arXiv:2411.06529cs.LGcond-mat.mtrl-sci2024-11被引 2

用热力学启发的神经算子加速异质材料弹性变形预测

Thermodynamically-Informed Iterative Neural Operators for Heterogeneous Elastic Localization

  • 基于材料本构方程的热力学编码,迭代求解弹性场
  • 在复杂异质结构上实现更快更准的变形预测,速度优势显著
  • 适合需高效模拟非均匀材料的工程与科学计算场景

工程问题常涉及系数空间变化且不连续的控制方程求解。即使对于线性椭圆问题,传统数值求解器在处理大量系数场到解的映射时也会成为计算瓶颈。同时,神经算子类机器学习方法因系数场中存在剧烈突变和高对比度,以及训练数据信息不足,难以有效拟合该映射。本文聚焦计算力学中的典型问题:在周期边界条件下,预测异质材料结构的局部弹性变形场。我们构建了一种混合近似方法,采用热力学启发的迭代神经算子(TherINO)。不同于将系数场直接输入并迭代于学习的隐空间,我们使用来自本构方程的热力学编码,并在解空间本身进行迭代。通过一系列案例研究,揭示了该设计在效率、精度和灵活性上的优势。还分析了模型在分布外系数场下的稳定性和外推性能,展示了预测弹性量时更优的速度-精度权衡。

原文摘要 · Abstract (English)

Engineering problems frequently require solution of governing equations with spatially-varying discontinuous coefficients. Even for linear elliptic problems, mapping large ensembles of coefficient fields to solutions can become a major computational bottleneck using traditional numerical solvers. Furthermore, machine learning methods such as neural operators struggle to fit these maps due to sharp transitions and high contrast in the coefficient fields and a scarcity of informative training data. In this work, we focus on a canonical problem in computational mechanics: prediction of local elastic deformation fields over heterogeneous material structures subjected to periodic boundary conditions. We construct a hybrid approximation for the coefficient-to-solution map using a Thermodynamically-informed Iterative Neural Operator (TherINO). Rather than using coefficient fields as direct inputs and iterating over a learned latent space, we employ thermodynamic encodings -- drawn from the constitutive equations -- and iterate over the solution space itself. Through an extensive series of case studies, we elucidate the advantages of these design choices in terms of efficiency, accuracy, and flexibility. We also analyze the model's stability and extrapolation properties on out-of-distribution coefficient fields and demonstrate an improved speed-accuracy tradeoff for predicting elastic quantities of interest.

弹性建模神经算子热力学异质材料

Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。