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【新文速递】2024年9月2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 4 篇,Journal of the Mechanics and Physics of Solids 1 篇,Mechanics of Materials 1 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 2 篇

International Journal of Solids and Structures

A novel cohesive interlayer model considering friction

Jiang Yu, Bin Gong, Chenrui Cao, Chun’an Tang

doi:10.1016/j.ijsolstr.2024.113049

一种新的考虑摩擦的内聚层间模型

To understand the influence of friction on the shear-slip behavior of heterogeneous brittle composites, a novel cohesive interlayer model that can effectively capture the friction effect was proposed based on the classical Park-Paulino-Roesler model. Meanwhile, the unified potential energy function governing the interface tangential and normal behaviors was introduced to realize the mechanical interaction between Mode I fracture and Mode II fracture, and a smooth friction growth function was added in the elastic deformation stage for calculating the accurate contact pressure and friction force. Furthermore, the capability of the proposed model in addressing unloading and reloading was improved, and the fracture energy can vary accordingly during cyclic loading. To verify the effectiveness of the proposed model, it was examined by modelling the shear behavior of a masonry wallette. The results show that the relative error of the proposed model is 14.92% which is much lower than those of the other three pre-existing models when calculating the displacement corresponding to peak shear stress. Meanwhile in terms of peak shear stress and initial displacement at residual stage, the relative errors of the proposed model are only 1.82% and 5.04%, respectively, indicating the high accuracy. Besides, the tangent stiffness determined by the second-order integration of the potential energy function is also continuous and smooth, which ensures the effective convergence of the proposed cohesive model.

为了了解摩擦对非均质脆性复合材料剪切滑移行为的影响,在经典Park-Paulino-Roesler模型的基础上,提出了一种能够有效捕捉摩擦效应的黏结层间模型。同时,引入控制界面切向和法向行为的统一势能函数,实现I型断裂和II型断裂的力学相互作用,并在弹性变形阶段加入光滑摩擦增长函数,精确计算接触压力和摩擦力。此外,该模型还提高了处理卸载和再加载问题的能力,并且在循环加载过程中断裂能会发生相应的变化。为了验证所提出模型的有效性,通过模拟砌体钱包的剪切行为进行了检验。结果表明,在计算峰值剪应力对应位移时,所提模型的相对误差为14.92%,远低于其他3种已有模型的相对误差。同时,对于峰值剪应力和残余阶段初始位移,模型的相对误差仅为1.82%和5.04%,具有较高的精度。此外,由势能函数二阶积分确定的切向刚度也是连续的、光滑的,保证了所提内聚模型的有效收敛。


Flexural wave propagation in canonical quasicrystalline-generated waveguides

Zhijiang Chen, Massimiliano Gei, Lorenzo Morini

doi:10.1016/j.ijsolstr.2024.113050

典型准晶波导中的弯曲波传播

We investigate the propagation of harmonic flexural waves in periodic two-phase phononic multi-supported continuous beams whose elementary cells are designed according to the quasicrystalline standard Fibonacci substitution rule. The resulting dynamic frequency spectra are studied with the aid of a trace-map formalism which provides a geometrical interpretation of the recursive rule governing traces of the relevant transmission matrices: the traces of three consecutive elementary cells can be represented as a point on the surface defined by an invariant function of the square root of the circular frequency, and the recursivity implies the description of a discrete orbit on the surface. In analogy with the companion axial problem, we show that, for specific layouts of the elementary cell (the canonical configurations), the orbits are almost periodic. Likewise, for the same layouts, the stop-/pass-band diagrams along the frequency domain are almost periodic. Several periodic orbits exist and each corresponds to a self-similar portion of the dynamic spectra whose scaling law can be investigated by linearising the trace map in the neighbourhood of the orbit. The obtained results provide a new piece of theory to better understand the dynamic behaviour of two-phase flexural periodic waveguides whose elementary cell is obtained from quasicrystalline generation rules.

本文研究了周期两相声子多支连续梁中谐波弯曲波的传播,这些连续梁的基本单元是根据准晶标准斐波那契替换规则设计的。由此产生的动态频谱通过轨迹映射形式进行了研究,该形式提供了控制相关传输矩阵轨迹的递归规则的几何解释:三个连续的初等单元的轨迹可以表示为表面上的一个点,该点由圆频率的平方根的不变函数定义,递归性意味着表面上的离散轨道的描述。在与伴随轴问题的类比中,我们表明,对于基本单元的特定布局(规范构型),轨道几乎是周期性的。同样,对于相同的布局,沿频域的阻/通带图几乎是周期性的。存在几个周期轨道,每个周期轨道对应于动态光谱的一个自相似部分,其标度规律可以通过线性化轨道附近的迹图来研究。所得结果为更好地理解两相弯曲周期波导的动力学行为提供了新的理论依据,该两相弯曲周期波导的基本单元是根据准晶生成规则获得的。


Neural network based rYld2004 anisotropic hardening model under non-associated flow rule for BCC and FCC metals

Songchen Wang, Hongchun Shang, Can Zhou, Miao Han, Yanshan Lou

doi:10.1016/j.ijsolstr.2024.113052

基于rYld2004神经网络的BCC和FCC金属非关联流动规则下各向异性硬化模型

This paper extends the reduced Yld2004 (rYld2004) function to present the anisotropic hardening behavior for body-centered cubic and face-centered cubic metals under the proportional loading conditions based on neural network. The parameters of the rYld2004 anisotropic hardening model (AH_rYld2004) are determined by the uniaxial tensile yield stresses along 0°, 15°, 30°, 45°, 60°, 75° and 90° from the rolling direction as well as equibiaxial tension. The evolution of anisotropic parameters are described by the back propagation neural network optimized by ant colony optimization algorithm. The predicted data by AH_rYld2004 and some common anisotropic models are compared with the experimental results to verify the precision of the AH_rYld2004 in characterizing anisotropic hardening. The comparison proves that the AH_rYld2004 precisely characterize the anisotropic evolution with increasing plastic deformation for AA 3003-O and QP980. Simultaneously, the AH_rYld2004 function based on neural network is used to accurately simulate of circular cup deep drawing for AA 3003-O and uniaxial tension for QP980. The results indicate that the AH_rYld2004 model is capable to accurately represent the plastic anisotropic evolution for uniaxial tension along seven loading directions and equibiaxial tension.

本文扩展了简化 Yld2004(rYld2004)函数,在神经网络的基础上提出了体心立方和面心立方金属在比例加载条件下的各向异性硬化行为。rYld2004 各向异性硬化模型 (AH_rYld2004) 的参数由与轧制方向成 0°、15°、30°、45°、60°、75° 和 90°的单轴拉伸屈服应力以及等轴拉伸决定。各向异性参数的演变是通过蚁群优化算法优化的反向传播神经网络来描述的。将 AH_rYld2004 和一些常见各向异性模型的预测数据与实验结果进行比较,以验证 AH_rYld2004 在表征各向异性硬化方面的精确性。比较结果证明,AH_rYld2004 能精确表征 AA 3003-O 和 QP980 随塑性变形增加而发生的各向异性演变。同时,使用基于神经网络的 AH_rYld2004 函数精确模拟了 AA 3003-O 的圆杯深冲和 QP980 的单轴拉伸。结果表明,AH_rYld2004 模型能够准确表示七个加载方向的单轴拉伸和等轴拉伸的塑性各向异性演变。


ANN based optimization of nano-beam oscillations with intermolecular forces and geometric nonlinearity

Naveed Ahmad Khan, Muhammad Sulaiman, Benzhou Lu

doi:10.1016/j.ijsolstr.2024.113054

基于神经网络的分子间力和几何非线性纳米束振荡优化

In this study, we investigate the effect of Van der Waals and Casimir forces on the mathematical model of nano-electromechanical systems (NEMS) such as nano-beam actuators that contain cantilever and double cantilever beams. The singular nonlinear boundary value problem governing the beam-type actuators, including geometric nonlinearity is solved by using an intelligent strength of feedforward artificial neural networks (ANNs) and hybridization of optimization algorithms such as arithmetic optimization algorithm (AOA) and active set algorithm (ASA). The proposed ANN-AOA-AS algorithm is employed to quantify the effect of changes in applied voltage, dispersion forces, geometric nonlinearity parameters, and initial axial strain on the deflection of the beam. Furthermore, to validate the results obtained by the proposed algorithm, statistical analyses are conducted to compare the approximate solutions with state-of-the-art methodologies available in the latest literature. In addition, performance indicators are defined such as mean square error (MSE), Nash–Sutcliffe efficiency (NSE), mean absolute deviations (MAD), root mean square error (RMSE), and Error in Nash–Sutcliffe efficiency (ENSE) to study the accuracy and efficiency of the solutions. The results show that these indicators’ mean percentage values lie around 10^−4 to 10^−6 which reflects the perfect modeling of the approximate solutions.

在本研究中,我们研究了范德华力和卡西米尔力对纳米机电系统(NEMS)数学模型的影响,例如包含悬臂梁和双悬臂梁的纳米梁式致动器。利用前馈人工神经网络(ANN)的智能优势以及算术优化算法(AOA)和主动集算法(ASA)等优化算法的混合,解决了支配梁型致动器(包括几何非线性)的奇异非线性边界值问题。所提出的 ANN-AOA-AS 算法用于量化外加电压、分散力、几何非线性参数和初始轴向应变的变化对梁挠度的影响。此外,为了验证拟议算法获得的结果,还进行了统计分析,将近似解与最新文献中的先进方法进行比较。此外,还定义了性能指标,如均方误差 (MSE)、纳什-苏克里夫效率 (NSE)、平均绝对偏差 (MAD)、均方根误差 (RMSE) 和纳什-苏克里夫效率误差 (ENSE),以研究求解的准确性和效率。结果表明,这些指标的平均百分比值在 10^-4 至 10^-6 之间,反映了近似解的完美建模。


Journal of the Mechanics and Physics of Solids

Strain fields and solitary strain waves as determining factors for the cross-sectional geometry of mouse incisor enamel

Brian N Cox, Prashant K Purohit, Shane N. White

doi:10.1016/j.jmps.2024.105840

应变场和孤立应变波作为小鼠切牙牙釉质横截面几何形状的决定因素

Dental enamel in the mouse incisor is the subject of one of the most detailed histological records of cell motion and action during the formation and shaping of any organ in any species. We test the hypothesis that the shape of the enamel body on a perpendicular cross-section of the long, sabre-like incisor can be predicted by assuming that the formative ameloblast cells respond to strain and strain-rate cues that inform individual cells of position and time. The strain field is generated when growth of the forming enamel stretches the ameloblast population. Simultaneously, the strain is relaxed by coherent wavy cell movements. We hypothesize that wave motion arises when cells maintain homeostasis in their area density, with the rate of their recovery from a density perturbation assumed proportional to the magnitude of the perturbation. Density homeostasis gives rise to a nonlinear wave equation; and the nonlinearity results in solitary waves propagating within computed strain fields. We predict the final thickness of the enamel by assuming ameloblasts stop generating enamel after they experience a critical strain condition. The thickness profile vs position is correctly determined to within a constant factor, which is the unknown rate constant in the wave equation. When the rate constant is calibrated by the peak amplitude of the thickness profile, the commencement of enamel formation (the onset of ameloblast secretion) vs position is then also correctly predicted by the passage of solitary waves, implying that the strain jump within the solitary wave may be the trigger for the onset of secretion.

小鼠门牙的牙釉质是任何物种中任何器官形成和成形过程中细胞运动和作用的最详细的组织学记录之一。我们测试了一个假设,即牙釉质体的形状可以通过假设形成成釉细胞对应变和应变率的线索作出反应来预测,这些线索可以告知单个细胞的位置和时间。当形成釉质的生长拉伸成釉细胞群时,产生应变场。同时,应变被相干波状细胞运动放松。我们假设,当细胞在其面积密度中保持稳态时,波浪运动就会产生,并且它们从密度扰动中恢复的速率假定与扰动的大小成正比。密度稳态产生非线性波动方程;非线性导致孤立波在计算应变场内传播。我们通过假设成釉细胞在经历临界应变条件后停止生成牙釉质来预测牙釉质的最终厚度。厚度剖面与位置的关系被正确地确定在一个常数因子之内,这个常数因子是波动方程中的未知速率常数。当速率常数由厚度分布图的峰值振幅校准时,也可以通过孤波的传递正确地预测成釉细胞形成的开始(成釉细胞分泌的开始)和位置,这意味着孤波内的应变跳变可能是分泌开始的触发因素。


Mechanics of Materials

Charging dependent electro-chemo-mechanical coupling behaviour of polymer electrolytes containing immobilized anions

Mingchao Wang

doi:10.1016/j.mechmat.2024.105143

含固定化阴离子的聚合物电解质的电荷依赖性电化学-机械耦合行为

Theoretical models have been developed to explore the electrodeposition stability between Li metal and salt-doped polymer electrolytes. However, there is still limited investigation on the coupling behavior between mechanics and electrochemistry in those novel nano-structured polymers with immobilized anions. In this work, we employ a multiphysics modelling framework to predict the electro-chemo-mechanical behavior of polymer electrolytes containing immobilized anions. We analyze the impacts of charging conditions, stress coupling and the immobilization of anions on their ion transport, electrical and mechanical properties during charging. Strengthening stress coupling is demonstrated to improve the diffusion-driven stability of electrodeposition, by enhancing limiting applied current densities. Compared with stress coupling, immobilizing anions surprisingly sustains the non-zero interfacial Li+-ion concentrations even at high applied currents, thereby mitigating the potential diffusion-driven instability of electrodeposition. Both stress/strain and overpotentials also get reduces with increasing the concentrations of immobilized anions. This theoretical work provides insights into the strategy of redesigning polymer electrolytes, and also lays foundation for the multiphysics modelling of electrodes and full-cell battery systems.

已经建立了理论模型来探索锂金属和盐掺杂聚合物电解质之间的电沉积稳定性。然而,对于这些具有固定阴离子的新型纳米结构聚合物的力学和电化学耦合行为的研究仍然有限。在这项工作中,我们采用多物理场建模框架来预测含有固定化阴离子的聚合物电解质的电化学-力学行为。我们分析了充电条件、应力耦合和阴离子固定化对充电过程中离子输运、电学和力学性能的影响。增强应力耦合被证明可以通过提高极限施加电流密度来提高电沉积的扩散驱动稳定性。与应力耦合相比,即使在高施加电流下,固定阴离子也能维持非零的界面Li+离子浓度,从而减轻了电沉积的潜在扩散驱动的不稳定性。应力应变和过电位也随固定阴离子浓度的增加而降低。这项理论工作为重新设计聚合物电解质的策略提供了见解,也为电极和全电池系统的多物理场建模奠定了基础。


International Journal of Plasticity

Effect of plastic deformability and fracture behaviour on interfacial toughening mechanism at Fe/Ni interfaces

Sien Liu, Shoichi Nambu

doi:10.1016/j.ijplas.2024.104107

塑性变形性能和断裂行为对Fe/Ni界面增韧机制的影响

Fracture at interface causes plastic deformation in the vicinity region. Conventional plastic energy dissipation theory indicates that ductile vicinity toughens the interface by absorbing plastic deformation energy. However, the microstructure in the vicinity directly affects local plastic deformability and fracture behaviour, implying a more complicated toughening mechanism. In this study, the effect of microstructure and hardness on fracture behaviour of Fe/Ni interface was investigated. By experimental approach, interfaces with and without dynamic recrystallization (DRX) were fabricated by controlling the bonding conditions. It showed that compression-induced plastic deformation is the main source of the hardening behaviour in the vicinity. Moreover, the interfaces with hardened DRX vicinities exhibited improved fracture toughness, which is inconsistent with the plastic energy dissipation theory. To clarify this observation, the crystal plasticity finite element method (CPFEM) approach was employed to distinguish the effects of plastic deformation and interfacial microstructure. The result showed that although higher plastic deformability in the vicinity absorbs more dissipated plastic energy, severe stress concentration at the interface leads to early fracture and poor toughness. On the other hand, the interfacial hardened DRXed grains disperse interfacial stress distribution and provide potential sub-crack sites. A combined result of uniform plastic deformation and fracture energy dissipation is responsible for the improved toughness at interfaces with DRXed grains.

界面断裂引起邻近区域的塑性变形。传统的塑性能量耗散理论认为,邻近的延性通过吸收塑性变形能使界面增韧。然而,附近的微观组织直接影响到局部的塑性变形能力和断裂行为,这意味着一个更复杂的增韧机制。研究了显微组织和硬度对Fe/Ni界面断裂行为的影响。通过实验方法,通过控制键合条件制备了具有动态再结晶和不具有动态再结晶的界面。结果表明,压缩引起的塑性变形是附近硬化行为的主要来源。此外,DRX附近硬化的界面断裂韧性有所提高,这与塑性耗能理论不一致。为了澄清这一观察结果,采用晶体塑性有限元方法(CPFEM)来区分塑性变形和界面微观结构的影响。结果表明,虽然附近较高的塑性变形能吸收更多的耗散塑性能,但界面处严重的应力集中导致了早期断裂和较差的韧性。另一方面,界面硬化的DRXed晶粒分散了界面应力分布,提供了潜在的子裂纹位置。均匀塑性变形和断裂能量耗散的共同作用是DRXed晶粒界面韧性提高的主要原因。


Thin-Walled Structures

An overview on the ballistic performance of woven-fabric-based flexible protective systems: experimental and numerical studies

Yi Zhou, Meng Ma, Ahmmed Nur, Rui Zhang, Ziming Xiong, Yuan Lin, Yuhang Xiang, Zhongwei Zhang

doi:10.1016/j.tws.2024.112394

基于织物的柔性防护系统的弹道性能综述:实验和数值研究

With the advancement of firearms and explosive weapons on the battlefield or during law enforcement, the requirements of flexible protective systems have been made more challenging, primarily in that the protective armor should provide better protection with reduced weight and limited restriction on mobility. Confronted by such a challenge, engineering design of ballistic fabrics and panels becomes a reasonable approach to provide better protection using fibers and structures that are currently available for this application. The currently most used commercially available high-performance fibers are aramid and Ultra-high-molecular-weight polyethylene (UHMWPE). Most ballistic fabrics are manufactured by weaving and cross-plying, though knitting, braiding, and nonwoven techniques catch up or even move ahead very fast. In this paper, a comprehensive review of the ballistic impact of woven fabric is presented. The first section of this paper introduces the background of this topic and the relevant previous review papers summarizing the numerous publications in this field. This is followed by the presentation of the experimental techniques used to characterize the performance and responses of woven fabrics. Apart from experimental work, a summarization of the modeling techniques, such as early semi-empirical, analytical, and most recent numerical models are considered. In addition, the underlying mechanisms of energy absorption and their corresponding influencing factor that bias the responses is discussed. Based on the influencing factors, approaches to further improve the penetration resistance of woven fabrics is highlighted in the final section.

随着战场上或执法过程中火器和爆炸性武器的进步,对柔性防护系统的要求变得更具挑战性,主要是防护装甲应在减轻重量和限制机动性的情况下提供更好的防护。面对这样的挑战,防弹织物和面板的工程设计成为一种合理的方法,使用目前可用于该应用的纤维和结构来提供更好的保护。目前最常用的商用高性能纤维是芳纶和超高分子量聚乙烯(UHMWPE)。大多数防弹织物是通过编织和交叉粘合制造的,尽管针织、编织和非织造技术正在迎头赶上,甚至发展得很快。本文对机织物的弹道冲击进行了综述。本文的第一部分介绍了本课题的背景和相关的文献综述,总结了该领域的大量出版物。随后介绍了用于表征机织织物的性能和响应的实验技术。除了实验工作外,还考虑了建模技术的总结,例如早期的半经验模型,分析模型和最近的数值模型。此外,还讨论了能量吸收的基本机理及其影响响应偏差的因素。最后在分析影响因素的基础上,提出了进一步提高机织物抗渗透性能的途径。


Residual mechanical properties of corroded ultra-high-strength steels and weld metals

Man-Tai Chen, Zhichao Gong, Huan Cao, Jingjing Zhang, Fengming Ren, Johnny Ching Ming Ho, Mianheng Lai

doi:10.1016/j.tws.2024.112397

腐蚀超高强度钢和焊缝金属的残余力学性能

This paper presents an in-depth investigation into the residual mechanical properties of ultra-high-strength steels and weld metals after exposure to corrosive environment. The tensile specimens of weld metals were fabricated using ER100S-G, ER110S-G, ER120S-G feedstock wires by robotic gas metal arc welding, whilst ultra-high-strength steel tensile coupon specimens were machined from the Q890 and Q960 steel plates. The high-strength steel and weld metal tensile specimens were exposed to neutral salt spray accelerated corrosion conditions. Six exposure durations were designed to achieve different corrosion degrees of specimens. A total of 23 corroded ultra-high-strength steel tensile coupon specimens and 19 corroded high-strength weld metal specimens were included. The geometric profiles of corroded steel specimens were determined via non-contact 3D laser scanning. Monotonic tensile tests were conducted to determine the stress-strain responses and key mechanical properties of corroded steel and weld specimens. Mechanical properties deterioration of corroded ultra-high-strength steels and weld metals are reported and discussed. Prediction equations on the residual mechanical properties regarding the tensile loading capacity, yield stress and ultimate tensile stress of ultra-high-strength steels and weld metals after exposure to corrosive environment were established.

本文对超高强度钢和焊缝金属在腐蚀环境下的残余力学性能进行了深入研究。焊接金属的拉伸试样采用ER100S-G、ER110S-G、ER120S-G原料丝,采用机器人气体保护金属电弧焊制作,Q890和Q960钢板加工超高强度钢拉伸试样。将高强度钢和焊缝金属拉伸试样置于中性盐雾加速腐蚀条件下。为了达到不同的腐蚀程度,设计了6种暴露时间。共包括23个腐蚀的超高强度钢拉伸试样和19个腐蚀的高强焊缝金属试样。采用非接触式三维激光扫描确定了腐蚀钢试样的几何轮廓。进行了单调拉伸试验,以确定腐蚀钢和焊缝试样的应力应变响应和关键力学性能。本文报道并讨论了受腐蚀的超高强度钢和焊缝金属的力学性能恶化。建立了超高强度钢和焊缝金属在腐蚀环境下的拉伸载荷能力、屈服应力和极限拉应力的残余力学性能预测方程。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemDeform断裂复合材料非线性化学ADS焊接裂纹理论爆炸材料机器人控制
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首次发布时间:2024-11-21
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【新文速递】2024年8月31日固体力学SCI期刊最新文章

今日更新:Journal of the Mechanics and Physics of Solids 2 篇,Mechanics of Materials 1 篇,Thin-Walled Structures 1 篇Journal of the Mechanics and Physics of SolidsRecovering Mullins damage hyperelastic behaviour with physics augmented neural networksMartin Zlatić, Marko Čanađijadoi:10.1016/j.jmps.2024.105839 用物理增强神经网络恢复Mullins损伤超弹性行为The aim of this work is to develop a neural network for modelling incompressible hyperelastic behaviour with isotropic damage, the so-called Mullins effect. This is obtained through the use of feed-forward neural networks with special attention to the architecture of the network in order to fulfil several physical restrictions such as objectivity, polyconvexity, non-negativity, material symmetry and thermodynamic consistency. The result is a compact neural network with few parameters that is able to reconstruct the hyperelastic behaviour with Mullins-type damage. The network is trained with artificially generated plane stress data and even correctly captures the full 3D behaviour with much more complex loading conditions. The energy and stress responses are correctly captured, as well as the evolution of the damage. The resulting neural network can be seamlessly implemented in widely used simulation software. Implementation details are provided and all numerical examples are performed in Abaqus.这项工作的目的是开发一个神经网络来模拟具有各向同性损伤的不可压缩超弹性行为,即所谓的穆林斯效应。这是通过使用前馈神经网络获得的,特别注意网络的结构,以满足一些物理限制,如客观性、多凸性、非负性、材料对称性和热力学一致性。结果得到了一个具有较少参数的紧凑神经网络,能够重建具有mullins型损伤的超弹性行为。该网络使用人工生成的平面应力数据进行训练,甚至可以在更复杂的加载条件下正确捕获完整的3D行为。能量和应力响应被正确捕获,以及损伤的演变。所得到的神经网络可以在广泛使用的仿真软件中无缝实现。提供了实现细节,并在Abaqus中执行了所有数值示例。A generalized phase-field cohesive zone model (μPF-CZM) for fractureJian-Ying Wudoi:10.1016/j.jmps.2024.105841断裂的广义相场内聚区模型(μPF-CZM)In this work a generalized phase-field cohesive zone model (μPF-CZM) is proposed within the framework of the unified phase-field theory for brittle and cohesive fracture. With the introduction of an extra dissipation function for the crack driving force, in addition to the geometric function for the phase-field regularization and the degradation function for the constitutive relation, theoretical and application scopes of the original PF-CZM are broadened greatly. These characteristic functions are analytically determined from the conditions for the length scale insensitivity and a non-shrinking crack band in a universal, optimal and rationalized manner, for almost any specific traction–separation law. In particular, with an optimal geometric function, the crack irreversibility can be considered without affecting the target traction–separation softening law. Not only concave softening behavior but also high-order cohesive traction, both being limitations of the previous works, can be properly dealt with. The global fracture responses are insensitive not only to the phase-field length scale but also to the traction order parameter, though the crack bandwidth might be affected by both. Despite the loss of variational consistency in general cases, the resulting μPF-CZM is still thermodynamically consistent. Moreover, the existing numerical implementation can be adopted straightforwardly with minor modifications. Representative numerical examples are presented to validate the proposed μPF-CZM and to demonstrate its capabilities in capturing brittle and cohesive fracture with general softening behavior. The insensitivity to both the phase-field length scale and the traction order parameter is also sufficiently verified.本文在脆性和内聚断裂统一相场理论框架内提出了广义相场内聚区模型(μPF-CZM)。除了相场正则化的几何函数和构成关系的退化函数外,还引入了额外的裂纹驱动力耗散函数,从而大大拓宽了原始 PF-CZM 的理论和应用范围。这些特征函数是根据长度尺度不敏感性和无收缩裂缝带的条件,以通用、优化和合理化的方式分析确定的,几乎适用于任何特定的牵引分离定律。特别是,利用最优几何函数,可以在不影响目标牵引分离软化规律的情况下考虑裂纹不可逆问题。不仅凹面软化行为,而且高阶内聚牵引力也能得到适当处理,而这两种行为都是以前工作的局限。全局断裂响应不仅对相场长度尺度不敏感,而且对牵引阶次参数也不敏感,尽管裂纹带宽可能会受到两者的影响。尽管在一般情况下失去了变分一致性,但所得到的 μPF-CZM 在热力学上仍然是一致的。此外,现有的数值实现方法只需稍加修改即可直接采用。为了验证所提出的 μPF-CZM 并证明其在捕捉具有一般软化行为的脆性和内聚断裂方面的能力,我们给出了具有代表性的数值示例。相场长度尺度和牵引阶参数的不敏感性也得到了充分验证。Mechanics of MaterialsCompression behavior of 316L diamond lattice structures fabricated via additive manufacturing with variable cell sizesJiaxi Zhao, Zulei Liang, Zhonggang Sundoi:10.1016/j.mechmat.2024.105135增材制造316L不同尺寸金刚石晶格结构的压缩性能The unit size effect of 316L diamond lattice structures was systematically investigated through experiments, theory, and simulations. Experimental tests demonstrated that reducing the cell size to 5 mm and 2.5 mm enhances the load carrying capacity and energy absorption of the structures. Additionally, analytical solutions were developed to acceptably estimate the elastic modulus and yield strength of diamond lattice structures. Finite element simulations, incorporating elastic, plastic, and ductile damage models, were utilized to depict the entire deformation evolution at different strain levels. These simulations were found to be precisely consistent with experimental observations. The results confirmed a transition from non-uniform deformation to uniform large-scale plastic deformation. This transition is attributed to either locally fractured struts caused by longer struts in structures with large cell sizes or largely deformed, non-ruptured short beams in structures with smaller cell sizes. Comparisons with previous reports indicated that the current structures with a cell size of 2.5 mm exhibit outstanding mechanical performance, making them desirable candidates for engineering applications.通过实验、理论和模拟等方法系统地研究了316L金刚石晶格结构的单位尺寸效应。实验结果表明,将微孔尺寸减小到5 mm和2.5 mm可以提高结构的承载能力和能量吸收能力。此外,还开发了可接受的分析解来估计金刚石晶格结构的弹性模量和屈服强度。结合弹性、塑性和延性损伤模型的有限元模拟用于描述不同应变水平下的整个变形演变过程。这些模拟结果与实验观察结果完全一致。结果证实了从非均匀变形到均匀大尺度塑性变形的转变。这种转变要么是由于大单元尺寸结构中较长的支柱局部断裂,要么是由于较小单元尺寸结构中较大变形但未破裂的短梁。与先前的报告比较表明,目前电池尺寸为2.5 mm的结构具有出色的机械性能,使其成为工程应用的理想候选者。Thin-Walled StructuresDynamic response analysis of cylindrical lithium-ion battery under impact loadings: A theoretical studyZi-xuan Huang, Xin-chun Zhang, Li-qiang An, Li-xiang Rao, Li-rong Gu, Chun-yan Lidoi:10.1016/j.tws.2024.112385冲击载荷下圆柱形锂离子电池动态响应分析的理论研究The prediction of serious deformation for lithium-ion batteries (LIBs) under impact loadings becomes an important challenge for engineering application. In this paper, a theoretical model is developed to investigate the dynamic responses of cylindrical LIBs based on the membrane factor method. The cylindrical LIB is simplified as double-layer structure consisting of the casing and jellyroll. The plastic yield criterion is established by utilizing tensile yield strengths and the corresponding membrane factor fn is defined. The dynamic responses of the cell under radial impact loading are explored. The accuracy of this method is verified by the corresponding finite element (FE) results. In addition, a comprehensive quantitative analysis of the governing factors of fn is conducted under different boundary conditions. Using the theoretical model, the response characteristics of the cell under different initial velocities and masses are investigated. The approximate equation for the variation of the maximum deflection with initial velocity and the saturation impact time are presented. The tendency of the deformation changing with size and tensile properties of the cell is obtained. These researches will provide technical support for the failure prediction and structural safety design of cylindrical cells.预测锂离子电池(LIB)在冲击载荷下的严重变形是工程应用中的一项重要挑战。本文基于膜因子法建立了一个理论模型来研究圆柱形锂离子电池的动态响应。圆柱形 LIB 被简化为由外壳和胶卷组成的双层结构。利用拉伸屈服强度建立了塑性屈服准则,并定义了相应的膜因子 fn。探讨了电池在径向冲击载荷下的动态响应。相应的有限元(FE)结果验证了该方法的准确性。此外,还在不同边界条件下对 fn 的控制因子进行了全面的定量分析。利用理论模型,研究了电池在不同初始速度和质量下的响应特性。给出了最大挠度随初速度和饱和冲击时间变化的近似方程。还得出了变形随电池尺寸和拉伸特性变化的趋势。这些研究将为圆柱形电池的失效预测和结构安全设计提供技术支持。来源:复合材料力学仿真Composites FEM

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