eagar-tsai

eagar-tsai is a Python library implementing the Eagar–Tsai moving heat source model to estimate melt pool dimensions (length, width, depth) for a scanning laser over a semi-infinite solid. Temperature fields are computed via a 1D integral; melt pool dimensions are extracted from the liquidus isotherm. Built-in plotting covers temperature field heatmaps and power–velocity printability maps.

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Overview

The model computes temperature fields produced by a Gaussian laser beam moving over a semi-infinite solid. Melt pool dimensions are extracted from the liquidus isotherm.

Reference: T. W. Eagar and N.-S. Tsai, "Temperature Fields Produced by Traveling Distributed Heat Sources," Welding Journal (Research Supplement), December 1983, pp. 346-s–354-s.

Integrand reformulation: Sasha Rubenchik, LLNL, 2015.

Features

Fast integration via a compiled C extension exposed as a LowLevelCallable, enabling QUADPACK to call the integrand at C speed with zero Python overhead per evaluation; pure-Python fallback when the extension is unavailable
Batch DataFrame API with optional multiprocessing parallelism
Printability maps: sweep laser power x scan speed and classify every grid point into keyhole, lack of fusion, balling, or defect-free; each point is an independent parallel task for full CPU utilization
Immutable dataclasses for beam, material, and domain parameters
Iterative domain expansion — automatically enlarges the simulation grid if the melt pool touches a boundary
Temperature field access — compute_single_point returns a MeltPoolResult that always includes the full 2-D surface and depth temperature planes as an embedded TemperatureField; result.plot() produces a two-panel heatmap figure
3D temperature volume — plot_temperature_field_3d computes the full volumetric temperature distribution and renders an interactive or off-screen 3-D visualization via PyVista, with an optional liquidus isotherm contour surface and VTI export

Installation

Install eagar-tsai with uv or pip. The C extension is compiled automatically during installation; no separate build step is needed.

# Recommended — using uv
uv add eagar-tsai

# Alternative — using pip
pip install eagar-tsai

Quick Start

The example below computes melt pool dimensions for a single set of laser and material parameters. Pass BeamParameters, MaterialProperties, and SimulationDomain to compute_single_point to get length, width, and depth at the liquidus isotherm.

from eagar_tsai import BeamParameters, MaterialProperties, SimulationDomain, compute_single_point

beam = BeamParameters(
        beam_diameter=100e-6,
        power=200.0,
        velocity=0.5,
        absorptivity=0.35
)

material = MaterialProperties(
        liquidus_temperature=1700.0,
        thermal_conductivity=30.0,
        density=7800.0,
        specific_heat=700.0
)

domain = SimulationDomain(
        x_length_um=1200.0,
        y_length_um=1200.0,
        z_depth_um=1000.0,
        spatial_resolution_um=1.0
)

result = compute_single_point(beam, material, domain)

print(f"Length: {result.length_um:.1f} µm")
print(f"Width:  {result.width_um:.1f} µm")
print(f"Depth:  {result.depth_um:.1f} µm")

See the Usage page for batch DataFrame processing, temperature field visualization, printability maps, and parallel processing.