ASTM-E2126-Backbone-Curve-Tool is a Python-based graphical application for processing cyclic hysteresis test data and automatically generating backbone (envelope) curves, ASTM E2126 Equivalent Energy Elastic-Plastic (EEEP) bilinear idealizations, stiffness degradation curves, and energy dissipation plots. The application processes experimental displacement-force data stored in text files and produces engineering plots, CSV files, and summary reports. An overview of the software interface and its usage is available in the following video:
Cite this Tool:
The overall workflow implemented by ASTM-E2126-Backbone-Curve-Tool is illustrated Figure 1. Starting from cyclic hysteresis test data, the application automatically extracts backbone curves, computes ASTM E2126 Equivalent Energy Elastic-Plastic (EEEP) bilinear idealizations, evaluates engineering properties, and exports publication-ready figures and CSV reports.
Figure 1. Workflow of the ASTM-E2126-Backbone-Curve-Tool.
Experimental cyclic loading tests are commonly performed to evaluate the seismic performance of structural systems. Processing these datasets manually to extract backbone curves and engineering properties is time-consuming and prone to errors.
ASTM-E2126-Backbone-Curve-Tool automates the complete post-processing workflow by implementing the ASTM E2126 EEEP method. The software extracts backbone curves, calculates engineering parameters, generates publication-quality plots, and exports numerical results for further analysis.
The application provides an interactive graphical user interface (GUI) designed for researchers and practicing structural engineers.
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Backbone Curve Extraction
- Automatically extracts positive and negative backbone (envelope) curves from cyclic hysteresis data.
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ASTM E2126 Bilinear Idealization
- Computes the Equivalent Energy Elastic-Plastic (EEEP) bilinear model using ASTM E2126 methodology.
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Positive, Negative and Average Backbone Curves
- Separates positive and negative branches and computes the average backbone response.
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Engineering Properties
- Peak force
- Peak displacement
- Yield force
- Yield displacement
- Ultimate force
- Ultimate displacement
- Initial stiffness
- Energy dissipation
- Ductility
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Cycle Analysis
- Automatic cycle identification
- Stiffness degradation
- Energy dissipation per loading cycle
- Cumulative energy dissipation
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Interactive GUI
- Modern Tkinter interface
- Interactive Matplotlib plotting
- Zoom and pan
- Crosshair cursor
- Live coordinate display
- Click-to-inspect data points
- Specimen search
- Previous/Next specimen navigation
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Professional Plot Export
- PNG
- SVG
- Adjustable export DPI
- Copy plot directly to clipboard
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Batch Processing
- Processes multiple TXT files automatically.
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Automatic Report Generation
- Summary CSV containing engineering properties for every specimen.
The application follows the workflow below:
- Prepare cyclic hysteresis data in TXT format.
- Select the input folder containing all specimens.
- Choose an output folder.
- Process all files with a single click.
- Review generated plots interactively.
- Export plots and numerical results.
- Use the generated CSV files for further structural analysis or publication.
The software automatically creates organized folders containing:
- All Backbone Curves (Plots)
- All Backbone Curves (CSVs)
- Positive-Negative-Average Plots
- Positive-Negative-Average CSVs
- Bilinear Idealization Plots
- Bilinear Idealization CSVs
- Stiffness Degradation Plots
- Stiffness Degradation CSVs
- Energy Dissipation Plots
- Energy Dissipation CSVs
- Summary Report
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Export cyclic hysteresis data as TXT files.
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Place all TXT files inside a single input folder.
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Run the application:
python BBCurve.py- Select:
- Input Folder
- Output Folder
- Click:
Process All TXT Files
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Review results using the interactive plot viewer.
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Export figures and reports if required.
The software implements engineering procedures based on:
- ASTM E2126
- Equivalent Energy Elastic-Plastic (EEEP) Bilinear Idealization
- Backbone (Envelope) Curve Extraction
- Stiffness Degradation Analysis
- Energy Dissipation Analysis
- Ductility Calculation
This software is intended for:
- Structural Engineers
- Earthquake Engineers
- Researchers
- Graduate Students
- Laboratory Engineers
- Universities and Research Institutes
This project is licensed under the MIT License. You are free to use, modify, and distribute this software under the terms of the license.
- Developer: Tufail Mabood
- Contact: WhatsApp
- Note: This project is open-source. Contributions and improvements are welcome.
This project is open-source. Contributions, feature requests, and improvements are welcome.