【新文速递】2024年9月7日复合材料SCI期刊最新文章

3天前浏览52

今日更新：Composite Structures 1 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 1 篇，Composites Science and Technology 2 篇

Composite Structures

A size-dependent nonlinear analysis of perovskite solar panels with FG-CNTR-TPMS substrates

Nam V. Nguyen, Kim Q. Tran, Nicholas Fantuzzi, H. Nguyen-Xuan

doi:10.1016/j.compstruct.2024.118548

具有fg - cnr - tpms衬底的钙钛矿太阳能电池板的尺寸相关非线性分析

Perovskite Solar Cells (PSCs) have achieved substantial developments in transforming solar energy into electrical power in recent years, resulting in their widespread application in various interdisciplinary engineering applications. However, the ongoing challenge lies in developing effective mathematical computations to analyze their mechanical behavior under various working scenarios, particularly for nonlinear problems. Being together with the fast growth of new conjugated materials aimed at improving the power conversion efficiencies (PCEs) of solar cells, understanding their mechanical features is crucial for achieving optimal and reliable designs. In this study, we focus on (1) presenting a newly designed PSC structure based on nature-inspired triply periodic minimal surface (TPMS) architectures with agglomerated CNTs reinforcement and (2) investigating a NURBS-based isogeometric approach to determine nonlinear bending and free vibration responses with size-dependent effects. The PSC structures are modeled as a multi-layered microplate, including thin solar cells and a functionally graded carbon nanotube-reinforced TPMS (FG-CNTR-TPMS) substrate layer. After deriving FG-CNTR-TPMS architectures, the strong and weak forms of the geometrically nonlinear behavior of microplates under static bending and free vibration with large amplitude conditions are established. The high performance and accuracy of the current approach are compared with the analytic approach and other available solutions. The obtained results demonstrated that the size effects significantly influence static deflections as well as frequencies of advanced PSC structures. In addition, the significant contribution of high-performance FG-CNTR-TPMS substrates in improving the size-dependent nonlinear performance of the original PSCs structure is discussed and elucidated.

近年来，钙钛矿太阳能电池(PSCs)在将太阳能转化为电能方面取得了长足的发展，在各种跨学科工程应用中得到了广泛的应用。然而，目前的挑战在于开发有效的数学计算来分析它们在各种工作情况下的力学行为，特别是非线性问题。随着旨在提高太阳能电池功率转换效率(pce)的新型共轭材料的快速发展，了解其机械特性对于实现最佳和可靠的设计至关重要。在本研究中，我们的重点是(1)提出了一种基于自然启发的三周期最小表面(TPMS)结构的新设计PSC结构，并带有聚集体碳纳米管增强;(2)研究了一种基于nurbs的等几何方法，以确定具有尺寸依赖效应的非线性弯曲和自由振动响应。PSC结构被建模为多层微板，包括薄太阳能电池和功能梯度的碳纳米管增强TPMS (fg - cnr -TPMS)衬底层。在推导fg - cnr - tpms结构的基础上，建立了微板在静态弯曲和大振幅自由振动条件下几何非线性行为的强弱形式。并与解析法和其他现有的求解方法进行了比较。结果表明，尺寸效应对高级PSC结构的静挠度和频率有显著影响。此外，高性能fg - cnr - tpms衬底在改善原psc结构的尺寸相关非线性性能方面的重要贡献进行了讨论和阐明。

Composites Part A: Applied Science and Manufacturing

Cellulose fibre foam templated porous epoxy composites: Wetting matters

Veronika Biegler, Philip Verdross, Robert T. Woodward, Alexander Bismarck

doi:10.1016/j.compositesa.2024.108461

纤维素纤维泡沫模板多孔环氧复合材料:润湿物质

Cellulose foams were used to produce porous epoxy-composites. The influence of fibre wetting by the resins on foam morphology and resulting compression properties was investigated. Impregnated foam morphology determined the composite structures and their mechanical properties. Fibre preforms of various densities (40–80 kg·m−3) were prepared by frothing surfactant stabilised fibre suspensions. The preforms, exhibiting compressive strengths of 0.02 MPa, were impregnated with three different resins (a lignin-based resin BLER/MA, and two commercial formulations, A/A and A/XB). Depending on the formation of closed- or open-cell structures in the cured foam composites, compressive strengths of up to 2 MPa (BLER/MA), 33 MPa (A/A), or 23 MPa (A/XB), and compressive moduli of up to 47 MPa (BLER/MA), 468 MPa (A/A), or 379 MPa (A/XB) were obtained. The surface area, fibre coverage homogeneity, and composite morphology were investigated in relation to wetting. A tool kit for fibre foam templated porous composite design is provided.

采用纤维素泡沫制备多孔环氧树脂复合材料。研究了树脂润湿纤维对泡沫形态和压缩性能的影响。浸渍泡沫形态决定了复合材料的结构和力学性能。用表面活性剂稳定的纤维悬浮液泡沫法制备了不同密度(40-80 kg·m−3)的纤维预制体。用三种不同的树脂(木质素基树脂BLER/MA和两种商业配方a / a和a /XB)浸渍预制体，其抗压强度为0.02 MPa。根据固化泡沫复合材料中闭孔或开孔结构的形成，抗压强度可达2 MPa (BLER/MA)、33 MPa (A/A)或23 MPa (A/XB)，压缩模量可达47 MPa (BLER/MA)、468 MPa (A/A)或379 MPa (A/XB)。研究了表面面积、纤维覆盖均匀性和复合材料形态与润湿的关系。提供了一种用于泡沫纤维模板多孔复合材料设计的工具箱。

Composites Part B: Engineering

The magnesium-doped CSH/BCP promotes alveolar bone regeneration by mediating M2 macrophage polarization via miR-21-5p/Smad2 axis

Jing Zhou, Su Sun, Jia Xu, Tingting Yan, Yan He, Lingpeng Zhang, Chaofeng Liu, Yonghui Zhang, Yan Liu, Qingsong Ye

doi:10.1016/j.compositesb.2024.111811

镁掺杂CSH/BCP通过miR-21-5p/Smad2轴介导M2巨噬细胞极化促进牙槽骨再生

The repair of alveolar bone defects is a complex biological process that involves the interplay between implant materials, bone marrow mesenchymal stem cells (BMSCs), and the immune cells present in the surrounding area. Moreover, the polarization of macrophages induced by implant materials has been shown to play a crucial role in regulating bone regeneration. Recent studies have discovered that M2 macrophages promote the osteogenic differentiation of BMSCs by activating the TGF-β/BMP signaling pathway. However, the molecular mechanisms underlying the regulation of bone regeneration in BMSCs by macrophages remain unclear. Our in vivo study demonstrated that a 10% magnesium (Mg2+)-doped calcium sulfate hemihydrate -biphasic calcium phosphate (CSH/BCP) composite ceramic material was effective in repairing alveolar bone defects in rabbits. In our in vitro study, we observed that this ceramic material could induce M2 macrophage polarization and reduce inflammation. Moreover, the conditioned media obtained from M2 macrophages promoted the osteogenic differentiation of BMSCs. Additionally, our research showed that overexpression of miR-21-5p inhibited M2 macrophage polarization and reduced the osteogenic differentiation capacity of BMSCs. Co-overexpression of miR-21-5p and Smad2 in macrophages partially reversed the effects of miR-21-5p on the osteogenic differentiation of BMSCs and macrophage polarization. These findings suggested that Mg2+-doped CSH/BCP composite ceramic materials could enhance M2 macrophage polarization through the miR-21-5p/Smad2 axis, and the microenvironment of M2 macrophages could further promote the osteogenic differentiation of BMSCs. The findings presented in this work offer valuable insights into the molecular mechanisms that regulate bone regeneration in BMSCs and the role of macrophages in this process.

牙槽骨缺损的修复是一个复杂的生物学过程，涉及植入材料、骨髓间充质干细胞(BMSCs)和周围免疫细胞之间的相互作用。此外，种植材料诱导的巨噬细胞极化在调节骨再生中起着至关重要的作用。近期研究发现M2巨噬细胞通过激活TGF-β/BMP信号通路促进BMSCs的成骨分化。然而，巨噬细胞调控骨髓间充质干细胞骨再生的分子机制尚不清楚。我们的体内研究表明，10%镁(Mg2+)掺杂硫酸钙半水-双相磷酸钙(CSH/BCP)复合陶瓷材料可有效修复家兔牙槽骨缺损。在我们的体外研究中，我们观察到这种陶瓷材料可以诱导M2巨噬细胞极化，减轻炎症。此外，从M2巨噬细胞中获得的条件培养基促进了骨髓间充质干细胞的成骨分化。此外，我们的研究表明，过表达miR-21-5p抑制M2巨噬细胞极化，降低BMSCs的成骨分化能力。巨噬细胞中miR-21-5p和Smad2的共过表达部分逆转了miR-21-5p对BMSCs成骨分化和巨噬细胞极化的影响。这些结果表明，Mg2+掺杂CSH/BCP复合陶瓷材料可以通过miR-21-5p/Smad2轴增强M2巨噬细胞极化，M2巨噬细胞的微环境可以进一步促进BMSCs的成骨分化。本研究的发现为骨髓间充质干细胞骨再生调控的分子机制以及巨噬细胞在这一过程中的作用提供了有价值的见解。

Composites Science and Technology

Bioinspired 3D printed metamaterial for wideband microwave absorption and aerodynamic efficiency

Chaoqun Ge, Huaiyu Dong, Zonghan Li, Chen Yu, Zhichen Wang, Yingjian Sun, Yixing Huang, Tian Zhao, Ying Li, Liuying Wang

doi:10.1016/j.compscitech.2024.110846

生物启发的3D打印超材料，用于宽带微波吸收和空气动力学效率

To further decrease the mass and thickness of multifunctional wideband microwave absorption metamaterials (MAMs), this study applies photonic crystal principles to the field of microwave absorption. Drawing inspiration from the structural coloration regulation of Morpho Menelaus scales, a novel integrated bioinspired MAM named MM is designed. MM possesses low drag coefficient, hydrophobicity, mechanical load-bearing capacity, and wideband radar stealth functionality. Utilizing PA6@CF filaments and material extrusion 3D printing technology, mechanical test specimens and MM specimens optimized through particle swarm optimization (PSO) are rapidly fabricated at low cost. Reflectivity tests at normal incidence reveal that MM (with a thickness of 8 mm) achieves an effective absorption bandwidth (EAB) of 33.4 GHz within the 2–40 GHz frequency range. Under transverse magnetic polarization and 60° oblique incidence conditions, MM demonstrates a coverage rate of 98.5 % for EAB. Furthermore, three-point bending tests demonstrate MM's excellent deformation capabilities (up to 50 mm) and mechanical load-bearing performance (bending strength reaching 78 MPa), laying the groundwork for its application on complex surfaces. Lastly, targeting the application of microwave absorption metamaterials on high-speed moving objects, comparative analysis of MM and five typical MAMs reveals that MM exhibits the lowest drag coefficient (Cd = 0.132). In summary, this study offers a straightforward and replicable method for designing, optimizing, fabricating, and evaluating MAMs, while suggesting aerodynamic performance as a novel metric for assessing their multifunctional capabilities.

为了进一步降低多功能宽带微波吸收超材料(MAMs)的质量和厚度，本研究将光子晶体原理应用于微波吸收领域。从墨涅劳斯大Morpho Menelaus鳞片的结构色彩调节中获得灵感，设计了一种新型的集成生物MAM，名为MM。MM具有低阻力系数、疏水性、机械承载能力和宽带雷达隐身功能。利用PA6@CF长丝和材料挤压3D打印技术，通过粒子群优化(PSO)快速制作机械试件和MM试件，成本低。正入射反射率测试表明，MM(厚度为8 MM)在2-40 GHz频率范围内的有效吸收带宽(EAB)为33.4 GHz。在横磁极化和60°斜入射条件下，MM对EAB的覆盖率为98.5%。此外，三点弯曲试验表明，MM具有优异的变形能力(高达50 MM)和机械承载性能(弯曲强度达到78 MPa)，为其在复杂表面上的应用奠定了基础。最后，针对微波吸收超材料在高速运动物体上的应用，MM与5种典型MAMs的对比分析表明MM具有最低的阻力系数(Cd = 0.132)。总之，本研究为mam的设计、优化、制造和评估提供了一种简单、可复制的方法，同时建议将空气动力学性能作为评估其多功能能力的新指标。

Revealing the Nanoscale Reinforcing Mechanism: How Topological Structure of Carbon Black Clusters Influence the Mechanics of Rubber

Chenchen Tian, Xinyang Liu, Jingjie Kou, Chao Wang, Lin Xu, Nanying Ning, Chao Lu, Ming Tian

doi:10.1016/j.compscitech.2024.110847

揭示纳米级增强机制:炭黑团簇的拓扑结构如何影响橡胶的力学

The mechanical reinforcement of rubber by carbon black (CB) depends strongly on its the size and topography of CB clusters. However, the underlying mechanisms remain largely unexplored. This study uses atomic force microscopy (AFM) to probe interfacial properties at the nanoscale to elucidate the influence of the CB topological structure on macroscopic mechanical properties. A substantial amount of high-modulus bound rubber is found inside the CB aggregates, particularly in highly branched ones. This phenomenon plays a critical role in reinforcement, as corroborated by quantitative AFM nanomechanics, chain segment motion results and theoretical calculations. A quantitative analysis of the filler network reveals that the branched chain structure effectively reduces the packing spacing and improves the stress transfer efficiency.

炭黑对橡胶的机械增强在很大程度上取决于炭黑团簇的大小和形貌。然而，潜在的机制在很大程度上仍未被探索。本研究利用原子力显微镜(AFM)在纳米尺度上探测界面性能，以阐明CB拓扑结构对宏观力学性能的影响。大量的高模量结合橡胶在炭黑聚集体中被发现，特别是在高度分支的聚集体中。定量AFM纳米力学、链段运动结果和理论计算均证实了这一现象在强化过程中起着至关重要的作用。对填料网络的定量分析表明，支链结构有效地减小了填料间距，提高了应力传递效率。

来源：复合材料力学仿真Composites FEM

【新文速递】2024年9月11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 2 篇，Thin-Walled Structures 1 篇International Journal of Solids and StructuresTowards a rational approach for multi-axial experimental campaigns for rubberlike materialBenjamin Martin, Erwan Verron, Michel Coret, Nathan Sellesdoi:10.1016/j.ijsolstr.2024.113060探讨类橡胶材料多轴实验运动的合理方法This work takes up the developments around the logarithmic strain tensor and uses the invariants of this tensor to propose a new approach to multi-axiality of fatigue experiments for elastomers. This study leads to the introduction of a new notion, modality, which is intended as the microscopic counterpart of uni- and multi-axiality. This notion is quantified by the K3 invariant (mode of deformation) of the logarithmic strain tensor, and is used to rationalize tension-torsion experimental campaigns. It is illustrated using two examples: the perfect cylinder and the AE2 “diabolo” sample. We then propose a methodology for building a test campaign based on this new definition.这项工作围绕对数应变张量展开，并利用该张量的不变量提出了弹性体疲劳实验多轴性的新方法。这项研究引入了一个新概念--模态，作为单轴性和多轴性的微观对应概念。该概念通过对数应变张量的 K3 不变式（变形模式）进行量化，并用于合理解释拉伸-扭转实验活动。我们用两个例子对其进行了说明：完美圆柱体和 AE2 “空竹”样品。然后，我们提出了基于这一新定义的试验方法。Journal of the Mechanics and Physics of SolidsA covariant formulation for finite strain modelling of orthotropic elasticity and orthotropic plasticity with plasticity-induced evolution of orthotropy: Application to natural fibresChristian C. Celigoj, Manfred H. Ulzdoi:10.1016/j.jmps.2024.105846具有塑性诱导正交异性演化的正交异性弹性和正交异性塑性有限应变模型的协变公式:在天然纤维中的应用We introduce a rate-independent model for orthotropic elastic and orthotropic plastic material behaviour in a hyper-elasto-plastic framework at finite strains. The model is based on the postulate of covariance and does not rely on a multiplicative decomposition of the deformation gradient. Furthermore, a plastic-deformation-induced evolution of orthotropy is considered, similar to the notion of plastic spin. We propose that the orthotropic strain energy function and the orthotropic yield criterion are guided by identical structural tensors that evolve with plasticity. The modelled material behaviour is significant for natural fibres such as flax, hemp, or pulp fibres. Our formulation has three findings. Firstly, the covariant formulation of plasticity provides rate equations for the plastic variables and the structural tensors suitable for reproducing stress–strain diagrams of natural fibres. Secondly, the introduction of plastic-deformation-induced evolution of orthotropy in the proposed covariant setting results in a non-associative plasticity algorithm. Thirdly, the covariant setting allows the incorporation of suitable constitutive equations for the structural tensors to evolve orthotropy. The latter successfully models the stiffness increase in stress–strain diagrams of cyclic tensile tests of natural fibres.我们介绍了在有限应变下超弹塑性框架中正交各向异性弹性和正交各向异性塑性材料行为的速率无关模型。该模型基于协方差假设，不依赖于变形梯度的乘法分解。此外，考虑了塑性变形诱导的正交异性演化，类似于塑性自旋的概念。我们提出正交各向异性应变能函数和正交各向异性屈服准则由相同的随塑性演化的结构张量指导。模拟材料的行为是显著的天然纤维，如亚麻，大麻，或纸浆纤维。我们的公式有三个发现。首先，塑性协变公式提供了适于再现天然纤维应力-应变图的塑性变量和结构张量的速率方程。其次，在所提出的协变设置中引入塑性变形诱导的正交异性进化导致非关联塑性算法。第三，协变设置允许结合合适的本构方程的结构张量发展正交异性。后者成功地模拟了天然纤维循环拉伸试验的应力-应变图中的刚度增加。Mechanics of MaterialsA Statistical High-order Reduced Model for Nonlinear Random Heterogeneous Materials with Three-scale Micro-ConfigurationsZhiqiang Yang, Shanqiao Huang, Yi Sundoi:10.1016/j.mechmat.2024.105149具有三尺度微观结构的非线性随机非均质材料的统计高阶简化模型An effective statistical higher-order three-scale reduced homogenization (SHTRH) method is established to analyze the nonlinear random heterogeneous materials with multiple micro-configurations. Firstly, the various unit cell functions based on the microscale and mescoscale regions are given, and two expected homogenization coefficients are computed through Kolmogorov’s strong laws of large number. Further, the nonlinear homogenized equations are formulated, and the corresponding reduced-order multiscale systems for displacement and stress solutions are derived by using the high-order unit cell solutions and homogenized solutions. The key features of the new statistical multiscale methods are (i) the novel reduced models established to solve the inelastic problems of random composites at a fraction of cost, (ii) the high-order homogenized solutions which do not need high-order continuity for the macro solutions of the random problems and (iii) the statistical high-order multiscale algorithms developed for analyzing the nonlinear random composites with three-scale structures. Finally, the effectiveness and correctness of the algorithm are confirmed according to several hyperelastic, plasticity and damage periodic/random composites with multiple-scale configurations. The computation shows that the proposed SHTRH methods are useful for analyzing the macroscopic nonlinear performance, and can efficiently catch the microscopic and mesoscopic information for the random heterogeneous composites.建立了一种有效的统计高阶三尺度简化均质化(SHTRH)方法来分析具有多种微观构型的非线性随机非均质材料。首先，给出了基于微尺度和中尺度区域的各种单体胞函数，并利用Kolmogorov强大数定律计算了两个期望的均匀化系数。在此基础上，建立了非线性均质化方程，并利用高阶单元胞解和均质化解导出了相应的降阶多尺度位移和应力解。新统计多尺度方法的主要特点是:(1)建立了新的简化模型，以较低的成本求解随机复合材料的非弹性问题;(2)随机问题宏观解的高阶均匀化解不需要高阶连续性;(3)开发了用于分析具有三尺度结构的非线性随机复合材料的统计高阶多尺度算法。最后，以多尺度结构的超弹性、塑性和损伤周期/随机复合材料为例，验证了算法的有效性和正确性。计算结果表明，所提出的SHTRH方法可用于分析随机非均质复合材料的宏观非线性性能，并能有效地捕获其微观和细观信息。Modeling plasticity-mediated void growth at the single crystal scale: A physics-informed machine learning approachKarl Garbrecht, Andrea Rovinelli, Jacob Hochhalter, Paul Christodoulou, Ricardo A. Lebensohn, Laurent Capolungodoi:10.1016/j.mechmat.2024.105151在单晶尺度上模拟塑性介导的空洞生长:一种物理信息的机器学习方法Modeling the evolution of voids during plastic flow as well as their effects on plastic dissipation is critical for both component manufacturing and lifetime estimation purposes. To this end, we propose a rate-dependent constitutive model to homogenize the effects of semi-randomly distributed voids on single crystal plasticity whilst capturing void interaction and plastic anisotropy. The present work focuses on the case of face centered cubic crystals to introduce an anisotropic gauge function applicable within the crystal plasticity formalism. The approach combines analytical methods to describe the micromechanics of the system in combination with symbolic regression to capture analytically intractable mechanisms from data. The hybrid framework uses a physics-informed genetic programming-based symbolic regression algorithm to solve a multiform optimization problem simultaneously producing a new gauge function and a new strain rate equation. This is also a multi-objective optimization problem with many competing objectives. A new search and selection step is introduced to the genetic algorithm that promotes convergence toward a global solution that better satisfies all the objectives. Overall, the symbolic equations produced leverage data-driven methods to achieve greater accuracy than comparable alternatives on an analytically intractable problem while maintaining model transparency.模拟塑性流动过程中空洞的演化及其对塑性耗散的影响对于部件制造和寿命估计都是至关重要的。为此，我们提出了一个速率相关的本构模型，以均匀化半随机分布的空洞对单晶塑性的影响，同时捕捉空洞相互作用和塑性各向异性。本文以面心立方晶体为例，介绍了一种适用于晶体塑性形式的各向异性规范函数。该方法结合了分析方法来描述系统的微观力学，并结合符号回归从数据中捕获分析难以处理的机制。该混合框架采用基于物理信息遗传规划的符号回归算法来解决多形式优化问题，同时产生新的规范函数和新的应变率方程。这也是一个有许多竞争目标的多目标优化问题。在遗传算法中引入了一个新的搜索和选择步骤，以促进收敛到一个更好地满足所有目标的全局解。总的来说，产生的符号方程利用数据驱动的方法，在保持模型透明度的同时，在分析棘手问题上获得比可比替代方案更高的准确性。Thin-Walled StructuresExperimental and theoretical studies on 3D printed short and continuous carbon fiber hybrid reinforced compositesXiangren Kong, Guangyong Sun, Quantian Luo, Veniamin Brykin, Jin Qiandoi:10.1016/j.tws.2024.112406 3D打印短连续碳纤维混杂增强复合材料的实验与理论研究3D-printed carbon fiber composites hold significant potential in aerospace applications because of their lightweight, high strength and complex structure fabrication capabilities. However, additive manufacturing characteristics such as high porosity, anisotropy and continuous fiber content significantly affect the mechanical properties of printed parts. The aim of this study is to investigate the influence of hybrid printing of short and continuous carbon fibers on the mechanical properties and failure mechanisms of composites and to develop a model to predict elastic properties considering porosity. First, mechanical testing and characterization of short and continuous fiber reinforced polyamide (nylon) print filaments are performed. The results indicate that the elastic modulus and ultimate strength of continuous carbon fiber filaments reach 60 GPa and 1500 MPa, respectively, while the strength and elastic modulus of short carbon fiber filaments reach 60 MPa and 1 GPa, respectively. Then tensile specimens with different continuous fiber orientations and different continuous fiber placement sequences are printed and tested using a multi-material 3D printing technique. The specimens are characterized before and after testing using scanning electron microscopy and microscopy to assess the porosity and failure mechanisms of specimens with different configurations. The results show that the mechanical properties of the printed parts are much lower than those of the print filaments, which proves the serious negative impact of the material extrusion process on the mechanical properties of the printed structural parts. Finally, an analytical method for predicting the elastic behavior of printed composites is developed by introducing the porosity factor in the volume-averaged stiffness model. For continuous and short fiber filled composites with different fiber contents and printing orientations, the predicted results are in agreement with the experiments, and the prediction error is greatly reduced from 30% to less than 5%.3d打印碳纤维复合材料由于其轻量化、高强度和复杂结构的制造能力，在航空航天应用中具有巨大的潜力。然而，增材制造的高孔隙率、各向异性和连续纤维含量等特性会显著影响打印件的力学性能。本研究的目的是研究短碳纤维和连续碳纤维混合打印对复合材料力学性能和破坏机制的影响，并建立考虑孔隙率的弹性性能预测模型。首先，对短纤维和连续纤维增强聚酰胺(尼龙)打印长丝进行了力学测试和表征。结果表明:连续碳纤维长丝的弹性模量和极限强度分别达到60 GPa和1500 MPa，短碳纤维长丝的强度和弹性模量分别达到60 MPa和1 GPa。然后采用多材料3D打印技术对不同连续纤维取向和不同连续纤维放置顺序的拉伸试样进行打印和测试。利用扫描电镜和显微镜对试验前后的试样进行表征，评估不同构型试样的孔隙率和破坏机制。结果表明，打印件的力学性能远低于打印长丝的力学性能，证明了材料挤压工艺对打印结构件力学性能的严重负面影响。最后，在体积平均刚度模型中引入孔隙率因子，提出了一种预测打印复合材料弹性性能的解析方法。对于不同纤维含量和打印方向的连续和短纤维填充复合材料，预测结果与实验结果吻合较好，预测误差从30%大大降低到5%以下。来源：复合材料力学仿真Composites FEM