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STAAD showing 2 different unity check values. 2

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cgstrucg

Structural
Mar 21, 2018
135
Hello,

I have a STAAD code which is a simple beam design with loads and I was doing steel design. On performing design I got the results of beam unity check to be 0.74 (Actual Ratio). But on double clicking the beam and then going to Steel Design Section I see Unity check to be 0.41. This is weird. Can someone please give me an explanation on this. Uploaded the image and STAAD Code. I am using STAAD.Pro V8i (SELECTseries 6) 20.07.11.33

Thanks

STAAD Code

STAAD PLANE
START JOB INFORMATION
ENGINEER DATE 08-Feb-18
END JOB INFORMATION
INPUT WIDTH 79
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 16.169 0 0;
MEMBER INCIDENCES
1 1 2;
DEFINE MATERIAL START
ISOTROPIC STEEL
E 4.176e+006
POISSON 0.3
DENSITY 0.489024
ALPHA 6e-006
DAMP 0.03
TYPE STEEL
STRENGTH FY 5184 FU 8352 RY 1.5 RT 1.2
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
1 TABLE ST W8X35
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
2 FIXED BUT FX FZ MX MY MZ
1 PINNED
LOAD 1 LOADTYPE Dead TITLE LOAD CASE 1
SELFWEIGHT Y -1
MEMBER LOAD
1 CON GY -7.407 8.9167
1 CON GY -8.955 14.9167
PERFORM ANALYSIS
PARAMETER 1
CODE AISC UNIFIED 2010
DFF 360 ALL
DJ1 1 ALL
DJ2 2 ALL
FU 9360 ALL
FYLD 7200 ALL
METHOD ASD
UNB 16.169 ALL
UNT 7.583 ALL
CHECK CODE ALL
FINISH
 
 https://files.engineering.com/getfile.aspx?folder=5a385e97-f04c-4007-8a06-43d34ab6f8c7&file=1.PNG
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I tested thins in STAAD.pro 20.07.11.82 and in the Connect Edition and I only see the 0.41 value. Must be something about build 20.07.11.33
 
On performing design I got the results of beam unity check to be 0.74 (Actual Ratio). But on double clicking the beam and then going to Steel Design Section I see Unity check to be 0.41.


I'm getting the same thing (I have build 20.07.11.45).

I think the reason is: you are specifying a allowable deflection value. The double click on the beam is giving the steel unity check as per AISC.....the design results is giving the ratio of allowable deflection you are using. And since you are utilizing more of your allowable deflection (0.74) than your allowable stress (0.41).....the higher ratio is what is given in the post-processing under design results.

 
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