PyAnsys Example - modal analysis of a cylinder in stiff ground

FGOMEZ

This example was built during the PyANSYS 2025 at Lyon with the help of R.LIBERT (JE) and F.GOMEZ (JE).

In this example we build an circular cylinder fixed on stiff ground, mesh, perform a modal analysis and display results using PyAnsys and ansys products in headless mode.

The project is built with:

• main.py => python script to perform all the stuff. The cylinder parameters and files naming are editable at the start of the main
• Geom_template.py => python template designed with SpaceClaim autoscript + modifications to generate the geometry file geom.py that will be processed by space claim to build the geometry.
• Mechanical_template.py => python template designe with Mechanical autoscript + modifications to generate the mecanical file mechanical.py that will be processed by Mechanical
• Requirement.txt => pip freeze > requirements.txt to backup our python installation

FGOMEZ

main.py

import os
 
from ansys.mechanical.core import launch_mechanical
from ansys.geometry.core import launch_modeler_with_spaceclaim  
 
 
#%% Inputs parameters
# ~~~~~~~~~~~~~~~~~~~
geom_template_file_name = "Geom_template.py"
meca_template_file_name = "Mechanical_template.py"
geom_file_name = "Geom.py"
geom_CAD_name = "Geom.x_t"
meca_file_name = "Mechanical.py"
P4= 1000 # inner radius
P6= 1500 # external radius
P7= 500 # length
 
# %% Functions
# ~~~~~~~~~~~~
 
def create_geom(geometry_CAD, geom_template_file, geom_file, P4, P6, P7):
    with open(geom_template_file,'r') as f:
        content = f.read()
    content = content.replace("INT_P4",str(P4)) 
    content = content.replace("INT_P6",str(P6))
    content = content.replace("INT_P7",str(P7))
    content = content.replace("CHAR_geometry_CAD",'r"'+ geometry_CAD + '"')
    with open(geom_file,'w') as f:
        content = f.write(content)
 
def create_meca_script(geometry_CAD,meca_template_file_name, workdir):
    with open(meca_template_file_name,'r') as f:
        content = f.read()
    content = content.replace("CHAR_geometry_CAD",'r"'+ geometry_CAD + '"')
    content = content.replace("CHAR_export_folder",'r"'+ workdir + '"')
    with open(meca_file_name,'w') as f:
        content = f.write(content)
# %% # Working directory and biuld input files "geom_file" "Mechanical.py"
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
workdir = os.getcwd()
geometry_file = os.path.join(workdir,geom_file_name)
geometry_CAD = os.path.join(workdir,geom_CAD_name)
geometry_template_file = os.path.join(workdir,geom_template_file_name)
mechanical_file = os.path.join(workdir,meca_file_name)
 
# Build the geom_file
create_geom(geometry_CAD, geometry_template_file, geometry_file, P4, P6, P7)
print("created", geom_file_name, " succefully")
 
# Build de Mechanical.py
create_meca_script(geometry_CAD, meca_template_file_name, workdir)
print("created", meca_file_name, " succefully")
 
# %% Building the geometry
# ~~~~~~~~~~~~~~~~~~~~~~~~
sc = launch_modeler_with_spaceclaim(hidden=True)  # hidden=True => headless mode activated !
# 
result, design = sc.run_discovery_script_file(
    file_path= geometry_file,
    import_design=True  # Set to True to get updated design  
    )
# close SpaceClaim
sc.close()
 
# %%
# Launch Mechanical
# ~~~~~~~~~~~~~~~~~
# Launch a new Mechanical session in batch, setting the ``cleanup_on_exit``
# argument to ``False``. To close this Mechanical session when finished,
# this example must call  the ``mechanical.exit()`` method.
 
mechanical = launch_mechanical(batch=True, cleanup_on_exit=False) # batch=False GUI activated
print(mechanical)
print("=>print mechanical succefully !")
 
# %%
# Initialize variable for workflow
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Set the ``part_file_path`` variable on the server for later use.
# Make this variable compatible for Windows, Linux, and Docker containers.
 
project_directory = mechanical.project_directory
print(f"project directory = {project_directory}")
 
# Upload the file to the project directory.
mechanical.upload(file_name=geometry_CAD, file_location_destination=project_directory)
 
# Build the path relative to project directory.
base_name = os.path.basename(workdir)
combined_path = os.path.join(project_directory, base_name)
part_file_path = combined_path.replace("\\", "\\\\")
mechanical.run_python_script(f"part_file_path='{part_file_path}'")
 
# Verify the path.
result = mechanical.run_python_script("part_file_path")
print(f"part_file_path on server: {result}")
 
 
# %%
# Run the Mechanical script to attach the geometry and set up and solve the
# analysis.
 
output = mechanical.run_python_script_from_file(mechanical_file)
 
print(output)
print("=>print output succefully !")
 
# %%
# Download output file from solve and print contents
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Download the ``solve.out`` file from the server to the current working
# directory and print the contents. Remove the ``solve.out`` file.
 
def get_solve_out_path(mechanical):
    solve_out_path = ""
    for file_path in mechanical.list_files():
        if file_path.find("solve.out") != -1:
            solve_out_path = file_path
            break
 
    return solve_out_path
 
 
def write_file_contents_to_console(path):
    with open(path, "rt") as file:
        for line in file:
            print(line, end="")
 
 
solve_out_path = get_solve_out_path(mechanical)
 
if solve_out_path != "":
    current_working_directory = os.getcwd()
 
    local_file_path_list = mechanical.download(
        solve_out_path, target_dir=current_working_directory
    )
    solve_out_local_path = local_file_path_list[0]
    print(f"Local solve.out path : {solve_out_local_path}")
 
    write_file_contents_to_console(solve_out_local_path)
 
    os.remove(solve_out_local_path)
 
# %%
# Close Mechanical
# ~~~~~~~~~~~~~~~~
# Close the Mechanical session.
 
mechanical.exit()