Frequently Asked Questions (FAQ)

Search FAQ

Show Filter Hide Filter





Customer Support 24/7

Knowledge Base

In addition to our technical support (e.g. via chat), you’ll find resources on our website that may help you with your design using Dlubal Software.

Newsletter

Receive information including news, useful tips, scheduled events, special offers, and vouchers on a regular basis.

  • Answer

    In RSTAB and RFEM, you can create combinations automatically according to different standards. In the case of a purely linear calculation, the generation of result combinations can be defined in the model general data. The attached video shows the automatic generation.
  • 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")
        iModel.GetApplication.LockLicense
        
    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.PrepareModification
        iSecs.DeleteObjects ("All")
        iSecs.FinishModification
        
        '   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
        
        sec.no = 1
        sec.Name = "solid section"
        sec.Plane = GlobalPlaneInPositiveX
        sec.ShowValuesInIsolines = False
        sec.Type = SectionOnSolidSectionLine
        sec.ObjectList = "1"
        
        iSecs.PrepareModification
        iSecs.SetSection sec
        iSecs.FinishModification

    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
        
        sec.no = 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.PrepareModification
        iSecs.SetSection sec
        iSecs.FinishModification

    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

    If the cross-section consists of several unconnected partial sections, the sum of the moments of inertia is calculated without the parallel axis theorem components. The cross-section shown in Figure 01 consists of two angle sections that are not connected to each other.

    Figure 01 - Cross-Section Consisting of Several Unconnected Partial Sections

    The individual angle sections have the following moments of inertia:

    Iy,1,2 = 180.39 cm4 (referred to the centroidal axes y, z)

    Iz,1,2 = 65.05 cm4 (referred to the centroidal axes y, z)

    The moments of inertia of the entire cross-section result in:

    Iy,1+2 = 2 ⋅ Iy,1,2 = 2 ⋅ 180.39 = 360.78 cm4 (referred to the centroidal axes y, z)

    Iz,1+2 = 2 ⋅ Iz,1,2 = 2 ⋅ 65.05 = 130.11 cm4 (referred to the centroidal axes y, z)

    If the cross-section consists of several connected partial sections, the sum of the moments of inertia is calculated with the parallel axis theorem components. The cross-section shown in Figure 02 consists of two connected angle sections.

    Figure 02 - Cross-Section Consisting of Several Connected Partial Sections

    The individual angle sections have the following cross-section properties:

    A1,2 = 16.25 cm²

    yS,0,1,2 = ±2.30 cm (referred to the zero point)

    zS,0,1,2 = 3.07 cm (referred to the zero point)

    Iy,1,2 = 180.39 cm4 (referred to the centroid axes y, z)

    Iz,1,2 = 65.05 cm4 (referred to the centroid axes y, z)

    The cross-section properties of the entire cross-section result in:

    yS,0,1+2 = 0.00 cm (referred to the zero point)

    zS,0,1+2 = 3.07 cm (referred to the zero point)

    Iy,1+2 = 2 ⋅ Iy,1,2 + 2 ⋅ A1,2 ⋅ (zS,0,1,2 - zS,0,1+2

    Iy,1+2 = 2 ⋅ 180.39 + 2 ⋅ 16.25 ⋅ (3.07 - 3.07)² = 360.78 cm4 (referred to the centroidal axes y, z)

    Iz,1+2 = 2 ⋅ Iz,1,2 + 2 ⋅ A1,2 ⋅ (yS,0,1,2 - yS,0,1+2

    Iz,1+2 = 2 ⋅ 65.05 + 2 ⋅ 16.25 ⋅ (2.30 - 0.00)² = 301.46 cm4 (referred to the centroidal axes y, z)

  • Answer

    The COMPOSITE‑BEAM program allows for design of composite beams according to the preliminary standard ENV 1994‑1‑1:1992:10.

    Until further notice, the pre-standard is only implemented. The design according to EN 1994‑1‑1 is currently not possible.

    See also the product description of COMPOSITE‑BEAM on the product page under the following link.

  • Answer

    After the calculation, you can switch to the result window "2.4 Required Reinforcement by x‑Location" in the RF‑CONCRETE Members (RFEM) or CONCRETE (RSTAB) add-on module.

    Here, you can select a certain result row for a particular design and x-location (upper table in Window 2.4). Then, you can evaluate the intermediate results in the lower table in Window 2.4. This covers the "Neutral Axis Depth x", for example. The location of the neutral axis for the selected design location is displayed in the graphic on the right of Window 2.4 .

    Figure 01 - Depth of Neutral Axis in Window "2.4 Required Reinforcement by x-Location"

    Furthermore, you can display the distribution of the neutral axis depth along the member length graphically in the model or in "Result Diagrams on Member."

    Figure 02 - Distribution of Intermediate Value "x" in Dialog Box "Result Diagram on Member"

  • 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")
        iModel.GetApplication.LockLicense
        

    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
        iModel.GetApplication.UnlockLicense
        Set iModel = Nothing

    End Sub
  • Answer

    In the CRANEWAY program, you can select the display of load combinations for the individual design situations in the middle of Window 1.5 Load Combinations.
  • Answer

    When using the COM interface (RF‑COM or RS‑COM), you can create a comment by using the guide object interface IGuideObjects. The following is an example program that creates a comment:

    Sub test_comment()

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

    On Error GoTo e
        
        Dim iModelData As RFEM5.IModelData2
        Set iModelData = iModel.GetModelData
        
        Dim iGuiObj As RFEM5.IGuideObjects
        Set iGuiObj = iModel.GetGuideObjects
        
        Dim comm As RFEM5.Comment
        
        '   set frame type
        comm.Frame = CircularFrameType
        
        '   set reference object type
        comm.ObjectType = GeneralObjectType
        comm.ObjectNo = 1
        
        '   set point if GeneralObjectType is choosen
        comm.Point.X = 2
        comm.Point.Y = 4
        comm.Point.Z = 6
        
        '   set offset from reference object
        comm.Offset.X = 0.5
        comm.Offset.Y = 1
        comm.Offset.Z = 1.5
        comm.Rotation = 1
        
        '   set text of comment
        comm.Text = "testcomment"
        
        '   transfer object to program
        iGuiObj.PrepareModification
        iGuiObj.SetComment comm
        iGuiObj.FinishModification
        
    e:  If Err.Number <> 0 Then MsgBox Err.description, , Err.Source
        
        Set iModelData = Nothing
        iModel.GetApplication.UnlockLicense
        Set iModel = Nothing

    End Sub

    The selection of the reference or the element to which the comment is refferred to is defined by the type (ObjectType) first. Here, it is possible to select, for example, a member, a node or any point in space. Next, the number of the reference object is specified via ObjectNo (for example, Member 1). If you have selected a free point, it is set by Point.
    Finally, you can specify an offset which results from the reference object.
  • Answer

    Section F2 out of the AISC 360-16 [1] states that doubly symmetric I-Shapes and Channels that are bent about their major axis must be compact sections in order to be designed. An example of this can be seen below.



    Non-compact sections cannot be designed according to F2. Figure 2 shows a non-designable section.

1 - 10 of 174

Contact us

Did you find your question?
If not, contact us via our free e-mail, chat, or forum support, or send us your question via the online form.

+49 9673 9203 0

info@dlubal.com

First Steps

First steps

We provide hints and tips to help you get started with the main programs RFEM and RSTAB.

Wind Simulation & Wind Load Generation

With the stand-alone program RWIND Simulation, wind flows around simple or complex structures can be simulated by means of a digital wind tunnel.

The generated wind loads acting on these objects can be imported to RFEM or RSTAB.

Your support is by far the best

“Thank you for the valuable information.

I would like to pay a compliment to your support team. I am always impressed how quickly and professionally the questions are answered. I have used a lot of software with a support contract in the field of structural analysis, but your support is by far the best. ”