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How to generate STAAD model using Excel VBA

Generate *.std file without openstaad API

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By Vivek Patel
7 min read
How to generate STAAD model using Excel VBA

Overview

  • In this tutorial, I’ll show you how to generate a STAAD file using VBA without using the OpenSTAAD API.
  • Generating STAAD models automatically frees you from a lot of manual labor, depending on the model size and the amount of iteration you want to do to optimize your design.
  • This method is better because:
    • It doesn’t require the OPENSTAAD API, so your code will work with all versions of STAAD, including really old ones.
    • You can generate multiple models. This is especially important for bridge structures, where you need to generate multiple models with different load combinations or checks.
    • Since we are doing this in Excel VBA, you can directly link your Excel geometry or load parameters with the VBA code. I normally keep my model generation code with my Excel design sheet so I can link all of my model parameters with my design and don’t have to change inputs in multiple places.
    • No need to learn the OPENSTAAD API, since we’re just using the STAAD command file, which most users are already familiar with.
  • Cons:
    • If you need to modify or work with an existing model, then it’s better to use the OPENSTAAD API.
  • To simplify this tutorial, we will do this in multiple iterations.
  • I am assuming that
    • you have a basic knowledge of VBA and how to add modules and create new sub
    • you have good understanding of STAAD command file

Setup

  • Create new macro enable excel file
  • Add inputs for STAAD model
  • To keep things simple, we’re going to generate simple Fixed beam
  • For STAAD commands, you can refer to this documentation

Output1 Screenshot 1 : Excel sheet with input parameters

Generate STAAD file

Create Blank STAAD file

  • Create new Module and add below sample code to create blank STAAD file
  • After creating your blank staad files you can start adding code for each element one by one as shown below
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Sub CreateModel()

' Create a new text file for the model at active workbook's path
Open ThisWorkbook.Path & "\Model.std" For Output As #1

' Write the model data to the file
Print #1, "STAAD SPACE"
Print #1, "START JOB INFORMATION"
Print #1, "ENGINEER DATE " & Format(Date, "dd-mmm-yy")
Print #1, "END JOB INFORMATION"
Print #1, "INPUT WIDTH 79"
Print #1, "UNIT METER MTON"

'<<< Add your remaining model code here >>>

' Specify End of STAAD file
Print #1, "FINISH"

' Close the file after writing to save model data
Close #1

'success message
MsgBox "Model successfully generated"

End Sub

Add Nodes and Beams

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' Add nodes
Print #1, "JOINT COORDINATES"
Print #1, "1 0 0 0;"
Print #1, "2 3.0 0 0;"

' Add Beam Elements
Print #1, "MEMBER INCIDENCES"
Print #1, "1 1 2;"

Add Material and Section Properties

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' Define Material Properties
Print #1, "DEFINE MATERIAL START"
Print #1, "ISOTROPIC CONCRETE"
Print #1, "E 2.21467e+006"
Print #1, "POISSON 0.17"
Print #1, "DENSITY 2.40262"
Print #1, "ALPHA 1e-005"
Print #1, "DAMP 0.05"
Print #1, "TYPE CONCRETE"
Print #1, "STRENGTH FCU 2812.28"
Print #1, "END DEFINE MATERIAL"

' Define Section Properties
Print #1, "MEMBER PROPERTY AMERICAN"
Print #1, "1 PRIS YD 0.3 ZD 0.3"
Print #1, "CONSTANTS"
Print #1, "MATERIAL CONCRETE ALL"

Add Supports

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' Define Support Conditions
Print #1, "SUPPORTS"
Print #1, "1 2 FIXED"

Add Loads

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'Add Dead load
Print #1, "LOAD 1 LOADTYPE None TITLE DEAD LOAD"
Print #1, "MEMBER LOAD"
Print #1, "1 UNI GY -10"

'Add Live load
Print #1, "LOAD 2 LOADTYPE None TITLE LIVE LOAD"
Print #1, "MEMBER LOAD"
Print #1, "1 CON GY -50 1.5 0"

Add Load Combinations

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'Add Load Combinations
Print #1, "LOAD COMB 101 ULTIMATE LOAD"
Print #1, "1 1.5 2 1.3"

Add Analysis Command

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Print #1, "PERFORM ANALYSIS"

STAAD FILE

  • Your Generated STAAD file should look like this
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STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 15-May-25
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER MTON
JOINT COORDINATES
1 0 0 0;
2 3.0 0 0;
MEMBER INCIDENCES
1 1 2;
DEFINE MATERIAL START
ISOTROPIC CONCRETE
E 2.21467e+006
POISSON 0.17
DENSITY 2.40262
ALPHA 1e-005
DAMP 0.05
TYPE CONCRETE
STRENGTH FCU 2812.28
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
1 PRIS YD 0.3 ZD 0.3
CONSTANTS
MATERIAL CONCRETE ALL
SUPPORTS
1 2 FIXED
LOAD 1 LOADTYPE None TITLE DEAD LOAD
MEMBER LOAD
1 UNI GY -10
LOAD 2 LOADTYPE None TITLE LIVE LOAD
MEMBER LOAD
1 CON GY -50 1.5 0
LOAD COMB 101 ULTIMATE LOAD
1 1.5 2 1.3
PERFORM ANALYSIS
FINISH

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Sub CreateModel()

' Inputs variables
Dim length As Double
Dim width As Double, depth As Double
Dim deadLoad As Double, liveLoad As Double

' Read inputs from the active sheet
length = CDbl(ActiveSheet.Range("B1").Value)
width = CDbl(ActiveSheet.Range("B2").Value)
depth = CDbl(ActiveSheet.Range("B3").Value)
deadLoad = -CDbl(ActiveSheet.Range("B4").Value)
liveLoad = -CDbl(ActiveSheet.Range("B5").Value)

' Create a new text file for the model at active workbook's path
Open ThisWorkbook.Path & "\Model.std" For Output As #1

' Write the model data to the file
Print #1, "STAAD SPACE"
Print #1, "START JOB INFORMATION"
Print #1, "ENGINEER DATE " & Format(Date, "dd-mmm-yy")
Print #1, "END JOB INFORMATION"
Print #1, "INPUT WIDTH 79"
Print #1, "UNIT METER MTON"

' Add nodes
Print #1, "JOINT COORDINATES"
Print #1, "1 0 0 0;"
Print #1, "2 " & length & " 0 0;"

' Add Beam Elements
Print #1, "MEMBER INCIDENCES"
Print #1, "1 1 2;"

' Define Material Properties
Print #1, "DEFINE MATERIAL START"
Print #1, "ISOTROPIC CONCRETE"
Print #1, "E 2.21467e+006"
Print #1, "POISSON 0.17"
Print #1, "DENSITY 2.40262"
Print #1, "ALPHA 1e-005"
Print #1, "DAMP 0.05"
Print #1, "TYPE CONCRETE"
Print #1, "STRENGTH FCU 2812.28"
Print #1, "END DEFINE MATERIAL"

' Define Section Properties
Print #1, "MEMBER PROPERTY AMERICAN"
Print #1, "1 PRIS YD " & depth & " ZD " & width
Print #1, "CONSTANTS"
Print #1, "MATERIAL CONCRETE ALL"

' Define Support Conditions
Print #1, "SUPPORTS"
Print #1, "1 2 FIXED"

'Add Dead load
Print #1, "LOAD 1 LOADTYPE None TITLE DEAD LOAD"
Print #1, "MEMBER LOAD"
Print #1, "1 UNI GY " & deadLoad

'Add Live load
Print #1, "LOAD 2 LOADTYPE None TITLE LIVE LOAD"
Print #1, "MEMBER LOAD"
Print #1, "1 CON GY " & liveLoad & " " & length / 2 & " 0"

'Add Load Combinations
Print #1, "LOAD COMB 101 ULTIMATE LOAD"
Print #1, "1 1.5 2 1.3"

Print #1, "PERFORM ANALYSIS"

' Specify End of STAAD file
Print #1, "FINISH"
' Close the file after writing to save model data
Close #1

'success message
MsgBox "Model successfully generated"

End Sub

Conclusion

  • This is my prefered method to generate STAAD models due to its simplicity.
  • I know lot of user just create STAAD model using excel formula’s since they don’t want to deal with VBA Code
  • This method is better because you can auto-generate a lot of code using AI and leverage loops and conditional statements to create more complex models.
  • If you’re bit new to VBA then use AI tools like ChatGPT to understand or modify specific parts of code

If you have any questions or want to discuss something : Join our comment section

VBA, VBA-STAAD
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