International Journal of Mechanical Sciences最新文献_第9页

Modelling of axial thrust force considering 3D rolling deformation 考虑三维滚动变形的轴向推力模型

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-18 DOI: 10.1016/j.ijmecsci.2024.109738

Shuilin Lin , Qinghua Song , Chao Ma , Jianliang Sun , Marian Wiercigroch

The axial thrust force in the rolling deformation zone is influenced by interconnected factors, such as the metal transverse flow velocity, rolling pressure distribution, and strip shear deformation, often resulting in roll wear and a lower strip surface quality. Despite its significance in the design and manufacturing of strip mills, the available literature primarily focuses on the single-variable complete difference method as a means of evaluating this force. In this study, a novel approach is proposed for calculating the axial thrust force in the rolling deformation zone, incorporating the coupling variables of the 3D rolling space. The accuracy of the results is confirmed using data obtained from an industrial test rig, indicating that the axial thrust force in the rolling deformation zone can be precisely calculated through the integration of the energy method and the 3D difference method. The results indicate that the axial thrust force decreases with the transverse flow of the metal and the transverse shear deformation of the strip. It increases with a non-uniform distribution of rolling pressure and grows as the crossover angle increases. Conversely, the axial thrust force decreases with an increasing reduction rate of the strip. In general, a non-uniform distribution of rolling pressure enhances the axial thrust force, albeit with a minor effect when the crossover angle exceeds 0.8° Conversely, metal transverse flow significantly reduces the axial thrust force when the crossover angle is small (φ < 0.4°), but only marginally so when the crossover angle falls within the range of 0.4° to 1.0°

轧制变形区的轴向推力受金属横向流速、轧制压力分布和板带剪切变形等相互关联因素的影响，通常会导致轧辊磨损和板带表面质量下降。尽管这种力在板带轧机的设计和制造中非常重要，但现有文献主要集中在将单变量完全差分法作为评估这种力的手段。本研究提出了一种计算轧制变形区轴向推力的新方法，其中包含三维轧制空间的耦合变量。利用从工业试验台获得的数据证实了计算结果的准确性，表明通过能量法和三维差分法的整合，可以精确计算滚动变形区的轴向推力。结果表明，轴向推力随着金属的横向流动和带材的横向剪切变形而减小。轴向推力随着轧制压力的不均匀分布而增大，并随着交叉角的增大而增大。相反，轴向推力随着带钢减薄率的增加而减小。相反，当交叉角较小时（φ < 0.4°），金属横向流动会显著减小轴向推力，但当交叉角在 0.4°至 1.0°范围内时，轴向推力会略有减小。

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引用次数: 0

An analytical method for broadband acoustic analysis of 2D cavities containing or bounded by porous materials 对含有多孔材料或以多孔材料为边界的二维空腔进行宽带声学分析的分析方法

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-18 DOI: 10.1016/j.ijmecsci.2024.109717

Xueyi Zhao , Xiang Liu , Jianqiang Guo

Real-life vibro-acoustic systems often involve porous treatments, resulting in complex-valued and frequency-dependent models that are challenging to solve. Traditional prediction techniques like the finite element (FE) method requires huge computational cost, especially in the mid to high frequency ranges. This paper develops a novel spectral dynamic stiffness (SDS) formulation, using very few number of degrees of freedom but describing the broadband acoustic behaviour of acoustic cavities with porous materials highly accurately. The method employs frequency-dependent shape function that satisfies exactly the (damped) Helmholtz equation to describe the (equivalent) acoustic pressure field, and also features an innovative approach to use the fast-convergent Modified Fourier series to describe any arbitrary acoustic BCs. Finally, the SDS matrices for cavities containing or bounded by porous materials are formulated in an analytical manner. It is demonstrated that the method exhibits a much higher computational efficiency over the FE package COMSOL, at least 6 times faster than the COMSOL with a similar level of accuracy, and benchmark solutions are provided. This promising method can provide a powerful tool for systems with porous materials that have frequency-dependent characteristics, paving the way for efficient and accurate acoustic analysis in complex engineering applications.

现实生活中的振动声学系统往往涉及多孔处理，从而产生复杂的数值和频率相关模型，这对求解具有挑战性。传统的预测技术（如有限元（FE）方法）需要巨大的计算成本，尤其是在中高频率范围内。本文开发了一种新颖的频谱动态刚度（SDS）公式，使用很少的自由度，但能高度精确地描述多孔材料声腔的宽带声学行为。该方法采用了与频率相关的形状函数，完全满足（阻尼）亥姆霍兹方程来描述（等效）声压场，同时还采用了一种创新方法，使用快速收敛修正傅里叶级数来描述任意声波 BC。最后，以分析的方式制定了包含多孔材料或以多孔材料为边界的空腔的 SDS 矩阵。结果表明，与 FE 软件包 COMSOL 相比，该方法具有更高的计算效率，在精度相近的情况下至少比 COMSOL 快 6 倍，并提供了基准解。对于具有频率相关特性的多孔材料系统，这种前景广阔的方法可以提供一个强大的工具，为复杂工程应用中高效、准确的声学分析铺平道路。

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引用次数: 0

Space–time topology optimization for anisotropic materials in wire and arc additive manufacturing 线材和电弧增材制造中各向异性材料的时空拓扑优化

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-18 DOI: 10.1016/j.ijmecsci.2024.109712

Kai Wu , Weiming Wang , Fred van Keulen , Jun Wu

Wire and Arc Additive Manufacturing (WAAM) has great potential for efficiently producing large metallic components. However, like other additive manufacturing techniques, materials processed by WAAM exhibit anisotropic properties. Assuming isotropic material properties in design optimization thus leads to less efficient material utilization. Instead of viewing WAAM-induced material anisotropy as a limitation, we consider it an opportunity to improve structural performance. This requires the integration of process planning into structural design. In this paper, we propose a novel method to utilize material anisotropy to enhance the performance of structures both during fabrication and in their use. Our approach is based on space–time topology optimization, which simultaneously optimizes the structural layout and the fabrication sequence. To model material anisotropy in space–time topology optimization, we derive the material deposition direction from the gradient of the pseudo-time field, which encodes the fabrication sequence. Numerical results demonstrate that leveraging material anisotropy effectively improves the performance of intermediate structures during fabrication as well as the overall structure.

线弧增材制造（WAAM）在高效生产大型金属部件方面具有巨大潜力。然而，与其他增材制造技术一样，WAAM 加工的材料也具有各向异性。因此，在优化设计时假设材料具有各向同性，会降低材料利用效率。我们不会将 WAAM 引起的材料各向异性视为一种限制，而是将其视为提高结构性能的机会。这就需要将工艺规划与结构设计相结合。在本文中，我们提出了一种利用材料各向异性来提高结构在制造和使用过程中性能的新方法。我们的方法基于时空拓扑优化，可同时优化结构布局和制造顺序。为了在时空拓扑优化中建立材料各向异性模型，我们从伪时域梯度推导出材料沉积方向，伪时域梯度编码了制造顺序。数值结果表明，利用材料各向异性可以有效改善制造过程中的中间结构以及整体结构的性能。

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引用次数: 0

Vibration suppression in SDOF systems coupled to a nonlinear energy sink under colored noise 彩色噪声下与非线性能量汇耦合的 SDOF 系统的振动抑制

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-17 DOI: 10.1016/j.ijmecsci.2024.109718

Mengmeng Li , Di Liu , Yong Xu

This study analyzes the stochastic vibration suppression and optimization of the single-degree-of-freedom (SDOF) system equipped with the cubic stiffness nonlinear energy sink (NES) under colored noise excitation. Two theoretical methods are proposed: an integrated method (denoted as EL-ELM) that combines evolutionary Lyapunov theory with the equivalent linearization method, and the other is an empirical formula. Using EL-ELM, the coupled nonlinear system is simplified to an equivalent linear stochastic system, allowing for a theoretical analysis of the impact of NES structural parameters on suppression performance and the precise determination of optimal parameter configurations for the best suppression effects. Subsequently, based on the results from the EL-ELM and the response data, an empirical formula has been developed that clearly describes the comprehensive laws governing the optimal NES parameters as they vary with vibration system parameters and stochastic excitation. Through error analysis and comparison of the two methods, it is found that the empirical formula significantly outperforms EL-ELM in terms of accuracy and computational cost, but it is contingent on solid prior knowledge. This study explores the influence of NES structural parameters on the system’s dynamic response and energy, further validating the effectiveness of the proposed methods in identifying optimal structural parameters. The phenomenon of targeted energy transfer (TET) under different NES structural parameters is also explained. The methodologies introduced in this study have strengthened the theory of vibration suppression. Specifically, the empirical formula excels in accuracy and computational efficiency by effectively using prior knowledge. The EL-ELM method, owing to its theoretical insights, is vital for analyzing complex stochastic nonlinear models. Combining these approaches offers guidance for advancing vibration control in theoretical and practical domains.

本研究分析了单自由度（SDOF）系统在彩色噪声激励下的随机振动抑制和优化问题，该系统配备了立方刚度非线性能量汇（NES）。本文提出了两种理论方法：一种是将进化李雅普诺夫理论与等效线性化方法相结合的综合方法（称为 EL-ELM），另一种是经验公式。利用 EL-ELM，耦合非线性系统被简化为等效线性随机系统，从而可以从理论上分析 NES 结构参数对抑制性能的影响，并精确确定最佳参数配置，以获得最佳抑制效果。随后，根据 EL-ELM 的结果和响应数据，开发了一个经验公式，清晰地描述了最佳 NES 参数随振动系统参数和随机激励变化的综合规律。通过误差分析和两种方法的比较，发现经验公式在精度和计算成本方面明显优于 EL-ELM，但这取决于扎实的先验知识。本研究探讨了 NES 结构参数对系统动态响应和能量的影响，进一步验证了所提方法在确定最佳结构参数方面的有效性。此外，还解释了不同 NES 结构参数下的目标能量转移（TET）现象。本研究引入的方法加强了振动抑制理论。具体而言，经验公式通过有效利用先验知识，在准确性和计算效率方面表现出色。EL-ELM 方法由于其理论洞察力，对于分析复杂的随机非线性模型至关重要。将这些方法结合起来，可为在理论和实践领域推进振动控制提供指导。

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引用次数: 0

Parametric instability analysis of rotors under anisotropic boundary conditions 各向异性边界条件下转子的参数失稳分析

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-16 DOI: 10.1016/j.ijmecsci.2024.109739

Xing Tan , Pengfei Deng , Weiting Chen , Stefano Zucca , Teresa Maria Berruti , Tao Wang , Huan He

Ensuring rotor stability is a major concern in engineering, as instabilities can lead to catastrophic failures. Existing literature shows that anisotropic boundary conditions significantly affect the parametric instability characteristics of rotors under periodical axial loads. However, there is little literature systematically analyzing the formation mechanism of parametric resonance under these boundary conditions or providing a detailed classification of the parametric instability regions. Therefore, this paper presents a comprehensive parametric instability analysis of a rotor subjected to periodic axial loads under anisotropic boundary conditions. A novel approach based on the multiple scales method is proposed to address anisotropy in the boundary conditions. Using this approach, the analytical boundaries of the parametric instability regions are derived, and a proof regarding the absence of certain parametric resonances is presented. These analytical solutions are validated by numerical results obtained from the discrete transition matrix method, which form the basis for systematically investigating the effects of anisotropy in direct or cross-coupling stiffness/damping coefficients on the rotor instability. The key scientific contributions of this work include: Deriving analytical instability boundaries, providing a more efficient alternative to purely numerical methods while maintaining high accuracy; Demonstrating the absence of parametric resonance of difference type under both isotropic or anisotropic boundary conditions; Discovering that anisotropy in stiffness coefficients can induce self-interaction within a given forward or backward whirl mode, as well as interaction between two forward or two backward whirl modes, leading to additional instability regions; Reducing anisotropy in direct damping coefficients may increase critical dynamic load coefficients, potentially enhancing rotor safety; If the cross-coupling stiffness coefficients exceed the threshold for triggering intrinsic instability, the rotor may become unstable in all operating conditions. All these findings offer insights into the stability management of rotors under various operating conditions and provide valuable guidance for designing and operating safer, more efficient rotor systems.

确保转子的稳定性是工程领域的一个主要问题，因为不稳定性可能导致灾难性故障。现有文献表明，各向异性边界条件会显著影响转子在周期性轴向载荷作用下的参数失稳特性。然而，很少有文献系统地分析这些边界条件下参数共振的形成机理，或对参数失稳区域进行详细的分类。因此，本文对各向异性边界条件下承受周期性轴向载荷的转子进行了全面的参数失稳分析。本文提出了一种基于多尺度法的新方法来解决边界条件中的各向异性问题。利用这种方法，得出了参数不稳定性区域的分析边界，并证明不存在某些参数共振。离散过渡矩阵法获得的数值结果验证了这些分析解，为系统研究直接或交叉耦合刚度/阻尼系数各向异性对转子不稳定性的影响奠定了基础。这项工作的主要科学贡献包括推导出分析不稳定性边界，在保持高精度的同时，为纯数值方法提供了更有效的替代方法；证明在各向同性或各向异性边界条件下均不存在差分类型的参数共振；发现刚度系数的各向异性可在给定的前向或后向旋流模式内引起自相互作用，以及两个前向或两个后向旋流模式之间的相互作用，从而导致额外的不稳定区域；降低直接阻尼系数的各向异性可能会增加临界动载荷系数，从而提高转子的安全性；如果交叉耦合刚度系数超过了引发内在不稳定性的阈值，转子可能会在所有运行条件下变得不稳定。所有这些发现为转子在各种运行条件下的稳定性管理提供了启示，并为设计和运行更安全、更高效的转子系统提供了宝贵的指导。

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引用次数: 0

An origami metamaterial with distinct mechanical properties in three orthotropic directions 在三个正交方向上具有不同机械特性的折纸超材料

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-16 DOI: 10.1016/j.ijmecsci.2024.109713

Mengyue Li , Houhua Chen , Jiayao Ma , Yan Chen

Origami-inspired mechanical metamaterials have recently gained increasing attention in various engineering fields due to their unique properties determined by the microstructure geometry. Most origami metamaterials are designed and optimized to achieve specific targets, such as smooth force response or high energy absorption, while it is difficult for a single origami structure to bear distinct mechanical behaviors in different directions simultaneously. In this paper, we present a novel origami metamaterial which demonstrates remarkably programmable anisotropic mechanical properties in three orthotropic directions under quasi-static compression. Through a combination of theoretical analysis, experiments and numerical simulations, this newly designed metamaterial is proved to exhibit a rigid origami folding mode when loaded in the x-direction, resulting in low specific energy absorption (SEA) and compressive stiffness. Conversely, when loaded in the y-direction, the metamaterial achieves high SEA and stiffness due to buckling deformation, which is three times larger than the corresponding data in the x-direction. Furthermore, in the z-direction, the metamaterial initially undergoes a rigid origami folding mode followed by panel buckling, resulting in a graded response with intermediate SEA and stiffness. The proposed metamaterials demonstrate significant potential for applications in versatile scenarios.

受折纸启发的机械超材料因其由微结构几何形状决定的独特性能，近年来在各个工程领域受到越来越多的关注。大多数折纸超材料的设计和优化都是为了实现特定的目标，如平滑的力响应或高能量吸收，而单一的折纸结构很难同时在不同方向上承担不同的力学行为。在本文中，我们介绍了一种新型折纸超材料，它在准静态压缩条件下，在三个正交方向上展示了可编程的各向异性机械特性。通过理论分析、实验和数值模拟相结合的方法，证明了这种新设计的超材料在 x 方向加载时表现出刚性折纸折叠模式，从而产生较低的比能量吸收（SEA）和压缩刚度。相反，当在 y 方向加载时，超材料因屈曲变形而获得了较高的比能量吸收（SEA）和刚度，是 x 方向相应数据的三倍。此外，在 z 方向上，超材料最初经历了刚性折纸折叠模式，然后是面板屈曲，从而产生了具有中等 SEA 和刚度的分级响应。所提出的超材料展示了在多种应用场景中的巨大应用潜力。

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引用次数: 0

On anisotropic local bifurcation based on hypoplastic model 基于低塑性模型的各向异性局部分岔论

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-14 DOI: 10.1016/j.ijmecsci.2024.109733

Guo-Wei Fan , Xue-Feng Li , Wei Wu

The incipience of shear band in homogeneous granular materials is well captured by the bifurcation analysis. Most bifurcation analyses are based on isotropic plastic constitutive models. In this paper, a hypoplastic constitutive model is presented by considering a fabric tensor for inherent anisotropy. Based on this model, we carry out bifurcation analysis for the plane strain case, and then extend the analysis to consider general three-dimensional stress state. The theoretical results are compared with experiments on sand conducted using a plane strain device and a true triaxial device. It's indicated the salient features of stress-strain behaviour and shear band formation are well captured by our analyses.

分岔分析可以很好地捕捉到均质颗粒材料中剪切带的萌发。大多数分岔分析都基于各向同性的塑性构造模型。本文通过考虑内在各向异性的织物张量，提出了一种低塑性构造模型。基于该模型，我们对平面应变情况进行了分岔分析，然后将分析扩展到一般的三维应力状态。我们将理论结果与使用平面应变装置和真正的三轴装置进行的砂实验进行了比较。结果表明，我们的分析很好地捕捉到了应力-应变行为和剪切带形成的显著特征。

引用次数: 0

Critical physics-informed fatigue life prediction of laser 3D printed AlSi10Mg alloys with mass internal defects 具有大量内部缺陷的激光 3D 打印 AlSi10Mg 合金的临界物理学疲劳寿命预测

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-14 DOI: 10.1016/j.ijmecsci.2024.109730

Yanan Hu , Yufeng She , Shengchuan Wu , Qianhua Kan , Huan Yu , Guozheng Kang

The significant scatter in high cycle fatigue life of additively manufactured metallic components presents an increasing challenge to structural integrity. This fatigue life variation is radically attributed to the differences in physical features of critical defects that lead to crack initiation. To address this issue, this paper proposes an integrated framework for identifying critical defects and predicting fatigue life using physics-informed machine learning, with a focus on the impact of 3D defect features. By employing X-ray tomography, high cycle fatigue tests, and fractography analyses on post-mortem specimens, a dataset associated with mass internal defects is first built up to correlate the spatial geometric features of critical defects with fatigue life. A kernel support vector machine is then used to formulate a critical defect identification model, aimed at identifying critical defects among numerous defects by evaluating their geometric attributes. Finally, a fatigue life prediction model is developed using a physics-informed neural network, which incorporates the influence of defect geometry on fatigue life as physical constraints in the loss function. The integrated framework demonstrates that fatigue life predictions from identified critical defects in each specimen exhibit small deviations, with the average prediction falling within twice the error bands. This study is expected to provide a valuable reference for fatigue assessment of additively manufactured components through sequential critical defect identification and fatigue life prediction.

快速成型金属部件的高循环疲劳寿命存在明显差异，这对结构完整性提出了日益严峻的挑战。这种疲劳寿命差异的根本原因在于导致裂纹产生的关键缺陷的物理特征存在差异。为解决这一问题，本文提出了一个综合框架，利用物理信息机器学习识别关键缺陷并预测疲劳寿命，重点关注三维缺陷特征的影响。通过采用 X 射线断层扫描、高循环疲劳测试和死后试样的断裂分析，首先建立了与大量内部缺陷相关的数据集，从而将关键缺陷的空间几何特征与疲劳寿命联系起来。然后，使用核支持向量机建立关键缺陷识别模型，旨在通过评估缺陷的几何属性，从众多缺陷中识别出关键缺陷。最后，利用物理信息神经网络开发了疲劳寿命预测模型，该模型将缺陷几何形状对疲劳寿命的影响作为损失函数中的物理约束条件。综合框架表明，根据每个试样中已识别的关键缺陷预测的疲劳寿命偏差很小，平均预测值在误差带的两倍以内。这项研究有望通过连续的关键缺陷识别和疲劳寿命预测，为增材制造部件的疲劳评估提供有价值的参考。

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引用次数: 0

Coupled crystal plasticity-phase field simulation of twin-twin interaction in magnesium 镁中孪晶相互作用的晶体塑性-相场耦合模拟

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-14 DOI: 10.1016/j.ijmecsci.2024.109734

Jiachen Hu , Bo Xu , Junyuan Xiong , Chao Yu , Guozheng Kang

Twin-twin interactions significantly influence the mechanical properties of magnesium and its alloys. A thorough understanding of the underlying mechanisms governing these interactions is essential for designing Mg alloys with enhanced strength and toughness. In this work, a crystal plasticity-twin coupled phase field (CP-TPF) model incorporating multiple extension twin variants and considering the role of dislocation slipping is proposed to investigate the interactions between/among the same twin variants and those between co-zone twin variants in Mg single crystals. The model incorporates an additional energy term to represent the interaction among different twin variants and couples the CP and TPF models through order parameters and stress tensor. The simulated results show that the interaction between the same twin variants can either promote or inhibit the twin propagation, and multiple twins tend to generate concurrently in Mg single crystal to minimize the free energy associated with the accumulation of elastic strain. During co-zone twin-twin interaction, localized thickening of the recipient twin occurs due to the concentrated stresses induced by the intrusion twin, and the mutual extrusion of the two twins leads to blunting of the intrusion twin tip. Both the coalescence of the same twin variants and the formation of twin-twin boundaries between the co-zone twin variants contribute to the effective mechanism of twinning-induced hardening. Moreover, local dislocation accommodation plays a crucial role in twin-twin interactions. It relaxes the stress concentration near the twin tips and twin-twin boundaries and significantly contributes to the uneven migration of the twin boundary.

孪晶相互作用对镁及其合金的机械性能有重大影响。要设计出具有更高强度和韧性的镁合金，就必须透彻了解支配这些相互作用的基本机制。在这项工作中，我们提出了一个晶体塑性-孪晶耦合相场（CP-TPF）模型，该模型包含多个延伸孪晶变体，并考虑了位错滑动的作用，用于研究镁单晶中相同孪晶变体之间的相互作用以及共区孪晶变体之间的相互作用。该模型包含一个额外的能量项来表示不同孪晶变体之间的相互作用，并通过阶次参数和应力张量将 CP 和 TPF 模型耦合起来。模拟结果表明，相同孪晶变体之间的相互作用既可以促进也可以抑制孪晶的传播，镁单晶中往往会同时产生多个孪晶，以尽量减少与弹性应变累积相关的自由能。在共区孪晶-孪晶相互作用过程中，由于侵入孪晶引起的集中应力，受体孪晶发生局部增厚，两个孪晶的相互挤压导致侵入孪晶尖端变钝。相同孪晶变体的凝聚和同区孪晶变体之间孪晶-孪晶边界的形成都是孪晶诱导硬化的有效机制。此外，局部位错容纳在孪晶-孪晶相互作用中起着至关重要的作用。它放松了孪晶尖端和孪晶-孪晶边界附近的应力集中，极大地促进了孪晶边界的不均匀迁移。

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引用次数: 0

Sequential dual-scale approach for microstructure-informed ductile fracture prediction 基于微观结构的韧性断裂预测序列双尺度方法

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-13 DOI: 10.1016/j.ijmecsci.2024.109719

Jinwook Jung , Hyukjae Lee , Woojin Cho , Byeong-Seok Jeong , Yoon Seok Ko , Sung-Il Kim , Dong-Ik Kim , Myoung-Gyu Lee , Heung Nam Han

This study presents a novel dual-scale finite element method to establish a microstructure-informed ductile fracture criterion for ferrite–martensite dual-phase (DP) steel. At the macroscale, an anisotropic plasticity model with rate-dependent hardening was employed to simulate the material's deformation history. Simultaneously, at the microscale, a dislocation density-based crystal plasticity model was utilized to simulate deformation within a representative volume element (RVE) of the dual-phase steel, constructed using tomography aided by a plasma-focused ion beam/electron backscatter diffraction system.

The material properties of the ferrite and martensite phases were determined through X-ray diffraction (XRD) analysis and load-displacement measurements obtained via nanoindentation for each phase. The RVE simulation results were validated against experimentally measured mechanical properties and microstructural changes. The local deformation history at the fracture initiation site, extracted from the macroscale model, was used as boundary conditions for the microscale RVE simulation; sequential dual-scale approach. The models were applied to specimens with varying notch radii, generating different local stress triaxialities and accumulated shear strains at fracture onset. This process allowed the establishment of a ductile fracture criterion, which was further tested in a hole expansion experiment, demonstrating close alignment with experimental data.

This sequential dual-scale analysis effectively predicts the deformation behavior of multiphase metallic materials by incorporating realistic microstructures while minimizing computational costs. Consequently, the proposed ductile fracture prediction technique offers a robust method with broad applicability across various metallic materials.

本研究提出了一种新颖的双尺度有限元方法，用于建立铁素体-马氏体双相钢（DP）的微观结构韧性断裂准则。在宏观尺度上，采用随硬化速率变化的各向异性塑性模型模拟材料的变形历史。同时，在微观尺度上，采用基于位错密度的晶体塑性模型模拟双相钢代表性体积元素（RVE）内的变形，RVE 是在等离子体聚焦离子束/电子反向散射衍射系统的辅助下，利用断层扫描技术构建的。RVE 模拟结果与实验测量的机械性能和微观结构变化进行了验证。从宏观模型中提取的断裂起始点的局部变形历史被用作微观 RVE 模拟的边界条件；顺序双尺度方法。这些模型适用于具有不同缺口半径的试样，在断裂发生时产生不同的局部应力三轴度和累积剪切应变。这一过程建立了韧性断裂标准，并在扩孔实验中进行了进一步测试，结果表明该标准与实验数据密切吻合。这种顺序双尺度分析方法通过结合现实的微观结构有效地预测了多相金属材料的变形行为，同时最大限度地降低了计算成本。因此，所提出的韧性断裂预测技术提供了一种稳健的方法，广泛适用于各种金属材料。

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引用次数: 0