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【新文速递】2024年1月12日固体力学SCI期刊最新文章

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今日更新:International Journal of Solids and Structures 1 篇,Journal of the Mechanics and Physics of Solids 1 篇,Mechanics of Materials 1 篇,Thin-Walled Structures 1 篇

International Journal of Solids and Structures

Multiscale simulation of polymer curing of composites combined mean-field homogenisation methods at large strains

Peter Lenz, Rolf Mahnken

doi:10.1016/j.ijsolstr.2023.112642

复合材料聚合物固化的多尺度模拟,结合大应变下的均场均质化方法

This work introduces a coupled thermo-chemo-mechanical framework for simulating the polymerisation process of composites, accounting for large strains. The framework encompasses the microscale, mesoscale and, macroscale. The microscale represents a step-growth polymerisation mechanism, which is modelled as a system of multiple growing spheres. These spheres are further decomposed into concentric layers of solid, resin, and curing agent material. At the mesoscale, the composite is divided into inclusions and the polymer matrix. The macroscale is considered as a homogeneous material. In order to describe the behaviour of the heterogeneous scales, mean-field homogenisation methods are employed. These methods have been developed before for linear elastic materials. However, considering finite deformations, a special treatment is necessary to accurately account for the effects of such deformations. Effective properties at all scales are obtained using the Mori–Tanaka, Voigt, Reuss, and Voigt–Reuss–Hill average mean-field homogenisation method. The results demonstrate how the different homogenisation methods influence the curing process and, consequently, the macroscopic response of the composite material.

这项研究引入了一个热-化学-机械耦合框架,用于模拟复合材料的聚合过程,并考虑到大应变。该框架包括微观尺度、中观尺度和宏观尺度。微观尺度代表一种阶跃生长聚合机制,它被模拟为一个由多个生长球组成的系统。这些球体进一步分解成固体、树脂和固化剂材料的同心层。在中尺度上,复合材料分为夹杂物和聚合物基体。宏观尺度被视为均质材料。为了描述异质尺度的行为,采用了均场均质化方法。这些方法以前是针对线性弹性材料开发的。然而,考虑到有限变形,有必要采用特殊的处理方法来准确地解释这种变形的影响。使用 Mori-Tanaka、Voigt、Reuss 和 Voigt-Reuss-Hill 平均均场均质法获得了所有尺度上的有效特性。结果表明了不同的均质化方法如何影响固化过程,进而影响复合材料的宏观响应。


Journal of the Mechanics and Physics of Solids

Enhancing toughness through geometric control of the process zone

Sage Fulco, Michal K. Budzik, Kevin T. Turner

doi:10.1016/j.jmps.2024.105548

通过对加工区的几何控制提高韧性

Material architecture provides an opportunity to alter and control the fracture process zone shape and volume by redistributing the local stresses at a crack tip. Properly designed structures can enlarge the plastic zone and enhance the effective toughness. Here, we use a pillar array as a model structure to demonstrate how variations in geometry at a crack tip control the size and shape of the plastic zone and can be used to engineer the effective toughness. Elastic–plastic finite element simulations are used to show how the pillar width, spacing, and height can be varied to tailor the size and shape of the plastic zone. A set of analytical mechanics models that accurately estimate the shape, volume, and resulting toughness as a function of the base material properties and geometry are also presented. A case study extends the analysis to sets of non-regular pillar arrays to illustrate how architecture can be used to alter toughness along the crack path.

材料结构通过重新分配裂纹尖端的局部应力,为改变和控制断裂过程区的形状和体积提供了机会。设计合理的结构可以扩大塑性区并提高有效韧性。在此,我们以支柱阵列为模型结构,展示了裂纹尖端几何形状的变化如何控制塑性区的大小和形状,并可用于设计有效韧性。我们使用弹塑性有限元模拟来展示如何通过改变支柱的宽度、间距和高度来调整塑性区的大小和形状。此外,还介绍了一套分析力学模型,该模型可准确估计形状、体积和由此产生的韧性与基础材料特性和几何形状的函数关系。案例研究将分析扩展到非规则支柱阵列,以说明如何利用结构沿裂纹路径改变韧性。


Mechanics of Materials

Mean field homogenization schemes using averages of stress, strain and strain energy density and applications

Tao Fu, Chuanying Li, Hao Hu, Xianghe Peng

doi:10.1016/j.mechmat.2024.104911

使用应力、应变和应变能密度平均值的平均场均质化方案及其应用

The average of stress (AS) and average of strain (AN) were often used in the development of conventional mean-field homogenization (MFH) schemes, but their correlation with the average of strain energy density (AE) has rarely been discussed. In this work, we examined the correlations of AE with AS and AN, and found that AE can be reduced to the product of AS or AN under uniform boundary stress or linear surface displacement associated with a uniform strain field. By introducing a reference matrix and using any two among AE, AS and AN, three MFH schemes were developed: NS (using AN and AS); NE (using AN and AE); and SE (using AS and AE). Following the concept of the Mori-Tanaka's (MT) method, three MFH schemes obtained above were reduced to MT-NS, MT-NE and MT-SE, respectively. Effective elastic properties of composites consisting of isotropic elastic matrices and spherical isotropic elastic inclusions were predicted using these schemes and compared with experimental results. The comparison revealed that MT-SE and MT-NS can reasonably replicate the experimental results in the case of moderate particle volume fractions and ratios between the Young's moduli of matrix and the reinforcement particles, demonstrating the validity of the MFH schemes. This work is significant because it not only clarifies the correlation of AE with AN and AS, but also provides more options for the development of MFH schemes, which can enrich the theory and methods for the analysis of the effective properties of composites.

应力平均值(AS)和应变平均值(AN)经常被用于传统均场均质化(MFH)方案的开发,但它们与应变能量密度平均值(AE)的相关性却很少被讨论。在这项工作中,我们研究了 AE 与 AS 和 AN 的相关性,发现在均匀边界应力或与均匀应变场相关的线性表面位移条件下,AE 可以简化为 AS 或 AN 的乘积。通过引入参考矩阵并使用 AE、AS 和 AN 中的任意两个,开发出三种 MFH 方案:NS(使用 AN 和 AS);NE(使用 AN 和 AE);SE(使用 AS 和 AE)。按照森田中(Mori-Tanaka,MT)方法的概念,上述三种 MFH 方案分别简化为 MT-NS、MT-NE 和 MT-SE。利用这些方案预测了由各向同性弹性基体和球形各向同性弹性夹杂物组成的复合材料的有效弹性特性,并与实验结果进行了比较。比较结果表明,在颗粒体积分数和基体与增强颗粒的杨氏模量比适中的情况下,MT-SE 和 MT-NS 可以合理地复 制实验结果,证明了 MFH 方案的有效性。这项工作意义重大,不仅阐明了 AE 与 AN 和 AS 的相关性,还为 MFH 方案的开发提供了更多选择,丰富了复合材料有效性能分析的理论和方法。


Thin-Walled Structures

Numerical simulation of corroded circular hollow section steel columns: A corrosion evolution approach

Yun Zhao, Xuhong Zhou, Fei Xu, Tak-Ming Chan

doi:10.1016/j.tws.2024.111594

腐蚀圆形空心截面钢柱的数值模拟:腐蚀演变方法

This study introduces a numerical simulation method for corroded circular hollow section steel columns, utilising a newly developed corrosion evolution model. This model was formulated by characterising the corrosion morphology and calibrating parameters throughout the entire corrosion process. An interpolation method was implemented to estimate the number of corrosion pits, based on experimentally measured corrosion ratios. Consequently, this allowed for the numerical prediction of the time-varying corrosion morphologies. Finite element (FE) models, incorporating this corrosion evolution model, were constructed. These corroded column models underwent validation through comparison with experimental findings. To further establish the effectiveness of the proposed FE models in predicting the structural behaviour of corroded members, FE models were also developed using the traditional uniform thickness reduction approach for comparative analysis. The results revealed that the proposed FE models for corroded structures offer a more accurate prediction of mechanical performance, particularly in instances of severe corrosion damage.

本研究利用新开发的腐蚀演化模型,介绍了腐蚀圆形空心截面钢柱的数值模拟方法。该模型是通过描述整个腐蚀过程中的腐蚀形态和校准参数而建立的。根据实验测得的腐蚀比,采用内插法估算腐蚀坑的数量。因此,这样就可以对随时间变化的腐蚀形态进行数值预测。结合这种腐蚀演变模型,构建了有限元 (FE) 模型。这些腐蚀柱模型通过与实验结果的对比进行了验证。为了进一步确定所提出的有限元模型在预测腐蚀构件结构行为方面的有效性,还使用传统的均匀减厚方法开发了有限元模型,以进行对比分析。结果表明,针对腐蚀结构提出的有限元模型能够更准确地预测机械性能,尤其是在严重腐蚀损坏的情况下。




来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemDeform断裂复合材料化学UG裂纹理论材料多尺度控制
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首次发布时间:2024-11-05
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【新文速递】2024年1月17日固体力学SCI期刊最新文章

今日更新:Mechanics of Materials 1 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 3 篇Mechanics of MaterialsTime–temperature correlations of amorphous thermoplastics at large strains based on molecular dynamics simulationsWuyang Zhao, Rui Xiao, Paul Steinmann, Sebastian Pfallerdoi:10.1016/j.mechmat.2024.104926基于分子动力学模拟的大应变下非晶态热塑性塑料的时间-温度相关性In this paper, we investigate the time–temperature correlation of amorphous thermoplastics at large strains based on coarse-grained molecular dynamics simulations. This correlation behavior is characterized by the strain hardening modulus in uniaxial tension simulations at different strain rates across the glass transition region. The temperature regime is divided into a melt zone, a glassy zone, and a transition zone between them, according to the storage modulus calculated from dynamic mechanical analysis (DMA) at small strains. In the melt zone, the existence of time–temperature superposition (TTS) at large strains is verified by constructing a master curve of the hardening modulus. The obtained shift factors are then compared to those from DMA at small strains, showing that the TTS behavior is transferable between small and large strains. In the glassy zone, the effects of time and temperature are not superposable at large strains but still can be correlated. To demonstrate this correlation behavior, we introduce a level set of the hardening modulus with a variable pair of strain rate and temperature. Pairs lying in the same level result in coincident stress–strain curves at large strains. The transferability of the correlation behavior between large and small strains is validated by comparing these stress–strain curves at small strains in the pre-yield region. In the transition zone, the correlation behavior is studied with both aforementioned methods, showing that TTS is applicable to large strains but not transferable to small strains. Finally, we propose a phenomenological constitutive model for uniaxial tension to demonstrate the time–temperature correlation at large strains, considering different constant strain rates and temperatures.在本文中,我们基于粗粒度分子动力学模拟研究了大应变下非晶热塑性塑料的时间-温度相关性。在不同的应变速率下,单轴拉伸模拟的应变硬化模量表征了这种相关行为。根据动态力学分析(DMA)计算的小应变下的存储模量,将温度区划分为熔融区、玻璃化区和两者之间的过渡区。通过构建硬化模量主曲线,验证了在大应变下熔体存在时间-温度叠加现象。然后将得到的位移因子与DMA在小应变下的位移因子进行比较,表明TTS行为在小应变和大应变之间是可转移的。在玻璃区,时间和温度的影响在大应变下不重叠,但仍然可以相关。为了证明这种相关行为,我们引入了应变速率和温度对可变的硬化模量水平集。在大应变下,处于同一水平的对导致应力-应变曲线一致。通过对预屈服区小应变应力-应变曲线的比较,验证了大应变与小应变相关行为的可转移性。在过渡区,用上述两种方法研究了相关行为,表明TTS适用于大菌株,但不适用于小菌株。最后,我们提出了单轴拉伸的现象学本构模型,以证明在大应变下,考虑不同的恒定应变率和温度下的时间-温度相关性。International Journal of PlasticityInfluences of the evolving plastic behavior of sheet metal on V-bending and springback analysis considering different stress statesChong Zhang, Yanshan Loudoi:10.1016/j.ijplas.2024.103889考虑不同应力状态下板料塑性行为变化对v型弯曲和回弹分析的影响Bending is a common forming process that covers various stress states during sheet metal forming, mainly from uniaxial to plane strain states of both tension and compression depending on the inner or outer sides of the sheet. To model the tension-compression asymmetry (TCA) at different stress states, a five stress states-sensitive (Five-SSS) yield function is proposed. The non-linear effect of stress triaxiality η on plasticity is considered. Multiple analytical calibration methods are obtained for the Five-SSS function by considering different groups of stress states from equi-biaxial compression to equi-biaxial tension. One of the methods considers the uniaxial tension, uniaxial compression, plane strain tension, plane strain compression and equi-biaxial tension, which is used to simulate the V-bending process of an advanced high-strength steel QP1180 and a magnesium alloy AZ31. A modified Lode-dependent anisotropic-asymmetric (LAA) function is adopted as plastic potential to model both the TCA and evolution of r-value. The Five-SSS + modified LAA functions can predict the double shift of neutral layer during V-bending for the two investigated materials due to multiple reverse loading in the neutral layer shift zone. For the springback prediction of V-bending, it is observed that the Five-SSS yield function can highly improve the prediction accuracy compared to other functions because it models the TCA under both uniaxial and plane strain states. In addition, the TCA of unloading modulus should be considered for AZ31 to significantly improve the accuracy of springback prediction.弯曲是一种常见的成形工艺,它涵盖了金属板材成形过程中的各种应力状态,主要是从单轴应变到平面应变的拉伸和压缩状态,具体取决于板材的内侧或外侧。为了模拟不同应力状态下的拉伸-压缩不对称(TCA),提出了五应力状态敏感(Five-SSS)屈服函数。考虑了应力三轴性 η 对塑性的非线性影响。通过考虑从等轴压缩到等轴拉伸的不同应力状态组,获得了五应力状态敏感屈服函数的多种分析校准方法。其中一种方法考虑了单轴拉伸、单轴压缩、平面应变拉伸、平面应变压缩和等轴拉伸,用于模拟先进高强度钢 QP1180 和镁合金 AZ31 的 V 形弯曲过程。采用改进的 Lode-dependent anisotropic-asymmetric (LAA) 函数作为塑性势能来模拟 TCA 和 r 值的演变。由于中性层偏移区存在多重反向加载,Five-SSS + 改进的 LAA 函数可以预测两种被研究材料在 V 型弯曲过程中中性层的双重偏移。对于 V 形弯曲的回弹预测,可以观察到,与其他函数相比,Five-SSS 屈服函数可以极大地提高预测精度,因为它对单轴和平面应变状态下的 TCA 都进行了建模。此外,应考虑 AZ31 的卸载模量 TCA,以显著提高回弹预测精度。Thin-Walled StructuresLow-velocity impact behavior of origami-inspired honeycomb acoustic metamaterial structureYao Chen, Pan Shi, Jialong Wei, Tianyu Xie, Jian Feng, Pooya Sarehdoi:10.1016/j.tws.2024.111607 折纸蜂窝声学超材料结构的低速冲击性能The ancient origami technique has inspired numerous acoustic metamaterials, and varieties of honeycomb sandwich structures with remarkable energy absorption capacity. This study introduces an origami-inspired honeycomb acoustic metamaterial structure designed for engineering applications that demand both impact resistance and sound absorption. This acoustic metamaterial structure is created by bonding the panel containing periodically distributed perforated holes and the panel without perforations to periodical Bellow tube unit cells. The acoustic wave propagation and drop-weight impact simulations are conducted to investigate the acoustic performance and low-velocity impact behavior of the structure. The results show that the Bellow honeycomb structure exhibits superior sound absorption capacity over the two frequency ranges, outperforming conventional honeycomb structures. In comparison to conventional hexagonal honeycomb structure, we find that the Bellow acoustic metamaterial structure demonstrates enhanced impact resistance and energy absorption capacity. Its mechanical performance under low-velocity impact can be further enhanced by increasing story height. Besides, matrix material of the origami foldcore can be tailored to suit various application scenarios. This novel acoustic metamaterial structure holds promise for applications in noise control with transportation, civil, mechanical, and aerospace engineering.古老的折纸技术启发了许多声学超材料,以及各种具有显著能量吸收能力的蜂窝夹层结构。本研究介绍了一种折纸蜂窝声学超材料结构,设计用于需要抗冲击和吸声的工程应用。这种声学超材料结构是通过将含有周期性分布穿孔孔的面板和没有穿孔的面板粘合到周期性波纹管单元细胞上而形成的。为了研究结构的声学性能和低速冲击特性,进行了声波传播和落锤冲击仿真。结果表明,波纹管蜂窝结构在两个频率范围内的吸声能力均优于传统蜂窝结构。与传统的六边形蜂窝结构相比,我们发现波纹管声学超材料结构具有更强的抗冲击能力和吸能能力。在低速冲击下,增加层高可进一步提高其力学性能。此外,折纸折纸芯的基体材料可以定制,以适应各种应用场景。这种新型声学超材料结构有望应用于交通、土木、机械和航空航天工程的噪声控制。Auxetic Pattern Design for Concentric-tube Robots Using an Active DNN-Metaheuristics OptimizationJieun Park, Jeong Min Hur, Soyeon Park, Do-Nyun Kim, Gunwoo Nohdoi:10.1016/j.tws.2024.111603基于主动dnn -元启发式优化的同心管机器人辅助图案设计We optimized the design parameters of three auxetic patterns to minimize the bending stiffness-to-torsional stiffness ratios (EI/GJ) in concentric-tube robots while maintaining minimal compliance. We proposed a deep neural network-based metaheuristics optimization framework that incorporates active data generation close to the Pareto front and retraining of the surrogate model. Iterative procedure of data generation and surrogate model retraining yielded improved optimal solutions due to enhanced prediction accuracy of the surrogate model near the Pareto front, with minimal added data. The auxetic patterns optimized using our method achieved lower EI/GJ values compared to the recently reported design with identical tube specifications.为了在保持最小柔度的同时最小化同心管机器人的弯曲刚度/扭转刚度比(EI/GJ),我们对三种辅助模式的设计参数进行了优化。我们提出了一个基于深度神经网络的元启发式优化框架,该框架结合了接近帕累托前沿的主动数据生成和代理模型的再训练。数据生成和代理模型再训练的迭代过程得到了改进的最优解,因为代理模型在Pareto前沿附近的预测精度提高了,并且添加的数据最少。与最近报道的具有相同管规格的设计相比,使用我们的方法优化的消声模式获得了更低的EI/GJ值。Partially self-centering braces with NiTi- and Fe-SMA U-shaped dampersShuling Hu, M. Shahria Alam, Yuelin Zhang, Zhenghao Ding, Xiuzhang Hedoi:10.1016/j.tws.2024.111605部分自定心支架与NiTi和Fe-SMA u形阻尼器Partially self-centering behavior has been considered a promising and beneficial solution for achieving seismic resilience of building structures in the life-cycle span. This paper aims to develop an innovative partially self-centering brace (PSB) with NiTi-based shape memory alloy (NiTi-SMA) and iron-based shape memory alloy (Fe-SMA) U-shaped dampers. NiTi-SMA and Fe-SMA U-shaped dampers are the main nonlinear components and provide self-centering and energy-absorbing capacities, respectively. The PSB's self-centering capability can be flexibly controlled by adjusting the contribution of NiTi-SMA and Fe-SMA U-shaped dampers. The working principle, desired nonlinear behaviors, and preliminary design methods of PSBs were first introduced. This is followed by parametric 3D numerical simulations of PSBs, where the efficiency of the modeling of NiTi-SMA and Fe-SMA U-shaped dampers was verified based on test results. The cyclic loading results indicate that only U-shaped dampers developed nonlinear behavior and other components can maintain elastic, and the designed PSB can achieve the desired partial self-centering behavior with simple construction. Parametric analysis outcomes illustrate that an increased contribution of Fe-SMA U-shaped dampers could reduce the self-centering capacity while enhancing the hysteretic energy-dissipation capacity and maximum loading capacities of PSBs. Evaluating the seismic performance of structures with PSBs involved parametric dynamic analyses of single-degree-of-freedom systems. These analyses revealed that in comparison to fully self-centering systems, partially self-centering systems featuring PSBs could achieve lower force requirements, diminished absolute acceleration responses, and acceptable residual deformations, all while being designed to achieve the same maximum deformations. The analysis results affirm the potential of the proposed PSB as a promising lateral force-resisting element for augmenting the life-cycle advantages of self-centering building structures by striking a balance between initial construction expenses, structural damage control, and nonstructural damage control.部分自定心行为被认为是实现建筑结构全寿命抗震性能的一种有前途和有益的解决方案。本文旨在开发一种新型的部分自定心支撑(PSB),该支撑采用镍基形状记忆合金(NiTi-SMA)和铁基形状记忆合金(Fe-SMA) u型阻尼器。NiTi-SMA和Fe-SMA u型阻尼器是主要的非线性部件,分别提供自定心和吸能能力。通过调整nti - sma和Fe-SMA u型阻尼器的贡献,可以灵活地控制PSB的自定心能力。首先介绍了psb的工作原理、期望的非线性行为和初步设计方法。随后对psb进行了参数化三维数值模拟,并根据试验结果验证了NiTi-SMA和Fe-SMA u型阻尼器建模的有效性。循环加载结果表明,只有u型阻尼器表现出非线性行为,其他部件均保持弹性,所设计的PSB结构简单,能达到预期的部分自定心性能。参数分析结果表明,增加Fe-SMA u型阻尼器的贡献可以降低psb的自定心能力,同时提高psb的滞回耗能能力和最大承载能力。评价带psb结构的抗震性能涉及单自由度体系的参数动力分析。这些分析表明,与完全自定心系统相比,具有psb的部分自定心系统可以实现更低的力要求,减少绝对加速度响应,并可以接受残余变形,同时实现相同的最大变形。分析结果肯定了所提出的PSB作为一种有希望的横向抗力元件的潜力,通过在初始施工费用、结构损伤控制和非结构损伤控制之间取得平衡,增加自定心建筑结构的生命周期优势。来源:复合材料力学仿真Composites FEM

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