Hello! I'm trying to create a surface model to use for FEM in Nastran-In-CAD. For that reason I'm splitting a surface body into several different faces to apply loads on. I want to automate this using Nastran's iLogic functionality.
(Nastran-In-CAD iLogic documentation)
When using the Nastran iLogic commands you need to give the ID of the entity (in my case the ID of the face). The problem is that the numbering of faces seems to be random after performing SplitFaces(), so I can't tell in advance what ID a face has.
Here is the iLogic code I am running:
' Set a reference to the Inventor application Dim _invApp As Inventor.Application _invApp = ThisApplication ' Create a new part document Dim oDoc As PartDocument oDoc = _invApp.Documents.Add(DocumentTypeEnum.kPartDocumentObject, _invApp.GetTemplateFile(DocumentTypeEnum.kPartDocumentObject)) ' Set a reference to the component definition Dim oPartCompDef As PartComponentDefinition oPartCompDef = oDoc.ComponentDefinition ' Set a reference to the transient geometry Dim oTG As TransientGeometry = _invApp.TransientGeometry ' --- Sketch and extrude a half cylinder --- Dim oSketch As PlanarSketch Dim oArc As SketchArc ' Create a center point. Dim oCenter As Point2d oCenter = oTG.CreatePoint2d(0, 0) ' Create a new sketch oSketch = oPartCompDef.Sketches.Add(oPartCompDef.WorkPlanes.Item(3)) ' Add a sketch on workplane 3 (the x-y plane) oArc = oSketch.SketchArcs.AddByCenterStartSweepAngle(oCenter, 100, 0, Math.PI) ' Add a Arc to the sketch, input: centerpoint, radius in cm, sweep angle in radians Dim oProfile As Profile oProfile = oSketch.Profiles.AddForSurface ' Store the sketch as a profile (to use for extrude) ' Define the extrusion. Dim oExtrudeDef As ExtrudeDefinition Dim Operation As PartFeatureOperationEnum = PartFeatureOperationEnum.kSurfaceOperation ' Surface extrusion oExtrudeDef = oPartCompDef.Features.ExtrudeFeatures.CreateExtrudeDefinition(oProfile, Operation) ' Profile to extrude and what type of operation. Call oExtrudeDef.SetDistanceExtent(300, PartFeatureExtentDirectionEnum.kPositiveExtentDirection) ' Set length of extrude (cm) and the direction ' Create the extrusion Dim oExtrude As ExtrudeFeature oExtrude = oPartCompDef.Features.ExtrudeFeatures.Add(oExtrudeDef) ' Use the oExtrudeDef to create the extrude ' --- Access the surface body of the extrude --- Dim oSurfaceBody As SurfaceBody oSurfaceBody = oExtrude.SurfaceBodies.Item(1) ' --- Create two horizontal workplanes --- Dim oPlane1 As WorkPlane oPlane1 = oPartCompDef.WorkPlanes.AddByPlaneAndOffset(oPartCompDef.WorkPlanes.Item(3), 100) Dim oPlane2 As WorkPlane oPlane2 = oPartCompDef.WorkPlanes.AddByPlaneAndOffset(oPartCompDef.WorkPlanes.Item(3), 200) ' --- Create two vertical workplanes --- Dim oPlane3 As WorkPlane oPlane3 = oPartCompDef.WorkPlanes.AddByLinePlaneAndAngle(oPartCompDef.WorkAxes.Item(3), oPartCompDef.WorkPlanes.Item(2), 50 * Math.PI / 180) Dim oPlane4 As WorkPlane oPlane4 = oPartCompDef.WorkPlanes.AddByLinePlaneAndAngle(oPartCompDef.WorkAxes.Item(3), oPartCompDef.WorkPlanes.Item(2), 130 * Math.PI / 180) ' --- Split the surface body using the horizontal planes --- Dim oSplitFeature1 As SplitFeature oSplitFeature1 = oPartCompDef.Features.SplitFeatures.SplitFaces(oPlane1, True, oSurfaceBody) Dim oSplitFeature2 As SplitFeature oSplitFeature2 = oPartCompDef.Features.SplitFeatures.SplitFaces(oPlane2, True, oSurfaceBody) ' --- Split the surface body using the vertical planes --- Dim oSplitFeature3 As SplitFeature oSplitFeature3 = oPartCompDef.Features.SplitFeatures.SplitFaces(oPlane3, True, oSurfaceBody) Dim oSplitFeature4 As SplitFeature oSplitFeature4 = oPartCompDef.Features.SplitFeatures.SplitFaces(oPlane4, True, oSurfaceBody) oDoc.ObjectVisibility.UserWorkPlanes = False ' Hide all user-created workplanes
(This creates a new part file each time. The reason for that is so that the face numbering starts at one even if you run the code several times.)
Press Home view so the the model is visible. Enter Nastran-In-CAD and start the Idealization command. Select "Shell Elements" and check the "Associated Geometry" box. When selecting a face I can see the ID it has.
If I run the code several times and check the numbering of the faces I get different results. Here is a picture with some of the combinations (model in the same view as above):
Anyone that has an idea how to fix this or if there is a way to work around this problem? Any thoughts are appreciated!
