lamkit

lamkit is a Python toolkit for composite laminate analysis, focused on:

• Laminate stress/strain response based on Classical Lamination Theory (CLT)
• LaRC05 failure index evaluation
• Lekhnitskii analytical solutions for infinite anisotropic plates with a hole:
  • Unloaded hole (bypass far-field stresses)
  • Loaded hole (cosine bearing-load distribution)
  • Combined loading (CombinedLoadHole): superposition of bypass and bearing
• Open-hole plate's effective (homogenisation) properties
• Linear buckling analysis of laminates
• Objective/constraint evaluation for laminate optimization tasks
• Layup engineering-requirement checks and feasibility rating against a layup attribute database

Installation

Requirements

• Python >=3.9
• Core dependencies: numpy, pandas, matplotlib
• Optional: scipy (linear buckling and layup feasibility rating)

Install from PyPI

pip install lamkit

Install for local development

pip install -e .[dev,docs]

Quick Start

The following example creates a laminate and evaluates ply-surface fields under membrane loading:

import numpy as np
from lamkit import Laminate, Ply
from lamkit.analysis.material import IM7_8551_7

ply = Ply(IM7_8551_7, thickness=0.125)  # mm
stacking = [45, -45, 0, 90, 90, 0, -45, 45]
laminate = Laminate(stacking=stacking, plies=ply)

# N = [Nxx, Nyy, Nxy, Mxx, Myy, Mxy]
N = np.array([80.0, 0.0, 0.0, 0.0, 0.0, 0.0])
field = laminate.evaluate_laminate(N)

print(field[["index_ply", "index_surface", "z", "sigma_1", "sigma_2", "tau_12", "FI_max"]].head())

Examples

The example/ directory contains runnable scripts:

1. Laminate response (CLT + LaRC05)
   example/1-laminate/example_laminate.py
   Computes through-thickness stress/strain and LaRC05 index distributions with plots.

2. Lekhnitskii unloaded-hole solution
   example/2-lekhnitskii-solution/example_unloaded_hole.py
   Solves and visualizes open-hole stress fields.

3. Laminate open-hole field analysis
   example/3-open-hole/example_open_hole.py
   Couples laminate equivalent compliance with open-hole fields and generates failure envelopes/boundary maps.

4. Effective stiffness with hole homogenization
   example/4-effective-stiffness/example_effective_stiffness.py
   Compares laminate stiffness A (without hole) and homogenized stiffness A_eff (with hole).

5. Laminate linear buckling
   example/5-laminate-buckling/example_buckling.py
   Computes buckling eigenvalues and saves buckling mode plots.

6. Optimization objective/constraint evaluation
   example/6-laminate-optimization-task/example_laminate_opt_function.py
   Demonstrates combined displacement, failure, and buckling constraint evaluation for design tasks.

7. Layup feasibility rating
   example/7-layup-feasibility/example_layup_feasibility.py
   Scores a candidate stacking (ply counts, bending lamination parameters) by distance to the nearest layups in a CSV database.

8. Loaded-hole (bearing) field analysis
   example/8-loaded-hole/example_loaded_hole.py
   Computes ply-level stress/strain and LaRC05 failure indices around a bearing-loaded hole using CombinedLoadHole with zero bypass stresses. Plots mid-plane strains, ply-enveloped failure index fields, and hole-boundary FI maps.

9. Combined bearing and bypass loading
   example/9-combined-loading/example_combined_loading.py
   Superimposes an UnloadedHole (far-field bypass) and a LoadedHole (cosine bearing distribution) via CombinedLoadHole. Generates mid-plane stress contour plots, ply-enveloped LaRC05 failure index maps, and a hole-boundary FI distribution across angle and thickness.

Common Development Commands

Run tests

pytest

Build distribution package

python -m build

Build documentation

cd docs
sphinx-build -b html . _build/html