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  • Answer

    The stresses of a surface can be read out via the COM interface. First, you need the interface to the model (IModel) and then the interface for the calculation (ICalculation2). Using this interface, you can get the interface for the results (IResults2):

    Sub stresses_surfaces_example ()
    Dim iApp As RFEM5.Application
    Dim iModel As RFEM5.model
    Set iModel = GetObject (, "RFEM5.Model")

    On Error GoTo E

    If Not iModel Is Nothing Then
    'get interface from model
    Set iApp = iModel.GetApplication
    'get interface from calculation
        Dim iCalc As RFEM5.ICalculation2
        Set iCalc = iModel.GetCalculation
    'get interface from results from loadcase 1
    Dim iRes As RFEM5.IResults2
        Set iRes = iCalc.GetResultsInFeNodes(LoadCaseType, 1)
    'get equivalent stresses
    Dim str_equ () As RFEM5.SurfaceEquivalentStresses
    str_equ = iRes.GetSurfaceEquivalentStresses (1, AtNo, VonMisesHypothesis)
    End If

    If Err.Number <> 0 Then
    MsgBox Err.Number & "" & Err.description
    End If

    If Not iApp Is Nothing Then
    End If

    The GetSurfaceEquivalentStresses function requires the calculation hypothesis to be specified. In the above case, the results of the Von Mises stress are read out. Please note that the COM interface uses SI units so that the stress is transferred in N/m².

  • Answer

    The *.dll and *.tlb files were probably not updated correctly on your computer. Please proceed as follows:

    1. Rename the following folders in Dlubal.bak:

         C:\Program Files (x86)\Common Files\Dlubal

         C:\Program Files\Common Files\Dlubal

    2. Reinstall RFEM or RSTAB.

    3. Move the files from the newly created Dlubal folders to the respective Dlubal.bak folders (overwrite all).

    4. Rename the Dlubal.bak folder to Dlubal.

  • Answer

    In principle, a section is an element, such as a member, and is also created in the same way. First, the interface to the objects is required. For a member, this would be IModelData, and for sections, it would be ISections. This interface can be found in IModel3:

    Sub test_section()
    '   get interface from the opened model and lock the licence/program
        Dim iModel As RFEM5.IModel3
        Set iModel = GetObject(, "RFEM5.Model")
    On Error GoTo E
        Dim iSecs As RFEM5.ISections
        Set iSecs = iModel.GetSections()

    All sections created previously are deleted first, and then two new sections are created.
    The first section should be a solid section with a visible sectional area (see Figure 01). The data are entered in a similar way as in RFEM. As a type, "SectionOnSectionalArea" is selected, the corner points of the section are set by using "EdgePoint," and a "Vector" defines the direction of the section:

       '   first delete all sections
        iSecs.DeleteObjects ("All")
        '   set section on solid
        Dim sec As RFEM5.Section
        sec.EdgePointA.X = 2
        sec.EdgePointA.Y = 5
        sec.EdgePointA.Z = 0
        sec.EdgePointB.X = 2
        sec.EdgePointB.Y = 8
        sec.EdgePointB.Z = 0
        = 1
        sec.Name = "solid section"
        sec.Plane = GlobalPlaneInPositiveX
        sec.ShowValuesInIsolines = False
        sec.Type = SectionOnSolidSectionLine
        sec.ObjectList = "1"
        iSecs.SetSection sec

    As already known from other elements, the new section is finally transferred in a Prepare-/FinishModification block. As the second section, a surface section is to be created (see Figure 02). For this, it is necessary to use the "SectionViaSurfacePlane" type. In addition to the vector of the section direction, you have to select the display plane of the results for the surface section. In the following example, the xy plane is selected by setting "GlobalPlaneInPositiveX."

    '   set section on surface
        sec.EdgePointA.X = 2
        sec.EdgePointA.Y = 0
        sec.EdgePointA.Z = 0
        sec.EdgePointB.X = 2
        sec.EdgePointB.Y = 3
        sec.EdgePointB.Z = 0
        = 2
        sec.Name = "surface section"
        sec.Plane = GlobalPlaneInPositiveX
        sec.ShowValuesInIsolines = True
        sec.Type = SectionViaSurfacePlane
        sec.ObjectList = "1"
        sec.Vector.X = 0
        sec.Vector.Y = 0
        sec.Vector.Z = 1
        iSecs.SetSection sec

    It is also possible to get the results of a section by using the separate method "GetResultsInSection" of the "IResults2" interface. In the following, the shear forces on the surface section are obtained. The distribution of the internal forces is set to "Continuous within Surfaces" by means of "ContinuousDistributionWithinObjects":

     '   get results
        Dim iCalc As ICalculation2
        Set iCalc = iModel.GetCalculation
        Dim iRes As IResults2
        Set iRes = iCalc.GetResultsInFeNodes(LoadCaseType, 1)
        Dim secRes() As RFEM5.SectionResult
        secRes = iRes.GetResultsInSection(2, AtNo,
          ShearForceVy,ContinuousDistributionWithinObjects, False)

    Under Downloads, you can find the Excel macro and the test file to comprehend the program.
  • Answer

    In order to only calculate specific load cases, load combinations, or result combinations in the same way as the "To Calculate..." command (see Figure 01), you can use the CalculateBatch method of the ICalculation interface. For the transfer, the method expects a field with the load type of Loading. This Loading includes the number of the load, and the type (for example, a load combination):

    Sub batch_test()
    '   get interface from the opened model and lock the licence/program
        Dim iModel As RFEM5.IModel3
        Set iModel = GetObject(, "RFEM5.Model")

    On Error GoTo e
        '   get interface for calculation
        Dim iCalc As ICalculation2
        Set iCalc = iModel.GetCalculation
        '   create array with loading types
        Dim loadings(3) As Loading
        loadings(0).no = 1
        loadings(0).Type = LoadCaseType
        loadings(1).no = 4
        loadings(1).Type = LoadCaseType
        loadings(2).no = 4
        loadings(2).Type = LoadCombinationType
        '   calculate all loadings from the array at once
        iCalc.CalculateBatch loadings

    e:  If Err.Number <> 0 Then MsgBox Err.description, , Err.Source
        Set iModelData = Nothing
        Set iModel = Nothing

    End Sub
  • Answer

    An imperfection is considered as a load and is transferred via the interface of the load case. Provided that the interface to the model has already been imported, the interface to the loads (ILoads) followed by the interface to Load Case 1 (ILoadCase) will subsequently be imported, if it has already been created before:

            '   set loadcases
            Dim iLoads As iLoads
            Set iLoads = model.GetLoads
            '   get load case
            Dim iLc1 As ILoadCase
            Set iLc1 = iLoads.GetLoadCase(1, AtNo)
            '   define imperfection
            Dim imperf As Imperfection
            imperf.Comment = "test"
            imperf.Direction = LocalZType
            imperf.Inclination = 200
   = 1
            imperf.ObjectList = 1
            imperf.Precamber = 300
            imperf.PrecamberActivity = ActivityAccording_EN_1993_1_1
            '   set imperfection
            iLc1.SetImperfection imperf

    The data of the imperfection is then filled out first, here for Member 1, and then transferred within the Prepare-/FinishModification block of the Interfaces load case.

  • Answer

    To modify an existing element, you have to get the interface to the corresponding element, in this case on an example of a member:

        Dim iModel As RSTAB8.model
        Set iModel = GetObject(, "RSTAB8.Model")
        Dim iModData As IModelData
        Set iModData = iModel.GetModelData
        Dim iMem As RSTAB8.IMember
        Set iMem = iModData.GetMember(1, AtNo)

    Use this code to get the interface to Member 1, which should already be created. Then, you can use the .GetData () method of the interface to get the member data.

    If you want to modify the data (such as the member rotation here), you can subsequently transfer it to the program within the Prepare-/FinishModification block with the method .SetData ().

        Dim mem As RSTAB8.Member
        mem = iMem.GetData
        mem.Rotation.Angle = 0.5
        mem.Rotation.Type = RSTAB8.Angle
        iMem.SetData mem
  • Answer

    The following code shows how to get different calculation parameters via the COM interface. It also shows how to specify the setting for deactivating shear stiffness:

        '   get model interface
        Set iApp = iModel.GetApplication()
        '   get calculation interface
        Dim iCalc As RFEM5.ICalculation2
        Set iCalc = iModel.GetCalculation
        '   get surface bending theory
        Dim calc_bend As RFEM5.BendingTheoryType
        calc_bend = iCalc.GetBendingTheory
        '   get settings for nonlinearities
        Dim calc_nl As RFEM5.CalculationNonlinearities
        calc_nl = iCalc.GetNonlinearities
        '   get precision and tolerance settings
        Dim calc_prec As RFEM5.PrecisionAndTolerance
        calc_prec = iCalc.GetPrecisionAndTolerance
        '   get calculation settings
        Dim calc_sets As RFEM5.CalculationSettings
        calc_sets = iCalc.GetSettings
    'get calculate options
        Dim calc_opts As RFEM5.CalculationOptions
        calc_opts = iCalc.GetOptions
        '   set ShearStiffness to false
        calc_opts.ShearStiffness = False
        iCalc.SetOptions calc_opts

    Under Downloads, you can find the EXCEL macro.
  • Answer

    First, a result beam is created as in the case of a normal member:

        Dim model As RFEM5.model
        Set model = GetObject(, "RFEM5.Model")

        On Error GoTo e

        Dim data As IModelData
        Set data = model.GetModelData

        Dim members(0) As RFEM5.Member
        members(0).No = 3
        members(0).LineNo = 12
        members(0).Type = ResultBeamType
        members(0).StartCrossSectionNo = 1
        members(0).EndCrossSectionNo = 1
        members(0).Comment = "result beam 1"

        data.SetMembers members

    Then, it is necessary to take the IMember interface from the corresponding member, and use the GetExtraData method to get the interface to IResultMember. Now, this interface can be used to read or write the ResultMember data. Please note that the Prepare-/Finishmodification block is required when writing:

        Dim iMem As IMember
        Set iMem = data.GetMember(3, AtNo)
        Dim iRMem As IResultBeam
        Set iRMem = iMem.GetExtraData
        Dim RMem As ResultBeam
        RMem = iRMem.GetData
        RMem.IncludeSurfaces = "1"
        RMem.IncludeSolids = "all"
        RMem.Integrate = WithinCuboidGeneral
        Dim params(0 To 3) As Double
        RMem.Parameters = params
        RMem.Parameters(0) = 0.5
        RMem.Parameters(1) = 0.5
        RMem.Parameters(2) = 0.1
        RMem.Parameters(3) = 0.1
        iRMem.SetData RMem

    The completed EXCEL macro and the corresponding test file are attached.
  • Answer

    Friction is a nonlinearity and can therefore only be modified via the interface to the member hinge.

    For this, it is first necessary to create the member hinge, if not already available. Then, the IMemberHinge interface is brought to the member hinge and then to the nonlinearity (here IFriction). Then, you can use the methods GetData and SetData to modify the data (here Friction):

    Sub SetMemberHingeFriction ()

        Dim model As RFEM5.model
        Set model = GetObject(, "RFEM5.Model")

        On Error GoTo e

        Dim data As IModelData
        Set data = model.GetModelData

        Dim hinge(0 To 0) As RFEM5.MemberHinge

        hinge(0).No = 1
        hinge(0).RotationalConstantX = 1
        hinge(0).RotationalConstantY = 2
        hinge(0).RotationalConstantZ = 3
        hinge(0).TranslationalConstantX = 4
        hinge(0).TranslationalConstantY = 5
        hinge(0).TranslationalConstantZ = 6
        hinge(0).Comment = "Member Hinge 1"
        hinge(0).TranslationalNonlinearityX = FrictionAType

        data.SetMemberHinges hinge
        ' get interface for member hinge
        Dim imemhing As IMemberHinge
        Set imemhing = data.GetMemberHinge(1, AtNo)
        ' get interface for nonlinearity 'friction'
        Dim iFric As IFriction
        Set iFric = imemhing.GetNonlinearity(AlongAxisX)
        ' get friction data
        Dim fric As Friction
        fric = iFric.GetData
        fric.Coefficient1 = 0.3
        ' set friction data
        iFric.SetData fric
    e:  If Err.Number <> 0 Then MsgBox Err.Description, , Err.Source

        Set data = Nothing
        Set model = Nothing

    End Sub

    In the case of the friction Vy + Vz, the Coefficient2 is used to set the second coefficient. The spring constant in the Friction dialog box is controlled by the translational spring of the member hinge. In this particular case, this is TranslationalConstantX for the X‑direction (see Figure 01).

  • Answer

    The asynchronous calculation is used if a self-created program should only open or continue operating RFEM or RSTAB. When the calculation is complete, the event is transferred via a delegate. You can find a C# example in a Visual Studio project under Downloads below.

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