NODAL_SUPPORTS with SteelEffectiveLength

amazigh · October 15, 2025, 4:24pm

How to use NODAL_SUPPORTS with SteelEffectiveLength with the new API ?
I have this but there is a problem with NODAL_SUPPORTS :

#—-Longueurs efficaces
rfem.types_for_steel_design.SteelEffectiveLengths(
	no=1,members=[],member_sets = barres_poteaux,
	flexural_buckling_about_y = True, flexural_buckling_about_z = True,
	torsional_buckling = False, lateral_torsional_buckling = True,
	principal_section_axes = True,geometric_section_axes = False,
	name = 'Longueur_Efficace_Poteau',
	nodal_supports = [[rfem.types_for_steel_design.SteelEffectiveLengths.NodalSupportsRow.SupportType.SUPPORT_TYPE_FIXED_ALL,
					 True, 0.0, rfem.types_for_steel_design.SteelEffectiveLengths.NodalSupportsRow.EccentricityType.ECCENTRICITY_TYPE_NONE,
					 0.0, 0.0, 0.0, 0.0, rfem.types_for_steel_design.SteelEffectiveLengths.NodalSupportsRow.SupportInY.SUPPORT_IN_Y_SUPPORT_STATUS_YES]],
	factors = [[1.0, 1.0, 1.0, 1.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]],
	intermediate_nodes = True, different_properties = True,                                                                                 
	factors_definition_absolute = False,
	import_from_stability_analysis_enabled = False,
	determination_mcr_europe = rfem.types_for_steel_design.SteelEffectiveLengths.DETERMINATION_MCR_EUROPE_EIGENVALUE)

Mod Edit: code formatting

soeren.omieczynski · October 16, 2025, 7:34am

Hi amazigh,

welcome to the Dlubal Community

I would recommend to format code using backticks, which is much easier to read and which will increase the chance that other users help.

Best regards
Sören

Samuel · October 16, 2025, 8:16am

Hey mate,

I don’t actually have a steel add-in so can’t test this myself, but I’ve used the api a bit so I figured I’d see if I could maybe find a solution

Looking at the NodalSupportsRow section of the
SteelBoundaryConditions — Dlubal API documentation

I think you are maybe missing some arguments, nodes List[int] is probably the most important as I assume it dictates which node the support is applied to (I assume you have to create the nodes first).

Try this,

nodal_supports = [[
    1,  # no
    "",  # description
    rfem.types_for_steel_design.SteelEffectiveLengths.NodalSupportsRow.SupportType.SUPPORT_TYPE_FIXED_ALL,
    True,   # support_in_z
    0.0,    # support_spring_in_y
    rfem.types_for_steel_design.SteelEffectiveLengths.NodalSupportsRow.EccentricityType.ECCENTRICITY_TYPE_NONE,
    0.0,    # eccentricity_ez
    0.0, 0.0, 0.0,  # restraint_spring_about_x, _about_z, _warping
    rfem.types_for_steel_design.SteelEffectiveLengths.NodalSupportsRow.SupportInY.SUPPORT_IN_Y_SUPPORT_STATUS_YES,
    rfem.types_for_steel_design.SteelEffectiveLengths.NodalSupportsRow.RestraintAboutX.RESTRAINT_ABOUT_X_SUPPORT_STATUS_YES,
    rfem.types_for_steel_design.SteelEffectiveLengths.NodalSupportsRow.RestraintAboutZ.RESTRAINT_ABOUT_Z_SUPPORT_STATUS_YES,
    rfem.types_for_steel_design.SteelEffectiveLengths.NodalSupportsRow.RestraintWarping.RESTRAINT_WARPING_SUPPORT_STATUS_YES,
    [1, 2]  # nodes -> replace with your node IDs
]]

Some of these arguments (like description) are probably option, but I always like to fill them all out in the order they appear in the documentation (and give comments for easy matching) when I first try a new piece of code

Let me know how you go, I probably won’t be able to help to much because I don’t actually have the add in to test…

Samuel

tomas.pail · October 16, 2025, 9:11am

Hi amazigh,

we have been able to replicate the issue - the problem is probably that steel design effective lengths generally do not return the complete settings for nodal_supports.

For that already bug ID 240654 is registered.

Reagrds

amazigh · October 16, 2025, 1:35pm

Hi Thomas,
Did you solved the problem ?
Kind regards,

tomas.pail · October 16, 2025, 6:32pm

Not yet, still in the backlog but we will look on that with higher priority now.
Let you know, when it’s fixed.
Regards

PSA001 · January 5, 2026, 6:06pm

I have been having a hard time with creating nodal support rows for EC3 using the following versions:

API2 v2.12.10 with RFEM6.12.0010
API2 v2.12.12 with RFEM6.12.0012
API2 v2.12.13 with RFEM6.12.0013

In the code below I set-up everything, and the member set is created correctly except for the nodal support rows.

=========================================================

public List<IMessage> Get_iMessages(bool useDefaultNumber)
{
    List<IMessage> list = new List<IMessage>();

    int selNro = this.Building.List_nros_steelEffectiveLengths.Count + 1;
    this.Building.List_nros_steelEffectiveLengths.Add(selNro);

    ec3EffectiveLength.NodalSupportsTable ns_table = new ec3EffectiveLength.NodalSupportsTable();
    
    foreach (ec3EffectiveLength.NodalSupportsRow row in Get_List_ec3EffectiveLength_NodalSupportsRow())
    {
        ns_table.Rows.Add(row);
    }
    

    list.Add(new RfemApi2.SteelDesign.SteelEffectiveLengths()
    {
        MemberSets = { this.Number },
        FlexuralBucklingAboutY = true,
        FlexuralBucklingAboutZ = true,
        TorsionalBuckling = true,
        LateralTorsionalBuckling = true,
        IntermediateNodes = true,
        DifferentProperties = true,
        Comment = "testing",
        NodalSupports = ns_table,
    });

    list.Add(new RfemApi2.StructureCore.MemberSet()
    {
        No = this.Number,
        Name = this.ToString(),
        Members = { Get_listOfNros_members() },
        SetType = RfemApi2.StructureCore.MemberSet.Types.SetType.Continuous,
        DesignPropertiesActivated = true,
        SteelEffectiveLengths = selNro,
    });

    

    return list;
}

=========================================================

In the code above, the list of IMessage json items that the method Get_List_ec3EffectiveLength_NodalSupportsRow() returns is as below:

=========================================================

{ "no": 1, "supportType": "SUPPORT_TYPE_INDIVIDUALLY", "supportInZ": true, "eccentricityType": "ECCENTRICITY_TYPE_NONE", "supportInY": "SUPPORT_IN_Y_SUPPORT_STATUS_YES", "restraintAboutX": "RESTRAINT_ABOUT_X_SUPPORT_STATUS_YES", "restraintAboutZ": "RESTRAINT_ABOUT_Z_SUPPORT_STATUS_NO", "restraintWarping": "RESTRAINT_WARPING_SUPPORT_STATUS_NO", "nodes": [ 1 ] }

{ "no": 2, "supportType": "SUPPORT_TYPE_FIXED_ALL", "supportInZ": true, "eccentricityType": "ECCENTRICITY_TYPE_NONE", "supportInY": "SUPPORT_IN_Y_SUPPORT_STATUS_YES", "restraintAboutX": "RESTRAINT_ABOUT_X_SUPPORT_STATUS_YES", "restraintAboutZ": "RESTRAINT_ABOUT_Z_SUPPORT_STATUS_YES", "restraintWarping": "RESTRAINT_WARPING_SUPPORT_STATUS_YES", "nodes": [ 2 ] }

{ "no": 3, "supportType": "SUPPORT_TYPE_NONE", "supportInZ": false, "eccentricityType": "ECCENTRICITY_TYPE_NONE", "supportInY": "SUPPORT_IN_Y_SUPPORT_STATUS_NO", "restraintAboutX": "RESTRAINT_ABOUT_X_SUPPORT_STATUS_NO", "restraintAboutZ": "RESTRAINT_ABOUT_Z_SUPPORT_STATUS_NO", "restraintWarping": "RESTRAINT_WARPING_SUPPORT_STATUS_NO", "nodes": [ 3 ] }

=========================================================

also, the final list of IMessage json items sent to RFEM6 for the creation of the memberset looks like below:

=========================================================

{ "comment": "testing", "memberSets": [ 1 ], "flexuralBucklingAboutY": true, "flexuralBucklingAboutZ": true, "torsionalBuckling": true, "lateralTorsionalBuckling": true, "nodalSupports": { "rows": [ { "no": 1, "supportType": "SUPPORT_TYPE_INDIVIDUALLY", "supportInZ": true, "eccentricityType": "ECCENTRICITY_TYPE_NONE", "supportInY": "SUPPORT_IN_Y_SUPPORT_STATUS_YES", "restraintAboutX": "RESTRAINT_ABOUT_X_SUPPORT_STATUS_YES", "restraintAboutZ": "RESTRAINT_ABOUT_Z_SUPPORT_STATUS_NO", "restraintWarping": "RESTRAINT_WARPING_SUPPORT_STATUS_NO", "nodes": [ 1 ] }, { "no": 2, "supportType": "SUPPORT_TYPE_FIXED_ALL", "supportInZ": true, "eccentricityType": "ECCENTRICITY_TYPE_NONE", "supportInY": "SUPPORT_IN_Y_SUPPORT_STATUS_YES", "restraintAboutX": "RESTRAINT_ABOUT_X_SUPPORT_STATUS_YES", "restraintAboutZ": "RESTRAINT_ABOUT_Z_SUPPORT_STATUS_YES", "restraintWarping": "RESTRAINT_WARPING_SUPPORT_STATUS_YES", "nodes": [ 2 ] }, { "no": 3, "supportType": "SUPPORT_TYPE_NONE", "supportInZ": false, "eccentricityType": "ECCENTRIC...

{ "no": 1, "name": "IPE 300 | Continuous members: 1,2", "setType": "SET_TYPE_CONTINUOUS", "members": [ 1, 2 ], "designPropertiesActivated": true, "steelEffectiveLengths": 1 }

=========================================================

As seen in the images below, the memberset is correct, and all the settings (except for the buckling lengths which I didn't assign) are correct but the nodal support table rows are wrong. Based on the json messages sent to RFEM6, there should have been 3 nodal support rows, but there are only 2 of them, which also don't have the designated DOF requested by the code.

The boolean 'IntermediateNodes = true, only checks the checkbox 'Intermediate node' but the list of rows does not insert them in the table. When I manually click the 'insert button' it addes the rows, for which I haven'y found an equivalent in the code.

I didn't find any examples for this in the list of examples in the documentations page. Also the standard documentation pages (here, here) do not provide examples or hints.

Also, when get the same object back from RFEM6 using API2, below, it shows that it disregarded the information I sent to it.

Property Name	Value
BucklingFactorValueType	Theoretical
CbFactorAisc	0
CbFactorCsa	0
CbFactorNbr	0
Comment	testing
DeterminationCbAisc	BasicValue
DeterminationCbCsa	BasicValue
DeterminationCbNbr	BasicValue
DeterminationMcrAisc	Eigenvalue
DeterminationMcrBs5	Eigenvalue
DeterminationMcrCsa	Eigenvalue
DeterminationMcrEurope	Eigenvalue
DeterminationMcrGb50	EigenvalueMethod
DeterminationMcrIs800	Eigenvalue
DeterminationMcrNbr8800	Eigenvalue
DeterminationMcrSans	Eigenvalue
DeterminationMcrSia263	Eigenvalue
DeterminationOfElasticCriticalStressAisi	FiniteStripMethod
DeterminationOmega2Sans	BasicValue
DifferentProperties	TRUE
Factors	{ rows: [ { flexuralBucklingU: 1, flexuralBucklingV: 1, torsionalBuckling: 1 } ] }
FactorsDefinitionAbsolute	FALSE
FlexuralBucklingAboutY	TRUE
FlexuralBucklingAboutZ	TRUE
GeneratingObjectInfo
GeometricSectionAxes	FALSE
HasBucklingFactorValueType	FALSE
HasCbFactorAisc	FALSE
HasCbFactorCsa	FALSE
HasCbFactorNbr	FALSE
HasComment	TRUE
HasDeterminationCbAisc	FALSE
HasDeterminationCbCsa	FALSE
HasDeterminationCbNbr	FALSE
HasDeterminationMcrAisc	FALSE
HasDeterminationMcrBs5	FALSE
HasDeterminationMcrCsa	FALSE
HasDeterminationMcrEurope	TRUE
HasDeterminationMcrGb50	FALSE
HasDeterminationMcrIs800	FALSE
HasDeterminationMcrNbr8800	FALSE
HasDeterminationMcrSans	FALSE
HasDeterminationMcrSia263	FALSE
HasDeterminationOfElasticCriticalStressAisi	FALSE
HasDeterminationOmega2Sans	FALSE
HasDifferentProperties	TRUE
HasFactorsDefinitionAbsolute	TRUE
HasFlexuralBucklingAboutY	TRUE
HasFlexuralBucklingAboutZ	TRUE
HasGeneratingObjectInfo	FALSE
HasGeometricSectionAxes	TRUE
HasIdForExportImport	TRUE
HasImportFromStabilityAnalysisEnabled	TRUE
HasIntermediateNodes	TRUE
HasIsGenerated	TRUE
HasLateralTorsionalBuckling	TRUE
HasMemberType	FALSE
HasMemberTypeYy	FALSE
HasMemberTypeZz	FALSE
HasMetadataForExportImport	TRUE
HasModificationFactorAlphaRestrainedSegmentsAs	FALSE
HasModificationFactorAlphaUnrestrainedSegmentsAs	FALSE
HasModificationFactorCbAisi	FALSE
HasModificationFactorCbAisiUserDefinedValue	FALSE
HasMomentModificationRestrainedSegmentsAs	FALSE
HasMomentModificationUnrestrainedSegmentsAs	FALSE
HasName	TRUE
HasNo	TRUE
HasOmega2FactorSans	FALSE
HasPrincipalSectionAxes	TRUE
HasSlendernessReductionRestrainedSegmentsAs	FALSE
HasSlendernessReductionUnrestrainedSegmentsAs	FALSE
HasStabilityImportDataFactorsDefinitionAbsolute	FALSE
HasStabilityImportDataMemberY	FALSE
HasStabilityImportDataMemberZ	FALSE
HasStabilityImportDataModeNumberY	FALSE
HasStabilityImportDataModeNumberZ	FALSE
HasStabilityImportDataUserDefinedY	FALSE
HasStabilityImportDataUserDefinedZ	FALSE
HasStandardOfEffectiveLengths	FALSE
HasTorsionalBuckling	TRUE
HasUserDefinedNameEnabled	TRUE
IdForExportImport	0af6b4ed-cdb1-42b8-8aeb-a1fd7f783024
ImportFromStabilityAnalysisEnabled	FALSE
IntermediateNodes	TRUE
IsGenerated	FALSE
LateralTorsionalBuckling	TRUE
Lengths	null
Members	[Collection: 0 items]
MemberSets	[Collection: 1 items]
MemberType	Beam
MemberTypeYy	Beam
MemberTypeZz	Beam
MetadataForExportImport
ModificationFactorAlphaRestrainedSegmentsAs	0
ModificationFactorAlphaUnrestrainedSegmentsAs	0
ModificationFactorCbAisi	BasicValue
ModificationFactorCbAisiUserDefinedValue	0
MomentModificationRestrainedSegmentsAs	BasicValue
MomentModificationUnrestrainedSegmentsAs	BasicValue
Name	Standard
No	1
NodalSupports	{ rows: [ { supportType: SUPPORT_TYPE_FIXED_IN_Z_Y_AND_TORSION, supportInZ: true, eccentricityType: ECCENTRICITY_TYPE_NONE, supportInY: SUPPORT_IN_Y_SUPPORT_STATUS_YES, restraintAboutX: RESTRAINT_ABOUT_X_SUPPORT_STATUS_YES, restraintAboutZ: RESTRAINT_ABOUT_Z_SUPPORT_STATUS_NO, restraintWarping: RESTRAINT_WARPING_SUPPORT_STATUS_NO }, { supportType: SUPPORT_TYPE_FIXED_ALL, supportInZ: true, eccentricityType: ECCENTRICITY_TYPE_NONE, supportInY: SUPPORT_IN_Y_SUPPORT_STATUS_YES, restraintAboutX: RESTRAINT_ABOUT_X_SUPPORT_STATUS_YES, restraintAboutZ: RESTRAINT_ABOUT_Z_SUPPORT_STATUS_YES, restraintWarping: RESTRAINT_WARPING_SUPPORT_STATUS_YES } ] }
Omega2FactorSans	0
PrincipalSectionAxes	TRUE
SlendernessReductionRestrainedSegmentsAs	AccTo5611
SlendernessReductionUnrestrainedSegmentsAs	AccTo5611
StabilityImportDataFactors	null
StabilityImportDataFactorsDefinitionAbsolute	FALSE
StabilityImportDataLengths	null
StabilityImportDataLoadingY	null
StabilityImportDataLoadingZ	null
StabilityImportDataMemberY	0
StabilityImportDataMemberZ	0
StabilityImportDataModeNumberY	0
StabilityImportDataModeNumberZ	0
StabilityImportDataUserDefinedY	FALSE
StabilityImportDataUserDefinedZ	FALSE
StandardOfEffectiveLengths	Aisc360
TorsionalBuckling	TRUE
UserDefinedNameEnabled	FALSE

I'm setting up the code by following the hints given in the documentation class definitions and the objects read from RFEM, but it does not work. @frank.faulstich, @robert.milrath, @tomas.pail, do you know why this is happening?

tomas.pail · January 14, 2026, 7:45am

Hi amazigh & PSA001,

let me share that in 6.13.0001 | 2.13.1 the issue with missing intermediate nodes in the EffectiveLengths.NodalSupportsRow has been solved.

Looking forward for the feedback.
Regards

amazigh · January 14, 2026, 11:40am

Hello,
Ohhh thanks a lot !! Very good news