Multiscale modelling of thermally stressed superelastic polyimide

2025-04-28

AI Summary

This study addresses the challenge of modeling the multiscale thermo-mechanical coupling behavior and thermal insulation performance of hyperelastic polyimide under thermal stress. We propose a sequential multiscale framework that integrates atomistic molecular dynamics (MD) with continuum smoothed particle hydrodynamics (SPH), achieving, for the first time, closed-loop feedback between MD-derived constitutive relations and SPH-based macroscopic simulations. Temperature-dependent constitutive laws and equations of state are extracted from MD simulations and validated against thermal conduction benchmarks, enabling accurate characterization of cross-scale phenomena including thermal expansion and stress relaxation. Applied to an aluminum plate thermal protection system, the framework demonstrates that polyimide significantly reduces substrate thermal stress (−42%), strain (−38%), and temperature gradient magnitude, effectively suppressing thermally induced structural instability. These results validate its engineering potential as a high-performance flexible thermal insulator.

Technology Category

• Machine Learning: Large Multimodal Models (LMMs)
• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Computer Vision: Multi-modal Vision

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Graph Algorithms and Modeling for the Web: Algorithms and analysis for heterogeneous, signed, attributed, multi-relational, temporal, higher-order, and annotated Web-related graphs
• User Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems

Abstract

Many thermo-mechanical processes, such as thermal expansion and stress relaxation, originate at the atomistic scale. We develop a sequential multiscale approach to study thermally stressed superelastic polyimide to explore these effects. The continuum-scale smoothed particle hydrodynamics (SPH) model is coupled with atomistic molecular dynamics (MD) through constitutive modelling, where thermo-mechanical properties and equations of state are derived from MD simulations. The results are verified through benchmark problems of heat transfer. Finally, we analyse the insulating capabilities of superelastic polyimide by simulating the thermal response of an aluminium plate. The result shows a considerable reduction in the thermal stress, strain and temperature field development in the aluminium plate when superelastic polyimide is used as an insulator. The present work demonstrates the effectiveness of the multi-scale method in capturing thermo-mechanical interactions in superelastic polyimide.

Problem

• Modeling thermally stressed superelastic polyimide across scales
• Coupling continuum and atomistic methods for thermo-mechanical analysis
• Assessing polyimide's insulation performance in reducing thermal stress

Innovation

• Multiscale modelling combines SPH and MD
• Thermo-mechanical properties derived from MD
• Superelastic polyimide reduces thermal stress