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This repository contains the implementation of a Graph Neural Network (GNN) framework for predicting buckling behavior of thin-walled structures with and without 1D stiffeners, as presented in the Master's thesis by Ömer Kurt at Middle East Technical University.

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Graph Neural Networks as Surrogate Models for Structural Analysis: A Study on Buckling Behavior

This repository contains the implementation of a Graph Neural Network (GNN) framework for predicting buckling behavior of thin-walled structures with and without 1D stiffeners, as presented in the Master's thesis by Ömer Kurt at Middle East Technical University.

Overview

This research develops a novel approach to structural analysis using Graph Neural Networks as surrogate models, specifically focusing on predicting buckling behavior of thin-walled structures. The framework addresses computational challenges in traditional finite element analysis by providing an efficient machine learning-based alternative that maintains engineering-grade accuracy while achieving computational speeds approximately two orders of magnitude faster than conventional methods.

Key Features

  • Comprehensive Data Generation Pipeline: Automated generation of diverse structural geometries using Bezier curves
  • Advanced Graph Representation: Novel approach incorporating super nodes and virtual edges for enhanced information flow
  • Rotational/Translational Invariance: PCA-based coordinate transformation ensuring generalization across different orientations
  • Dual Architecture Support: Implementation of both GraphSAGE and CustomGNN architectures
  • Multi-scale Analysis: Support for both non-stiffened and stiffened structures
  • Efficient Buckling Prediction: Accurate prediction of critical buckling eigenvalues

Main Contributions

  1. Data Generation Framework

    • Bezier curve-based shape generation system creating diverse yet physically meaningful geometries
    • Systematic load case generation with comprehensive coverage of realistic loading scenarios
    • Advanced dataset balancing methodology addressing inherent biases in structural response distributions
  2. Architectural Innovations

    • Novel coordinate transformation approach based on principal component analysis
    • Enhanced information flow mechanisms through virtual edges and super node architecture
    • Specialized pooling strategies optimized for global property prediction
  3. Practical Applications

    • Demonstrated effectiveness in buckling behavior prediction
    • Significant computational efficiency gains (100× faster than traditional FEA)
    • Framework for rapid stiffener layout optimization

Performance Results

Non-Stiffened Structures

  • Validation MAPE: 5.5%
  • Test MAPE: 6.73%

Stiffened Structures

  • Validation MAPE: 12.5%
  • Test MAPE: 17.64%

Technical Details

Dataset Generation

  • Shape dimensions: 700-1000mm
  • Material: Aluminum alloy (E=76 GPa, ν=0.3)
  • Analysis types: Linear static and linear buckling
  • Dataset sizes: 40,000 (non-stiffened) and 80,000 (stiffened) cases

Model Architecture

  • Base architecture: GraphSAGE with 6 layers
  • Hidden dimension: 512
  • Enhanced features: Super node for global information aggregation
  • Pooling: Mean pooling for buckling prediction

Training Infrastructure

  • GPUs: NVIDIA Tesla V100 and P100 (16GB VRAM)
  • Batch size: 16 (memory-constrained)
  • Training time: ~10 hours for base dataset

Requirements

  • Python 3.8+
  • PyTorch 1.10+
  • PyTorch Geometric
  • NumPy, SciPy, scikit-learn
  • MSC Nastran (for FEA validation)

Limitations and Future Work

  • Currently limited to 2D thin-walled structures
  • Linear analysis only (no post-buckling behavior)
  • Isotropic materials only
  • Future extensions could include:
    • 3 D structures and complex assemblies
    • Non-linear analysis capabilities
    • Composite materials

Citation

If you use this work in your research, please cite:

@mastersthesis{kurt2025graph,
title={Graph Neural Networks as Surrogate Models for Structural Analysis: A Study on Buckling Behavior},
author={Kurt, {"O}mer},
year={2025},
school={Middle East Technical University (Turkey)}
}

The full thesis is available at: https://open.metu.edu.tr/handle/11511/113521

Acknowledgments

This research was conducted at Middle East Technical University and Turkish Aerospace Industries under the supervision of Prof. Dr. Ulaş Yaman. Computational resources were provided by TRUBA (Turkish National e-Infrastructure).

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This repository contains the implementation of a Graph Neural Network (GNN) framework for predicting buckling behavior of thin-walled structures with and without 1D stiffeners, as presented in the Master's thesis by Ömer Kurt at Middle East Technical University.

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