How do I retrieve Natural Frequencies from a Modal Analysis using DPF in Mechanical?

Ayush Kumar
Ayush Kumar Member, Moderator, Employee Posts: 389
First Anniversary Ansys Employee Solution Developer Community of Practice Member First Answer
edited June 2023 in Structures

How do I retrieve Natural Frequencies from a Modal Analysis using DPF in Mechanical?

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  • Ayush Kumar
    Ayush Kumar Member, Moderator, Employee Posts: 389
    First Anniversary Ansys Employee Solution Developer Community of Practice Member First Answer
    Answer ✓

    Using Time Frequency Support. If the Modal analysis is damped the frequencies are stored as imaginary frequencies.

    import mech_dpf
    
    mech_dpf.setExtAPI(ExtAPI)
    import Ans.DataProcessing as dpf
    
    dpf.DataProcessingCore.LoadLibrary("math", r"C:\Program Files\ANSYS Inc\v211\aisol\bin\winx64\Ans.Dpf.Math.dll")
    
    # Please change the analysis system index
    ds = mech_dpf.GetDataSources(0)
    
    time_provider = dpf.operators.metadata.time_freq_provider()
    time_provider.inputs.data_sources.Connect(ds)
    

    Damped Modal Analysis

    natural_freqs = time_provider.outputs.time_freq_support.GetData().ImaginaryFreqs.Data
    

    Undamped Modal Analysis

    natural_freqs = time_provider.outputs.time_freq_support.GetData().TimeFreqs.Data