Plot and animate mode shapes with DPF

This example shows how to extract mode shapes from a modal analysis result and how to plot and animate them.

from ansys.dpf import core as dpf
from ansys.dpf.core import animation
from ansys.dpf.core import examples

Retrieve mode shapes

# Load the result file as a model
model = dpf.Model(examples.download_modal_frame())
print(model)

# Extract the displacement results which define mode shapes
disp = model.results.displacement.on_all_time_freqs.eval()

DPF Model
------------------------------
Modal analysis
Unit system: NMM: mm, ton, N, s, mV, mA, degC
Physics Type: Mechanical
Available results:
     -  displacement: Nodal Displacement
     -  stress: ElementalNodal Stress
     -  elastic_strain: ElementalNodal Strain
     -  element_euler_angles: ElementalNodal Element Euler Angles
------------------------------
DPF  Meshed Region:
  5886 nodes
  2842 elements
  Unit: mm
  With solid (3D) elements
------------------------------
DPF  Time/Freq Support:
  Number of sets: 6
Cumulative     Frequency (Hz) LoadStep       Substep
1              253.615690     1              1
2              317.918491     1              2
3              329.825709     1              3
4              575.619678     1              4
5              621.973976     1              5
6              667.364882     1              6

Plot mode shapes

# Get the frequency scoping (available frequency IDs for disp)
freq_scoping = disp.get_time_scoping()
# Get the frequency support (all available frequencies in the model)
freq_support = disp.time_freq_support
# Get the unit from the time_freq_support
unit = freq_support.time_frequencies.unit

# For each ID in the scoping
for freq_set in freq_scoping:
    # Get the associated frequency in the time_freq_support
    freq = freq_support.get_frequency(cumulative_index=freq_set - 1)
    # Get the associated mode shape as a displacement field
    disp_mode = disp.get_field_by_time_complex_ids(freq_set, 0)
    # Extract the mode frequency and unit
    text = f"{freq:.3f}{unit}"
    # Plot the mode displacement field on the deformed mesh
    disp_mode.plot(deform_by=disp_mode, scale_factor=2.0, text=text)

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Animate a mode shape To suppress window pop-up, set the off_screen argument to True. ~~~~~~~~~~~~~~~~~~~~

animation.animate_mode(disp, mode_number=1, save_as="tmp.gif", off_screen=True)