Extracting Results from STAAD Pro. Using VBA

Linear interpolation is done only for spectrum and time history load cases. For static cases, the program calculates the forces and moments from first principles.

If this doesn't answer your question, please attach the macro and the STAAD model.

I am attaching both my staad file & Macro. After extracting through this macro i found that if I choose an 

intermediate section which does not fall in 12 ranges in which staad splits the member, there is an error 

in the result. i.e the extracted result is linearly interpolated if the section is between that range. Help me 

in this.

Regards

Gokul

STAAD FILE

STAAD PLANE

START JOB INFORMATION

ENGINEER DATE 18-Jul-13
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 0 0; 2 1 0 0;
MEMBER INCIDENCES
1 1 2;
DEFINE MATERIAL START
ISOTROPIC CONCRETE
E 2.17185e+007
POISSON 0.17
DENSITY 23.5616
ALPHA 1e-005
DAMP 0.05
END DEFINE MATERIAL
MEMBER PROPERTY
1 PRIS YD 1 ZD 1
CONSTANTS
MATERIAL CONCRETE ALL
SUPPORTS
1 2 PINNED
LOAD 1 LOADTYPE None  TITLE LOAD CASE 1
MEMBER LOAD
1 UNI GY -10
PERFORM ANALYSIS PRINT ALL
FINISH

MACRO

Sub ex1()
Dim objopenstaad As Object
Dim endforces(6) As Double
Set objopenstaad = CreateObject("openstaad.output.1")
objopenstaad.selectstaadfile Cells(2, 1).Value
objopenstaad.getintermediatememberforcesatdistance 1, 0.3, 1, endforces(0)
objopenstaad.closestaadfile
Set objopenstaad = Nothing
Cells(1, 1) = endforces(5) * 0.112984788
End Sub

I am attaching both my staad file & Macro. After extracting through this macro i found that if I choose an 

intermediate section which does not fall in 12 ranges in which staad splits the member, there is an error 

in the result. i.e the extracted result is linearly interpolated if the section is between that range. Help me 

in this.

Regards

Gokul

STAAD FILE

STAAD PLANE

START JOB INFORMATION

ENGINEER DATE 18-Jul-13
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 0 0; 2 1 0 0;
MEMBER INCIDENCES
1 1 2;
DEFINE MATERIAL START
ISOTROPIC CONCRETE
E 2.17185e+007
POISSON 0.17
DENSITY 23.5616
ALPHA 1e-005
DAMP 0.05
END DEFINE MATERIAL
MEMBER PROPERTY
1 PRIS YD 1 ZD 1
CONSTANTS
MATERIAL CONCRETE ALL
SUPPORTS
1 2 PINNED
LOAD 1 LOADTYPE None  TITLE LOAD CASE 1
MEMBER LOAD
1 UNI GY -10
PERFORM ANALYSIS PRINT ALL
FINISH

MACRO

Sub ex1()
Dim objopenstaad As Object
Dim endforces(6) As Double
Set objopenstaad = CreateObject("openstaad.output.1")
objopenstaad.selectstaadfile Cells(2, 1).Value
objopenstaad.getintermediatememberforcesatdistance 1, 0.3, 1, endforces(0)
objopenstaad.closestaadfile
Set objopenstaad = Nothing
Cells(1, 1) = endforces(5) * 0.112984788
End Sub

Hi,

The values extracted using “Output.GetIntermediateMemberForcesAtDistance” function matches with the values reported in STAAD.Pro. For example, consider the attached macro. I have extracted all the member forces using this macro and compared with STAAD results. In the attached screenshot, you can find that the values match with the member forces reported in the member query box of STAAD.Pro.

Also I checked the value at an intermediate point(dist= 0.55m) and found that the value is -1.2375 kNm where as the linearly interpolated values is 1.2292 kNm. So the OpenSTAAD function does not report the linearly interpolated values.