frame_postprocess

What is it?

frame_postprocess is an open-source python package that facilitates the postprocessing of seismic nonlinear response history analyses (NLRHA) of 2D OpenSees models of moment frames.

frame_postprocess was the main post-processing tool in following publications:

• Galvis, F. A. (2022). “Seismic Risk and Post-Earthquake Recovery of Older Tall Buidings with Welded Steel Moment Frames.”Ph.D. thesis. John A. Blume Earthquake Engineering Center, Stanford University.

• Galvis, F. A., Deierlein, G. G., Yen, W., and Molina Hutt, C., Correal J. F., (2022). Detailed Database of Tall Pre-Northridge Steel Moment Frames for Earthquake Performance Evaluations. (In review).

• Galvis, F. A., Deierlein, G. G., Zsarnoczay3, A., and Molina Hutt, C., (2022). Seismic screening method for tall pre-Northridge welded steel moment frames based on the collapse risk of a realistic portfolio. (In preparation).

What can I use it for?

Collect data from OpenSees tcl outputs

The package has multiple functions to read and store in the proper format the output files from OpenSees tcl models. These outputs are conveniently stored in .csv files appropiate for the loss assessment package pelicun (https://github.com/NHERI-SimCenter/pelicun). Detailed results that include hinge rotations, damage index for welded connections, and panel zone response and stored in a unique HDF file.

Plotting frame elevations

The package is capable of plotting 2D frames with any of the following configurations:

• Setbacks
• Podiums
• Atriums
• Interrupted columns lines
• Atypical story heights

The reponse of beam hinges, column hinges, splices, and panel zones can be presented as shown in Figure 1. For welded steel moment frames, the package treats the connection damage index (see SteelFractureDI material in OpenSees) as an engineering demand parameter (EDPs).

Figure 1. Example collapse mechanisms plotted with frame_postprocessing functions.

Plotting EDP responses

The EDPs can be easily plotted in height overlaying relevant statistics for collapse and non-collapse simulations as shown in Figure 2 and Figure 3.

Figure 2. Example EDP results for the non-collapse NLRHAs of a building in a scenario earthquake analysis.

Figure 3. Example EDP results for the collapse NLRHAs of a building in a scenario earthquake analysis.

Calculating fragility curver from multi-stripe analysis

frame_postprocess also includes functions to compute and plot the collapse fragility function of a structure from the results of a multi-stripe analysis (Figure 4).

Figure 4. Example collapse fragility curve from the results of a multi-stripe analysis.

How can I get started?

The Example/1_Raw_NLRHA_results folder includes raw OpenSees results from a tcl model created by the package galvisf/ModelerWSMFA. These results are collected by the Juyter notebook Example_frame_postprocess_collect.ipynb and stored in the folder Example/2_Collected_NLRHA_results. Juyter notebook Example_frame_postprocess_plot.ipynb generates the figures shown above for the example building and store them in Example/3_Output_figures. More examples can be found on the supplemental material for the publications listed above.

Installation

frame_postprocess is available at the Python Package Index (PyPI) at the url https://pypi.org/project/frame-postprocess/0.1/. You can simply install it using pip as follows:

pip install frame_postprocess

License

frame_postprocess is distributed under the MIT license, see LICENSE.

Contact

Francisco Galvis, galvisf@alumni.stanford.edu