Download this example

Download this example as a Jupyter Notebook or as a Python script.

---

3D Rotational Actuator

In this example the rotational position of the actuator is defined and controled by a global parameter named angle. By leveraging the magnetostatics formulation we can sweep through the rotational motion and calculate the change in coil inductance, and field in a non-linear core.

The model also shows how to set up a custom non-linear material using BH curve data.

Keywords: Maxwell3D, 3D, magnetostatic, rotational motion, parametric sweep, inductance, installation example

Prerequisites

Perform imports

import os
import tempfile
import time
import csv

import ansys.aedt.core  # Interface to Ansys Electronics Desktop

Define constants

AEDT_VERSION = "2025.1"
NUM_CORES = 4
NG_MODE = False  # Open AEDT UI when it is launched.

Create temporary directory

Create a temporary working directory. The name of the working folder is stored in temp_folder.name.

Note: The final cell in the notebook cleans up the temporary folder. If you want to retrieve the AEDT project and data, do so before executing the final cell in the notebook.

temp_folder = tempfile.TemporaryDirectory(suffix=".ansys")

Launch Maxwell 3d

Create an instance of the Maxwell3d class. The Ansys Electronics Desktop will be launched with an active Maxwell2D design. The m3d object is subsequently used to create and simulate the actuator model.

project_name = os.path.join(temp_folder.name, "rotational_actuator.aedt")
m3d = ansys.aedt.core.Maxwell3d(
    project=project_name,
    design="3d_magsta_actuator",
    solution_type="Magnetostatic",
    version=AEDT_VERSION,
    non_graphical=NG_MODE,
    new_desktop=True,
)

PyAEDT INFO: Python version 3.10.11 (tags/v3.10.11:7d4cc5a, Apr  5 2023, 00:38:17) [MSC v.1929 64 bit (AMD64)].
PyAEDT INFO: PyAEDT version 0.18.dev0.
PyAEDT INFO: Initializing new Desktop session.
PyAEDT INFO: Log on console is enabled.
PyAEDT INFO: Log on file C:\Users\ansys\AppData\Local\Temp\pyaedt_ansys_5c76ef36-73bd-4138-a21c-c23cf5643952.log is enabled.
PyAEDT INFO: Log on AEDT is disabled.
PyAEDT INFO: Debug logger is disabled. PyAEDT methods will not be logged.
PyAEDT INFO: Launching PyAEDT with gRPC plugin.
PyAEDT INFO: New AEDT session is starting on gRPC port 54607.
PyAEDT INFO: Electronics Desktop started on gRPC port: 54607 after 6.616901397705078 seconds.
PyAEDT INFO: AEDT installation Path C:\Program Files\ANSYS Inc\v251\AnsysEM
PyAEDT INFO: Ansoft.ElectronicsDesktop.2025.1 version started with process ID 10152.
PyAEDT INFO: Project rotational_actuator has been created.
PyAEDT INFO: Added design '3d_magsta_actuator' of type Maxwell 3D.
PyAEDT INFO: Aedt Objects correctly read

Model Preparation

Declare and initialize design parameters

The angle parameter will be used to sweep through the actuators rotational motion

m3d["angle"] = "29deg"

Create 3D model

Set model units

m3d.modeler.model_units = "mm"

PyAEDT INFO: Modeler class has been initialized! Elapsed time: 0m 0sec

Create non-linear magnetic material with single valued BH curve

Create list with BH curve data

bh_curve = [[0.0, 0.0],
            [4000.0, 1.413],
            [8010.0, 1.594],
            [16010.0, 1.751],
            [24020.0, 1.839],
            [32030.0, 1.896],
            [40030.0, 1.936],
            [48040.0, 1.967],
            [64050.0, 2.008],
            [80070.0, 2.042],
            [96080.0, 2.073],
            [112100.0, 2.101],
            [128110.0, 2.127],
            [144120.0, 2.151],
            [176150.0, 2.197],
            [208180.0, 2.24],
            [272230.0, 2.325],
            [304260.0, 2.37],
            [336290.0, 2.42],
            [396000.0, 2.5]]

Create custom material and add it to the AEDT library using the add_material method

arm_steel = m3d.materials.add_material(name="arm_steel")
arm_steel.conductivity = 2000000
arm_steel.permeability.value = bh_curve

PyAEDT INFO: Materials class has been initialized! Elapsed time: 0m 0sec
PyAEDT INFO: Adding new material to the Project Library: arm_steel
PyAEDT INFO: Material has been added in Desktop.

Create outer arm

outer_arm = m3d.modeler.create_cylinder(orientation=ansys.aedt.core.constants.AXIS.Z ,origin=[0,0,0],radius=104.5,height=25.4,num_sides=0, name="Outer_arm", material=arm_steel.name)
cylinder_tool = m3d.modeler.create_cylinder(orientation=ansys.aedt.core.constants.AXIS.Z ,origin=[0,0,0],radius=83.1,height=25.4,num_sides=0, name="Cylinder_tool")
m3d.modeler.subtract([outer_arm],[cylinder_tool], keep_originals=False)
box_1 = m3d.modeler.create_box(origin=[-13.9 ,0 ,0],sizes=[27.8,-40,25.4], name="Box1")
m3d.modeler.move(box_1,vector=[0,-45,0])
m3d.modeler.duplicate_and_mirror(assignment=box_1,origin=[0,0,0],vector=[0,1,0])
m3d.modeler.unite([outer_arm, box_1.name, box_1.name+"_1"])
cylinder_1 = m3d.modeler.create_cylinder(orientation=ansys.aedt.core.constants.AXIS.Z ,origin=[0,0,0],radius=53.75,height=25.4,num_sides=0, name="Cylinder1")
m3d.modeler.subtract([outer_arm],[cylinder_1], keep_originals=False)
outer_arm.color="(192 192 192)"

PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Union of 3 objects has been executed.
PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec

Create inner arm

inner_arm = m3d.modeler.create_cylinder(orientation=ansys.aedt.core.constants.AXIS.Z ,origin=[0,0,0],radius=38.1,height=25.4,num_sides=0, name="Inner_arm", material=arm_steel.name)
shaft = m3d.modeler.create_cylinder(orientation=ansys.aedt.core.constants.AXIS.Z ,origin=[0,0,0],radius=25.4,height=25.4,num_sides=0, name="shaft")
m3d.modeler.subtract([inner_arm],[shaft], keep_originals=False)
box_2 = m3d.modeler.create_box(origin=[-12.7 ,0 ,0],sizes=[25.4,-20,25.4], name="Box2")
m3d.modeler.move(box_2,vector=[0,-35,0])
m3d.modeler.duplicate_and_mirror(assignment=box_2,origin=[0,0,0],vector=[0,1,0])
m3d.modeler.unite([inner_arm, box_2.name, box_2.name+"_1"])
finalpole2 = m3d.modeler.create_cylinder(orientation=ansys.aedt.core.constants.AXIS.Z ,origin=[0,0,0],radius=51.05,height=25.4,num_sides=0, name="finalpole2")
m3d.modeler.intersect(assignment=[inner_arm, finalpole2])
inner_arm.color="(192 192 192)"

PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Union of 3 objects has been executed.
PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Intersection Succeeded

Create a local/relative coordinate system

m3d.modeler.create_coordinate_system(origin=[0 ,0 ,12.7],reference_cs="Global",name="RelativeCS1",mode="axis",x_pointing=[1 ,0 ,0],y_pointing=[0 ,1 ,0])

<ansys.aedt.core.modeler.cad.modeler.CoordinateSystem at 0x2109b195c60>

Apply rotation on relative coordinate system

m3d.modeler.rotate(assignment=[inner_arm], axis="RelativeCS1" , angle="angle")

True

Create coils

coil1 = m3d.modeler.create_rectangle(orientation=ansys.aedt.core.constants.AXIS.X,origin=[0,0,15.5],sizes=[17,24], name="coil1", material="copper")
coil1.color="(249 186 70)"
path_rectangle = m3d.modeler.create_rectangle(orientation=ansys.aedt.core.constants.AXIS.Y,origin=[-17,0,-15.5],sizes=[31,34], name="path")
m3d.modeler.uncover_faces([path_rectangle.faces[0]])
m3d.modeler.sweep_along_path(assignment=coil1, sweep_object=path_rectangle)
round = m3d.modeler.create_cylinder(orientation=ansys.aedt.core.constants.AXIS.Y ,origin=[0,0,0],radius=46.238512086788,height=17,num_sides=0, name="Round")
m3d.modeler.intersect(assignment=[coil1, round])
m3d.modeler.move(assignment=coil1,vector=[0,54.5,0])
m3d.modeler.duplicate_and_mirror(assignment=coil1,origin=[0,0,0],vector=[0,1,0])
m3d.modeler.section(assignment=coil1,plane='XY')
m3d.modeler.section(assignment=coil1.name + "_1",plane='XY')

PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Intersection Succeeded

True

Create air region

bgnd = m3d.modeler.create_box(origin=[-250 ,-250 ,-250],sizes=[500,500,500], name="bgnd")
bgnd.transparency = 1

Create Coil Terminals by Separating Sheet bodies

coil_terminal1 = coil1.name + "_1_Section1_Separate1"
coil_terminal2 = coil1.name + "_Section1"
m3d.modeler.separate_bodies(assignment=coil_terminal2)
m3d.modeler.delete(assignment=coil1.name + "_Section1_Separate1")
m3d.modeler.separate_bodies(assignment=coil1.name + "_1_Section1")
m3d.modeler.delete(assignment=coil1.name + "_1_Section1")

PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Deleted 1 Objects: coil1_Section1_Separate1.
PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Deleted 1 Objects: coil1_1_Section1.

True

m3d.modeler.fit_all()

Assign boundary conditions

m3d.assign_current(assignment=coil_terminal1, amplitude=675.5, solid=False, name="Current_1")
m3d.assign_current(assignment=coil_terminal2, amplitude=675.5, solid=False, name="Current_2")

PyAEDT INFO: Boundary Current Current_1 has been created.
PyAEDT INFO: Boundary Current Current_2 has been created.

<ansys.aedt.core.modules.boundary.common.BoundaryObject at 0x210a0130850>

Define solution setup

m3d.assign_matrix(assignment=["Current_1", "Current_2"],matrix_name="Matrix1")
m3d.assign_torque(assignment=inner_arm.name, is_virtual=True, coordinate_system="Global", axis="Z", torque_name="Virtual_Torque")

PyAEDT INFO: Boundary Matrix Matrix1 has been created.
PyAEDT INFO: Boundary Torque Virtual_Torque has been created.

<ansys.aedt.core.modules.boundary.maxwell_boundary.MaxwellParameters at 0x210a0131030>

setup = m3d.create_setup("MySetup")
print(setup.props)
setup.props["MaximumPasses"] = 10
setup.props["PercentRefinement"] = 30
setup.props["PercentError"] = 1
setup.props["MinimumPasses"] = 2
setup.props["RelativeResidual"] = 1e-3

{'Enabled': True, 'MeshLink': {'ImportMesh': False}, 'MaximumPasses': 10, 'MinimumPasses': 2, 'MinimumConvergedPasses': 1, 'PercentRefinement': 30, 'SolveFieldOnly': False, 'PercentError': 1, 'SolveMatrixAtLast': True, 'UseIterativeSolver': False, 'RelativeResidual': 1e-06, 'NonLinearResidual': 0.001, 'SmoothBHCurve': False, 'MuOption': {'MuNonLinearBH': True}, 'Name': 'MySetup'}

parametric_sweep = m3d.parametrics.add(variable="angle",start_point="0", end_point="30", step="5",
                                       variation_type="LinearStep",name="ParametricSetup1")
parametric_sweep.add_calculation(calculation="Virtual_Torque.Torque")
parametric_sweep.add_calculation(calculation="Matrix1.L(Current_1, Current_1)")
parametric_sweep.add_calculation(calculation="Matrix1.L(Current_1, Current_2)")
parametric_sweep.add_calculation(calculation="Matrix1.L(Current_2, Current_1)")
parametric_sweep.add_calculation(calculation="Matrix1.L(Current_2, Current_2)")
parametric_sweep.props["ProdOptiSetupDataV2"]["SaveFields"] = True

PyAEDT INFO: Parsing C:/Users/ansys/AppData/Local/Temp/tmp_oa6yc22.ansys/rotational_actuator.aedt.
PyAEDT INFO: File C:/Users/ansys/AppData/Local/Temp/tmp_oa6yc22.ansys/rotational_actuator.aedt correctly loaded. Elapsed time: 0m 0sec
PyAEDT INFO: aedt file load time 0.015563488006591797

Run analysis

parametric_sweep.analyze(cores=NUM_CORES)

PyAEDT INFO: Key Desktop/ActiveDSOConfigurations/Maxwell 3D correctly changed.
PyAEDT INFO: Solving Optimetrics
PyAEDT INFO: Key Desktop/ActiveDSOConfigurations/Maxwell 3D correctly changed.
PyAEDT INFO: Design setup ParametricSetup1 solved correctly in 0.0h 8.0m 41.0s

True

Postprocess

Create a Rectangular plot of Coil Inductance vs. Rotational Angle

m3d.post.create_report(
    expressions=["Matrix1.L(Current_1, Current_1)",
                 "Matrix1.L(Current_1, Current_2)"],
    variations={"angle": "All"},
    plot_name="Coil Inductance vs. Angle",
    primary_sweep_variable="angle",
    plot_type="Rectangular Plot",
)

PyAEDT INFO: PostProcessor class has been initialized! Elapsed time: 0m 0sec
PyAEDT INFO: PostProcessor class has been initialized! Elapsed time: 0m 0sec
PyAEDT INFO: Post class has been initialized! Elapsed time: 0m 0sec

<ansys.aedt.core.visualization.report.standard.Standard at 0x210b047fdf0>

Create field plots on the surface of the actuator’s arms

m3d.post.create_fieldplot_surface(
    assignment=[inner_arm, outer_arm], quantity="Mag_B", plot_name="Mag_B1", field_type="Fields")

PyAEDT INFO: Active Design set to 3d_magsta_actuator

<ansys.aedt.core.visualization.post.field_data.FieldPlot at 0x210a0132110>

m3d.post.create_fieldplot_surface(
    assignment=[inner_arm, outer_arm], quantity="B_Vector", plot_name="B_Vector1", field_type="Fields")#

PyAEDT INFO: Active Design set to 3d_magsta_actuator

<ansys.aedt.core.visualization.post.field_data.FieldPlot at 0x210a0131f30>

Finish

Save the project

m3d.save_project()
m3d.release_desktop()
# Wait 3 seconds to allow AEDT to shut down before cleaning the temporary directory.
time.sleep(3)

PyAEDT INFO: Project rotational_actuator Saved correctly
PyAEDT INFO: Desktop has been released and closed.

Clean up

All project files are saved in the folder temp_folder.name. If you’ve run this example as a Jupyter notebook, you can retrieve those project files. The following cell removes all temporary files, including the project folder.

temp_folder.cleanup()

---

Download this example

Download this example as a Jupyter Notebook or as a Python script.