Read M, K and C matrices and compute energy of each DOF

robertavarela
robertavarela New Altair Community Member
edited October 2020 in Community Q&A

Hello, community.

 

@Kosuke IKEDA and I recently worked on a DMIGPCH reader for OML. It is an output file from OptiStruct with reduced M (mass), K (stiffness) and C (damping) matrices that can be fed into external data files to be used in subsequent analyses.

 

These are ASCII files whose tags MAAX, KAAX and BAAX identify what is data from mass, stiffness and damping, respectively:

image.png.c5ac65156c1292f33c16fbcf73f6f5a6.png

Each value represents the nodal real value of the matrix. With it, it's possible to compute the eigen values and energy distribution of each degree of freedom.

<?xml version="1.0" encoding="UTF-8"?>image.thumb.png.c3f12bf248deb5c89fa785bbba94e960.png

Regards,

 

Roberta

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Answers

  • robertavarela
    robertavarela New Altair Community Member
    edited June 2020

    Based on the same script, @Kosuke IKEDA created an example connecting OptiStruct Activate, where K, M and C matrices were converted from OS to ABCD matrices (state-space system):

    image.png.1515a4adc5d6faf73e7857760aa37ebe.png

    Which may be imported in Activate then.

     

    The impulse response results match OS transient:

    image.png.e1c5cc6992488f74f26344977ead5f45.png

    Regards,

     

    Roberta

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