Sandwich panel example

This example defines a composite lay-up for a sandwich panel using PyACP. It only shows the PyACP part of the setup. For a complete composite analysis, see PyMAPDL workflow.

---

Import the standard library and third-party dependencies.

import pathlib
import tempfile

Import the PyACP dependencies.

from ansys.acp.core import (
    ACPWorkflow,
    FabricWithAngle,
    Lamina,
    PlyType,
    get_directions_plotter,
    launch_acp,
    print_model,
)
from ansys.acp.core.extras import ExampleKeys, get_example_file
from ansys.acp.core.material_property_sets import ConstantEngineeringConstants, ConstantStrainLimits

Start ACP and load the model

Get the example file from the server.

tempdir = tempfile.TemporaryDirectory()
WORKING_DIR = pathlib.Path(tempdir.name)
input_file = get_example_file(ExampleKeys.BASIC_FLAT_PLATE_DAT, WORKING_DIR)

Launch the PyACP server and connect to it.

acp = launch_acp()

Define the input file and instantiate an ACPWorkflow instance. The ACPWorkflow class provides convenience methods that simplify file handling. It automatically creates a model based on the input file.

workflow = ACPWorkflow.from_cdb_or_dat_file(
    acp=acp,
    cdb_or_dat_file_path=input_file,
    local_working_directory=WORKING_DIR,
)

model = workflow.model
print(workflow.working_directory.path)
print(model.unit_system)

/tmp/tmp_sugwbh0
mks

Visualize the loaded mesh.

mesh = model.mesh.to_pyvista()
mesh.plot(show_edges=True)

Static Scene

Interactive Scene

/home/runner/.cache/pypoetry/virtualenvs/ansys-acp-core-O77fA6pn-py3.12/lib/python3.12/site-packages/trame_vuetify/widgets/vuetify.py:495: SyntaxWarning: invalid escape sequence '\|'
  """

Create the sandwich materials

Create the UD material and its corresponding fabric.

engineering_constants_ud = ConstantEngineeringConstants.from_orthotropic_constants(
    E1=5e10, E2=1e10, E3=1e10, nu12=0.28, nu13=0.28, nu23=0.3, G12=5e9, G23=4e9, G31=4e9
)

strain_limit = 0.01
strain_limits = ConstantStrainLimits.from_orthotropic_constants(
    eXc=-strain_limit,
    eYc=-strain_limit,
    eZc=-strain_limit,
    eXt=strain_limit,
    eYt=strain_limit,
    eZt=strain_limit,
    eSxy=strain_limit,
    eSyz=strain_limit,
    eSxz=strain_limit,
)

ud_material = model.create_material(
    name="UD",
    ply_type=PlyType.REGULAR,
    engineering_constants=engineering_constants_ud,
    strain_limits=strain_limits,
)

ud_fabric = model.create_fabric(name="UD", material=ud_material, thickness=0.002)

Create a multi-axial stackup and a sublaminate. Stackups and sublaminates help quickly build repeating laminates.

biax_carbon_ud = model.create_stackup(
    name="Biax_Carbon_UD",
    fabrics=(
        FabricWithAngle(ud_fabric, -45),
        FabricWithAngle(ud_fabric, 45),
    ),
)


sublaminate = model.create_sublaminate(
    name="Sublaminate",
    materials=(
        Lamina(biax_carbon_ud, 0),
        Lamina(ud_fabric, 90),
        Lamina(biax_carbon_ud, 0),
    ),
)

Create the core material and its corresponding fabric.

engineering_constants_core = ConstantEngineeringConstants.from_isotropic_constants(E=8.5e7, nu=0.3)

core = model.create_material(
    name="Core",
    ply_type=PlyType.ISOTROPIC_HOMOGENEOUS_CORE,
    engineering_constants=engineering_constants_core,
    strain_limits=strain_limits,
)

core_fabric = model.create_fabric(name="core", material=ud_material, thickness=0.015)

Create the Lay-up

Define a rosette and oriented selection set. Plot the orientations.

rosette = model.create_rosette(origin=(0.0, 0.0, 0.0), dir1=(1.0, 0.0, 0.0), dir2=(0.0, 1.0, 0.0))

oss = model.create_oriented_selection_set(
    name="oss",
    orientation_point=(0.0, 0.0, 0.0),
    orientation_direction=(0.0, 1.0, 0),
    element_sets=[model.element_sets["All_Elements"]],
    rosettes=[rosette],
)

model.update()
plotter = get_directions_plotter(model=model, components=[oss.elemental_data.orientation])
plotter.show()

Static Scene

Interactive Scene

Create the modeling plies which define the lay-up of the sandwich panel.

modeling_group = model.create_modeling_group(name="modeling_group")

bottom_ply = modeling_group.create_modeling_ply(
    name="bottom_ply",
    ply_angle=0,
    ply_material=sublaminate,
    oriented_selection_sets=[oss],
)

core_ply = modeling_group.create_modeling_ply(
    name="core_ply",
    ply_angle=0,
    ply_material=core_fabric,
    oriented_selection_sets=[oss],
)


top_ply = modeling_group.create_modeling_ply(
    name="top_ply",
    ply_angle=90,
    ply_material=ud_fabric,
    oriented_selection_sets=[oss],
    number_of_layers=3,
)

Update and print the model.

model.update()
print_model(workflow.model)

Model
    Material Data
        Materials
            1
            UD
            Core
        Fabrics
            UD
            core
        Stackups
            Biax_Carbon_UD
        Sublaminates
            Sublaminate
    Element Sets
        All_Elements
    Edge Sets
        _FIXEDSU
    Geometry
    Rosettes
        12
        Rosette
    Lookup Tables
    Selection Rules
    Oriented Selection Sets
        oss
    Modeling Groups
        modeling_group
            bottom_ply
                ProductionPly
                    P1L1__bottom_ply
                    P1L2__bottom_ply
                ProductionPly.2
                    P2L1__bottom_ply
                ProductionPly.3
                    P3L1__bottom_ply
                    P3L2__bottom_ply
            core_ply
                ProductionPly.4
                    P1L1__core_ply
            top_ply
                ProductionPly.5
                    P1L1__top_ply
                ProductionPly.6
                    P2L1__top_ply
                ProductionPly.7
                    P3L1__top_ply

/home/runner/.cache/pypoetry/virtualenvs/ansys-acp-core-O77fA6pn-py3.12/lib/python3.12/site-packages/ansys/mapdl/core/launcher.py:822: UserWarning: The environment variable 'PYMAPDL_START_INSTANCE' is set, hence the argument 'start_instance' is overwritten.
  warnings.warn(
/home/runner/.cache/pypoetry/virtualenvs/ansys-acp-core-O77fA6pn-py3.12/lib/python3.12/site-packages/ansys/mapdl/core/component.py:174: SyntaxWarning: invalid escape sequence '\>'
  """Collection of MAPDL components.