PyOMA and PyOMA_GUI: A Python module and software for Operational Modal Analysis

This software was created to perform output-only modal identification (Operational Modal Analysis, OMA).

OMA allows the experimental estimation of the modal parameters (natural frequencies, mode shapes, damping ratios) of a structure from measurements of the vibration response in operational condition.

People and institution involved

PyOMA was born thanks to the collaboration of three main institutions:

• Norwegian Institute of Wood Technology (Norsk Treteknisk Institutt) - Dr. Dag Pasquale Pasca
• University of L'Aquila (Italy) - Dr. Angelo Aloisio
• Politecnico di Torino University - Dr. Marco Martino Rosso, Dr. Stefanos Sotiropulos and Prof. Giuseppe Carlo Marano

PyOMA Team presentation

What is PyOMA?

PyOMA is a python module that allows to perform OMA on ambient vibration measurments datasets.

PyOMA include the following algorithms:

1. Frequency Domain Decomposition (FDD)
   1. a. Original Frequency Domain Decomposition (FDD)
   2. a. Enhanced Frequency Domain Decomposition (EFDD)
   3. a. Frequency Spatial Domain Decomposition (FSDD)
2. Stochastic Subspace Identification (SSI)
   1. a. Covariance-driven Stochastic Subspace Identification (cov-SSI)
   2. b. Data-driven Stochastic Subspace Identification (dat-SSI)

To better untersdand the workflow of the functions, see the workflow here.

What is PyOMA_GUI? A brief software overview

PyOMA_GUI is a graphical user interface software developed in PyQt5, which implements in a single integrated tool the operational modal analysis of civil structures with output-only measurement data. This software utilises the aforementioned functionalities offered by the PyOMA python module. Therefore, PyOMA_GUI provides a remarkably user-friendly interface to improve the accessibility of the PyOMA module, ensuring widespread usage both for scientists, researchers, and even for applied civil and structural engineers. The main features PyOMA_GUI provides are listed below:

• Importing data tab;
• Definition of the geometry of the structure and the monitoring system (channels and degrees of freedom, DOFs);
• Preprocessing of signals tool with detrending and decimation options;
• Dynamic identification algorithms with visualization of the results (graphs, modal shapes);
• Post-processing tabs and output exportation functionalities;

The executable file PyOMA_GUI.exe for windows is already available here.

A short manual to guide the user into an introductory example is available here.

How to cite this software

If you use this software or the code, please don't forget to cite this work:

Dag Pasquale Pasca, Angelo Aloisio, Marco Martino Rosso et al., PyOMA and PyOMA_GUI: A Python module and software for Operational Modal Analysis. SoftwareX (2022) 101216, https://doi.org/10.1016/j.softx.2022.101216.

Appreciated!