3pc-lamfail 1.0.3

Python library for ply-wise stress, strain, and failure analysis of anisotropic laminates.

3pc-lamfail

3pc-lamfail is a Python library used for ply-wise stress and strain analysis of shear deformable anisotropic laminates under hygrothermal and mechanical loads. It provides a Lamfail class to calculate stresses, strains, and various margins of safety (MS) based on classical and first-order shear deformation theories.

Installation

Use the package manager pip to install 3pc-lamfail. Since the package and its dependencies are available on PyPI, you can install them directly:

pip install 3pc-lamfail

API Reference

Lamfail Class

The primary component of this package is the Lamfail class, which takes a panel and a load case to compute detailed failure metrics.

from lamfail.lamfail import Lamfail

Required Parameters

When initializing Lamfail, the following parameters are required:

• panel (Panel): An instance of the Panel class (from 3pc-panel) containing the laminate definition and geometry.
• loads (Loads): An instance of the Loads class (from 3pc-loads) containing the load case and environmental conditions.

Calculated Properties

The class automatically calculates the following properties lazily:

• NT, MT: Thermal in-plane loads and moments.
• NC, MC: Hygral in-plane loads and moments.
• ek0: Mid-plane strains and curvatures [ex0, ey0, gxy0, kx0, ky0, kxy0].
• gT0: Mid-plane transverse strains [gyz0, gxz0].
• tauyz, tauxz: Transverse shear stresses for each ply.
• stress: Total stress in reference coordinate axes (x-y-z) for each ply (bottom, mid, top).
• stressM, stressT, stressH: Mechanical, thermal, and hygral components of stress in reference axes.
• stress1, stressM1, stressT1, stressH1: Stresses transformed to material coordinate axes (1-2-3).
• strain, strainM, strainT, strainH: Strains in reference coordinate axes.
• strain1, strainM1, strainT1, strainH1: Strains in material coordinate axes.

Margins of Safety (MS)

The following failure theories are implemented:

• stress1MS: Max Stress theory using total stress.
• stressM1MS: Max Stress theory using mechanical stress.
• strain1MS: Max Strain theory using total strain.
• strainM1MS: Max Strain theory using mechanical strain.
• tsaiHill1MS, tsaiHillM1MS: Tsai-Hill failure theory (Total/Mechanical).
• tsaiWu1MS, tsaiWuM1MS: Tsai-Wu failure theory (Total/Mechanical).

Methods

Lamfail.fromDict(**kwargs)

Initializes a Lamfail instance using a dictionary of keyword arguments.

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Usage Examples

Basic Initialization

Below is an example of performing a failure analysis on a panel under a specific load case.

from panel.panel import Panel
from loads.loads import Loads
from lamfail.lamfail import Lamfail

# Assuming pnl (Panel) and ld (Loads) are already defined
lf = Lamfail(panel=pnl, loads=ld)

# Access Margins of Safety for Ply 1 (bottom ply)
print("Max Stress MS (Material Axes):", lf.stress1MS["1"]["mid"])
print("Tsai-Wu MS:", lf.tsaiWu1MS["1"]["mid"])

# Access stresses
print("Total Stress (x-y-z):", lf.stress["1"]["top"])

Commands

The package provides a command-line interface entry point. After installing, you can run the application using:

lamfail input.cfg

(This entry point is defined in lamfail.__main__:main)

Options

• config (positional): Specify the configuration file (.cfg) to run the analysis.
• -h, --help: Show the help message and exit.
• -v, --version: Show the version number.
• -s, --sample: Copy example files (materials, plies, laminates, etc.) to the current directory.

Citation

If you use this library in your research or work, please cite it as follows:

APA Format:

Rastogi, N., & Seresta, O. (2026). 3pc-lamfail: Python library for ply-wise stress, strain, and failure analysis of anisotropic laminates. PyPI. https://pypi.org/project/3pc-lamfail/

BibTeX:

@software{3pc_lamfail,
  author = {Rastogi, Naveen and Seresta, Omprakash},
  title = {3pc-lamfail: Python library for ply-wise stress, strain, and failure analysis of anisotropic laminates},
  year = {2026},
  url = {https://pypi.org/project/3pc-lamfail/}
}