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【新文速递】2024年9月7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,International Journal of Plasticity 1 篇,Thin-Walled Structures 10 篇

International Journal of Solids and Structures

Competing behavior of interface delamination and wafer cracking during peeling film from ultra-thin wafer

Wei Jian, Hanbin Yin, Ying Chen, Xue Feng

doi:10.1016/j.ijsolstr.2024.113058

超薄硅片剥离过程中界面分层与晶圆开裂的竞争行为

Peeling the front-side film from the flexible and ultra-thin wafer is a critical procedure for the fabrication of ultra-thin chips. For a successful peeling process, the following conditions are required simultaneously: the interface between the film and the wafer is debonded, the interface between the wafer and the substrate remains undelaminated, and the wafer stays intact. However, there are relatively few studies focusing on the underlying mechanism in this peeling process. Here, a theoretical model is developed to investigate the competing behavior of interface delamination and wafer cracking for the bilayer film-substrate system. Based on the constant-stress (Dugdale) cohesive law and Euler-Bernoulli beam theory, both the competing interface delamination criterion and the wafer cracking criterion are determined. The corresponding competing maps of interface delamination and wafer cracking are obtained, in which the interface delamination path and the wafer safety status can be predicted. The effect of several dimensionless parameters on the competing behavior of interface delamination and wafer cracking is examined systematically, including the property of the geometry, the material, and the interface of the bilayer film-substrate system. The theoretical model is validated by both finite element analysis (FEA) and experimental results. This research aims to provide some guidance for optimizing the peeling parameters and contribute to a higher success rate of peeling process.

从柔性超薄晶圆上剥离正面薄膜是制造超薄芯片的关键工序。对于一个成功的剥离过程,同时需要以下条件:薄膜和晶圆之间的界面是脱粘的,晶圆和衬底之间的界面保持不分层,晶圆保持完整。然而,对这一剥落过程的潜在机制的研究相对较少。本文建立了一个理论模型来研究双层薄膜-衬底体系中界面分层和晶圆开裂的竞争行为。基于恒应力(Dugdale)内聚规律和欧拉-伯努利梁理论,确定了竞争界面分层判据和晶圆开裂判据。得到了相应的界面分层和晶圆开裂竞争图,可以预测界面分层路径和晶圆安全状态。系统地研究了几种无量纲参数对界面分层和晶圆开裂竞争行为的影响,包括双层膜-衬底系统的几何特性、材料特性和界面特性。通过有限元分析和实验验证了理论模型的正确性。本研究旨在为优化脱皮工艺参数,提高脱皮工艺的成功率提供一定的指导。


Journal of the Mechanics and Physics of Solids

Intrinsic Interlayer Shear Strength of Graphite

Yelingyi Wang, Shizhe Feng, Deli Peng, Tengfei Li, Cheng Zheng, Zubo Cai, Zhanghui Wu, Quanshui Zheng, Zhiping Xu

doi:10.1016/j.jmps.2024.105853

石墨的层间固有剪切强度

Graphite holds significant values in the energy and electronics industries due to its unique properties. As a quintessential example of highly anisotropic materials, the shear strength measures one of its most fundamental mechanical properties. However, the lack of ideal materials and testing methods has led to a wide dispersion in the reported values. To address this issue, we utilized epitaxially grown single-crystal graphite and developed a high-throughput sample preparation method, along with a novel loading technique in this work. The intrinsic shear strength of AB-stacked graphite was determined to be τs = 62 MPa, by excluding the size effect in measurements. The results are further compared to highly oriented pyrolytic graphite specimens processed down to nanoscale thickness, highlighting the adverse impact of twisted single-crystalline interfaces between the graphitic layers. Additionally, we observed a distinctive failure mechanism with continuous and uniform cascade plastic slips across the thickness of graphite samples, which corresponds to an interlayer shear strength approaching τs. The intrinsic shear strength characterized in our work sets an upper limit for the interlayer shear resistance of graphite. The experimental procedure for measuring shear strength can be applied to other van der Waals materials.

石墨由于其独特的性能,在能源和电子工业中具有重要的价值。作为高度各向异性材料的典型例子,抗剪强度是其最基本的力学性能之一。然而,由于缺乏理想的材料和测试方法,导致了报道值的广泛分散。为了解决这个问题,我们利用外延生长单晶石墨,开发了一种高通量样品制备方法,以及一种新的负载技术。测定了ab堆积石墨的固有抗剪强度为τs = 62 MPa,排除测量中的尺寸效应。结果进一步与高度取向的热解石墨样品加工至纳米级厚度进行了比较,突出了石墨层之间扭曲单晶界面的不利影响。此外,我们观察到一种独特的破坏机制,即在石墨样品的厚度上连续而均匀的级联塑性滑移,这对应于层间剪切强度接近τ5 .本文所描述的固有抗剪强度为石墨的层间抗剪能力设定了一个上限。测定抗剪强度的实验方法可应用于其它范德华材料。


Mechanics of Materials

Exact solutions for functionally graded flexoelectric micro-cylinders

Jinchen Xie, Christian Linder

doi:10.1016/j.mechmat.2024.105148

功能梯度柔性电微缸的精确解决方案

The flexoelectric effect implies a wide application potential in micro- and nanoscale electromechanical systems, where cylinders are widely used due to their wide range of applications. At the same time, functionally graded materials combine the advantages of different materials to achieve optimized material properties. Motivated by these considerations, we use the generalized power series method for the first time to derive exact solutions to functionally graded flexoelectric cylinder problems, including pressure and shear scenarios. This research systematically investigates the effects of material gradation, characteristic length parameters, and flexoelectric coefficients on the intricate electromechanical coupling behavior of functionally graded flexoelectric micro-cylinders. In addition, a comparative analysis between the exact and mixed finite element solutions demonstrates remarkable agreement. In particular, this investigation pioneers the extension of the Lamé problem, a cornerstone of classical elasticity, into the advanced realm of higher-order electroelasticity in inhomogeneous materials. This advance holds great promise for the design and optimization of micro- and nanoscale electromechanical systems based on the principles of flexoelectricity.

挠性电效应在微纳米机电系统中具有广泛的应用潜力,其中气缸由于其广泛的应用范围而被广泛使用。同时,功能梯度材料结合不同材料的优点,实现材料性能的优化。出于这些考虑,我们首次使用广义幂级数方法来推导功能梯度柔性电动缸问题的精确解,包括压力和剪切情况。本研究系统地研究了材料级配、特征长度参数和挠曲电系数对功能梯度挠曲电微缸复杂机电耦合行为的影响。此外,对精确有限元解和混合有限元解进行了比较分析,结果表明两者具有显著的一致性。特别是,这项研究将经典弹性的基石lam<s:1>问题扩展到非均匀材料的高阶电弹性的高级领域。这一进展为基于柔性电原理的微纳米机电系统的设计和优化提供了巨大的希望。


International Journal of Plasticity

A new yield criterion for strength modeling from biaxial compression to biaxial tension

Lihuang Zheng, Jeong Whan Yoon

doi:10.1016/j.ijplas.2024.104113

从双轴压缩到双轴拉伸强度建模的屈服准则

Accurate strength modeling from equi-biaxial tension (EBT) to equi-biaxial compression (EBC) is critical for the plastic behavior prediction covering the wide-range of stress triaxiality encountered in sheet metal forming. To date, however, few yield criteria are available that can precisely model the initial yield and hardening behavior under six typical stress states between EBC and EBT, simultaneously. Furthermore, there is still a lack of a unified yield criterion for accurate strength modeling across various stress state ranges. To address the issues, a theoretical framework for constructing yield criteria dependent on stress states is provided and a new analytically described isotropic yield criterion is presented in this study. The flexibility in terms of the yield locus and application range is thoroughly explored to make the new yield criterion general. Subsequently, the isotropic yield criterion is extended into an analytically described anisotropic-asymmetric yield criterion. Furthermore, the extended yield criterion is applied to capture the initial yield behavior of DP980, AA5754-O, and AZ31 sheets, and the strain hardening behavior of QP1180 sheets at various stress states ranging from EBC to EBT along different loading directions. The predicted results from the extended criterion agree well with the corresponding experimental findings. The applications demonstrate that the proposed anisotropic-asymmetric yield criterion can effectively model the initial yield and hardening behavior of HCP, BCC, and FCC metal sheets under EBT, EBC, uniaxial tension (UT), plane strain tension (PST), shear (SH), and uniaxial compression (UC) in an analytical way.

从等双轴拉伸到等双轴压缩的精确强度建模,对于覆盖板料成形过程中所遇到的大范围应力三轴性的塑性行为预测至关重要。然而,迄今为止,很少有屈服准则能够同时精确模拟EBC和EBT之间六种典型应力状态下的初始屈服和硬化行为。此外,还缺乏统一的屈服准则来精确模拟各种应力状态范围内的强度。为了解决这一问题,本文提出了基于应力状态的屈服准则的理论框架,并提出了一种新的解析描述的各向同性屈服准则。深入探讨了屈服轨迹和适用范围的灵活性,使新屈服准则具有通用性。随后,将各向同性屈服准则推广为解析描述的各向异性-非对称屈服准则。应用扩展屈服准则捕捉了DP980、AA5754-O和AZ31板材在EBC ~ EBT不同应力状态下沿不同加载方向的初始屈服行为,以及QP1180板材的应变硬化行为。推广准则的预测结果与相应的实验结果吻合较好。应用结果表明,所提出的各向异性-非对称屈服准则可以有效地模拟HCP、BCC和FCC金属板在EBT、EBC、单轴拉伸(UT)、平面应变拉伸(PST)、剪切(SH)和单轴压缩(UC)作用下的初始屈服和硬化行为。


Thin-Walled Structures

Predicting Maximum Deflection of N-Edged Thin-Shelled Hyperbolic-Paraboloid Umbrella Using Machine Learning Techniques

Hamid ElDarwich, Iman Mansouri, Maria Garlock, Shengzhe Wang

doi:10.1016/j.tws.2024.112412

利用机器学习技术预测n边薄壳双曲抛物面伞的最大挠度

Many thin-shelled hyperbolic paraboloid (hypar) umbrella forms have been built in the last 60 years as roof coverings. While the stresses in these forms remain relatively low, the deflections are a critical design parameter, and one that must be considered by architects and engineers in the conceptual design phase, meaning the design stage when the scale and form is given to the structure. To-date, there is no closed-form solution that can predict the maximum deflection of umbrellas due to their highly varying and complex geometry. The best option for predicting deflection is via finite element analysis, which is time-consuming for conceptual (preliminary) design purposes. In response, this paper uses machine learning via genetic programming (GP) and gene expression programming (GEP) to develop closed-form equations that predict the maximum corner deflection of N-edged hypar umbrellas – where N = 3, 4, 5, 6, 7, and 8. For a given a boundary condition and material, geometry is the most significant parameter influencing a shell's stiffness; thus, elastic finite element (FE) models use geometric properties as input variables (N, projected area, normalized rise, and shell thickness). The maximum corner deflection is recorded as an output and the FE analyses generate a large dataset of 53,754 results. It is observed that both GP and GEP can effectively parameterize the maximum deflection of N-edged hypar umbrellas, with GEP producing more concise, but relatively less accurate, equations than GP. While the formulations are trained using concrete material, a material factor multiplier transforms the results to other material properties within the assumption of elastic limits. The results of the study can be used to assist with conceptual design of hypar umbrellas and to validate complex FE models of hypar umbrellas. This research also illustrates the use of machine learning techniques as applied to the conceptual design of structures with highly varying geometries.

在过去的60年里,许多薄壳双曲抛物面伞形建筑被用作屋顶覆盖物。虽然这些形式的应力仍然相对较低,但挠度是一个关键的设计参数,建筑师和工程师在概念设计阶段必须考虑到这一点,这意味着在设计阶段,结构的规模和形式是给定的。迄今为止,由于雨伞高度变化和复杂的几何形状,没有封闭形式的解决方案可以预测雨伞的最大挠度。预测挠度的最佳选择是通过有限元分析,这对于概念(初步)设计目的是耗时的。作为回应,本文通过遗传编程(GP)和基因表达编程(GEP)使用机器学习来开发封闭形式方程,预测N边超伞的最大转角挠度-其中N = 3,4,5,6,7和8。对于给定的边界条件和材料,几何形状是影响壳刚度最显著的参数;因此,弹性有限元(FE)模型使用几何属性作为输入变量(N、投影面积、归一化高度和外壳厚度)。最大转角挠度被记录为输出,FE分析生成53,754个结果的大型数据集。观察到GP和GEP都能有效地参数化n边超伞的最大挠度,其中GEP生成的方程比GP更简洁,但精度相对较低。当公式使用混凝土材料进行训练时,材料因子乘数将结果转换为弹性极限假设内的其他材料属性。研究结果可用于辅助超超伞的概念设计和验证超超伞的复杂有限元模型。这项研究还说明了机器学习技术在高度变化几何结构概念设计中的应用。


Nonlinear dynamics and chaos of functionally graded graphene origami-enabled auxetic metamaterials doubly curved shells with bi-directionally stepped thickness in thermal environment

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

doi:10.1016/j.tws.2024.112420

热环境下功能梯度石墨烯折纸辅助超材料双向阶梯厚度双弯曲壳的非线性动力学与混沌

This paper presents the dynamic and chaotic responses of functionally graded graphene origami (GOri)-enabled auxetic metamaterials (GOEAMs) doubly curved shells featuring stepped thickness profiles in thermal environment. A novel analytical framework is introduced to investigate geometric variations and material distributions, highlighting their crucial roles. Specifically, the investigation delves into structural variations in shell thickness, characterized by abrupt changes in uni- or bi-directional orientations, encompassing both single and double stepped thickness profiles. The five geometric configurations of the stepped structures encompass plates, cylindrical shells, spherical shells, hyperbolic paraboloid shells, and elliptical paraboloid shells. The FG-GOEAM structures, comprising multiple layers with varied GOri distributions across their thickness, are scrutinized using genetic programming-assisted micromechanical models. Central to the present approach is the formulation of nonlinear kinematic relationships using Reddy’s third-order shear deformation theory alongside von Kármán’s nonlinear geometric assumptions, with equations of motion being solved utilizing Galerkin’s technique. Notably, the enhanced model is developed to address non-continuous thickness variation through integral calculus operations, enhancing computational efficiency and obviating the need for complex algorithms. To verify the accuracy of the proposed method, the obtained results are compared with those from published literature. The study thoroughly investigates the influence of material properties, thermal conditions, and geometric parameters on the free vibration and nonlinear behaviors of the structures. Key findings include: The shell stiffness of the functionally graded (FG) shell (X−WGr) surpasses that of the homogeneous shell (U−WGr). The transitions from periodic to chaotic states of the stepped structures are discerned through the analysis of the time history response, the phase plane illustrating the deflection-velocity relationship, and the Poincaré map. Increasing the thickness ratios and GOri content while reducing the folding degree of GOri results in a significant increase in the fundamental frequency and critical load, along with a simultaneous decrease in vibrational amplitudes.

本文介绍了具有阶梯厚度轮廓的功能分级石墨烯折纸(GOri)辅助超材料(GOEAMs)双曲面外壳在热环境中的动态和混沌响应。该研究引入了一个新颖的分析框架来研究几何变化和材料分布,突出了它们的关键作用。具体而言,该研究深入探讨了外壳厚度的结构变化,其特点是单向或双向方向的突然变化,包括单阶梯和双阶梯厚度剖面。阶梯结构的五种几何构造包括板、圆柱形壳、球形壳、双曲抛物面壳和椭圆抛物面壳。FG-GOEAM 结构由多层组成,各层厚度上的 GOri 分布各不相同,我们使用遗传编程辅助微机械模型对其进行了仔细研究。本研究方法的核心是利用 Reddy 的三阶剪切变形理论和 von Kármán 的非线性几何假设来建立非线性运动关系,并利用 Galerkin 技术求解运动方程。值得注意的是,增强型模型是通过积分微积分运算来解决非连续厚度变化问题的,从而提高了计算效率,并避免了对复杂算法的需求。为了验证所提方法的准确性,将获得的结果与已发表的文献进行了比较。研究深入探讨了材料特性、热条件和几何参数对结构自由振动和非线性行为的影响。主要发现包括 功能分级(FG)壳体(X-WGr)的壳体刚度超过了均质壳体(U-WGr)。通过分析时间历程响应、说明挠度-速度关系的相位平面以及波恩卡雷图,可以发现阶梯结构从周期状态到混沌状态的过渡。提高厚度比和 GOri 含量,同时降低 GOri 的折叠度,可显著提高基频和临界载荷,同时降低振幅。


Stochastic response of FGM slantingly coupled plates in aero-thermal environment using meshfree method

Xuanzhi Shi, Rui Zhong, Qingshan Wang, Bin Qin, Hailiang Xu

doi:10.1016/j.tws.2024.112395

气动-热环境下FGM斜耦合板随机响应的无网格分析

The paper investigates the dynamic characteristics of functionally graded slantingly coupled plate structures in an aerospace thermal environment using meshfree methods. The displacement and energy equations of sub-rectangular plates are derived based on the first-order shear deformation theory (FSDT) and Hamilton's principle. The functionally graded material (FGM) model in thermal environments is defined by the Voigt mixing rule, incorporating thermal elasticity theory and supersonic piston theory to characterize the effects of thermal and aerodynamic loads on structural dynamic properties. The pseudo-excitation method (PEM) is employed to analyze stochastic response vibrations. Finally, meshfree methods are utilized to solve the system's vibration properties as well as stationary/non-stationary stochastic response characteristics. The proposed approach aligns closely with both existing literature and finite element simulation outcomes. Furthermore, the paper elucidates the influence patterns of load types, excitation types, and boundary conditions on the free and stochastic vibration characteristics of FG slantingly coupled plate structures. This study contributes to a deeper understanding of the dynamic properties of functionally graded coupled structures for researchers in the aerospace field.

本文采用无网格法研究了航天热环境下功能梯度斜耦合板结构的动态特性。基于一阶剪切变形理论(FSDT)和Hamilton原理,推导了亚矩形板的位移和能量方程。采用Voigt混合规则定义热环境下的功能梯度材料(FGM)模型,结合热弹性理论和超音速活塞理论来表征热载荷和气动载荷对结构动力性能的影响。采用伪激励法(PEM)分析随机响应振动。最后,利用无网格法求解系统的振动特性以及平稳/非平稳随机响应特性。所提出的方法与现有文献和有限元模拟结果密切相关。进一步阐明了载荷类型、激励类型和边界条件对FG倾斜耦合板结构自由和随机振动特性的影响规律。本研究有助于航空航天领域的研究人员对功能梯度耦合结构的动力特性有更深入的了解。


Compression after impact behavior of asymmetrically tapered laminates: Experimental and numerical studies

Xiaonan Yu, Xiwu Xu, Luofeng Huang, Qing Qin, Chao Zhang

doi:10.1016/j.tws.2024.112403

非对称锥形层压板的冲击后压缩性能:实验与数值研究

This paper presents experimental and numerical studies on the compression after impact (CAI) behavior of composite tapered laminates. It introduces newly designed impact platforms and compression fixtures specifically tailored for the specimens. Drop-weight impacts are applied to the center of the specimens, and the resulting damage is briefly described. Compression tests are then conducted on both non-impacted and impacted specimens, with strain gauges used to monitor the strain distribution. Internal damage is detected using CT scanning and ultrasonic C-scan techniques. The numerical simulations are performed using ABAQUS/Explicit finite element analysis (FEA), incorporating an intra-laminar progressive damage model and an inter-laminar cohesive model, while additionally modeling resin pockets as elastomers. The simulation and experimental results indicate that before compression failure, impact damage in the thin section minimally affects the out-of-plane displacement, which is predominantly influenced by structural asymmetry. Stress concentration is observed at the junction between the thin and tapered sections in the compression test, while in the CAI test, stress concentration appears in the impact zone. The impact induces a notable shift in failure location and damage modes, resulting in decreased compressive strength, although the impact on stiffness remains minimal.

本文对复合材料锥形层合板的冲击后压缩(CAI)性能进行了实验和数值研究。它引入了新设计的冲击平台和压缩夹具,专门为试样量身定制。落重冲击作用于试件的中心,并简要描述了由此产生的损伤。然后在非冲击和冲击试样上进行压缩试验,用应变片监测应变分布。使用CT扫描和超声c扫描技术检测内部损伤。数值模拟使用ABAQUS/显式有限元分析(FEA)进行,结合层流内渐进损伤模型和层流间黏结模型,同时将树脂袋建模为弹性体。仿真和实验结果表明,在压缩破坏前,薄截面的冲击损伤对面外位移的影响最小,面外位移主要受结构不对称的影响。在压缩试验中,在细截面和锥形截面交界处观察到应力集中,而在CAI试验中,应力集中出现在冲击区。冲击引起破坏位置和损伤模式的显著变化,导致抗压强度下降,但对刚度的影响仍然很小。


A novel self-centring jacket-type offshore wind turbine structure: A proof-of-concept study and seismic fragility analysis

Ke Ke, Wuhua Xie, Xuhong Zhou, Yuhang Wang, Xiuzhang He

doi:10.1016/j.tws.2024.112407

一种新型自定心导管式海上风力涡轮机结构:概念验证研究和地震易损性分析

Recent installations of jacket-type offshore wind turbines (JOWTs) in seismically active regions have drawn increasing concerns regarding the seismic safety of JOWTs. To enhance the seismic performance of JOWTs, a novel self-centring jacket-type offshore wind turbine (SCJOWT) design is proposed in this study by replacing the traditional transition piece (TP) connecting the tower and jacket with a novel TP system equipped with the self-centring energy dissipation bearing (SCEDB). The SCJOWT is designed with three states of seismic behaviour: initial, controlled rocking, and post-earthquake restoring, and exhibits good ductility, self-centring capacity, and flexibility in adjusting hysteretic behaviours. The benefits of the SCJOWT in seismic mitigation over the traditional JOWT are evaluated by a comparative study. First, the finite element models of a 5-MW JOWT prototype structure and nine SCJOWT structures equipped with the SCEDBs of various flag-shaped hysteretic behaviours are developed, and the rationality of the modelling techniques is verified by test data. Then, the seismic dynamic responses of the structures are carefully examined. Finally, seismic fragility analyses are performed based on a suite of design-spectrum-compliant ground motions. The results show that the SCJOWT can mitigate the fragility of collapse and serviceability compared to the JOWT. Moreover, the hysteretic behaviour of SCEDBs has a significant influence on the seismic fragility of SCJOWTs, and hence the seismic performance of SCJOWTs can be optimised by modulating the structural hysteretic parameters.

最近在地震活跃地区安装的导管式海上风力涡轮机(JOWTs)引起了人们对JOWTs地震安全性的日益关注。为了提高海上风电机组的抗震性能,本文提出了一种新型的自定心导管套式海上风电机组(SCJOWT)设计方案,将连接塔架和导管套的传统过渡件(TP)替换为带有自定心耗能轴承(SCEDB)的新型导管套系统。SCJOWT设计具有三种地震行为状态:初始状态、可控摇摆状态和震后恢复状态,并具有良好的延展性、自中心能力和调节迟滞行为的灵活性。通过对比研究,评估了SCJOWT与传统JOWT相比在抗震方面的优势。首先,建立了一个5mw JOWT原型结构和9个具有不同旗形滞回行为的scedb的SCJOWT结构的有限元模型,并通过试验数据验证了建模技术的合理性。然后,仔细检查了结构的地震动力响应。最后,基于一套符合设计谱的地面运动进行了地震易损性分析。结果表明,与JOWT相比,SCJOWT可以减轻坍塌的易碎性和可维护性。此外,scedb的滞回特性对scjots的地震易损性有显著影响,因此可以通过调节结构滞回参数来优化scjots的抗震性能。


Design Method for Axially Compressed H-sectional Aluminium Alloy Slender Column Based on CSM

Guohan Chen, Pengcheng Li, Han Bao, Yunchang Huang, Chenglin Liu, Tianhao Zhang, Gang Xiong

doi:10.1016/j.tws.2024.112417

基于CSM的轴向压缩h型钢铝合金细长柱设计方法

In this study, a section-limiting stress that considers the influence of cross-section slenderness on the load-carrying capacity proposed by the continuous strength method (CSM) is introduced for the first time in the design of axially compressed H-section aluminium alloy slender columns. Experimental and numerical simulation tests are conducted on these columns to understand their axial compression performance and failure modes, with subsequent validation of the numerical simulation methods. Using the CSM limiting stress, imperfection factor, and stability calculation factor, this study proposes a design method for the overall stability load-carrying capacity of axially compressed H-section aluminium alloy slender columns. The load-carrying capacity predictions of the proposed design method are compared with those of the European, American, Australian/New Zealand, and Chinese design standards using axial compression tests and numerical simulations. An evaluation of these design methods and standards is also presented. In addition, reliability analyses are conducted following the approaches proposed by the American Institute of Steel Construction and the European design standard to assess the reliability levels of the aforementioned design methods and standards. Finally, the study presents a calculation example of an aluminium alloy slender column using the proposed design method.

本文首次将连续强度法(CSM)中考虑截面长细比对承载力影响的截面极限应力引入轴压h型铝合金细长柱的设计中。对这些柱进行了试验和数值模拟试验,了解了它们的轴压性能和破坏模式,并对数值模拟方法进行了验证。利用CSM极限应力、缺陷因子和稳定计算因子,提出了轴压h型钢铝合金细长柱整体稳定承载能力的设计方法。通过轴压试验和数值模拟,将提出的设计方法的承载能力预测与欧洲、美国、澳大利亚/新西兰和中国的设计标准进行了比较。对这些设计方法和标准进行了评价。此外,根据美国钢结构协会和欧洲设计标准提出的方法进行可靠性分析,对上述设计方法和标准的可靠性水平进行评估。最后,以某铝合金细长柱为例,给出了采用本文提出的设计方法的计算实例。


Experimental and numerical study on ballistic response of stitched aramid woven fabrics under normal and oblique dynamic impact

Xiaoyuan Zheng, Hao Wu, Xing Li, Qianran Hu, Ke Yan, Shaobo Qi, Mengqi Yuan

doi:10.1016/j.tws.2024.112424

缝式芳纶机织物在正、斜动力冲击下的弹道响应试验与数值研究

The objective of this study was to examine the influence of impact angle and stitching method on the ballistic properties of fabrics. Multi-layer stitched fabrics and multi-layer unstitched fabrics were designed and manufactured. Subsequent pull-out tests, as well as positive and oblique impact ballistic tests, were conducted. A validated yarn-level ballistic impact finite element model was established to analyze the effects of impact angle and stitching methods on ballistic properties, including stress distribution, back deformation, and energy absorption. The results of experiments and simulations demonstrate that impact angle and stitching methods significantly affect the impact resistance and response mechanism of the fabric. The suture treatment significantly enhanced the energy absorption capacity of PW4, with an average energy absorption ratio of 16.72% at various angles. This treatment facilitates stress propagation within the yarn, resulting in a maximum reduction of 576.00 mm2 in the low-stress area, thereby maximizing the yarn's load-bearing potential. The peak value of back deformation is decreased. In comparison to PW4-0, the peak value of out-of-plane deformation displacement of PWS4-0 is reduced by 17.89%. Additionally, the energy absorption mechanism of the fabric varied with the incident angle, showing a "falling-rising-falling" trend in total energy absorbed.

本研究的目的是研究冲击角度和缝合方式对织物弹道性能的影响。设计并制造了多层有缝织物和多层无缝织物。随后进行了拉出试验,以及正冲击和斜冲击弹道试验。建立了经过验证的纱线级弹道冲击有限元模型,分析了冲击角度和缝合方式对弹道性能的影响,包括应力分布、背变形和能量吸收。实验和仿真结果表明,冲击角度和拼接方式对织物的抗冲击性能和响应机理有显著影响。缝线处理显著增强了PW4的能量吸收能力,各角度的平均能量吸收比为16.72%。这种处理有利于纱线内部的应力传播,导致低应力区域最大减少576.00 mm2,从而最大化纱线的承载潜力。背变形峰值减小。与PW4-0相比,PWS4-0的面外变形位移峰值减小了17.89%。织物的吸能机制随入射角的变化而变化,总吸能呈现“下降-上升-下降”的趋势。


Compressive chord sidewall failure of equal-width RHS X joints with brace inclination

Sihyeong Park, Seon-Hu Kim, Cheol-Ho Lee

doi:10.1016/j.tws.2024.112425

带支撑倾斜的等宽RHS X节点受压弦边破坏

The compressive chord sidewall failure in equal-width RHS (rectangular hollow section) X joints has been extensively investigated in recent years, primarily due to the awareness of the excessive conservatism implied in the resistance formula of current design codes. However, most previous studies on chord sidewall failure have covered only the case of orthogonal joints where chord and brace members are joined at right angle. Consequently, non-orthogonal joints, involving brace inclination, have been rarely studied to date, despite their frequent use in the field application. This study investigates the effect of brace inclination on the chord sidewall strength, both analytically and numerically, with the aim of critically evaluating related design provisions and proposing necessary modifications. This study starts with noting that the design resistance calculation in current codes for chord sidewall failure typically consists of two steps, computing the strength of orthogonal joints first and then extending the orthogonal joint strength to that of the inclined joint. The rule for extending buckling-related parameters from orthogonal to inclined joints, as adopted in current design codes, is shown not to well reflect the actual load-transfer mechanism in the chord sidewall. A modified rule is proposed for inclined joints, with paying special attention to the significant coupled effects between brace inclination and chord stresses. Test-validated FE analysis is used to demonstrate that the proposed modification results in improved accuracy in predicting the chord sidewall failure strength of inclined joints.

近年来,等宽RHS(矩形空心截面)X节点的受压弦侧壁破坏得到了广泛的研究,这主要是由于人们意识到现行设计规范中阻力公式中隐含的过度保守性。然而,以往关于弦杆侧壁破坏的研究大多只涵盖了弦杆和支撑构件以直角连接的正交节点的情况。因此,尽管在现场应用中经常使用,但涉及支撑倾角的非正交节点迄今为止很少进行研究。本研究从分析和数值两方面探讨了支撑倾角对弦侧壁强度的影响,目的是批判性地评估相关设计规定并提出必要的修改。本文首先注意到,现行规范中斜拉索侧壁破坏的设计抗力计算一般分为两个步骤,首先计算正交节点的强度,然后将正交节点的强度扩展到斜节点的强度。结果表明,现行设计规范中有关屈曲参数由正交节点扩展到斜节点的规则并不能很好地反映弦侧壁的实际荷载传递机制。提出了一种适用于倾斜节点的修正规则,特别注意了支撑倾角和 弦应力之间的显著耦合效应。试验验证的有限元分析结果表明,修正后的方法提高了斜节理弦边破坏强度预测的准确性。


Numerical modeling and simulation prediction of the forming process of 3D-tubular braided composite reinforcements

Jinlei Li, Nahiène Hamila, Eduardo Guzman-Maldonado, Gildas L'Hostis, Peng Wang

doi:10.1016/j.tws.2024.112426

三维管状编织复合材料增强材料成形过程的数值模拟与仿真预测

Tubular braids with a hollow structure are considered to be ideal reinforcements for manufacturing composite pipes and cylindrical structures. The mechanical properties of the fabric are critical in the forming process. A new simulation approach based on the non-orthogonal hyperelastic constitutive model for predicting the mechanical behavior of tubular braided reinforcements during forming was proposed. The validity and accuracy of this approach were certified by the uniaxial tensile test of tubular braided fabrics and the maximum errors are less than 15%. In addition, preforming of fabrics on the tetrahedrons and cylinders has been investigated. The predicted shear angle and elongation of a single yarn of the tubular fabric after forming showed good agreement with experimental results. The maximum errors of shear angle and elongation of a single yarn are 10.4% and 9.8%, respectively. Furthermore, the formability of the fabric was also predicted to achieve damage-free preforms. This work thus gives a novelty perspective to further guide tubular braided fabric processing during the forming process.

具有中空结构的管状编织带被认为是制造复合管道和圆柱结构的理想增强材料。织物的机械性能在成型过程中是至关重要的。提出了一种基于非正交超弹性本构模型的管状编织增强件成形力学行为模拟方法。通过管状编织织物的单轴拉伸试验,验证了该方法的有效性和准确性,最大误差小于15%。此外,还对织物在四面体和圆柱体上的预成形进行了研究。预测的管状织物成型后单根纱线的剪切角和伸长率与实验结果吻合较好。单根纱线的剪切角和伸长最大误差分别为10.4%和9.8%。此外,还预测了织物的可成形性,以实现无损伤预成型。从而为进一步指导管状编织织物成形过程中的加工提供了一个新颖的视角。


Nonlinear Guided Wave Mixing in Weld Joints for Detection of Material Nonlinearity

Mohammed Aslam, Jaesun Lee

doi:10.1016/j.tws.2024.112428

焊接接头非线性导波混频检测材料非线性

The remarkable sensitivity of ultrasonic waves to detect the early stages of material degradation stems from their inherent nonlinear nature. However, distinguishing the nonlinearity induced by the measurement system from that of the weak materials remains a persistent challenge in second harmonic generation methods. Ultrasonic wave mixing has emerged as a feasible solution for isolating nonlinearities originating from the measurement system. While bulk waves, surface waves, and guided waves have undergone extensive study in wave mixing, the potential of feature-guided wave (FGW) mixing remains largely unexplored. This paper investigates the mutual interaction of FGWs to generate second-order mixed harmonic waves, focusing specifically on weld joints. Acoustic energy trapped along structural features such as weld joints exhibits reduced decay compared to uniform plates, making them ideal for nonlinear characterization. We investigate the effectiveness of FGW mixing for characterizing material nonlinearities in welded joints, utilizing phase velocity matching and resonance criteria to enhance the generation of mixed harmonic components. Through three-dimensional numerical simulations and experimental tests, we showcase the generation of mixed harmonics induced by the mixing of FGWs. Our findings underscore the potential of FGW mixing as a novel approach for enhancing nonlinear-based damage detection techniques in welded joints.

超声波在检测材料降解早期阶段的显著灵敏度源于其固有的非线性性质。然而,如何区分测量系统引起的非线性与弱材料引起的非线性仍然是二次谐波产生方法的一个长期挑战。超声波混频已成为隔离测量系统非线性的一种可行方法。虽然体波、面波和导波在波混频方面已经得到了广泛的研究,但特征导波(FGW)混频的潜力仍未得到充分的开发。本文以焊缝为研究对象,研究了fgw相互作用产生二阶混合谐波的过程。与均匀板相比,沿着结构特征(如焊接接头)捕获的声能表现出更少的衰减,使其成为非线性表征的理想选择。我们研究了FGW混合在表征焊接接头材料非线性方面的有效性,利用相速度匹配和共振准则来增强混合谐波分量的产生。通过三维数值模拟和实验测试,我们展示了FGWs混合引起的混合谐波的产生。我们的研究结果强调了FGW混合作为一种新方法的潜力,可以增强基于非线性的焊接接头损伤检测技术。




来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemAbaqusDeform振动复合材料非线性通用航空航天建筑电子理论电机材料试验曲面管道
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首次发布时间:2024-11-21
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【新文速递】2024年9月9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,International Journal of Plasticity 1 篇,Thin-Walled Structures 4 篇International Journal of Solids and StructuresElastic wave propagation in cubic non-centrosymmetric and chiral architectured materials: Insights from strain gradient elasticityG. Rosi, N. Auffray, C. Combescuredoi:10.1016/j.ijsolstr.2024.113059弹性波在立方非中心对称和手性结构材料中的传播:来自应变梯度弹性的见解In this paper, we investigate wave propagation in cubic periodic architectured materials. We analyse three different types of unit cells, with distinct symmetries (centrosymmetric, non-centrosymmetric chiral and non-centrosymmetric achiral) with the aim of investigating the consequences of such symmetries on the elastodynamic behaviour of the architectured material. To this end, numerical simulations are performed on unit cells representative of the three types, to extract phase velocities and polarisations of waves along different directions. It is shown that some unconventional couplings between the different eigensolutions give rise to circular or elliptically polarised waves, associated with dispersive effects (acoustical activity). Subsequently, a theoretical analysis using a generalised equivalent continuum model (strain gradient elasticity) is performed to analyse these results and unveil the links between the symmetries of the architecture and the macroscopic elastodynamic behaviour. Indeed, it is shown that strain gradient elasticity is able to discriminate between the three symmetry classes, that are seen as equivalent by a classic continuum theory.本文研究了波在三次周期结构材料中的传播。我们分析了三种不同类型的单体细胞,具有不同的对称性(中心对称、非中心对称手性和非中心对称非手性),目的是研究这种对称性对结构材料弹性动力学行为的影响。为此,在具有代表性的三种类型的单元胞上进行了数值模拟,以提取波沿不同方向的相速度和极化。结果表明,不同特征解之间的一些非常规耦合会产生与色散效应(声学活动)相关的圆形或椭圆形极化波。随后,使用广义等效连续体模型(应变梯度弹性)进行理论分析,以分析这些结果,并揭示结构对称性与宏观弹性动力学行为之间的联系。事实上,它表明应变梯度弹性能够区分三种对称类,这被看作是等效的经典连续统理论。Journal of the Mechanics and Physics of SolidsSelf-consistent solution of the Frank-Bilby equation for interfaces containing disconnectionsDavid B. Gordon, Ryan B. Sillsdoi:10.1016/j.jmps.2024.105845含断路界面的Frank-Bilby方程的自洽解The quantized Frank-Bilby equation can be used to identify interfacial line defect array configurations which relax the misorientation and/or misfit of a coherent crystalline interface. These line defect arrays may be comprised of dislocations and/or disconnections, which are interfacial steps with dislocation character. When an interface contains disconnections, solution of the quantized Frank-Bilby equation is complicated by the fact that the habit plane orientation is not known in advance because it depends on the unknown spacing of the disconnection array. We present a root-finding-based method for addressing this issue, enabling a self-consistent solution for arbitrary defect content. Our method has been implemented in an open-source code which enumerates all possible solutions given a list of candidate line defects. Two cases are presented employing the code: a misoriented FCC twin boundary and an FCC/BCC phase boundary with the Nishiyama-Wasserman orientation relationship. Both cases exhibit more than 10,000 solutions to the Frank-Bilby equation, with several hundred solutions categorized as “low energy” and thus plausible configurations for the actual interface. The resulting set of solutions can be utilized to predict and understand the properties of a given interface.量子化的Frank-Bilby方程可以用来识别界面线缺陷阵列构型,从而缓解相干晶体界面的取向错误和/或失配。这些线缺陷阵列可以由位错和/或断开组成,这是具有位错特征的界面步骤。当界面包含断线时,由于习惯面方向取决于断线阵列的未知间距,因此无法预先知道习惯面方向,这使得量子化Frank-Bilby方程的求解变得复杂。我们提出了一种基于根查找的方法来处理这个问题,为任意缺陷内容提供自一致的解决方案。我们的方法已经在一个开放源代码中实现,该代码列举了给定候选行缺陷列表的所有可能的解决方案。给出了两种应用该代码的情况:错误取向的FCC双边界和具有Nishiyama-Wasserman取向关系的FCC/BCC相边界。这两种情况都展示了Frank-Bilby方程的10,000多个解,其中数百个解被归类为“低能量”,因此对于实际界面的合理配置。结果的解决方案集可以用来预测和理解给定接口的属性。International Journal of PlasticityA generalised framework for modelling anisotropic creep-ageing deformation and strength evolution of 2xxx aluminium alloysXi Wang, Zhusheng Shi, Jianguo Lindoi:10.1016/j.ijplas.2024.1041142xxx铝合金各向异性蠕变时效变形和强度演化的一般框架The 2xxx aluminium alloys are extensively applied in the aerospace industry due to their lightweight and balanced performance characteristics. However, a comprehensive method for modelling both the anisotropic creep deformation and strengthening behaviour in creep age forming (CAF) for 2xxx aluminium alloys remains lacking. This paper presents a generalised framework for establishing constitutive models capable of describing the anisotropic creep deformation coupled with the microstructure and material strength evolutions during creep-ageing of both the original and the pre-deformed 2xxx series Al alloys. This framework extends the rolling direction-based material model to anisotropic scenarios at varying angles between the loading and rolling directions, by employing the non-uniform rational B-splines (NURBS). The details about the anisotropic model calibration and numerical simulation implementation are demonstrated. The feasibility of this method was verified by its application to various 2xxx series aluminium alloys with or without pre-deformation, through constitutive modelling and numerical simulation, with satisfactory agreements between prediction and experimental data. For the first time, the proposed framework provides a generalised routine for establishing anisotropic creep-ageing models for various 2xxx aluminium alloys.2xxx铝合金由于其轻质和平衡的性能特点而广泛应用于航空航天工业。然而,对于2xxx铝合金的各向异性蠕变变形和蠕变时效成形(CAF)强化行为的综合建模方法仍然缺乏。本文提出了建立本构模型的广义框架,该模型能够描述原始和预变形2xxx系列铝合金在蠕变时效过程中的各向异性蠕变变形、微观组织和材料强度演变。该框架通过采用非均匀有理b样条(NURBS),将基于轧制方向的材料模型扩展到加载方向和轧制方向之间不同角度的各向异性场景。详细介绍了各向异性模型的标定和数值模拟实现。通过本构建模和数值模拟,将该方法应用于预变形和不预变形的各种2xxx系列铝合金,验证了该方法的可行性,预测结果与实验数据吻合良好。提出的框架首次为建立各种2xxx铝合金的各向异性蠕变时效模型提供了一个通用的程序。Thin-Walled StructuresDelamination free forming of novel high interface strength metal-polymer laminatesR.K. Naik, S.K. Panda, V. Racherladoi:10.1016/j.tws.2024.112416 新型高界面强度金属-聚合物层压板的无分层成形A new class of metal-polymer-laminates, fabricated using wire mesh and “steel-chips” interlayer, is shown to have significantly high interface strength. A finite element model, calibrated using tensile, lap shear, and peel tests, is used to predict the deformation and failure of the laminates. Formability of the developed laminates is studied using the limiting-dome-height tests. The metal-polymer-laminates do not delaminate in any of the tests. A complete shift of forming-limit-curve towards biaxial-tension region is observed in strain-based forming limit diagram for the polymer side. Strain-path independent forming-limits are plotted in stress space, to negative the effect of non-proportional strain histories.一种新型的金属-聚合物层压板,由金属丝网和“钢屑”夹层制成,具有显著的高界面强度。使用拉伸、搭接剪切和剥离试验校准的有限元模型,用于预测层压板的变形和失效。利用极限顶高试验对所研制的层合板的成形性进行了研究。金属聚合物层压板在任何测试中都不会分层。在基于应变的聚合物侧成形极限图中,成形极限曲线完全向双轴拉伸区移动。在应力空间中绘制了与应变路径无关的形成极限,以消除非比例应变历史的影响。Regression-classification ensemble machine learning model for loading capacity and bucking mode prediction of cold-formed steel built-up I-section columnsYan Lu, Bin Wu, Wenchao Li, Tianhua Zhou, Yanchun Lidoi:10.1016/j.tws.2024.112427冷弯型钢组合截面柱承载力及屈曲模态预测的回归分类集成机器学习模型This paper presents a regression-classification ensemble machine learning (ML) model for load capacity and, in particular, buckling mode prediction with respect to cold-formed steel (CFS) I-section columns. The ML model comprises two sub-models, including the regression sub-model for load capacity prediction and the classification sub-model for buckling mode prediction. A total of 541 experimental and numerical data for CFS built-up I-section columns with varies geometric dimensions, material properties and buckling modes were collected from the literature to construct a dataset. To improve the accuracy and the explainability of the ML model on relative small-scale dataset, physical information-enhanced features based on the knowledge of the direct strength method were adopted as the input features of the ML model, including the yield strength, the elastic local buckling load, the elastic distortional buckling load and the elastic global buckling load, instead of directly using the parameters of geometric dimensions and material properties as the input features. The appropriateness of seven classical machine learning algorithms was compared, namely Decision Tree (DT), Random Forest (RF), Support Vector Machine (SVM), K-Nearest Neighbour (KNN), Adaptive Boosting (ADA), Extreme Gradient Boosting (XG), and Categorical Boosting (CB). The statistical analysis showed that the XG algorithm had the highest level of accuracy for both loading capacity and buckling mode prediction. In addition, the explainability analysis indicated that the developed ML model successfully learned the mechanical characteristic of CFS built-up I-section columns. Finally, the developed ML model was further compared with the existing codified method in the literature. The comparison results indicated that the developed ML model can significantly improve the level of accuracy for loading capacity and buckling mode prediction, which provides a promising alternative choice for the design of CFS built-up I-section columns本文提出了一个回归分类集成机器学习(ML)模型,用于承载能力,特别是关于冷弯型钢(CFS) i型截面柱的屈曲模式预测。ML模型包括两个子模型,分别是用于载荷能力预测的回归子模型和用于屈曲模态预测的分类子模型。本文收集了541个不同几何尺寸、材料性能和屈曲模态的CFS组合式工字截面柱的实验和数值数据,构建了数据集。为了提高ML模型在相对小尺度数据集上的准确性和可解释性,采用基于直接强度法知识的物理信息增强特征作为ML模型的输入特征,包括屈服强度、弹性局部屈曲载荷、弹性畸变屈曲载荷和弹性全局屈曲载荷,而不是直接使用几何尺寸和材料性能参数作为ML模型的输入特征。比较了决策树(DT)、随机森林(RF)、支持向量机(SVM)、k近邻(KNN)、自适应增强(ADA)、极端梯度增强(XG)和分类增强(CB)等7种经典机器学习算法的适用性。统计分析表明,XG算法对载荷能力和屈曲模态的预测精度最高。此外,可解释性分析表明,所建立的ML模型成功地学习了CFS组合工字截面柱的力学特性。最后,将所建立的机器学习模型与文献中已有的编码方法进行了进一步的比较。结果表明,所建立的ML模型能显著提高承载能力和屈曲模态预测的精度水平,为组合式工字截面柱的设计提供了一种有希望的替代选择A CO-HSDT isogeometric analysis for free vibration of matrix cracked FG-GPLRC plates coupled with stationary fluidWei Chen, Linxin Peng, Bing Sun, Wanruo Chen, Yaochu Fangdoi:10.1016/j.tws.2024.112441静止流体耦合下FG-GPLRC基体裂纹板自由振动的CO-HSDT等几何分析This paper for the first time proposes an efficiently C0-higer order shear deformation theory (HSDT) and isogeometric analysis (IGA) for the free vibration analysis of matrix cracked functionally graphene nanoplatelets reinforced composite (FG-GPLRC) plate coupled with stationary fluid. This case represents essential components of sophisticated structures utilized in industries such as shipbuilding, nuclear, marine, and naval. The properties of the four GPLs distributions of FG-GPLRC are evaluated by using a combination of the modified Halpin-Tsai micromechanics model and the rule of mixtures, while the degraded stiffness of cracked layers is predicted by the self-consistent micromechanical (SCM) model. The fluid is assumed to be homogeneous, inviscid, incompressible and irrotational, so the free-surface waves and hydrostatic pressure effects on structures are neglected. The governing equation of motion is derived by the Hamilton&#39;s principle, where three different fluid-plate interaction systems are taken into consideration. After validating the proposed method against existing literature, the effect of various parameters such as crack density, interaction boundary conditions (IBC), fluid level, GPLs distribution pattern, total number of layers, and geometric parameter on the free vibration of matrix cracked FG-GPLRC plate are investigated. It is believed that the finding in this paper may be helpful for the accurate design and analysis of matrix cracked FG-GPLRC plate submerged in fluid.本文首次提出了一种高效的c0 -高阶剪切变形理论(HSDT)和等几何分析(IGA),用于分析固定流体耦合下的基体裂纹功能石墨烯纳米片增强复合材料(FG-GPLRC)板的自由振动。这个案例代表了在造船、核、海洋和海军等行业中使用的复杂结构的重要组成部分。采用改进的Halpin-Tsai细观力学模型和混合规律对FG-GPLRC的四种GPLs分布特性进行了评价,并采用自洽细观力学模型对裂纹层的退化刚度进行了预测。假设流体是均匀的、无粘的、不可压缩的和无旋转的,因此忽略了自由表面波和静水压力对结构的影响。在考虑了三种不同的流-板相互作用系统的情况下,利用汉密尔顿原理推导了运动控制方程。在对照已有文献验证该方法的基础上,研究了裂纹密度、相互作用边界条件(IBC)、流体水平、gpl分布模式、层数和几何参数等参数对基体裂纹FG-GPLRC板自由振动的影响。本文的研究结果可为基体裂纹FG-GPLRC板在流体中的精确设计和分析提供参考。Impact Behavior of Advanced Films under Micro- and Nano-scales: A ReviewYujie Cheng, Jinlei Dong, Kailu Xiao, Minqiang Jiang, Chenguang Huang, Xianqian Wudoi:10.1016/j.tws.2024.112443先进薄膜在微纳米尺度下的冲击行为研究进展High-performance materials with excellent impact resistance are of fundamental importance in impact protective engineering. With the development of experimental facilities and numerical simulations at the micro- and nano-scales in recent years, some advanced films are found to show extraordinary energy absorption capacities, showing great promise as ideal bulletproof materials. In this paper, we review the dynamic behavior of four typical types of advanced films that are promising candidates as bulletproof materials subject to supersonic micro- and nano-ballistic impact. Their specific energy absorptions are summarized and the corresponding energy dissipation mechanisms are provided. The size effects are discussed. Some feasible design strategies for improving the impact resistance of the films are also introduced. It should be noted the current ballistic impact standards such as the NIJ standard do not apply to nanofilms. Based on LIPIT and MD simulations, the protective properties of the nanofilms have been obtained. We think that if the materials show high SEAs under micro- and nano-ballistic impact, they are expected to exhibit high impact resistance at the macro scale.具有优异抗冲击性能的高性能材料是冲击防护工程的基础。近年来,随着实验设备的发展和在微纳米尺度上的数值模拟,一些先进的薄膜显示出非凡的能量吸收能力,有望成为理想的防弹材料。在本文中,我们回顾了四种典型的有希望成为防弹材料的先进薄膜在超音速微纳米弹道冲击下的动态行为。总结了它们的比能量吸收,并给出了相应的能量耗散机制。讨论了尺寸效应。介绍了提高薄膜抗冲击性能的可行设计策略。应该指出的是,目前的弹道冲击标准,如NIJ标准,并不适用于纳米膜。基于LIPIT和MD模拟,得到了纳米膜的保护性能。我们认为,如果材料在微观和纳米弹道冲击下表现出较高的SEAs,则有望在宏观尺度上表现出较高的抗冲击性。来源:复合材料力学仿真Composites FEM

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