【新文速递】2024年5月27日固体力学SCI期刊最新文章

 

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，Thin-Walled Structures 4 篇

International Journal of Solids and Structures

Application of mesh-free and finite element methods in modelling nano-scale material removal from copper substrates: A computational approach

Rahul Yadav, Anuj Sharma, Sivakumar Kulasegaram, Sahar Alimohammadi, Dan Read, Emmanuel Brousseau

doi:10.1016/j.ijsolstr.2024.112891

无网格和有限元方法在模拟纳米级材料从铜衬底去除中的应用:一种计算方法

This study explores the modelling methodology using mesh-free smoothed particle hydrodynamics (SPH) and finite element modelling (FE) techniques to simulate the AFM-based nano-scratching processes for advancing precision engineering in nanotechnology. Tip wear in nano machining substantially increases the tip radius, thereby influencing the material removal mechanism and subsequently affecting the quality of machined nanostructures. In this context, this study examines the effects of rake angle (the inclination of the main cutting edge to the plane perpendicular to the scratched surface), tip radius and scratching depth on cutting forces, groove dimensions, and deformed thickness. This was achieved by implementing an in-house SPH method based particle code employing a Lagrangian algorithm, and an FE model incorporating the dynamic explicit algorithm implemented (in ABAQUS) to carry out nano-scratching simulations. The investigation revealed that the cutting mechanism transitioned to ploughing when the scratching depth decreased to 30% of the tip radius for OFHC-Cu workpiece material machined with a diamond tip. The dominance of normal forces over cutting forces during scratching indicated the side flow of material in the vicinity of the tip radius under intense contact pressure. The ploughing mechanism exhibited more sensitivity at a higher negative rake angle of 60°. Increased scratching depth and tip radius led to more significant material deformation owing to the induction of higher cutting forces, with the maximum deformation thickness 3.6 times the tip radius. The simulated results demonstrated favourable concordance with the experimental data.

本研究探索了利用无网格光滑粒子流体动力学(SPH)和有限元建模(FE)技术来模拟基于afm的纳米划痕过程的建模方法，以推进纳米技术的精密工程。纳米加工中尖端的磨损大大增加了尖端半径，从而影响材料的去除机制，进而影响加工的纳米结构的质量。在此背景下，本研究考察了前角(主切削刃与划痕表面垂直的平面的倾斜度)、刀尖半径和划痕深度对切削力、凹槽尺寸和变形厚度的影响。这是通过实现基于拉格朗日算法的粒子代码的内部SPH方法，以及包含动态显式算法的有限元模型(在ABAQUS中)来实现纳米划痕模拟来实现的。研究表明，金刚石刀尖加工的OFHC-Cu工件材料，当切削深度减小到刀尖半径的30%时，切削机制转变为犁耕。在刮擦过程中，法向力大于切削力的优势表明，在强接触压力下，材料在尖端半径附近的侧流。当负前倾角为60°时，犁耕机构表现出较高的敏感性。随着刮擦深度和刀尖半径的增加，由于切削力的增加，材料变形更加明显，最大变形厚度是刀尖半径的3.6倍。模拟结果与实验数据吻合较好。

Effective mechanical behaviors of transverse isotropic materials embedded compressible liquid inclusions with surface effects

Fei Ti, Chenlei Yu, Moxiao Li, Shaobao Liu, Tian Jian Lu, Xin Chen

doi:10.1016/j.ijsolstr.2024.112903

具有表面效应的可压缩液体包裹体中横向各向同性材料的有效力学行为

Porous media with fluid-saturated microchannels, prevalent in biomaterials, tissue engineering materials and flexible electronic devices, can be modelled as transverse isotropic materials. Surface effects can influence significantly the macro-mechanical responses of such materials, particularly for soft materials with micro- or nano-scale channels. In this study, we first develop constitutive laws for fluid saturated porous materials with microchannels by integrating the top-down (homogenization) approach with the bottom-up (micromechanics) approach. We then explicitly establish a connection between surface effects and macro-mechanical responses. Employing the generalized self-consistent model (GSCM), we estimate the effective parameters (i.e., coefficients in constitutive equations governing macro-mechanical responses), with fluid compressibility and surface effects accounted for. Our findings reveal that, as surface energy increases, the effective transverse shear modulus is enlarged, the effective plane strain bulk modulus, the unit uniaxial straining modulus and the cross modulus are all reduced, but the axial shear modulus remains nearly unchanged. As an application, we characterize the mechanical behaviors of the transverse isotropic fluid-saturated porous material with surface effects by connecting the classic Mandel solution with the estimated effective parameters. The pore pressure exhibits the Mandel-Cryer effect. The insights gained from this study are valuable for comprehending and exploring the intricate ways in which surface effects influence the mechanical responses of transversely isotropic fluid-saturated porous materials featuring sufficiently small channels.

具有流体饱和微通道的多孔介质，普遍存在于生物材料、组织工程材料和柔性电子器件中，可以建模为横向各向同性材料。表面效应可以显著影响这些材料的宏观力学响应，特别是对于具有微或纳米级通道的软材料。在这项研究中，我们首先通过将自顶向下(均质化)方法与自底向上(微力学)方法相结合，建立了具有微通道的流体饱和多孔材料的本构定律。然后，我们明确地建立了表面效应和宏观力学响应之间的联系。采用广义自洽模型(GSCM)，我们估计了有效参数(即控制宏观力学响应的本构方程中的系数)，并考虑了流体压缩性和表面效应。研究结果表明，随着表面能的增大，有效横向剪切模量增大，有效平面应变体模量、单位单轴应变模量和横向模量均减小，而轴向剪切模量基本保持不变。作为应用，我们通过将经典曼德尔解与估计的有效参数联系起来，表征了具有表面效应的横向各向同性流体饱和多孔材料的力学行为。孔隙压力表现出曼德尔-克莱尔效应。从这项研究中获得的见解对于理解和探索表面效应影响具有足够小通道的横向各向同性流体饱和多孔材料的力学响应的复杂方式有价值。

Thermomechanics of phase transformation induced localization in NiTi tubes. Part I experiments

Solon Tsimpoukis, Stelios Kyriakides

doi:10.1016/j.ijsolstr.2024.112905

镍钛管相变诱导局部化的热力学。第一部分实验

This two-Part study aims to illustrate and elucidate the effects of thermomechanical interactions in pseudoelastic NiTi structures that arise in the course of the reversible transformations between the austenitic and martensitic phases. Transformation leads to inhomogeneous deformation with the two phases coexisting and to latent heat-induced local heating/cooling. Part I first presents the results of displacement-controlled isothermal tension and compression experiments on NiTi tubes covering the pseudoelastic temperature regime. The experiments are conducted in a constant temperature circulating bath which suppresses thermomechanical interactions so the transformation front velocity is governed strictly by the applied displacement rate. The load/unload hystereses traced, quantify the transformation stresses and strains and will be used to calibrate the constitutive model of Part II. A set of isobaric experiments in which NiTi tubes are taken through a cool/heat cycle under constant stresses of different levels follow. The experiments are conducted in a custom small-scale environmental chamber with a circulating air stream run by a feedback temperature controller, coupled to load-controlled mechanical loading. The evolution of helical bands of the alternate phase is captured using digital image correlation. The results demonstrate that under such loading histories a strong interaction develops between the evolving inhomogeneous deformation, the latent heat and the surrounding environment. The speed of propagation of the helical fronts slows down or accelerates so as to match the rate at which heat is removed/added to the specimen by the airflow. Thus, here the evolution of localized deformation is strongly coupled to the interaction between the latent heats and heat transfer from the environment. The effect of the stress level on these events is examined through eight isobaric experiments, which provide a rich data set for evaluating constitutive models and structural analyses of these experiments such as those in Part II.

这两部分的研究旨在说明和阐明在奥氏体和马氏体之间可逆转变过程中出现的伪弹性NiTi结构中的热-机械相互作用的影响。相变导致两相并存的不均匀变形和潜热引起的局部加热/冷却。第一部分首先介绍了在假弹性温度下镍钛管的位移控制等温拉伸和压缩实验的结果。实验是在抑制热-力学相互作用的恒温循环浴中进行的，因此相变锋速度严格受施加位移速率的控制。加载/卸载滞后跟踪，量化转换应力和应变，并将用于校准第二部分的本构模型。在一系列等压实验中，镍钛管在不同水平的恒定应力下通过冷/热循环。实验在定制的小型环境室内进行，循环气流由反馈温度控制器运行，再加上负载控制的机械加载。利用数字图像相关技术捕获交替相位螺旋带的演变。结果表明，在这样的加载历史下，不断演化的非均匀变形、潜热和周围环境之间存在强烈的相互作用。螺旋锋的传播速度减慢或加速，以匹配气流除去/增加热量的速度。因此，局部变形的演变与潜热和环境传热之间的相互作用密切相关。应力水平对这些事件的影响是通过八个等压实验来检验的，这些实验为评估本构模型和这些实验的结构分析提供了丰富的数据集，如第二部分中的实验。

Thermomechanics of phase transformation induced localization in NiTi tubes. Part II constitutive modeling and simulations

Solon Tsimpoukis, Stelios Kyriakides, Chad M. Landis

doi:10.1016/j.ijsolstr.2024.112906

镍钛管相变诱导局部化的热力学。第二部分本构建模与仿真

In an isobaric test, typically used for establishing the transformation temperatures of SMAs, a specimen is taken through a cool/heat cycle at a prescribed stress level. The companion paper, Part I, demonstrated that such tests on NiTi tubes result in rather complex interactions between the helical bands of localized deformation induced by phase transformations, the associated latent heat, and the thermal exchange with the environment. These interactions were quantified using accurately controlled testing conditions and full-field diagnostics, and provide a challenging platform for evaluating analyses. In Part II this challenge is met by first extending the thermomechanical constitutive framework developed by our group to include variations of transformation stress, strain, and latent heat with temperature. Unique features of the model include: modeling the reversible phase transformations of NiTi through a single surface in the deviatoric stress–temperature space with the transformation strain and entropy as the internal variables; and use of softening to model the inhomogeneous deformation exhibited in tension. The model is calibrated to the isothermal results of Part I. The constitutive model is then incorporated into a fully coupled static displacement-thermally transient finite element analysis that is used to simulate the isobaric experiments on NiTi tubes of Part I over a range of stresses. The clamped ends of the experiment are idealized as radial constraints. Heat exchange between the structure and the environment is strictly by convection. Isobaric testing is simulated by taking the model tube through the cool/heat cycle of the experiment at the prescribed stress level. A small thickness depression at one of the ends is used to initiate localized transformation. The temperature-strain response is reproduced with the two transformations initiating at essentially the same temperatures as in the experiments, producing the correct transformation strains for all stress levels. Transformation of M propagates via a helical band at similar speeds as in the experiments, while transformation of A is via multipronged fronts for all cases. Successful reproduction of the velocities of the banded transformations is governed by the value of the convection coefficient. Overall, the reproduction of the isobaric experiments over a range of stress levels, validates the constitutive and structural models. It also points to the limitations of modeling the heat exchange between the specimen and the environment only by convection.

在等压试验中，通常用于确定sma的转变温度，试样在规定的应力水平下通过冷/热循环。配套论文第一部分表明，对镍钛管的此类测试导致相变引起的局部变形的螺旋带、相关潜热和与环境的热交换之间相当复杂的相互作用。这些相互作用通过精确控制的测试条件和全场诊断进行量化，并为评估分析提供了一个具有挑战性的平台。在第二部分中，通过首先扩展我们小组开发的热力本构框架来满足这一挑战，该框架包括转变应力、应变和潜热随温度的变化。该模型的独特之处在于:以相变应变和熵为内变量，模拟了NiTi在偏应力-温度空间中通过单一表面的可逆相变;并采用软化法模拟拉伸时的不均匀变形。该模型被校准为第一部分的等温结果。然后将本构模型纳入一个完全耦合的静态位移-热瞬态有限元分析，用于模拟第一部分的NiTi管在一定应力范围内的等压实验。实验的夹紧端被理想化为径向约束。结构和环境之间的热交换严格地通过对流进行。等压试验是通过在规定的应力水平下使模型管通过实验的冷热循环来模拟的。在一端的一个小的厚度下降被用来启动局部转变。温度-应变响应的再现与实验中在基本相同的温度下开始的两个转变，产生所有应力水平下正确的转变应变。M的变换以与实验相似的速度通过螺旋带传播，而a的变换在所有情况下都是通过多管齐下的前沿传播。条带变换速度的成功再现是由对流系数的值决定的。总的来说，在一系列应力水平上的等压实验的再现验证了本构和结构模型。它还指出了仅通过对流模拟试样和环境之间热交换的局限性。

Journal of the Mechanics and Physics of Solids

Microstructural and mechanistic insights into the Tension-Compression asymmetry of rapidly solidified Fe-Cr alloys: A phase field and strain gradient plasticity study

Namit Pai, Indradev Samajdar, Anirban Patra

doi:10.1016/j.jmps.2024.105695

快速凝固Fe-Cr合金拉压不对称的显微组织和机理:相场和应变梯度塑性研究

Rapid solidification in Additively Manufactured (AM) metallic materials results in the development of significant microscale internal stresses, which are attributed to the printing induced dislocation substructures. The resulting backstress due to the Geometrically Necessary Dislocations (GNDs) is responsible for the observed Tension-Compression (TC) asymmetry. We propose a combined Phase Field (PF)-Strain Gradient J2 Plasticity (SGP) framework to investigate the TC asymmetry in such microstructures. The proposed PF model is an extension of Kobayashi’s dendritic growth framework, modified to account for the orientation-based anisotropy and multi-grain interaction effects. The SGP model has consideration for anisotropic temperature-dependent elasticity, dislocation strengthening, solid solution strengthening, along with GND-induced directional backstress. This model is employed to predict the solute segregation, dislocation substructure and backstress development during solidification and the post-solidification anisotropic mechanical properties in terms of the TC asymmetry of rapidly solidified Fe-Cr alloys. It is observed that higher thermal gradients (and hence, cooling rates) lead to higher magnitudes of solute segregation, GND density, and backstress. This also correlates with a corresponding increase in the predicted TC asymmetry. The results presented in this study point to the microstructural factors, such as dislocation substructure and solute segregation, and mechanistic factors, such as backstress, which may contribute to the development of TC asymmetry in rapidly solidified microstructures.

增材制造（AM）金属材料的快速凝固会产生显著的微观内应力，这些内应力可归因于印刷诱导的位错子结构。由几何必备位错（GND）产生的反应力是造成观察到的拉伸-压缩（TC）不对称的原因。我们提出了一个相场（PF）-应变梯度 J2 塑性（SGP）组合框架，用于研究此类微结构中的 TC 不对称现象。所提出的相场模型是小林树枝状生长框架的扩展，经过修改以考虑取向各向异性和多晶粒相互作用效应。SGP 模型考虑了随温度变化的各向异性弹性、位错强化、固溶强化以及 GND 诱导的定向反应力。该模型用于预测凝固过程中的溶质偏析、位错亚结构和反应力发展，以及快速凝固铁铬合金在 TC 不对称方面的凝固后各向异性力学性能。据观察，较高的热梯度（以及冷却速率）会导致较高的溶质偏析、GND 密度和反应力。这也与预测的 TC 不对称程度相应增加有关。本研究的结果表明，微结构因素（如位错亚结构和溶质偏析）和机械因素（如背应力）可能会导致快速凝固微结构中 TC 不对称的发展。

Mechanics of Materials

Influence of the cell size and wall thickness on the compressive behaviour of fused filament fabricated PLA gyroid structures

Joaquim Justino Netto, Manuel Sardinha, Marco Leite

doi:10.1016/j.mechmat.2024.105051

胞室尺寸和壁厚对熔丝制备聚乳酸陀螺结构压缩性能的影响

The development of Additive Manufacturing (AM) has greatly facilitated the fabrication of cellular and lattice materials. Gyroid-based lattice structures, known for their distinctive properties such as interconnected porosity, high surface-to-volume ratio, and remarkable structural stiffness combined with specific energy absorption, have been extensively explored. Many studies examining the impact of design parameters on the mechanical properties of Gyroid lattice materials have utilized metal AM techniques. This research aims to evaluate the influence of two design parameters on the compressive properties of Gyroid structures obtained by fused filament fabrication (FFF). A full factorial analysis was employed to assess the effects of cell size and wall thickness on the compressive properties of polylactic acid (PLA) Gyroid lattices. Cell sizes were varied between 4 mm, 5 mm, and 10 mm, while wall thickness ranged from 0.4 mm, 0.6 mm, to 0.8 mm. After 3D printing, the print quality was assessed, samples were weighted and then subjected to compression testing. During compression, the lattices with 10 mm cells exhibited successive layer collapse, whereas the lattice with 4 mm and 5 mm cells displayed plastic deformation, marked by a plateau in the stress-strain curve. These behaviours were mostly independent of wall thickness, except for the 5 mm cell lattice with 0.4 mm wall thickness. The elastic modulus, yield stress and absorbed energy per volume aligned with the apparent density of the lattices, ranging between 1% and 12% of the bulk 3D printed material for both the stiffness and yield stress, and between 1% and 22% for the energy absorbed. Analysis of the fitted means indicated that doubling the cell size had a more significant impact on the measured properties than doubling the wall thickness, while doubling both the cell size and wall thickness exerted a more pronounced influence on the yield stress and strain. Notably, under the conditions of this study, the 3D printed PLA Gyroids behaved similarly to closed cell foams, despite their interconnected channels. Their compressive mechanical properties comparable to those of rigid polyurethane foams with closed cells.

增材制造(AM)的发展极大地促进了细胞和晶格材料的制造。基于陀螺的晶格结构以其独特的特性而闻名，如互联多孔性、高表面体积比和显著的结构刚度与比能吸收相结合，已被广泛探索。许多研究都是利用金属增材制造技术来研究设计参数对陀螺晶格材料力学性能的影响。本研究旨在评估两种设计参数对熔丝加工(FFF)获得的陀螺结构压缩性能的影响。采用全因子分析来评估细胞大小和壁厚对聚乳酸(PLA) Gyroid晶格压缩性能的影响。细胞大小在4毫米、5毫米和10毫米之间，壁厚从0.4毫米、0.6毫米到0.8毫米不等。3D打印完成后，对打印质量进行评估，对样品进行加权，然后进行压缩测试。在压缩过程中，含有10mm单元格的晶格表现出连续的层塌缩，而含有4mm和5mm单元格的晶格表现出塑性变形，在应力-应变曲线上表现为平台。除了壁厚为0.4 mm的5 mm晶格外，这些行为大多与壁厚无关。弹性模量、屈服应力和每体积吸收能量与晶格的表观密度一致，其刚度和屈服应力的范围在体块3D打印材料的1%到12%之间，吸收能量的范围在1%到22%之间。对拟合均值的分析表明，与壁厚加倍相比，加倍胞体尺寸对所测性能的影响更为显著，而加倍胞体尺寸和壁厚对屈服应力和应变的影响更为显著。值得注意的是，在本研究条件下，3D打印的PLA陀螺体的表现与闭孔泡沫相似，尽管它们的通道相互连接。它们的压缩机械性能与封闭孔的硬质聚氨酯泡沫相当。

Thin-Walled Structures

Stiffening patterns for freeform composite shell structures

Anastasiia Moskaleva, Sergey Gusev, Stepan Konev, Enrique Hernandez-Montes, Alexander Safonov

doi:10.1016/j.tws.2024.112037

自由形状复合壳结构的加劲模式

This paper investigates innovative approaches for enhancing the structural integrity of form-found shell structures with a focus on rib-based reinforcements. It discusses the significance of ribs in enhancing stability and addressing the sensitivity of form-found structures to various loads. Traditional methods such as increasing shell thickness or introducing supports often compromise efficiency and aesthetics. A more intelligent approach involves reinforcing the shell with ribs and advanced materials. Diverse rib patterns are presented, including geometric, biomimetic, and topological optimization-inspired designs, each adhering to a 50% volume constraint, when compared to the original shell. Physical testing and numerical simulations demonstrate that these rib patterns significantly increase stiffness and buckling resistance. The findings presented in the paper suggest that combining form-finding methodologies with well-designed rib patterns can create sustainable and resilient structures, contributing to a reduction in both the consumption of materials and the environmental impact of these structures.

本文研究了创新的方法，以提高形式发现的壳结构的结构完整性，重点是肋基增强。讨论了肋在提高稳定性和解决现形结构对各种荷载的敏感性方面的意义。增加外壳厚度或引入支撑等传统方法往往会损害效率和美观性。一种更智能的方法是用肋骨和先进材料加固外壳。不同的肋骨模式呈现，包括几何、仿生和拓扑优化设计，与原始外壳相比，每一种都坚持50%的体积限制。物理测试和数值模拟表明，这些肋型显著提高了刚度和抗屈曲能力。论文中的研究结果表明，将寻找形式的方法与精心设计的肋骨模式相结合，可以创造出可持续的、有弹性的结构，有助于减少这些结构的材料消耗和对环境的影响。

Modelling of welded aluminium connections in large-scale analyses

Sigurd Aune, David Morin, Magnus Langseth, Odd Sture Hopperstad, Arild Holm Clausen

doi:10.1016/j.tws.2024.112034

大型分析中焊接铝连接的建模

This article addresses large-scale analyses of welded aluminium connections where the weak zones are to be represented by a few shell elements. A combined experimental and numerical study on the behaviour and modelling of welded aluminium connections is presented, where a shell-element modelling framework applicable in large-scale analyses is proposed, accounting for geometrical instability, thinning, and ductile fracture. The proposed modelling framework is calibrated and validated using cross-weld tension tests. The test campaign involves tension testing of two Al-Mg-Si alloys and two welding techniques widely used in industrial applications. The shell-element simulations represented the response of the tests reasonably well.

本文讨论了焊接铝连接的大规模分析，其中薄弱区域将由几个壳单元表示。本文提出了一种结合实验和数值研究的铝焊接连接的行为和建模方法，其中提出了一种适用于大规模分析的壳单元建模框架，考虑了几何失稳、变薄和韧性断裂。提出的建模框架是校准和验证使用交叉焊接张力试验。测试活动包括两种Al-Mg-Si合金和两种在工业应用中广泛使用的焊接技术的张力测试。壳单元模拟较好地反映了试验的响应。

A data-driven procedure for one-dimensional dynamic analysis of thin-walled beams with arbitrary cross-sections

Lei Zhang, Tao Zeng, Weidong Zhu, Yuhang Zhu

doi:10.1016/j.tws.2024.112035

任意截面薄壁梁一维动力分析的数据驱动程序

This paper develops a one-dimensional dynamic model for thin-walled beams with arbitrary complex cross-sections in a data-driven way. In order to consider complicated deformations in the framework of a beam theory, a universal node system is first created to fit the deformed shape of a thin-walled cross-section, whether prismatic or curved, with or without symmetry. This helps to reduce the three-dimensional displacement field of the thin-walled beam to one dimension, and results in a preliminary higher-order beam model with limited precision loss. For the purpose of largely condense DOFs of the new model, a data-driven approach is proposed to identify cross-section deformation modes through the principal component analysis of free vibration deformation data of an unconstrained thin-walled beam. As a result, a compact set of core deformation modes are obtained and selected to update the preliminary model, leading to the refined higher-order beam model of high accuracy and efficiency. Examples are presented to illustrate the concrete implementation and check the effects of data-related controlling parameters of the proposed procedure. We also verify through numerical examples that the proposed model agrees well with plate/shell and other beam theories, and has remarkable advantages in physical interpretation, modeling simplicity and computation efficiency.

本文以数据驱动的方式建立了任意复杂截面薄壁梁的一维动力学模型。为了考虑梁理论框架中的复杂变形，首先创建了一个通用节点系统，以适应薄壁截面的变形形状，无论是棱柱形还是弯曲形，具有或不具有对称性。这有助于将薄壁梁的三维位移场降至一维，并得到精度损失有限的初步高阶梁模型。针对新模型的自由度较大的问题，提出了一种数据驱动的方法，通过对无约束薄壁梁自由振动变形数据的主成分分析来识别截面变形模式。得到并选择了一组紧凑的核心变形模态来更新初步模型，从而得到精度高、效率高的精细化高阶梁模型。通过实例说明了该方法的具体实现，并验证了与数据相关的控制参数的效果。通过数值算例验证了该模型与板壳等梁理论的一致性，在物理解释、建模简单、计算效率等方面具有显著优势。

Effects of internal configurations and its processing quality on compressive performance for 3D printed continuous fiber reinforced composites honeycomb sandwich

Fuji Wang, Hongquan Wang, Gongshuo Wang, Rao Fu, Shouyan Guan, Jianming Zhou

doi:10.1016/j.tws.2024.112046

三维打印连续纤维增强复合材料蜂窝夹层内部结构及其加工质量对其抗压性能的影响

Continuous fiber reinforced composites (CFRCs) 3D printing technology has the advantage of integrated fabricating for honeycomb sandwich structures, the load-bearing capacity of the fabricated honeycomb sandwich structures still needs to be investigated and improved. This study aims to reveal compression failure modes of 3D printed CFRCs honeycomb sandwich structures with various internal configurations by conducting flatwise compression tests. The deviations of single-layer CFRCs honeycomb cores with different core sizes and core heights and their impacts on the compression failure process were analyzed. A 3D printing method with multilayer cores and core/panel variable printing layer thickness was proposed, and the effects of multilayer core structure and different core printing parameters on the compressive properties of honeycomb sandwich structures were investigated. The results showed that interlayer cracking caused by core buckling deformation was the leading cause of failure of 3D printed CFRCs honeycomb sandwich structures when subjected to compression. The core buckling deformation could be suppressed by printing multilayer cores and using low core printing thickness, and the compression strength and specific energy absorption of the sandwich structures reached 38.1 MPa and 25.4 kJ/kg, respectively. This study provides guidance for the customization of the 3D printing process of CFRCs honeycomb sandwich structures.

连续纤维增强复合材料(CFRCs) 3D打印技术具有集成制造蜂窝夹层结构的优势，但所制备的蜂窝夹层结构的承载能力仍有待进一步研究和提高。本研究旨在通过平面压缩试验揭示3D打印CFRCs蜂窝夹层结构不同内部构型的压缩破坏模式。分析了不同芯尺寸和芯高的单层CFRCs蜂窝芯的受力偏差及其对压缩破坏过程的影响。提出了一种多层芯和芯/板可变打印层厚度的3D打印方法，研究了多层芯结构和不同芯打印参数对蜂窝夹层结构压缩性能的影响。结果表明:芯部屈曲变形引起的层间开裂是3D打印CFRCs蜂窝夹层结构受压破坏的主要原因;多层打印和低厚度打印可以抑制芯层的屈曲变形，夹层结构的抗压强度和比能吸收分别达到38.1 MPa和25.4 kJ/kg。本研究为CFRCs蜂窝夹层结构3D打印工艺定制提供指导。