Utility Functions

Standalone functions for working with tensile test data without class instantiation.

Input/Output Functions

load_csv()

load_csv(filepath, config=None)

Load tensile test data from CSV file.

Parameters:

filepath : str: Path to CSV file
config : TensileTestConfig, optional: Configuration for parsing. If None, uses defaults.

Returns: pd.DataFrame with columns: force, extension

from tensile.io import load_csv

df = load_csv("test_data.csv")
print(df.head())

load_batch()

load_batch(folder_path, pattern='*.csv', config=None)

Load multiple CSV files from a folder.

Parameters:

folder_path : str: Path to folder
pattern : str, default='*.csv': Glob pattern for file matching
config : TensileTestConfig, optional: Configuration for parsing

Returns: dict - {filename: DataFrame}

from tensile.io import load_batch

data_dict = load_batch("data/316L_A/")
for name, df in data_dict.items():
    print(f"{name}: {len(df)} rows")

Analysis Functions

calculate_youngs_modulus()

calculate_youngs_modulus(stress, strain, strain_range=(0.0005, 0.003))

Calculate Young's modulus from stress-strain data using linear regression.

Parameters:

stress : array-like: Stress values in MPa
strain : array-like: Strain values (dimensionless)
strain_range : tuple, default=(0.0005, 0.003): Strain range for linear fitting

Returns: dict - {'E_GPa': float, 'R2': float, 'n_points': int}

from tensile.analysis import calculate_youngs_modulus

result = calculate_youngs_modulus(stress, strain)
print(f"E = {result['E_GPa']:.1f} GPa (R² = {result['R2']:.4f})")

find_yield_strength()

find_yield_strength(stress, strain, offset=0.002)

Find yield strength (Rp0.2) using offset method.

Parameters:

stress : array-like: Stress values in MPa
strain : array-like: Strain values
offset : float, default=0.002: Offset strain (0.2% = 0.002)

Returns: dict - {'Rp02_MPa': float, 'strain_at_rp02': float}

from tensile.analysis import find_yield_strength

result = find_yield_strength(stress, strain)
print(f"Rp0.2 = {result['Rp02_MPa']:.1f} MPa")

detect_slippage()

detect_slippage(stress, strain, stress_threshold=50.0, strain_limit=0.005)

Detect initial slippage in stress-strain curve.

Parameters:

stress : array-like: Stress values in MPa
strain : array-like: Strain values
stress_threshold : float, default=50.0: Stress threshold in MPa
strain_limit : float, default=0.005: Max strain to check (0.5%)

Returns: dict - {'detected': bool, 'cutoff_index': int, 'cutoff_strain': float}

from tensile.segmentation import detect_slippage

result = detect_slippage(stress, strain)
if result['detected']:
    print(f"Slippage detected at strain {result['cutoff_strain']:.4f}")
    # Remove slippage region
    stress_clean = stress[result['cutoff_index']:]
    strain_clean = strain[result['cutoff_index']:]

Visualization Functions

plot_stress_strain()

plot_stress_strain(stress, strain, title="Stress-Strain Curve", markers=None)

Create interactive stress-strain plot with Plotly.

Parameters:

stress : array-like: Stress values in MPa
strain : array-like: Strain values
title : str, optional: Plot title
markers : dict, optional: Key points to annotate: {'Rp02': (x, y), 'Rm': (x, y)}

Returns: plotly.graph_objects.Figure

from tensile.visualization import plot_stress_strain

fig = plot_stress_strain(
    stress, strain,
    title="316L Tensile Test",
    markers={'Rp02': (0.01, 250), 'Rm': (0.15, 600)}
)
fig.show()

plot_batch_comparison()

plot_batch_comparison(tests_dict, overlay=True, title="Batch Comparison")

Compare multiple stress-strain curves on one plot.

Parameters:

tests_dict : dict: Dictionary of {name: (stress, strain)}
overlay : bool, default=True: If False, create subplots
title : str, optional: Plot title

Returns: plotly.graph_objects.Figure

from tensile.visualization import plot_batch_comparison

tests = {
    'Test_1': (stress1, strain1),
    'Test_2': (stress2, strain2),
    'Test_3': (stress3, strain3)
}
fig = plot_batch_comparison(tests, title="316L Batch A")
fig.show()

Quick Example Workflow

from tensile.io import load_csv
from tensile.cleaning import clean_data
from tensile.analysis import calculate_youngs_modulus, find_yield_strength
from tensile.visualization import plot_stress_strain

# Load data
df = load_csv("test.csv")

# Clean and calculate stress-strain
df_clean = clean_data(df, specimen_length=50.0, specimen_diameter=5.0)
stress = df_clean['stress'].values
strain = df_clean['strain'].values

# Analysis
E_result = calculate_youngs_modulus(stress, strain)
rp_result = find_yield_strength(stress, strain)

print(f"E = {E_result['E_GPa']:.1f} GPa")
print(f"Rp0.2 = {rp_result['Rp02_MPa']:.1f} MPa")

# Plot
markers = {'Rp02': (rp_result['strain_at_rp02'], rp_result['Rp02_MPa'])}
fig = plot_stress_strain(stress, strain, markers=markers)
fig.show()