALLDENSITY 0.283E-3 ALL
Example 2 :
UNIT METER KNSDEFINE MATERIAL STARTISOTROPIC STEELE 2.05e+008POISSON 0.3DENSITY 76.8195ALPHA 1.2e-005DAMP 0.03END DEFINE MATERIALCONSTANTSMATERIAL STEEL MEMBER 101 TO 121
So, if you are specifying an E value which is significantly different from that for steel, such as say, Aluminum, and then later asking the member to be designed according to a steel code, as in the following example, the above-mentioned warning message will appear.
UNIT FEET POUNDDEFINE MATERIAL STARTISOTROPIC ALUMINUME 1.44e+009POISSON 0.33DENSITY 169.344ALPHA 1.28e-005DAMP 0.03END DEFINE MATERIAL
CONSTANTSMATERIAL ALUMINUM MEMBER 21 TO 30
....PARAMETERCODE AISCCHECK CODE MEMBER 21 TO 30