结合有限元和机器学习优化镍金属纳米多孔结构的有效杨氏模量  

Optimization of Effective Young′s Modulus of Nickel Metallic Nanoporous Structures by Combining Finite Element Method and Machine Learning

作　　者：张颖 孙升 ZHANG Ying;SUN Sheng(Materials Genome Institute of Shanghai University,Shanghai 200444,China;Zhejiang Lab,Hangzhou 311100,Zhejiang,China)

机构地区：[1]上海大学材料基因组工程研究院,上海200444 [2]之江实验室,浙江杭州311100

出　　处：《力学季刊》2023年第3期581-591,共11页Chinese Quarterly of Mechanics

基　　金：国家自然科学基金(12072179,11672168);之江实验室科研攻关项目(2021PE0AC02)。

摘　　要：纳米多孔材料相比于其宏观块材具有许多优异而独特的性能.纳米材料的这些性能来源于其特征尺寸及几何形状.因此,通过改变纳米多孔结构实现对其性能的有效调控可以促进它们的实际应用.本文基于表面本征应力模型和分子动力学模拟结果,构建纳米多孔结构的宏观模型,对镍金属纳米多孔结构的力学变形进行了有限元模拟,计算不同镍金属纳米多孔结构由于韧带表面应力产生的初始应变,并进一步计算其有效杨氏模量.为实现纳米多孔结构力学性能的优化,建立基于高斯过程的代理模型,该模型可以对构型的有效杨氏模量进行高精度预测,与有限元相比实现了7个数量级的加速计算.最后使用该模型对全设计域结构的有效杨氏模量进行预测,得到杨氏模量最大的构型并进行了有限元验证.本工作实现了纳米多孔结构的跨尺度模拟,并利用代理模型大幅提高了计算效率,为具有优异性能的纳米多孔材料的优化设计提供了方法框架.Compared to their macroscopic bulk materials,nanoporous materials have many superior and unique properties which derive from their characteristic size and geometry.Therefore,the effective regulation of properties by changing the nanoporous structure can promote their practical applications.In this paper,based on the surface eigenstress model and molecular dynamics simulation results,the macroscopic model of nanoporous structure is constructed.The mechanical deformation of nickel metallic nanoporous structure is simulated by finite element method.The effective Young's modulus and the initial strain of different nickel metallic nanoporous structures due to ligament surface stress are calculated.In order to optimize the mechanical properties of nanoporous structures,a surrogate model based on Gaussian process is established,which can predict the effective Young's modulus of the configuration with high precision and achieve 7 orders of magnitude in computational acceleration compared with the finite element method.Finally,the model is used to predict the effective Young's modulus of the full design domain structures.The configuration with the largest Young's modulus is obtained and its finite element verification is performed.In this work,the multiscale simulation of nanoporous structures is realized,and the computational efficiency is greatly improved by using the surrogate model,which provides a framework for the computational optimization of the nanoporous materials with excellent properties.

关 键 词：纳米多孔结构 表面本征应力模型 代理模型 结构优化 

分 类 号：O341[理学—固体力学]