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【新文速递】2024年11月11日固体力学SCI期刊最新文章

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今日更新:Journal of the Mechanics and Physics of Solids 3 篇,International Journal of Plasticity 2 篇,Thin-Walled Structures 6 篇

Journal of the Mechanics and Physics of Solids

Fracture of polymer-like networks with hybrid bond strengths

Chase M. Hartquist, Shu Wang, Bolei Deng, Haley K. Beech, Stephen L. Craig, Bradley D. Olsen, Michael Rubinstein, Xuanhe Zhao

doi:10.1016/j.jmps.2024.105931

具有杂化键强度的类聚合物网络断裂

The design and functionality of polymeric materials hinge on failure resistance. While molecular-level details drive crack evolution in polymer networks, the connection between individual chain scission and bulk failure remains unclear and difficult to probe. In this work, we systematically study the fracture mechanics of polymer-like networks with hybrid bond strengths. We reveal that varying the ratio of strong and weak strands within otherwise identical networks gives a non-monotonic relationship between intrinsic fracture energy and strong strand fraction. Networks with some weak strands can counterintuitively outperform those with exclusively strong strands. Experiments on poly(ethylene glycol) gels and architected polymer-like lattices together with simulations unveil these properties. We show through computational visualization that strand type concentrations impact crack growth patterns and fracture energy trends. Cracks propagate through weak layers at low strong strand fractions. Aggregate clusters deflect or pin cracks at similar concentrations of strong and weak strands. Cracks blunt due to dispersed weak strand failure at high strong strand fractions. The sacrificial weak strands can notably deconcentrate stress near the crack tip, which toughens by delaying crack advancement. The interplay between concentration and clustering of strand types in networks with hybrid bond strengths, combined with crack growth phenomena and nonlocal energy release, provides insights into unusual fracture characteristics. Results shed light on fracture in polymer networks and percolated lattices.

高分子材料的设计和功能取决于抗破坏能力。虽然分子水平的细节驱动了聚合物网络中的裂缝演化,但单个链断裂和整体破坏之间的联系仍然不清楚,也难以探究。在这项工作中,我们系统地研究了具有混合键强度的类聚合物网络的断裂力学。我们发现,在其他相同的网络中,改变强链和弱链的比例给出了内在断裂能和强链分数之间的非单调关系。与直觉相反,一些弱链的网络比那些只有强链的网络表现得更好。对聚乙二醇凝胶和结构聚合物样晶格的实验以及模拟揭示了这些特性。我们通过计算可视化显示,链型浓度影响裂纹扩展模式和断裂能趋势。裂纹在弱层中以低强链分数传播。在强弱股的浓度相似的情况下,聚集簇会偏转或钉住裂缝。在高强度链分数下,由于分散的弱链失效,裂纹变钝。牺牲的弱链可以明显地分散裂纹尖端附近的应力,从而通过延迟裂纹的扩展来增韧。混合键强度网络中链类型的集中和聚集之间的相互作用,结合裂纹扩展现象和非局部能量释放,提供了对异常断裂特征的见解。结果揭示了聚合物网络和渗透晶格的断裂。


Micromechanics-based variational phase-field modeling of fatigue fracture

Mina Sarem, Nuhamin Eshetu Deresse, Els Verstrynge, Stijn François

doi:10.1016/j.jmps.2024.105932

基于细观力学的疲劳断裂变分相场模型

In this paper, we extend the micromechanics-based phase-field model to simulate fatigue failure. The coupling of a micromechanics-based framework with the phase-field approach helps to differentiate between failure modes, by distinguishing between open and closed microcracks. This integrated framework links continuum field variables, such as plastic strain and damage variable, to micromechanical mechanisms like frictional sliding and microcrack opening. We first improve the algorithm’s stability during loading-unloading in the tensile regime through a modification of the plasticity evolution equations. Next, we incorporate fatigue damage accumulation and deterioration due to cyclic loading into the micromechanics-based phase-field model. A fatigue degradation function, driven by free energy accumulation, is introduced to degrade the fracture energy upon reaching a specified threshold during cyclic loading. Various cyclic loads are applied to benchmark tests, both with and without imperfections (e.g. holes, inclusions, voids), under plane strain conditions to capture diverse failure modes. The results demonstrate the model’s capability to accurately describe tensile, shear, and mixed-mode fracture under cyclic loading. Furthermore, the model effectively simulates key features of fatigue behavior, including crack nucleation, growth, and coalescence.

在本文中,我们扩展了基于微力学的相场模型来模拟疲劳失效。基于微力学的框架与相场方法的耦合有助于通过区分开微裂纹和闭微裂纹来区分失效模式。该集成框架将连续场变量(如塑性应变和损伤变量)与微力学机制(如摩擦滑动和微裂纹打开)联系起来。首先,通过对塑性演化方程的修正,提高了算法在拉伸状态下的加载-卸载稳定性。接下来,我们将疲劳损伤积累和恶化纳入到基于微力学的相场模型中。在循环加载过程中,引入自由能积累驱动的疲劳退化函数,在达到指定阈值时对断裂能进行退化。在平面应变条件下,各种循环载荷应用于基准测试,包括有缺陷和没有缺陷(例如孔、夹杂物、空隙),以捕获不同的失效模式。结果表明,该模型能够准确描述循环荷载下的拉伸、剪切和混合模式断裂。此外,该模型有效地模拟了疲劳行为的关键特征,包括裂纹形核、扩展和合并。


Magnetostriction of soft-magnetorheological elastomers

Eric M. Stewart, Lallit Anand

doi:10.1016/j.jmps.2024.105934

软磁流变弹性体的磁致伸缩

Soft-magnetorheological elastomers (s-MREs) are particulate composites made of a non-magnetic elastomeric matrix dispersed with micron-sized particles of a “soft-magnetic” material. The phenomenon of magnetostriction in specimens made from s-MREs is the change in their shape when they are subjected to an external magnetic field. Experiments in the literature show that for circular cylindrical specimens subjected to an axially applied magnetic field the magnetostriction is strongly dependent on their aspect-ratio, with specimens with a low ratio of the length to the diameter exhibiting a larger tensile magnetostrictive strain than specimens with a large aspect-ratio — the “shape-effect.” This response is also hysteretic because of the underlying viscoelasticity of the matrix material. In this paper we report on a large deformation magneto-viscoelasticity theory for s-MREs and its finite element implementation. Using our theory we show that we can model this non-intuitive geometry-dependent magnetostrictive response of cylindrical s-MRE specimens. We show that the effect of the magnetization m of the cylinder is to decrease the magnetic field h within the cylinder relative to the applied magnetic field h_app outside the cylinder, the well-known demagnetization effect, and that this demagnetization is diminished in more slender cylinders due to magnetic fringing at the boundaries of the cylinder. This is the physical reason behind the macroscopically-observed “shape-effect.” Our magneto-viscoelasticity theory is quite broad, and it has many potential applications beyond modeling the magnetostriction of cylindrical specimens. As an example we apply the theory to study the bending actuation response of beams of s-MREs when they are subjected to magnetic fields at different incidence angles to their longitudinal axis.

软磁流变弹性体(s-MREs)是一种由非磁性弹性基体和微米级“软磁”材料颗粒组成的颗粒复合材料。s-MRE样品中的磁致伸缩现象是指在外部磁场作用下其形状的变化。文献中的实验表明,对于轴向施加磁场的圆柱形样品,其磁致伸缩强度强烈依赖于其长径比,长径比较小的样品比长径比较大的样品表现出更大的拉伸磁致伸缩应变——这就是“形状效应”。这种响应也具有滞后性,因为基体材料的粘弹性特性是其基础。在这篇论文中,我们报告了s-MRE的大变形磁流变弹性理论及其有限元实现。利用我们的理论,我们可以模拟圆柱形s-MRE样品中这种非直观的、与几何形状相关的磁致伸缩响应。我们证明了圆柱体的磁化强度m的作用是使圆柱体内部的磁场h相对于圆柱体外部的施加磁场h_app减小,这是众所周知的去磁效应。在更细的圆柱体中,由于圆柱体边界处的磁边缘效应,去磁效应会减弱。这是宏观上观察到的“形状效应”背后的物理原因。我们的磁致电弹性理论非常广泛,除了用于模拟圆柱形样品的磁致伸缩外,还有很多潜在的应用。例如,我们将该理论应用于研究当S-MREs在不同入射角的磁场作用下弯曲时的驱动响应。


International Journal of Plasticity

The evolution of grain boundary structure mediated by disclinations in magnesium alloys under superplastic deformation

Chunfeng Du, Yipeng Gao, Min Zha, Cheng Wang, Jian Wang, Hui-Yuan Wang

doi:10.1016/j.ijplas.2024.104167

超塑性变形下由位错介导的镁合金晶界组织演化

Superplastic deformation in metals and alloys, characterized by ultrahigh ductility (exceeding 300%) without cracking at elevated temperatures, is a critical process for manufacturing complex-shaped components. While a few grain-boundary (GB)-mediated deformation mechanisms have been identified as essential contributors to superplasticity in fine-grained polycrystals (grain size is typically less than 10 μm), it is still a challenge to maintain a steady fine-grained microstructure and sustainable plastic flow at high temperatures. Partially due to the lack of a quantitative description of dislocation-GB reactions, it has not been well recognized how grain coarsening can be suppressed by the external loading during superplastic deformation. In this work, we address this challenge by formulating a disclination-dislocation coupling equation within the Lie-algebra framework, providing a quantitative understanding of the interactions between disclinations, dislocations, and GBs. Using quasi-in-situ electron backscattered diffraction (EBSD) analysis in Mg alloys, we systematically investigate the multiscale interactions of the defects and their impact on grain structure evolution. Three key mechanisms that suppress conventional grain coarsening have been identified, i.e., disclination-assisted GB accommodation, disclination-GB pinning, and disclination-induced sub-GB crossing, all of which are captured by the proposed equation. This study contributes to the broader field of plasticity by linking macroscopic deformation behavior with microscopic mechanisms, offering new insights into the theory of superplastic deformation in metals and alloys.

金属和合金的超塑性变形是制造复杂形状部件的关键工艺,其特点是在高温下具有超高的延展性(超过300%)而不开裂。虽然一些晶界(GB)介导的变形机制已被确定为细晶多晶(晶粒尺寸通常小于10 μm)超塑性的重要贡献者,但在高温下保持稳定的细晶组织和可持续的塑性流动仍然是一个挑战。由于缺乏位错- gb反应的定量描述,人们还没有很好地认识到在超塑性变形过程中,外部载荷如何抑制晶粒粗化。在这项工作中,我们通过在李代数框架内制定斜位错-位错耦合方程来解决这一挑战,提供了对斜位错、位错和gb之间相互作用的定量理解。利用准原位电子背散射衍射(EBSD)技术,系统地研究了镁合金中缺陷的多尺度相互作用及其对晶粒组织演化的影响。本文确定了抑制常规晶粒粗化的三个关键机制,即斜倾角辅助的GB调节、斜倾角-GB钉住和斜倾角诱导的亚GB杂交,所有这些机制都被所提出的方程所捕获。该研究通过将宏观变形行为与微观机制联系起来,为金属和合金的超塑性变形理论提供了新的见解,从而拓宽了塑性研究领域。


Multiscale-informed irradiation growth model of Zr-Sn-Nb alloys

Changqiu Ji, Yang Li, Zhipeng Sun, Aiya Cui, Yong Xin, Yinan Cui

doi:10.1016/j.ijplas.2024.104177

Zr-Sn-Nb合金的多尺度辐照生长模型

A systematic multiscale-informed model is developed to predict the irradiation growth behavior of Zr-Sn-Nb alloys, which considers the anisotropy and temperature dependence of both plasticity and irradiation, as well as the alloying effect of Zr alloys. This model consists of a cluster dynamics submodel to consider the kinetics of irradiation defect, an alloying effect submodel informed by atomic simulations and experiments, a microstructure transition submodel derived from discrete dislocation dynamics, and a continuous irradiation growth submodel based on crystal plasticity. It effectively captures the irradiation-induced coevolution of multiple microstructures, including point defects, mobile clusters, dislocation lines and irradiation loops on the prismatic and basal plane, as well as Nb-induced precipitates. It is suitable for high-dose irradiation conditions as it reasonably considers the transition from high-density irradiation loops to tangled dislocation network. The predicted irradiation growth strain, as well as the density and size of irradiation loops, are in good agreement with almost all the available experiments for pure Zr, Zr-Sn, Zr- Nb, and Zr-Sn-Nb alloys at different irradiation doses in the temperature range of 473 - 673 K. This work is hoped to provide a powerful tool for developing irradiation resistance cladding materials.

考虑了Zr- sn - nb合金的各向异性和温度依赖性,以及Zr合金的合金化效应,建立了Zr- sn - nb合金辐照生长行为的系统多尺度信息模型。该模型由考虑辐照缺陷动力学的簇动力学子模型、基于原子模拟和实验的合金化效应子模型、基于离散位错动力学的微观结构转变子模型和基于晶体塑性的连续辐照生长子模型组成。它有效地捕获了辐照诱导的多种微观结构的共同演化,包括棱柱面和基面上的点缺陷、移动团簇、位错线和辐照环,以及nb诱导的析出相。该方法合理考虑了高密度辐照环向缠结位错网络的过渡,适用于高剂量辐照条件。在473 ~ 673 K温度范围内,对纯Zr、Zr- sn、Zr- Nb和Zr- sn -Nb合金在不同辐照剂量下的辐照生长应变、辐照环密度和辐照环尺寸的预测与几乎所有实验结果都吻合。本研究为开发耐辐照包层材料提供了有力的工具。


Thin-Walled Structures

High-velocity impact characteristics of 3D auxetic composite cylindrical shell panels: Theory and experiment

Hui Li, Yichen Deng, Zhengwei Zhang, Junxue Hou, Jin Zhou, Haizhou Wang, Haiyang Zhang, Xiangping Wang, Zhongwei Guan

doi:10.1016/j.tws.2024.112648

三维复合材料圆柱壳板的高速冲击特性:理论与实验

The high-velocity impact characteristics of 3D auxetic composite cylindrical shell panels are studied theoretically and experimentally. First, to predict the high-velocity impact parameters, including the residual velocity of the projectile, the energy absorption, and the ballistic limit, an analytical model of such structures consisting of two fiber/resin skins, two adhesive films, and a 3D auxetic lattice core is proposed, in which Reddy's higher-order shear deformation theory is employed to define the displacement variables. After taking into account the equivalent material properties of the core and various failure modes, energy absorption mechanisms, strain rate effect, and impact damage evolution issues of the constituent elements, governing equations and solutions are successfully obtained. To validate the model developed, detailed high-velocity impact tests with different initial velocities are then performed on such shell panel specimens with nylon and metal auxetic lattice cores fabricated by 3D printing technology. Finally, the influences of key geometric parameters of the core on impact properties are investigated, with some important design recommendations being refined to improve the impact resistance and energy absorption capabilities of the studied structure.

对三维复合材料圆柱壳板的高速冲击特性进行了理论和实验研究。首先,为了预测弹丸的剩余速度、能量吸收和弹道极限等高速冲击参数,提出了由两层纤维/树脂皮、两层胶膜和三维形变晶格核组成的高速冲击结构的解析模型,其中采用Reddy的高阶剪切变形理论定义位移变量。在考虑了芯材的等效材料特性和各失效模式、能量吸收机制、应变率效应、冲击损伤演化等问题后,成功地得到了控制方程和解。为了验证所开发的模型,然后在使用3D打印技术制造的尼龙和金属辅助晶格芯的壳板样品上进行了不同初始速度的详细高速冲击试验。最后,研究了核心关键几何参数对冲击性能的影响,并提出了一些重要的设计建议,以提高所研究结构的抗冲击和吸能能力。


Free vibration analysis of damaged laminated piezoelectric plates and composite plates with piezoelectric patch based on the Extended Layerwise Method

Yaogang Wu, Yuliang Duan, Jinyu Shao, Dinghe Li, Jianxin Xu

doi:10.1016/j.tws.2024.112666

基于扩展分层法的损伤压电层合板和带压电片的复合材料板的自由振动分析

The dynamic analytical models for a laminated piezoelectric plate and a laminated composite plate with piezoelectric patch containing the delamination, transverse crack and debonding damages are established by the Extended Layerwise Method (XLWM). The virtual kinetic energy is introduced into Hamilton’s principle, so resulting in mass matrices and displacement-dependent second mode derivatives in the finite element (FE) governing equations. Then, the FE governing equations for the laminated piezoelectric plate, and the characteristic equations of natural frequencies for the laminated piezoelectric plate with delamination and transverse crack are derived. The coupling model of the laminated composite plate and the piezoelectric patch is established by the displacement continuity and internal force equilibrium conditions at the nodes of the contact area. Based on the degrees of freedom (DoFs) in contact, the final governing equations is deduced, followed by the analysis of free vibration responses for both plates with various damages. The accuracy of natural frequencies for each plate is verified by comparing the results with those of FE simulation by ANSYS.

采用扩展分层法(XLWM)建立了含分层、横向裂纹和脱粘损伤的层压板和带压电片的层压复合材料板的动力分析模型。在Hamilton原理中引入虚动能,得到了质量矩阵和与位移相关的有限元控制方程二阶模态导数。在此基础上,推导了层压板的有限元控制方程,以及具有分层和横向裂纹的层压板的固有频率特征方程。根据接触区域节点处的位移连续性和内力平衡条件,建立了层合复合材料板与压电贴片的耦合模型。在接触自由度的基础上,推导了最终控制方程,并对两种损伤板的自由振动响应进行了分析。通过与ANSYS有限元模拟结果的比较,验证了各板固有频率的准确性。


Free vibration and nonlinear transient analysis of blast-loaded FGM sandwich plates with stepped face sheets: Analytical and artificial neural network approaches

Peng Shi, Vu Ngoc Viet Hoang, Jian Yang, Haoge Shou, Qi Li, Ferruh Turan

doi:10.1016/j.tws.2024.112667

层状夹层板的自由振动和非线性瞬态分析:解析和人工神经网络方法

This study investigates the free vibration and transient dynamic response of functionally graded material (FGM) sandwich plates with stepped face sheets (FGM-SPSFS) supported by viscoelastic foundation under blast loading. The research focuses on the effects of geometric configurations and material property variations across segments. Each plate comprises three layers: a homogeneous hard core and two FGM face sheets, divided horizontally into two segments with differing face sheet thicknesses, which enhance structural stiffness while maintaining a consistent total thickness. The material properties of the sandwich plates follow a power-law distribution. The formulations are based on higher-order shear deformation plate theory and von Kármán geometric nonlinearity, and are solved using Galerkin’s method. Validation is achieved by comparing the results with published literature and finite element analysis (FEA). Artificial neural network (ANN) models are developed to predict natural frequencies without extensive computational runs, employing Bayesian Regularization (BR) and Levenberg–Marquardt (LM) algorithms in MATLAB. A new graphical user interface (GUI) tool facilitates frequency predictions using the proposed ANN model. Key findings indicate that modifications to the stepped face sheets and core layers affect stiffness, natural frequency, and vibration amplitudes. Increasing the core-to-total thickness ratio enhances stiffness, resulting in higher frequencies and reduced displacement amplitudes. The LM algorithm outperforms the BR algorithm, with errors generally below 1%, compared to 2% to 4% for BR with the log-sigmoid function. This study offers valuable insights into the design and analysis of FGM sandwich structures for engineering applications.

研究了粘弹性基础支撑的功能梯度材料夹层板(FGM- spfs)在爆炸荷载作用下的自由振动和瞬态动力响应。研究的重点是几何结构和材料性能的变化在段间的影响。每个板由三层组成:一个均匀的硬芯和两个FGM面板,水平分为两个面板厚度不同的部分,在保持总厚度一致的同时增强结构刚度。夹层板的材料性能服从幂律分布。该公式基于高阶剪切变形板理论和von Kármán几何非线性,并采用伽辽金方法求解。通过将结果与已发表的文献和有限元分析(FEA)进行比较,实现了验证。在MATLAB中,利用贝叶斯正则化(BR)和Levenberg-Marquardt (LM)算法,开发了人工神经网络(ANN)模型来预测固有频率,而无需大量的计算运行。一个新的图形用户界面(GUI)工具便于使用所提出的人工神经网络模型进行频率预测。主要研究结果表明,对阶梯式面板和核心层的修改会影响刚度、固有频率和振动幅值。增加岩心与总厚度之比可以增强刚度,从而产生更高的频率和更小的位移幅值。LM算法优于BR算法,其误差通常低于1%,而使用log-sigmoid函数的BR的误差为2%至4%。该研究为FGM夹层结构的设计和分析提供了有价值的见解。


Machine learning-based axial compressive capacity estimation of cold-formed steel build-up sections

Jiaqiang Hu, Liqiang Jiang, Yi Hu, Jianguang He, Xinyuan Cheng, Jianjun Yang

doi:10.1016/j.tws.2024.112669

基于机器学习的冷弯型钢拼装截面轴向抗压能力估计

To consider the highly nonlinear and complex buckling behaviour of various sections of cold-formed steel (CFS) built-up columns, experimental and finite element (FE) methods are commonly used for calculating their axial compressive capacity, although these methods are time-consuming and costly. This paper proposes machine learning (ML) methods to overcome the issues of traditional methods for predicting the maximum axial load capacity (MALC) of CFS built-up columns. A total of 3839 samples from more than 33 different types of sections were collected from 43 published papers, including 817 experimental data and 3,022 FE simulation data. A total of 15 characteristic parameters, such as the second moment of area, the radius of gyration, and the polar second moment of area, are considered when nine different ML models are trained. The robustness of these models was compared via the Monte Carlo simulation method, and the predicted results were compared with the calculated results from the current codes. The results show that the extreme gradient boosting (XGB) model has higher accuracy and smaller prediction errors in estimating the MALC. The proportion of data with a relative percentage error less than 10% in the prediction results of the AISI-DSM codes is 45.31%, whereas the XGB model achieves a proportion of 87.57%, and the results calculated from current codes tend to be more conservative, with a large deviation, which needs to be further considered.

考虑到冷弯型钢(CFS)组合柱的各种截面高度非线性和复杂的屈曲行为,通常采用实验和有限元(FE)方法来计算其轴向抗压能力,尽管这些方法既耗时又昂贵。本文提出了机器学习(ML)方法来克服传统方法预测CFS组合柱最大轴向承载力(MALC)的问题。在43篇已发表的论文中,共收集了33个不同类型截面的3839个样本,其中实验数据817个,有限元模拟数据3022个。在训练9种不同的ML模型时,总共考虑了15个特征参数,如面积的第二矩、旋转半径和面积的极秒矩。通过蒙特卡罗模拟方法对模型的鲁棒性进行了比较,并将预测结果与现行规范的计算结果进行了比较。结果表明,极端梯度增强(XGB)模型在估计MALC时具有较高的精度和较小的预测误差。AISI-DSM代码预测结果中相对百分比误差小于10%的数据占比为45.31%,而XGB模型预测结果占比为87.57%,目前代码计算结果趋于保守,偏差较大,有待进一步考虑。


Multiscale fail-safe topology optimization for lattice structures

Huili Huang, Wei Ding, Huanfei Jia, Wenjie Zuo, Fei Cheng

doi:10.1016/j.tws.2024.112693

晶格结构的多尺度故障安全拓扑优化

In this paper, we address the critical issue of lattice structures losing functionality under local damage, which is a common safety deficiency in traditional lattice designs. A novel multiscale fail-safe topology optimization method is proposed to enhance the robustness of lattice structures. The method uses a simplified local damage model, aiming to minimize strain energy under the most critical failure scenarios, with design variables including macroscopic topology and geometric parameters of microscopic unit cells. By predefining an equivalent material model for the parameterized lattice structure, computational costs are significantly reduced. To overcome the non-differentiability of maximum strain energy, the Kreisselmeier-Steinhauser function is introduced as a substitute. Consequently, numerical simulation results demonstrate that this method effectively enhances lattice structure safety by providing more load-bearing paths to resist local damage. Compared to other fail-safe topology optimization methods, this approach expands the design space while maintaining the same computational cost, and it does not require adjustments to the predefined unit cell configuration for different working conditions.

本文讨论了传统晶格结构在局部损伤下失去功能的关键问题,这是传统晶格设计中常见的安全缺陷。为了提高晶格结构的鲁棒性,提出了一种新的多尺度故障安全拓扑优化方法。该方法采用简化的局部损伤模型,设计变量包括微观单元胞的宏观拓扑和几何参数,以在最关键的破坏场景下最小化应变能为目标。通过预先定义参数化晶格结构的等效材料模型,大大降低了计算成本。为了克服最大应变能的不可微性,引入了Kreisselmeier-Steinhauser函数作为替代。数值模拟结果表明,该方法通过提供更多的承重路径来抵抗局部损伤,有效地提高了点阵结构的安全性。与其他故障安全拓扑优化方法相比,该方法在保持相同计算成本的同时扩展了设计空间,并且不需要根据不同的工作条件调整预定义的单元配置。


Developing Lightweight Steel Profile and Lattice Polymeric Core Composite for Structural Use

Ieva Misiūnaitė, Arvydas Rimkus, Viktor Gribniak

doi:10.1016/j.tws.2024.112697

开发结构用轻钢型材和点阵聚合物芯复合材料

Embracing modular construction, advanced materials, and digital technologies can drive innovation in the building industry, address global material consumption challenges, and foster a sustainable future. This paper presents the innovative concept of the lightweight hybrid lattice-filled profile (HLFP) for modular engineering, which combines a thin-walled steel tubular shell and additively manufactured lattice structure (AMLS) as a lightweight core. The AMLS achieves precise shape, internal structure, and stiffness, ensuring the decided structural performance with minimum materials. This study provides a theoretical model of HLFP, focusing on adhesively bonded AMLS. The experimental verification demonstrates that the adhesively bonded AMLS ensures an additional 130% during the elastic stage and, even after partial debonding, maintains 50% of the mechanical resistance compared to the theoretical sum of the HLFP components. Reducing the infill density does not severely affect the load-bearing capacity of the HLFP—a fourfold decrease of the ALMS density (from 10% to 2.5%) results in a 20% decrease in the ultimate load. However, the sparse lattice structure alters the failure mechanism of ALMS, changing it from favorable ductile to dangerous brittle and determining the object for further optimization. The parametric study reveals the efficiency of the theoretical model for predicting the load-bearing capacity of HLFP. However, the finite element model developed in this study should be used for a more detailed analysis of the HLFP's structural behavior.

采用模块化建筑、先进材料和数字技术可以推动建筑行业的创新,解决全球材料消耗挑战,并促进可持续发展的未来。提出了面向模块化工程的轻量化混合网格填充型材(HLFP)的创新概念,该结构将薄壁钢管壳和增材制造的网格结构(AMLS)作为轻量化核心相结合。AMLS可以实现精确的形状、内部结构和刚度,以最少的材料确保确定的结构性能。本研究提供了一个HLFP的理论模型,重点研究粘接的AMLS。实验验证表明,粘接的AMLS在弹性阶段保证了额外的130%的机械阻力,即使在部分脱粘后,与HLFP组件的理论总和相比,仍保持了50%的机械阻力。降低填充密度不会严重影响hlfp的承载能力- ALMS密度降低四倍(从10%降至2.5%)导致极限载荷降低20%。然而,稀疏晶格结构改变了ALMS的破坏机制,使其从良好的延性变为危险的脆性,从而确定了进一步优化的目标。参数化研究表明,该理论模型对高强度混凝土结构承载力的预测是有效的。然而,在本研究中开发的有限元模型应该用于更详细的分析高铁的结构行为。



来源:复合材料力学仿真Composites FEM
ACTMechanicalAdditiveSystemMAGNET振动疲劳断裂复合材料非线性拓扑优化建筑电子增材裂纹理论爆炸材料
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【新文速递】2024年8月16日固体力学SCI期刊最新文章

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,International Journal of Plasticity 1 篇,Thin-Walled Structures 3 篇International Journal of Solids and StructuresThe stick-slip bending behavior of the multilevel helical structures: A 3D thin rod model with frictional contactYuchen Han, Jingshan Hao, Huadong Yong, Youhe Zhoudoi:10.1016/j.ijsolstr.2024.113005多层螺旋结构粘滑弯曲行为:含摩擦接触的三维细杆模型The multilevel helical structures in various engineering and natural fields offer excellent deformation flexibility and load bearing capabilities. Understanding the interplay between the local frictional contact and the geometric characteristics of the helical structure under complex external loads has attracted considerable interest. In this work, the effect of local frictional contact behaviors on the bending in multilevel helical structures is investigated by using a combination of theoretical modeling, finite element (FE) simulations, and experiments. In the case of pure bending, the kinematic parameters of the bent multi-stage helix are derived concisely by the idea of the kinematic analogy. The bending stiffness of the multi-stage helix is further obtained. In the case of the combined tension/torsion and bending, the 3D thin rod model incorporating Coulomb’s friction is established to describe the mechanical responses. It is found that the relationship between equivalent bending stiffness and the laying angle exhibits nonlinearity. A comparison with the classical Papailiou model reveals that, for helical structures at large laying angles, the influence of friction is primarily determined by the internal force in the tangential direction, which is the core assumption of the Papailiou model. However, in the case of small laying angles, the helical twisting characteristics and the contribution of the internal forces and moments in the other two directions (normal and binormal directions) to the friction cannot be ignored. Subsequently, a multilevel frictional contact transmission formulation is proposed according to the force action–reaction principle. Based on the above formulation, the non-simplified thin rod equations with Coulomb’s friction are extended to describe the multilevel stick-slip bending behaviors of the second stage cable (3*3). The dissipation capacity of helical structures is evaluated quantitatively under the hysteretic bending. Finally, the theoretical model is verified by FE simulations and experimental results. This work provides insights for unveiling the intrinsic relationship between the nonlinear bending and local frictional contact behaviors in the multilevel helical structures.多层螺旋结构在各种工程和自然领域中具有优异的变形灵活性和承载能力。复杂外载荷作用下螺旋结构的局部摩擦接触与几何特性之间的相互作用引起了人们的广泛关注。本文采用理论建模、有限元模拟和实验相结合的方法,研究了局部摩擦接触行为对多层螺旋结构弯曲的影响。在纯弯曲情况下,利用运动学类比的思想,简明地导出了弯曲多级螺旋的运动学参数。进一步得到了多级螺旋的弯曲刚度。在拉伸/扭转和弯曲复合作用下,建立了考虑库仑摩擦的细杆三维力学响应模型。结果表明,等效抗弯刚度与铺设角呈非线性关系。与经典Papailiou模型的对比表明,对于大铺放角的螺旋结构,摩擦的影响主要由切向内力决定,这是Papailiou模型的核心假设。然而,在铺设角较小的情况下,螺旋扭转特性以及其他两个方向(法向和法向)的内力和弯矩对摩擦的贡献是不可忽视的。随后,根据力-反作用原理,提出了多级摩擦接触传动公式。在此基础上,将含库仑摩擦的非简化细杆方程推广到描述二级索(3*3)的多级粘滑弯曲行为。对螺旋结构在滞回弯曲作用下的耗散能力进行了定量评价。最后,通过有限元仿真和实验结果对理论模型进行了验证。这项工作为揭示多层螺旋结构中非线性弯曲和局部摩擦接触行为之间的内在关系提供了见解。Journal of the Mechanics and Physics of SolidsEnhancement of adhesion strength in viscoelastic unsteady contactsC. Mandriota, N. Menga, G. Carbonedoi:10.1016/j.jmps.2024.105826粘弹性非定常接触中粘接强度的增强We present a general energy approach to study the unsteady adhesive contact of viscoelastic materials. Under the assumption of infinitely short-range adhesive interactions, we exploit the principle of virtual work to generalize Griffith’s local energy balance at contact edges to the case of a non-conservative (viscoelastic) material, subjected to a generic contact time–history. We apply the proposed energy balance criterion to study the approach-retraction motion of a rigid sphere in contact with a viscoelastic half-space. A strong interplay between adhesion and viscoelastic hysteretic losses is reported as the adhesion strength can strongly increase, depending on the loading history. Two different mechanisms govern the pull-off force increase during either approach-retraction cycles and approach – full relaxation – retraction tests. In the former case, hysteretic losses occurring close to the circular perimeter of the contact play the major role, significantly enhancing the energy release rate required change the contact size. In the latter case, instead, the pull-off enhancement depends on the glassy response of the whole material which, triggered by the fast retraction after relaxation, leads to a sort of ‘frozen’ state and flat-punch-like detachment mechanism (i.e., constant contact area). In this case, the JKR theory of adhesive contact cannot be invoked to relate the observed pull-off force to the effective adhesion energy, i.e. the energy release rate G , and strongly overestimates it. Therefore, a rigorous mathematical procedure is also proposed to correctly calculate the energy release rate in viscoelastic dissipative contacts.提出了一种研究粘弹性材料非定常粘接接触的通用能量方法。在无限短距离粘接相互作用的假设下,我们利用虚功原理将Griffith在接触边缘的局部能量平衡推广到非保守(粘弹性)材料的情况下,受到一般接触时程的影响。应用所提出的能量平衡准则,研究了刚性球体与粘弹性半空间接触时的接近-收缩运动。粘连和粘弹性滞回损失之间有很强的相互作用,据报道,粘连强度会随着加载历史的变化而显著增加。在接近-收放循环和接近-完全放松-收放测试中,有两种不同的机制控制着拉离力的增加。在前一种情况下,发生在接触圆周附近的滞回损耗起主要作用,显著提高了改变接触尺寸所需的能量释放率。在后一种情况下,拉脱增强取决于整个材料的玻璃响应,这种响应是由弛豫后的快速缩回触发的,导致一种“冻结”状态和平冲孔式分离机制(即恒定的接触面积)。在这种情况下,不能援引JKR黏着接触理论将观察到的拉脱力与有效黏着能即能量释放率G联系起来,并且严重高估了它。因此,还提出了一种严格的数学方法来正确计算粘弹性耗散接触的能量释放率。Mechanics of MaterialsMulti-scale FE analysis of coupled load-moisture mechanical behavior of saturated asphalt pavements considering transversely isotropic permeabilityMingyang Gong, Xin Sui, Zhen Leng, Binbin Yindoi:10.1016/j.mechmat.2024.105116考虑横向各向同性渗透率的饱和沥青路面荷载-水分耦合力学特性多尺度有限元分析Assessing the collective impacts of external loading and void pressure on the mechanical behavior of porous media presents a significant challenge due to its inherent heterogeneity and complex multi-physical field coupling mechanisms. This study addresses this challenge by developing a novel multiscale hydraulic-mechanical modeling framework to investigate the structural response of water-saturated asphalt pavement under sequential coupling hydro-mechanical loading. The framework comprises three key components. Firstly, incorporating an upscaling homogenization approach to establish the linkage of material properties between different scales; secondly, developing a downscaling transfer procedure to transfer the structural response across scales for insight into its multiphysics mechanisms; and finally, proposing a new sequential coupling algorithm in multiscale simulations for comprehensive multi-field coupling calculations. The primary outcomes of this study demonstrate that AC-graded pavements are susceptible to "down-top" cracks under hydro-mechanical loading, while OGFC-graded pavements have the potential to develop both "top-down" and "down-top" cracks. In AC-graded pavements, increasing the hydraulic head reduces stress concentrations, while in OGFC-graded pavements, changes in the permeability coefficient have a lesser impact on mechanical response. At the mesoscopic level, tensile stress concentrations in the asphalt mortar decrease significantly at higher temperatures. Furthermore, the OGFC-graded RVE model exhibits higher tensile stresses in the asphalt mortar compared to the AC-graded RVE model.由于多孔介质固有的非均质性和复杂的多物理场耦合机制,评估外部载荷和空隙压力对多孔介质力学行为的集体影响是一项重大挑战。本研究通过开发一种新颖的多尺度水力力学建模框架来研究水饱和沥青路面在顺序耦合水力力学载荷下的结构响应,从而解决了这一挑战。该框架包括三个关键部分。首先,采用上尺度均质化方法,建立不同尺度间材料性能的联系;其次,开发一个降尺度转移程序,以跨尺度转移结构响应,以深入了解其多物理场机制;最后,提出了一种新的多尺度模拟序列耦合算法,用于综合多场耦合计算。本研究的主要结果表明,在水-机械荷载作用下,ac级配路面容易出现“自上而下”裂缝,而ogfc级配路面则可能同时出现“自上而下”和“自上而下”裂缝。在ac级配路面中,增加水头可以降低应力集中,而在ogfc级配路面中,渗透系数的变化对力学响应的影响较小。在细观水平上,高温下沥青砂浆中的拉应力浓度显著降低。此外,与ac -分级RVE模型相比,ogfc分级RVE模型在沥青砂浆中表现出更高的拉应力。International Journal of PlasticityHigh-temperature creep mechanism of Ti-Ta-Nb-Mo-Zr refractory high-entropy alloys prepared by laser powder bed fusion technologyJunyi Feng, Binghao Wang, Yintao Zhang, Peilei Zhang, Changxi Liu, Xiaoli Ma, Kuaishe Wang, Lechun Xie, Ning Li, Liqiang Wangdoi:10.1016/j.ijplas.2024.104080 激光粉末床熔合Ti-Ta-Nb-Mo-Zr难熔高熵合金高温蠕变机理Creep resistance, which is one of the most important deformation modes, is rarely reported for refractory high entropy alloys (RHEAs). The experiment investigated the high-temperature creep mechanism of Ti-Ta-Nb-Mo-Zr RHEA prepared by laser powder bed fusion (LPBF) technology. The high cooling rate of LPBF suppresses most of the elemental segregation, but there are still over-solidified precipitates and a few continuous precipitates (CP). In the range of 923-1023 K, the stress exponent and activation energy were determined to be 3.2-3.4 and 261.5 ± 19.5 kJ/mol, respectively. Compared with other conventional alloys and HEAs, a large reduction of the minimum creep rate is found in the LPBF-built Ti1.5Ta0.5NbZrMo0.5 RHEA, indicating a significant improvement in high-temperature properties. The dislocation tangles at the interface is formed during the creep process and new Zr-rich CP phases are generated in the dislocation tangles region. The interfacial dislocation tangles is the result of the interaction between dislocations and two-phase mismatch stresses. The dislocation tangles prevents dislocations from further cutting the matrix phase, which is very favorable to the high-temperature creep performance. At the same time, the formation of this dislocation tangles greatly accelerates the nucleation process and growth rate of the new CP phase. The present work provides a pathway to design novel HEAs with improved high-temperature creep resistance.高温高熵合金的蠕变抗力是其最重要的变形模式之一,但目前对高温高熵合金的蠕变抗力研究较少。实验研究了激光粉末床熔融(LPBF)技术制备Ti-Ta-Nb-Mo-Zr RHEA的高温蠕变机理。高冷却速率抑制了大部分元素偏析,但仍存在过凝固析出相和少量连续析出相(CP)。在923 ~ 1023 K范围内,应力指数为3.2 ~ 3.4,活化能为261.5±19.5 kJ/mol。与其他传统合金和HEAs相比,lpbf构建的Ti1.5Ta0.5NbZrMo0.5 RHEA的最小蠕变速率大幅降低,表明其高温性能得到了显著改善。蠕变过程中在界面处形成位错缠结,在位错缠结区生成新的富zr CP相。界面位错缠结是位错与两相失配应力相互作用的结果。位错缠结阻止了位错进一步切削基体相,有利于提高材料的高温蠕变性能。同时,这种位错缠结的形成大大加快了新CP相的成核过程和生长速度。本工作为设计具有更好的高温蠕变性能的新型HEAs提供了途径。Thin-Walled StructuresRandom thermal-vibration mechanisms of sandwich ventral fin-type plate-shell systems with porous functionally graded coreShuangwei Hu, Qingshan Wang, Rui Zhong, Bin Qindoi:10.1016/j.tws.2024.112333多孔功能梯度岩心夹层腹鳍型板壳系统的随机热振动机理The stochastic thermal-vibration mechanisms within a sandwich ventral fin-type plate-shell system, featuring a porous functionally graded (FG) core, are exhaustively analyzed under various random loading conditions employing an innovative node-based, meshless computational approach. The studied structure is decoupled into several plates and open cylindrical panel according to the geometric characteristics, and the mechanical relationships at the structural boundaries or connection interfaces are equivalently simulated by using penalty parameters. Following the general Hamilton's principle, the meshless approach combined with the first-order shear deformation theory (FSDT) incorporating thermal effects is employed to derive the vibration equations of the sandwich ventral fin-type plate-shell systems. Also, the pseudo excitation method (PEM) is introduced to calculate stationary and nonstationary random responses. In order to verify the accuracy of the meshless algorithm in this study, the convergence and correctness are studied comprehensively. And then, the effects of some parameters such as temperature variation, porosity parameters, power-law index and random excitations on the thermal vibration characteristics of the sandwich ventral fin-type plate-shell systems with porous FG core are presented. The results show that the power-law index and temperature can increase the frequency parameter of the structure. The smooth power spectral density (PSD) excitation only affects the amplitude of the response curve, and does not affect the frequency corresponding to the peak. In the analysis of non-stationary random vibration, the influence of modulation parameters on response is very significant.采用创新的基于节点的无网格计算方法,对具有多孔功能梯度(FG)核心的夹层腹鳍型板壳系统在各种随机载荷条件下的随机热振动机制进行了详尽分析。将所研究的结构根据几何特性解耦为若干板和开式圆柱板,采用罚参数等效模拟结构边界或连接界面处的力学关系。根据Hamilton原理,采用无网格法结合考虑热效应的一阶剪切变形理论(FSDT),推导了夹层腹鳍型板壳系统的振动方程。同时,引入了伪激励法(PEM)来计算平稳和非平稳随机响应。为了验证本文无网格算法的准确性,对其收敛性和正确性进行了全面的研究。然后,研究了温度变化、孔隙率参数、幂律指数和随机激励等参数对多孔FG芯夹层腹鳍型板壳系统热振动特性的影响。结果表明,幂律指数和温度可以提高结构的频率参数。平滑功率谱密度(PSD)激励只影响响应曲线的幅值,而不影响峰值对应的频率。在非平稳随机振动分析中,调制参数对响应的影响是非常显著的。Nonlinear thermo-mechanical static stability analysis of FG-TPMS shallow spherical shellsDang Thuy Dong, Tran Quang Minh, Bui Tien Tu, Kim Q. Tran, H. Nguyen-Xuandoi:10.1016/j.tws.2024.112343FG-TPMS浅球壳的非线性热-机械静稳定性分析An analytical solution for the nonlinear static stability problem of functionally graded triply periodic minimal surface (FG-TPMS) shallow spherical shells is studied in the current research for the first time. Three common TPMS structures including Primitive (P), Gyroid (G), and I-graph and Wrapped Package-graph (IWP) with three models of functionally graded porosity distribution along the thickness are considered. The shallow spherical shells (shallow SSs) are subjected to combined thermo-mechanical loadings and rested on a nonlinear elastic foundation. The fundamental formulas are expressed based on the higher-order shear deformation theory (HSDT) and von Kármán's geometrical nonlinearities. Employing the Ritz energy minimization method, the explicit relationship between load and deflection is derived. Subsequently, the static stability behavior of FG-TPMS shallow SSs is investigated. Numerical illustrations are investigated to show the superior thermo-mechanical load-carrying performance of the FG-TPMS SSs compared to corresponding isotropic structures of the same weight. The significant effects of geometric parameters, nonlinear elastic foundation parameters, and the type of FG-TPMS structures on the nonlinear static stability behavior of shallow SSs are further considered.本文首次研究了功能梯度三周期最小表面(FG-TPMS)浅球壳非线性静稳定性问题的解析解。考虑了三种常见的TPMS结构,包括Primitive (P), Gyroid (G), I-graph和Wrapped Package-graph (IWP),以及沿厚度的三种功能梯度孔隙度分布模型。浅球壳在非线性弹性基础上承受热-力复合载荷。基本公式是基于高阶剪切变形理论(HSDT)和von Kármán的几何非线性来表达的。采用里兹能量最小化方法,推导了载荷与挠度之间的显式关系。随后,研究了FG-TPMS浅层SSs的静稳定性行为。数值计算表明,与同等重量的各向同性结构相比,FG-TPMS SSs具有优越的热机械承载性能。进一步考虑了几何参数、非线性弹性基础参数和FG-TPMS结构类型对浅层SSs非线性静力稳定行为的显著影响。Integrating parametric HFGMC and isogeometric RZT^{3,2} for multiscale damage modeling of composite structures: A numerical and experimental studyAryan Kheyabani, Adnan Kefaldoi:10.1016/j.tws.2024.112344将参数 HFGMC 和等几何 RZT^{3,2} 整合用于复合材料结构的多尺度损伤建模: 数值和实验研究In this research effort, a novel multiscale analysis scheme is proposed for damage modeling of composite laminates, sandwich structures, and stiffened plates relying on capabilities of the parametric HFGMC and isogeometric RZT^{3,2} formulations. The Ramberg Osgood (RO) model is incorporated into the micromechanics model to reflect polymer matrix material nonlinearities on the overall homogenized composite behavior. Carbon fibers are assumed to behave in a linear transversely isotropic manner. The higher order RZT^{3,2} theory employed at the macro level facilitates efficient applicability of the model to thick composite laminates and soft core sandwiches. On the other hand, it generates all three-dimensional stress components and thus ensures dimensional consistency between micro and macro levels. Numerical discretization and prediction of RZT^{3,2} kinematic variables are enabled by performing NURBS based isogeometric analysis (IGA) thereby enhancing modeling efficacy to a significant degree. Soft core plasticity and failure in the composite are evaluated at the macro level through the RO model and Hashin criteria, respectively. Applicability of the method is presented for thin and thick flat composite and sandwich laminates; and further extended to stiffened plates via developing a multipatch formulation. A comprehensive validation of our analysis is conducted by comparing the results with established benchmarks from the literature, experimental data, and three-dimensional finite element method (3D-FEM) simulations. Initially, a moderately thick, simply supported square laminate under transverse loading is examined, a common verification benchmark. Then, results from standard mechanical tests, including tensile, shear, and four-point bending tests on thin laminates, followed by experiments on moderately thick sandwich structures subjected to four-point bending, are presented. Finally, the analysis is extended to a stiffened plate under uniform pressure, demonstrating the method’s accuracy and applicability across diverse structural configurations.在这项研究工作中,利用参数 HFGMC 和等几何 RZT^{3,2} 公式的能力,为复合材料层压板、夹层结构和加劲板的损伤建模提出了一种新的多尺度分析方案。微观力学模型中加入了 Ramberg Osgood(RO)模型,以反映聚合物基体材料对整体均质复合材料行为的非线性影响。碳纤维被假定为线性横向各向同性材料。在宏观层面上采用的高阶 RZT^{3,2} 理论有助于将模型有效地应用于厚复合材料层压板和软芯三明治。另一方面,它生成了所有三维应力分量,从而确保了微观和宏观层面的尺寸一致性。通过执行基于 NURBS 的等几何分析 (IGA),实现了 RZT^{3,2} 运动变量的数值离散化和预测,从而在很大程度上提高了建模效率。通过 RO 模型和 Hashin 标准,分别对复合材料的软芯塑性和失效进行了宏观评估。该方法适用于薄、厚平板复合材料和三明治夹芯层压板,并通过开发多补丁配方进一步扩展到加劲板。通过将分析结果与文献、实验数据和三维有限元法(3D-FEM)模拟的既定基准进行比较,对我们的分析进行了全面验证。首先,对横向载荷作用下的中等厚度简支撑方形层压板进行了研究,这是一种常见的验证基准。然后,介绍标准机械测试的结果,包括薄层板的拉伸、剪切和四点弯曲测试,接着是中等厚度夹层结构承受四点弯曲的实验。最后,将分析扩展到均匀压力下的加劲板,证明了该方法在不同结构配置中的准确性和适用性。来源:复合材料力学仿真Composites FEM

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