3pc-material

3pc-material is a Python package for material description, specifically designed to handle orthotropic materials and failure theories like Tsai-Wu.

Installation

The package is publicly available on PyPI. You can install it using pip:

pip install 3pc-material

API Reference

Orthotropic Class

The primary component of this package is the Orthotropic class, which holds material properties and dynamically calculates properties for failure theories.

from material.orthotropic import Orthotropic

Required Parameters

When initializing Orthotropic directly, the following parameters are required:

• matID (str): Orthotropic material id.
• E1 (float): Elastic modulus in direction 1.
• E2 (float): Elastic modulus in direction 2.
• G12 (float): Shear modulus in 12 plane.
• G13 (float): Transverse shear modulus in 13 plane.
• G23 (float): Transverse shear modulus in 23 plane.
• v12 (float): Poisson's ratio in 21 plane.

Optional Physical Properties (Default: 0.0)

• rho (float): Density.
• alpha1 (float): Coefficient of thermal expansion in direction 1.
• alpha2 (float): Coefficient of thermal expansion in direction 2.
• beta1 (float): Coefficient of hygral expansion in direction 1.
• beta2 (float): Coefficient of hygral expansion in direction 2.

Optional Allowable Properties for Failure Theories (Default: 0.0)

• eps11_tension_allowable (float): Allowable tensile strain in direction 1.
• eps11_compression_allowable (float): Allowable compressive strain in direction 1.
• eps22_tension_allowable (float): Allowable tensile strain in direction 2.
• eps22_compression_allowable (float): Allowable compressive strain in direction 2.
• gamma12_allowable (float): Allowable shear strain in 12 plane.
• gamma23_allowable (float): Allowable shear strain in 23 plane.
• gamma13_allowable (float): Allowable shear strain in 13 plane.
• sig11_tension_allowable (float): Allowable tensile stress in direction 1.
• sig11_compression_allowable (float): Allowable compressive stress in direction 1.
• sig22_tension_allowable (float): Allowable tensile stress in direction 2.
• sig22_compression_allowable (float): Allowable compressive stress in direction 2.
• tau12_allowable (float): Allowable shear stress in 12 plane.
• tau23_allowable (float): Allowable shear stress in 23 plane.
• tau13_allowable (float): Allowable shear stress in 13 plane.

Calculated Properties

The class automatically calculates the following properties lazily:

• v21: Poisson's ratio in 21 plane. Formula: v12 * (E2 / E1).
• F1: Tsai-Wu parameter. Formula: (1.0 / sig11_tension_allowable) + (1.0 / sig11_compression_allowable).
• F2: Tsai-Wu parameter. Formula: (1.0 / sig22_tension_allowable) + (1.0 / sig22_compression_allowable).
• F11: Tsai-Wu parameter. Formula: -1.0 / (sig11_tension_allowable * sig11_compression_allowable).
• F22: Tsai-Wu parameter. Formula: -1.0 / (sig22_tension_allowable * sig22_compression_allowable).
• F12: Tsai-Wu parameter. Formula: -0.5 * sqrt(F11 * F22).

Methods

Orthotropic.fromDict(**kwargs)

Initializes an Orthotropic instance using a dictionary of keyword arguments. This is ideal for loading configurations from JSON files or dictionaries. Defaults apply identically to standard initialization.

Usage Examples

Basic Initialization

from material.orthotropic import Orthotropic

ortho = Orthotropic(
    matID="zg",
    E1=181.0,
    E2=10.3,
    G12=7.17,
    G13=7.17,
    G23=7.17,
    v12=0.28,
    sig11_tension_allowable=1500.0,
    sig11_compression_allowable=-1500.0,
    sig22_tension_allowable=50.0,
    sig22_compression_allowable=-150.0
)

print(f"Poisson's ratio v21: {ortho.v21}")
print(f"Tsai-Wu F1 parameter: {ortho.F1}")

Initializing from a Dictionary

You can load your materials directly from a JSON source.

// examples/material.json
{
    "materials": [
        {
            "matID": "zg",
            "E1": 181.0,
            "E2": 10.3,
            "G12": 7.17,
            "G13": 7.17,
            "G23": 7.17,
            "v12": 0.28,
            "rho": 1.6,
            "sig11_tension_allowable": 1500.0,
            "sig11_compression_allowable": -1200.0,
            "sig22_tension_allowable": 50.0,
            "sig22_compression_allowable": -250.0
        }
    ]
}

import json
from material.orthotropic import Orthotropic

with open('examples/material.json', 'r') as f:
    data = json.load(f)

materials = [Orthotropic.fromDict(**mat_dict) for mat_dict in data["materials"]]

for mat in materials:
    print(f"Material ID: {mat.matID}")
    print(f"Calculated Tsai-Wu F11: {mat.F11}")
    print(f"Calculated Tsai-Wu F22: {mat.F22}")
    print(f"Calculated Tsai-Wu F12: {mat.F12}")

Commands

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

material

(Currently, this serves as an entry point defined in material.main:main)