Nonlocal strain regularisation for models with multiple state variables using an example of UH model

IF 5.3 1区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers and Geotechnics Pub Date : 2025-04-28 DOI:10.1016/j.compgeo.2025.107296

Xiaotian Wu , Yangping Yao , Liang Dong , David M. Potts , Lidija Zdravkovic , Wenjie Cui

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引用次数: 0

Abstract

When the conventional finite element (FE) method is used in the simulation of strain-softening soils and the accompanying appearance of shear bands, the predicted results can exhibit a significant mesh dependency and may suffer from convergence difficulties. Nonlocal strain regularisation has been shown as one of the reliable approaches for overcoming such problems. This paper first demonstrates how a modified substepping stress point algorithm, that incorporates the nonlocal strain regularisation, can be developed for constitutive models which have multiple state variables in their hardening/softening rule. The algorithm is derived for the unified hardening (UH) model as an example of such models, which was developed to account for the constitutive characteristics of both clays and sands. The capability of the nonlocal UH model is then verified through analyses of boundary value problems involving dense sands, demonstrating a very good performance in eliminating the problem of mesh dependency while maintaining a stable solution process. Recommendations are also provided on how to determine the values of nonlocal parameters for the analysis of full-scale engineering problems using the proposed nonlocal algorithm.

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多状态变量模型的非局部应变正则化，以UH模型为例

传统有限元法在模拟应变软化土体及伴随出现的剪切带时，预测结果会表现出明显的网格依赖性，可能存在收敛困难。非局部应变正则化已被证明是克服这类问题的可靠方法之一。本文首先阐述了一种包含非局部应变正则化的改进次步进应力点算法，该算法可用于具有多个状态变量的硬化/软化本构模型。该算法是为统一硬化（UH）模型导出的，作为此类模型的一个例子，该模型是为了考虑粘土和砂土的本构特征而开发的。然后，通过分析涉及致密砂的边值问题，验证了非局部UH模型的能力，在消除网格依赖问题方面表现出非常好的性能，同时保持稳定的求解过程。对于如何使用所提出的非局部算法来确定全尺寸工程问题分析的非局部参数的值也提供了建议。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Computers and Geotechnics 地学-地球科学综合

CiteScore

9.10

自引率

15.10%

发文量

438

审稿时长

45 days

期刊介绍： The use of computers is firmly established in geotechnical engineering and continues to grow rapidly in both engineering practice and academe. The development of advanced numerical techniques and constitutive modeling, in conjunction with rapid developments in computer hardware, enables problems to be tackled that were unthinkable even a few years ago. Computers and Geotechnics provides an up-to-date reference for engineers and researchers engaged in computer aided analysis and research in geotechnical engineering. The journal is intended for an expeditious dissemination of advanced computer applications across a broad range of geotechnical topics. Contributions on advances in numerical algorithms, computer implementation of new constitutive models and probabilistic methods are especially encouraged.