Add FEM Constraint Tutorial/ro: Difference between revisions

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"App::PropertyBool", "NormalToBoundary",
"App::PropertyBool", "NormalToBoundary",
&quot;Parameter&quot;, &quot;Body heat flux&quot;)</pre>
&quot;Parameter&quot;, &quot;Body heat flux&quot;)</pre>
Modulul care conține proxy-ul ar putea părea puțin mai complicat. Dar pentru moment ajustați calea pictogramelor. Vom reveni la acest dosar.
The module containing the view proxy might look a little more complicated. But for now just adjust the icon path. We are going to come back to this file in later steps of the tutorial.
<pre>class ViewProxy(FemConstraint.ViewProxy):
<pre>class ViewProxy(FemConstraint.ViewProxy):
def getIcon(self):
def getIcon(self):

Revision as of 07:36, 6 September 2018

Tutorial
Topic
Level
Time to complete
Authors
M42kus
FreeCAD version
Example files
See also
None

În acest tutorial vom adăuga constrângerea vitezei fluxului la FreeCAD și vom implementa suportul pentru elmer solver. Asigurați-vă că ați citit și ați înțeles Extend FEM Module înainte de a citi acest tutorial.

Acest tutorial acoperă doar modul de implementare a constrângerilor în Python. Spre deosebire de constrângerile solver și ecuații, urmați structura modulului FEM clasic. Adică toate modulele unei constrângeri au loc în pachetul PyObjects sau PyGui.

Sumar

  1. Create document object: Obiectul documentului care se află în analiză și în care constrângerea poate fi parametrizată și legată de limite.
  2. Create GUI command: Adăugați o comandă la atelierul FEM care adaugă o constrângere a fluxului la analiza activă.
  3. Create a task panel: Panoul de sarcini este necesar pentru a permite utilizatorului să definească limitele la care dorește să definească constrângerea de viteză. Acest lucru face ca intrarea parametrilor să fie mai ușor de utilizat.
  4. Extend elmers writer: Adăugați suport pentru noua constrângere modulul Elmer FEM solver prin dezactivarea exportatorului de fișiere sif.

Crearea Documentului Obiect

În acest pas vom modifica următoarele fișiere:

  • src/Mod/Fem/CMakeLists.txt
  • src/Mod/Fem/App/CMakeLists.txt
  • src/Mod/Fem/ObjectsFem.py

și adăugați următoarele fișiere:

  • src/Mod/Fem/PyObjects/_FemConstraintFlowVelocity.py
  • src/Mod/Fem/PyGui/_ViewProviderFemConstraintFlowVelocity.py

Un document proxy și o vedere proxy sunt necesare pentru noua constrângere. Acestea se află în module separate. Proxy documentul în PyObjects și vederea proxy în PyGui. Trebuie doar să copiați modulele dintr-o constrângere existentă, de ex.

  • PyObjects/_FemConstraintSelfWeight.py
  • PyGui/_ViewProviderFemConstraintSelfWeight.py

Reglați tipul de variabilă și proprietățile la nevoile dvs. Proxy-ul documentului al constrângerii fluxului arată după cum urmează:

class Proxy(FemConstraint.Proxy):
    Type = "Fem::ConstraintFlowVelocity"
    def __init__(self, obj):
        super(Proxy, self).__init__(obj)
        obj.addProperty(
            "App::PropertyFloat", "VelocityX",
            "Parameter", "Body heat flux")
        obj.addProperty(
            "App::PropertyBool", "VelocityXEnabled",
            "Parameter", "Body heat flux")
        obj.addProperty(
            "App::PropertyFloat", "VelocityY",
            "Parameter", "Body heat flux")
        obj.addProperty(
            "App::PropertyBool", "VelocityYEnabled",
            "Parameter", "Body heat flux")
        obj.addProperty(
            "App::PropertyFloat", "VelocityZ",
            "Parameter", "Body heat flux")
        obj.addProperty(
            "App::PropertyBool", "VelocityZEnabled",
            "Parameter", "Body heat flux")
        obj.addProperty(
            "App::PropertyBool", "NormalToBoundary",
            "Parameter", "Body heat flux")

Modulul care conține proxy-ul ar putea părea puțin mai complicat. Dar pentru moment ajustați calea pictogramelor. Vom reveni la acest dosar.

class ViewProxy(FemConstraint.ViewProxy):
    def getIcon(self):
        return ":/icons/fem-constraint-flow-velocity.svg"

Add the two new modules to the build system like descripted in Extend FEM Module. Locate the correct list be searching for constraint modules.

As all objects of the FEM workbench the velocity constraint must be registerd in ObjectsFem.py. The following method adds a velocity constraint to the active document. This method will be used by the GUI command to add the constraint. It must be inserted somewhere in ObjectsFem.py.

def makeConstraintFlowVelocity(name="FlowVelocity"):
    obj = FreeCAD.ActiveDocument.addObject("Fem::ConstraintPython", name)
    import PyObjects._FemConstraintFlowVelocity
    PyObjects._FemConstraintFlowVelocity.Proxy(obj)
    if FreeCAD.GuiUp:
        import PyGui._ViewProviderFemConstraintFlowVelocity
        PyGui._ViewProviderFemConstraintFlowVelocity.ViewProxy(obj.ViewObject)
    return obj

Create GUI command

In this step we are going to modify the following files:

  • src/Mod/Fem/CMakeLists.txt
  • src/Mod/Fem/App/CMakeLists.txt
  • src/Mod/Fem/Gui/Workbench.cpp

and add the following new file:

  • src/Mod/Fem/PyGui/_CommandFemConstraintFlowVelocity.py

The command allows the user to actually add the constraint to the active analysis. Just copy a command from an existing constraint. Commands reside in the PyGui package. Adjust the resources attribute and the make method called in Activated to your needs. Also use a different command id in the addCommand call on the bottom of the module. The following class is the command class of the velocity constraint.

class Command(FemCommands.FemCommands):

    def __init__(self):
        super(Command, self).__init__()
        self.resources = {
            'Pixmap': 'fem-constraint-flow-velocity',
            'MenuText': QtCore.QT_TRANSLATE_NOOP(
                "FEM_ConstraintFlowVelocity",
                "Constraint Velocity"),
            'ToolTip': QtCore.QT_TRANSLATE_NOOP(
                "FEM_ConstraintFlowVelocity",
                "Creates a FEM constraint body heat flux")}
        self.is_active = 'with_analysis'

    def Activated(self):
        App.ActiveDocument.openTransaction(
            "Create FemConstraintFlowVelocity")
        Gui.addModule("ObjectsFem")
        Gui.doCommand(
            "FemGui.getActiveAnalysis().Member += "
            "[ObjectsFem.makeConstraintFlowVelocity()]")

Gui.addCommand('FEM_AddConstraintFlowVelocity', Command())

Add the new command file to the build system as decripted in Extend FEM Module. Locate the correct list be searching for existing command modules.

Put the command into Gui/Workbench.cpp to add it to the toolbar and menu. Search for an existing constraint of the same category as the new one (e.g. Flow) copy-paste it and adjust the command id. This should be done two times. Once for the menu and again for the toolbar.

Create a Task Panel

In this step we are going to modify the following file:

  • src/Mod/Fem/PyGui/_ViewProviderFemConstraintFlowVelocity.py

In FreeCAD constraint objects benefit greatly from task panels. Task panels can make use of more powerful input widgets which expose the unit of entered values directely to the user. The velocity constraint even requires the use of a task panel since a task panel is the only way of specifieing the face(s) on which the constraint shall be applied.

The location of the module in which task panels are implemented is not strictely defined. For the velocity constraint we are just going to put the task panel in the same module we put the view proxy. The task panel is quite complicated. It makes use of the FemSolectionWidgets.BoundarySelector(). Thats a qt widget which allows the user to select the boundaries on which the constraint shall be applied. In addition to this widget it generates another one by loading a ui file specifically created for the velocity constraint. Via this widget the velocity vector can be specified.

Most of the time is should be sufficient to just copy this class, use a suitable ui file (instead of TaskPanelFemFlowVelocity.ui) and adjust _initParamWidget() as well as _applyWidgetChanges(). If the new constraint requires bodies as references instead of boundaries just replace the BoundarySelector object with the SolidSelector.

class _TaskPanel(object):

    def __init__(self, obj):
        self._obj = obj
        self._refWidget = FemSelectionWidgets.BoundarySelector()
        # self._refWidget = FemSelectionWidgets.SolidSelector()
        self._refWidget.setReferences(obj.References)
        self._paramWidget = Gui.PySideUic.loadUi(
            App.getHomePath() + "Mod/Fem/PyGui/TaskPanelFemFlowVelocity.ui")
        self._initParamWidget()
        self.form = [self._refWidget, self._paramWidget]
        analysis = FemMisc.findAnalysisOfMember(obj)
        self._mesh = FemMisc.getSingleMember(analysis, "Fem::FemMeshObject")
        self._part = self._mesh.Part if self._mesh is not None else None
        self._partVisible = None
        self._meshVisible = None

    def open(self):
        if self._mesh is not None and self._part is not None:
            self._meshVisible = self._mesh.ViewObject.isVisible()
            self._partVisible = self._part.ViewObject.isVisible()
            self._mesh.ViewObject.hide()
            self._part.ViewObject.show()

    def reject(self):
        self._restoreVisibility()
        return True

    def accept(self):
        if self._obj.References != self._refWidget.references():
            self._obj.References = self._refWidget.references()
        self._applyWidgetChanges()
        self._obj.Document.recompute()
        self._restoreVisibility()
        return True

    def _restoreVisibility(self):
        if self._mesh is not None and self._part is not None:
            if self._meshVisible:
                self._mesh.ViewObject.show()
            else:
                self._mesh.ViewObject.hide()
            if self._partVisible:
                self._part.ViewObject.show()
            else:
                self._part.ViewObject.hide()

    def _initParamWidget(self):
        unit = "m/s"
        self._paramWidget.velocityXTxt.setText(
            str(self._obj.VelocityX) + unit)
        self._paramWidget.velocityYTxt.setText(
            str(self._obj.VelocityY) + unit)
        self._paramWidget.velocityZTxt.setText(
            str(self._obj.VelocityZ) + unit)
        self._paramWidget.velocityXBox.setChecked(
            not self._obj.VelocityXEnabled)
        self._paramWidget.velocityYBox.setChecked(
            not self._obj.VelocityYEnabled)
        self._paramWidget.velocityZBox.setChecked(
            not self._obj.VelocityZEnabled)
        self._paramWidget.normalBox.setChecked(
            self._obj.NormalToBoundary)

    def _applyWidgetChanges(self):
        unit = "m/s"
        self._obj.VelocityXEnabled = \
            not self._paramWidget.velocityXBox.isChecked()
        if self._obj.VelocityXEnabled:
            quantity = Units.Quantity(self._paramWidget.velocityXTxt.text())
            self._obj.VelocityX = float(quantity.getValueAs(unit))
        self._obj.VelocityYEnabled = \
            not self._paramWidget.velocityYBox.isChecked()
        if self._obj.VelocityYEnabled:
            quantity = Units.Quantity(self._paramWidget.velocityYTxt.text())
            self._obj.VelocityY = float(quantity.getValueAs(unit))
        self._obj.VelocityZEnabled = \
            not self._paramWidget.velocityZBox.isChecked()
        if self._obj.VelocityZEnabled:
            quantity = Units.Quantity(self._paramWidget.velocityZTxt.text())
            self._obj.VelocityZ = float(quantity.getValueAs(unit))
        self._obj.NormalToBoundary = self._paramWidget.normalBox.isChecked()

The view proxy must be extended to support the task panel we just implemented. The following extended view proxy opens the task panel when the user makes a double click on the constraint object in the tree view.

class ViewProxy(FemConstraint.ViewProxy):

    def getIcon(self):
        return ":/icons/fem-constraint-flow-velocity.svg"

    def setEdit(self, vobj, mode=0):
        task = _TaskPanel(vobj.Object)
        Gui.Control.showDialog(task)

    def unsetEdit(self, vobj, mode=0):
        Gui.Control.closeDialog()

    def doubleClicked(self, vobj):
        if Gui.Control.activeDialog():
            Gui.Control.closeDialog()
        Gui.ActiveDocument.setEdit(vobj.Object.Name)
        return True

Extend Elmers Writer

In this step we are going to modify the following file:

  • src/Mod/Fem/FemSolver/Elmer/Writer.py

The writer module contains methods for all equation types. Depending on the type of the constriant, boundary condition, initial condition or body force one has to modifiy different methods. For our flow velocity we have to adjust _handleFlowBndConditions(...).

def _handleFlowBndConditions(self):
    for obj in self._getMember("Fem::ConstraintFlowVelocity"):
        if obj.References:
            for name in obj.References[0][1]:
                if obj.VelocityXEnabled:
                    velocity = getFromUi(obj.VelocityX, "m/s", "L/T")
                    self._boundary(name, "Velocity 1", velocity)
                if obj.VelocityYEnabled:
                    velocity = getFromUi(obj.VelocityY, "m/s", "L/T")
                    self._boundary(name, "Velocity 2", velocity)
                if obj.VelocityZEnabled:
                    velocity = getFromUi(obj.VelocityZ, "m/s", "L/T")
                    self._boundary(name, "Velocity 3", velocity)
                if obj.NormalToBoundary:
                    self._boundary(name, "Normal-Tangential Velocity", True)
            self._handled(obj)