PyMAS: Python-based Direct Stiffness Method

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Project Overview

PyMAS is a versatile Python library designed for structural analysis using the Direct Stiffness Method. It offers a clear and intuitive object-oriented interface for defining structural elements, materials, loads, and supports. This makes it an excellent resource for civil engineering students, researchers, and professionals.

Key Features

• Intuitive API: Define structures, materials, and sections with a straightforward and clear syntax.
• Element Support: Easily define and work with truss, beam and frame 2D or 3D elements.
• Extensible Design: The architecture allows for future expansion to include more complex elements and analysis types.
• Open-Source: Freely available for use, modification, and distribution under the MIT License.

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Installation

The easiest way to install PyMAS is directly from PyPI using pip. It is recommended to use a virtual environment for your projects.

pip install pymas

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Quick Start: Usage Example

Here is a practical example demonstrating how to model a beam, apply loads, and perform a structural analysis.

from pymas import Structure

# dimensions of the rectangular cross section
b = 0.5  # cross section width, m
h = 1.0  # cross section heigh, m

# length and stiffness modulus
L = 10                 # beam length, m
E = 4700*28**0.5*1000  # Youn's modulus, kN/m2

# cross-section area and self weight
A = b*h  # cross-sectional area, m2
w = 24*A # self weight per length, kN/m

# create the beam-type model
model = Structure(type='beam')

# add materials
model.add_material('concrete 28 MPa', E)

# add cross sections
model.add_rectangular_section('0.5x1.0', base=b, height=h)

# add start and end beam joints
model.add_joint('a', x=0)
model.add_joint('b', x=L)

# add a frame for the beam
model.add_frame('beam', 'a', 'b', 'concrete 28 MPa', '0.5x1.0')

# add supports
model.add_support('a', r_uy=True)
model.add_support('b', r_uy=True)

# add load patterns
model.add_load_pattern('self weight')

# add distributed loads
model.add_distributed_load('self weight', 'beam', fy=-w)

# analyze the model
model.run_analysis()
model.export('simple_beam.json')

# show results
print(f'Θa: {model.displacements['self weight']['a'].rz:+.3e} rad')
print(f'Θb: {model.displacements['self weight']['b'].rz:+.3e} rad')
print(f'Ra: {model.reactions['self weight']['a'].fy:+.1f} kN')
print(f'Rb: {model.reactions['self weight']['b'].fy:+.1f} kN')
print(f'Mmax: {max(model.internal_forces['self weight']['beam'].mz):.1f} kN m')
print(f'νmax: {min(model.internal_displacements['self weight']['beam'].uy):.3e} m')

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Contributing

Contributions are welcome! If you would like to contribute, please follow these steps:

1. Fork the repository.
2. Create a new branch (git checkout -b feature/your-feature-name).
3. Make your changes and commit them (git commit -m 'Add new feature').
4. Push your changes to the branch (git push origin feature/your-feature-name).
5. Submit a Pull Request.

You can find here a good gide to this workflow.

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License

This project is licensed under the MIT License. See the LICENSE file for complete details.

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Contact

For support, questions, or to report bugs, please utilize the GitHub Issues page.