Computer Methods in Applied Mechanics and Engineering最新文献

Assessing the Capriccio method via one-dimensional systems for coupled continuum-particle simulations in various uniaxial load cases using a novel interdimensional comparison approach

IF 6.9 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Computer Methods in Applied Mechanics and Engineering

Pub Date : 2025-03-07 DOI: 10.1016/j.cma.2025.117817

Lukas Laubert , Felix Weber , Sebastian Pfaller

This contribution investigates sources of insufficiencies observed with the Capriccio method for concurrent continuum-particle coupling using a novel comparison technique. This approach maps the deformation states of three-dimensional (3D) coupled domains into a concise one-dimensional (1D) representation, which allows for a separate evaluation of the domain strains in a unified representation, enabling facile comparisons of the domain states during deformation. For the investigation, we employ both a 1D coupled system resembling the most relevant features of the full 3D Capriccio method as well as a corresponding 3D setup. Our analysis explores interactions between different material models in finite element (FE) and molecular dynamics (MD) domains. Based on various load cases studied in the 1D setup, we identify a resistance of the coupling region to spatial movement as the fundamental cause of strain convergence problems when applying the staggered solution scheme. Using the developed mapping approach, examination of the corresponding 3D setup reveals that these strain inconsistencies are even exacerbated by adverse relaxation effects in viscous MD models, particularly when coupled to a corresponding viscoelastic–viscoplastic FE model, leading to divergence from optimal strain. Our findings confirm that smaller strain increments in combination with larger load step numbers significantly improve strain convergence in all domains. Overall, this indicates the need for detailed sensitivity analysis of coupling parameter influences to reduce the identified motion resistance of the coupling region. Based on promising results in 1D, we further recommend exploring monolithic solving schemes for 3D systems to achieve optimal strain convergence for all types of Capriccio-based coupled particle and continuum material models. Moreover, our systematic approach of system definition and interdimensional comparison may serve as a model to assess other domain-decomposition coupling techniques.

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引用次数: 0

Dynamic particle packing to generate complex geometries

IF 6.9 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Computer Methods in Applied Mechanics and Engineering

Pub Date : 2025-03-06 DOI: 10.1016/j.cma.2025.117802

Muhammad Sameer , C. Fred Higgs III

Analyzing the discrete nature of solid structures is crucial, particularly in situations where system behavior relies on material discontinuities, such as fracture and wear, along with their subsequent effects. It is not only essential to investigate when failure or discontinuity occurs within a material, but also how it unfolds and impacts its surroundings. While numerical methods serve as effective tools for analyzing structural behavior, continuum-based approaches may not provide a comprehensive view when dealing with discontinuities in a material. Discrete models provide the capability to simulate these discontinuities by bonding discrete elements (particles) together, thereby also simulating continuum behavior. However, the challenge lies in packing these particles within a complex-shaped structure. The dynamic packing approach excels in generating a tightly packed, randomly arranged bonded-particle structure with consistent mechanical behavior. However, it struggles when it comes to generating complex geometries. Conversely, the geometric approach is proficient at generating complex structures but lacks the reliability needed to simulate engineering materials. The method outlined in this paper represents the first attempt to dynamically pack particles within a complex geometry while maintaining all the necessary mechanical properties to accurately model isotropic engineering materials. Such precision in structure and methodology is vital for calibrating the bonds, ensuring that the bonded-particle structure behaves similarly to real materials. As an example, several bonded-particle structures are generated and tested to demonstrate the complexity of their shapes and their realistic mechanical behavior.

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引用次数: 0

Three-dimensional varying-order NURBS discretization method for enhanced IGA of large deformation frictional contact problems

IF 6.9 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Computer Methods in Applied Mechanics and Engineering

Pub Date : 2025-03-05 DOI: 10.1016/j.cma.2025.117853

Vishal Agrawal

In this contribution, we introduce a varying-order (VO) NURBS discretization method to enhance the performance of the isogeometric analysis (IGA) technique for solving three-dimensional (3D) large deformation frictional contact problems involving two deformable bodies. Building on the promising results obtained from the previous work on the 2D isogeometric contact analysis (Agrawal and Gautam, 2020), this work extends the method’s capability for tri-variate NURBS-based discretization. The proposed method allows for independent, user-defined application of higher-order NURBS functions to discretize the contact surface while employing the minimum order NURBS for the remaining volume of the elastic solid. This flexible strategy enables the possibility to refine a NURBS-constructed solid at a fixed mesh with the controllable order elevation-based approach while preserving the original volume parametrization. The advantages of the method are twofold. First, employing higher-order NURBS for contact integral evaluations considerably enhances the accuracy of the contact responses at a fixed mesh, fully exploiting the advantage of higher-order NURBS specifically for contact computations. Second, the minimum order NURBS for the computations in the remaining bulk volume substantially reduces the computational cost inherently associated with the standard uniform order NURBS-based isogeometric contact analyses.

The capabilities of the proposed method are demonstrated using various contact problems between elastic solids with or without considering friction. The results with the standard uniform order of tri-variate NURBS-based discretizations are also included to provide a comprehensive comparative assessment. We show that to attain results of similar accuracy, the varying-order NURBS discretization uses a much coarser mesh resolution than the standard uniform-order NURBS-based discretization, hence leading to a major gain in computational efficiency for isogeometric contact analysis. The convergence study demonstrates the consistent performance of the method for efficient IGA of 3D frictional contact problems. Furthermore, the simplicity of the method facilitates its direct integration into the existing 3D NURBS-based IGA framework with only a few minor modifications.

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引用次数: 0

Region-optimal Gaussian process surrogate model via Dirichlet process for cold-flow and combustion emulations

IF 6.9 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Computer Methods in Applied Mechanics and Engineering

Pub Date : 2025-03-04 DOI: 10.1016/j.cma.2025.117894

Mingshuo Zhou , Ruiye Zuo , Chih-Li Sung , Yanjie Tong , Xingjian Wang

Surrogate modeling plays an increasingly important role in engineering design. The present work develops a novel surrogate model, region-optimal Gaussian process (roGP), to accurately emulate cold-flow and combustion fields in a significantly short time period. The model leverages an advanced statistical approach, Dirichlet process (DP) mixture model, to partition the entire spatial domain of concern into discrete subregions in a physics-informed manner. Each subregion contains the common features embedded in the collected dataset and is modeled by a Gaussian process (GP) with shared hyperparameters. Additionally, an active learning strategy iteratively refines the training dataset by prioritizing high-uncertainty regions, further enhancing predictive accuracy. The roGP model is evaluated on three representative cases of increasing complexity, consistently outperforming conventional GP-based surrogates. Results show that roGP effectively mitigates overfitting in independent GP models and reduces information loss in proper-orthogonal-decomposition GP models. In all test cases, roGP achieves superior spatial prediction accuracy, with relative root mean square errors below 5.5 %. A unique characteristic of the roGP model is that the DP-optimized subregions of roGP connect physics-alike coordinates among sampling design points. The entire pressure field in cold-flow case is effectively described by five subregions, while physical fields in two combustion cases require the elevated number of subregions due to their increased complexity. roGP achieves substantial acceleration in prediction time, up to eight orders of magnitude faster than numerical simulations. The developed surrogate model can be implemented to emulate a range of high-dimensional engineering applications with high accuracy and efficiency.

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引用次数: 0

A coupled thermo-chemo-mechanical peridynamic model for predicting process-induced residual stress in fiber-reinforced polymer composites

IF 6.9 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Computer Methods in Applied Mechanics and Engineering

Pub Date : 2025-03-04 DOI: 10.1016/j.cma.2025.117891

Weikang Sun , Jiaxiang Liew , Zhifei Tan , Yang Zhang , Binbin Yin

Fiber reinforced polymer (FRP) composites have extensive applications in aerospace, automobile, marine and sports industries, however, the process-induced residual stress developed during the cure process can lead to microcracks and weaken the macroscopic mechanical performance. In this work, we developed a multiscale PD framework for modeling thermo-chemo-mechanical behaviors of FRP composites for the first time. The whole cure process is modeled by a macroscale thermo-chemical coupling behavior of the FRP specimen followed by a microscale thermo-chemo-mechanical coupling process of the representative volume element (RVE) taken from the macro specimen. After the multiscale cure modeling, the resulted residual stress distribution is maintained when applying the mechanical loading. The proposed PD framework was validated by examining the temperature and degree of cure histories and the stress-strain curves against experimental data. The effects of periodic boundary condition (PBC) treatments, fiber content, fiber distribution and chemical shrinkage are explored. Cure-induced residual stress can amplify the local stress concentration and damage in the fiber‒matrix interfaces. Results show that PBC treatments have negligible influence on the final damage distribution while the fiber content and distribution can pose huge impact on the strain and stress history of the RVE. In addition, chemical shrinkage can complicate the stress state and impact the mechanical response of composites. This model can serve as a potential tool for predicting the process-induced residual stress and damage and contributes to improved composites designs.

{"title":"A coupled thermo-chemo-mechanical peridynamic model for predicting process-induced residual stress in fiber-reinforced polymer composites","authors":"Weikang Sun , Jiaxiang Liew , Zhifei Tan , Yang Zhang , Binbin Yin","doi":"10.1016/j.cma.2025.117891","DOIUrl":"10.1016/j.cma.2025.117891","url":null,"abstract":"<div><div>Fiber reinforced polymer (FRP) composites have extensive applications in aerospace, automobile, marine and sports industries, however, the process-induced residual stress developed during the cure process can lead to microcracks and weaken the macroscopic mechanical performance. In this work, we developed a multiscale PD framework for modeling thermo-chemo-mechanical behaviors of FRP composites for the first time. The whole cure process is modeled by a macroscale thermo-chemical coupling behavior of the FRP specimen followed by a microscale thermo-chemo-mechanical coupling process of the representative volume element (RVE) taken from the macro specimen. After the multiscale cure modeling, the resulted residual stress distribution is maintained when applying the mechanical loading. The proposed PD framework was validated by examining the temperature and degree of cure histories and the stress-strain curves against experimental data. The effects of periodic boundary condition (PBC) treatments, fiber content, fiber distribution and chemical shrinkage are explored. Cure-induced residual stress can amplify the local stress concentration and damage in the fiber‒matrix interfaces. Results show that PBC treatments have negligible influence on the final damage distribution while the fiber content and distribution can pose huge impact on the strain and stress history of the RVE. In addition, chemical shrinkage can complicate the stress state and impact the mechanical response of composites. This model can serve as a potential tool for predicting the process-induced residual stress and damage and contributes to improved composites designs.</div></div>","PeriodicalId":55222,"journal":{"name":"Computer Methods in Applied Mechanics and Engineering","volume":"439 ","pages":"Article 117891"},"PeriodicalIF":6.9,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Addressing concave boundaries in two-dimensional pointwise contact detection under the common-normal concept 在共同法线概念下解决二维点接触检测中的凹面边界问题

IF 6.9 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Computer Methods in Applied Mechanics and Engineering

Pub Date : 2025-03-03 DOI: 10.1016/j.cma.2025.117865

Lucas da Silva, Marina Vendl Craveiro, Alfredo Gay Neto

Contact search, the step where pairs of interacting points are identified, is crucial in computer methods for contact mechanics. This work explores the properties of contact pairs in a specific approach known as master-master method, combined with a hybrid-barrier enforcement method. The scope is on two-dimensional non-conformal contact, modeled as pointwise. Line-to-line and other instances of flat contact, for which a distribution of pressure over a region of finite size better represents their physics, are avoided. The main goal is to overcome the non-uniqueness of solutions when considering concave geometries. The bodies are defined by parameterized plane curves composed of strictly convex segments that represent either convex or concave boundaries. In the master-master approach, contact pairs are characterized by the common normal concept. Within this framework, contact pairs are classified into four types: convex-convex, matchable convex-concave, non-matchable convex-concave, and concave-concave. The Hessian of the squared distance function is analyzed for each type to further characterize them. Characterization using the Hessian matrix reveals that convex-convex and matchable convex-concave pairs are local minimizers of the squared distance function, while the other two types are either saddle points or maximizers. This enables a demonstration of the uniqueness of solutions for convex bodies. In the convex-concave case, projecting the concave boundary onto the convex one results in a univariate restricted objective function that distinguishes matchable pairs as minimizers and non-matchable pairs as maximizers. This function is used to propose a robust search algorithm that includes subdividing the domain into intervals with at most one minimizer, enabling the practical use of iterative minimization techniques to find all desired contact solutions. An algorithm for contact search that accommodates concave geometries is especially valuable in multibody applications.

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引用次数: 0

Forward and inverse simulation of pseudo-two-dimensional model of lithium-ion batteries using neural networks 利用神经网络对锂离子电池的伪二维模型进行正向和反向模拟

IF 6.9 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Computer Methods in Applied Mechanics and Engineering

Pub Date : 2025-03-02 DOI: 10.1016/j.cma.2025.117856

Myeong-Su Lee , Jaemin Oh , Dong-Chan Lee , KangWook Lee , Sooncheol Park , Youngjoon Hong

In this work, we address the challenges posed by the high nonlinearity of the Butler–Volmer (BV) equation in forward and inverse simulations of the pseudo-two-dimensional (P2D) model using the physics-informed neural network (PINN) framework. The BV equation presents significant challenges for PINNs, primarily due to the hyperbolic sine term, which renders the Hessian of the PINN loss function highly ill-conditioned. To address this issue, we introduce a bypassing term that improves numerical stability by substantially reducing the condition number of the Hessian matrix. Furthermore, the small magnitude of the ionic flux

j

often leads to a common failure mode where PINNs converge to incorrect solutions. We demonstrate that incorporating a secondary conservation law for the solid-phase potential

ψ

effectively prevents such convergence issues and ensures solution accuracy. The proposed methods prove effective for solving both forward and inverse problems involving the BV equation. Specifically, we achieve precise parameter estimation in inverse scenarios and reliable solution predictions for forward simulations.

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引用次数: 0

Octree-based scaled boundary finite element approach for polycrystal RVEs: A comparison with traditional FE and FFT methods

IF 6.9 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Computer Methods in Applied Mechanics and Engineering

Pub Date : 2025-03-01 DOI: 10.1016/j.cma.2025.117864

Shiva Kumar Gaddam , Sundararajan Natarajan , Anand K. Kanjarla

Finite Element Method (FEM) is one of the most widely used numerical techniques for solving partial differential equations. Despite its popularity, FEM faces challenges such as automatic mesh generation, handling stress singularities, and adaptive meshing. The recently developed Scaled Boundary Finite Element Method (SBFEM) overcomes these challenges by utilizing polyhedral elements, such as octree elements. SBFEM, combined with octree meshes, offer significant advantages over FEM, including rapid mesh transition, automatic mesh generation, adaptive meshing, and enhanced computational efficiency. Octree-based SBFEM has been successfully implemented and tested in various applications, such as homogenization, elastoplasticity, and adaptive phase-field fracture. However, its application to polycrystal representative volume elements (RVEs) remains unexplored. In this work, we implemented octree-based SBFEM for polycrystal RVEs and evaluated its performance for elasticity. A detailed algorithm is provided to generate balanced periodic octree meshes for polycrystal RVEs. The homogenized response and local stress fields are compared with those obtained from FEM and fast Fourier transforms (FFT). The results demonstrate that SBFEM closely matches with FEM and FFT while offering the added advantage of computational efficiency over FEM.

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引用次数: 0

Optimal solutions employing an algebraic Variational Multiscale approach part I: Steady Linear Problems

IF 6.9 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Computer Methods in Applied Mechanics and Engineering

Pub Date : 2025-03-01 DOI: 10.1016/j.cma.2025.117832

Suyash Shrestha , Marc Gerritsma , Gonzalo Rubio , Steven Hulshoff , Esteban Ferrer

This work extends our previous study from S. Shrestha et al. (2024) by introducing a new abstract framework for Variational Multiscale (VMS) methods at the discrete level. We introduce the concept of what we define as the optimal projector and present a discretisation approach that yields a numerical solution closely approximating the optimal projection of the infinite-dimensional continuous solution. In this approach, the infinite-dimensional unresolved scales are approximated in a finite-dimensional subspace using the numerically computed Fine-Scale Greens’ function of the underlying symmetric problem. The proposed approach involves solving the VMS problem on two separate meshes: a coarse mesh for the full PDE and a fine mesh for the symmetric part of the continuous differential operator. We consider the 1D and 2D steady advection–diffusion problems in both direct and mixed formulations as the test cases in this paper. We first present an error analysis of the proposed approach and show that the projected solution is achieved as the approximate Greens’ function converges to the exact one. Subsequently, we demonstrate the working of this method where we show that it can exponentially converge to the chosen optimal projection. We note that the implementation of the present work employs the Mimetic Spectral Element Method (MSEM), although, it may be applied to other Finite/Spectral Element or Isogeometric frameworks. Furthermore, we propose that VMS should not be viewed as a stabilisation technique; instead, the base scheme should be inherently stable, with VMS enhancing the solution quality by supplementing the base scheme.

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引用次数: 0

A robust and efficient rate-independent crystal plasticity model based on successive one-dimensional solution steps

IF 6.9 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Computer Methods in Applied Mechanics and Engineering

Pub Date : 2025-03-01 DOI: 10.1016/j.cma.2025.117815

B. Nijhuis, E.S. Perdahcıoğlu, A.H. van den Boogaard

An efficient stress update algorithm for rate-independent crystal plasticity is presented. A series of successive one-dimensional solution (SODS) steps traces the hypersurfaces describing the slip state for which the yield criteria of individual slip systems are fulfilled to identify the intersection of all hypersurfaces. This provides both the active set and all slip components without requiring iterative active set search procedures or inducing spurious slip on inactive systems. The basic SODS algorithm is accelerated by tracking the evolution of the active set. A fast Newton–Raphson procedure enables to obtain the solution for an unchanging active set directly, while line search and extrapolation procedures direct the SODS steps towards the solution faster. A regularised tangent modulus is proposed that eliminates stiffness jumps upon changes in active set to improve the convergence behaviour of outer (equilibrium) iterations conducted with the algorithm. The resulting stress update algorithm is highly stable and efficient, making it an attractive candidate for use in large-scale crystal plasticity FE simulations and homogenisation algorithms.

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引用次数: 0