Asari-Rashidi Multi-Ply Automotive Spot Welding Simulator 🔬

Overview

This interactive engineering platform offers real-time visualization and multi-axis parametric mapping of the process operating window (Weld Lobe) for automotive sheet steel assemblies. Driven by the proprietary Asari-Rashidi Nugget Growth Model, the simulator predicts thermodynamic and physical bonding thresholds across multi-ply material stacks.

The simulator bridges the gap between raw experimental values and finite element method (FEM) software (such as SORPAS) by instantly solving thickness-weighted resistivity scaling, thermal sink profiles, and expulsion limits.

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🚀 Key Evolutionary Features

1. Advanced 3D Volumetric Weld Lobe

• Maps the complete multi-variable process window across Current ($I$), Weld Time ($T$), and Electrode Force ($F$) simultaneously.
• Renders real-time interactive volumetric isosurfaces using WebGL via Plotly, automatically masking out sub-critical combinations based on industrial requirements ($4\sqrt{t_{min}}$).

2. Dual-Orientation 2D Cross-Section Slicing

• X-Y Plane (Current vs. Time): Evaluates traditional weld lobe maps at any discrete, slider-adjusted electrode force.
• X-Z Plane (Current vs. Force): Maps critical force-dependent contact-resistance paths at a selected hold time, tracking performance across varying clamping conditions.

3. Synchronized Transient Thermal Animation Map

• Uses a side-by-side graphical layout pairing your Plotly contour map directly with an embedded canvas rendering engine.
• Animates cycle-by-cycle transient developmental progress showing:
  • Electrode Thermal Sinks: Dynamic gradient fields cooling down the outer stack boundaries.
  • Heat Affected Zone (HAZ): Real-time expansion of solid-state structural modification rings.
  • Molten Weld Pool: Visually tracks the liquid phase front, dynamically converting to a high-contrast danger profile if localized parameters bypass the mathematical expulsion threshold.

4. Dynamic Operating Point Interactivity

• Integrates an interactive "crosshair marker" directly onto the analytical planes. Adjusting process settings updates the exact localized coordinate marker position while simultaneously computing its frame timeline for the playback loop.

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📐 Scientific & Engineering Principles

Nugget Diameter Formulation

The base model computes nugget growth ($D_{nugget}$) as a function of thermal energy input scaled across structural and chemical characteristics:

$$D_{nugget} = k_{approx} \cdot \left(\frac{I \cdot \eta_{tip}}{10000}\right)^2 \cdot \left(\frac{T}{10}\right) \cdot \left(\frac{300}{F}\right)^{0.25} \cdot 5.5$$

Where:

• $k_{approx}$: The thickness-weighted, resistivity-corrected base efficiency factor of your specific material ply stack.
• $\eta_{tip}$: Current density geometric scaler derived from electrode tip wear/contact diameter: $\eta_{tip} = (6.0 / d_{tip})^2$.

Dynamic Expulsion Threshold Bounds

Rather than assigning a static limit, the app computes a moving boundary line tracking localized pressure breakdowns and metal splashing conditions:

$$D_{expulsion} = (5.5 \cdot \sqrt{t_{min}}) \cdot \left(\frac{F}{300}\right)^{0.1} \cdot \left(\frac{d_{tip}}{6.0}\right)^{0.2}$$

In Current vs. Force cross-sections, the script actively resolves a structural difference matrix ($D_{nugget} - D_{expulsion} = 0$) to cleanly render the complex, curved red boundary path.

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🌐 Modern Automotive Material Database

Includes advanced high-strength steel (AHSS) and ultra-high-strength steel (UHSS) grades, accounting for localized chemical tracking factors:

• Mild Steel (JSC270)
• High Strength (JSC440)
• DP600 (Dual Phase)
• DP980 (Ultra High Strength)
• Boron Steel (Usibor 1500)
• Trip Steel (TRIP780)

Includes a toggle for surface coatings (Zinc Coated GA/GI) that automatically adjusts initial interfacial contact resistances by applying a 0.82\times scale adjustment.

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🛠️ Installation & Local Setup

Ensure you have Python 3.8+ installed, then complete the setup steps:

1. Clone the repository:

git clone [https://github.com/your-username/asari-rashidi-spot-weld.git](https://github.com/your-username/asari-rashidi-spot-weld.git)
cd asari-rashidi-spot-weld