【新文速递】2023年10月13日复合材料SCI期刊最新文章

今日更新：Composite Structures 4 篇，Composites Part A: Applied Science and Manufacturing 2 篇，Composites Part B: Engineering 4 篇，Composites Science and Technology 3 篇Composite StructuresMulti-patch isogeometric material optimization of bi-directional functionally graded platesWang Chao, Ma Liangliang, Bu Yang, Jie Zhao , Cheong Kang Haodoi:10.1016/j.compstruct.2023.117584双向功能分级板的多补丁等几何材料优化This study investigates an effective design methodology for the optimal material distribution of bi-directional functionally graded plates (2D-FGPs) with complex shape. In mechanical analysis, a multi-patch isogeometric method is used to analyze the statics of 2D-FGP, which is based on the third-order shear deformation theory and Nitsche’s technology. This method can effectively avoid the use of duplicate nodes in the parameterization of IGA for complex shapes to obtain C1-continuity of 2D-FGPs. In the optimal design problem, we have constructed a rectangular material design mesh (RMDM) based on the shape of 2D-FGPs, which can map the material distribution on the surface of plate to achieve the implementation of the optimization process. This two-dimensional B-spline control points of RMDM are set as the design variable with mass reduction and the first-order natural frequency maximization as optimization objectives, and limited arbitrary deflection as constraint conditions. In addition, an improved multi-objective particle swarm optimization algorithm (IMOPSO) is used to obtain a series of pareto optimization solutions that meet the needs of the designer. The validity and applicability of this innovative combination of multi-patch isogeometric analysis and IMOPSO are demonstrated through several numerical examples in integrated design. This approach further accomplishes the numerical unified CAD/CAE optimization design of 2D-FGPs across multiple non-smooth boundaries.本研究探讨了一种有效的设计方法，用于优化形状复杂的双向功能分级板（2D-FGP）的材料分布。在力学分析中，采用了基于三阶剪切变形理论和 Nitsche 技术的多补丁等几何方法来分析 2D-FGP 的静力学。该方法可有效避免在复杂形状的 IGA 参数化中使用重复节点，从而获得C1-2D-FGPs 的连续性。在优化设计问题中，我们根据 2D-FGPs 的形状构建了矩形材料设计网格（RMDM），它可以映射板表面的材料分布，从而实现优化过程的实施。以质量减小和一阶固有频率最大化为优化目标，以限制任意挠度为约束条件，将 RMDM 的二维 B 样条控制点设为设计变量。此外，还采用了改进的多目标粒子群优化算法（IMOPSO），以获得一系列符合设计者需求的帕累托优化解。通过几个综合设计中的数值示例，证明了这种创新性的多补丁等距几何分析和 IMOPSO 组合的有效性和适用性。这种方法进一步实现了跨越多个非光滑边界的 2D-FGP 数值统一 CAD/CAE 优化设计。Assembling Feather-like Reentrant Structures with Multiple Mechanical Properties Fabricated by Laser Powder Bed FusionLiu Ruiyao, Yao Guofeng, Zhang Jian, Yang Yanan, Xu Zezhou, Liu Yuting, Yu Zhenglei, ping Liang, Zhang Zhihui, Dong Lei, Han Chunyangdoi:10.1016/j.compstruct.2023.117599 利用激光粉末床熔融技术组装具有多种机械特性的羽毛状再入结构A new assembly design method for structural components is proposed. Inspired by the feathers of the grey crane, which have an energy dissipation effect, novel re-entrant scapus component and novel re-entrant double-crank component are proposed. Novel re-entrant structures are formed by assembling honeycomb structure (HS), poisson structure (PS), and chiral structure (CS). Laser powder bed fusion technology (LPBF) is utilized for the manufacturing of bio-inspired structures. And the impact of structural assembly on mechanical performance is comprehensively analyzed through experimental, numerical, and theoretical approaches. Euler theory is employed to predict the influence of bionic components on structural load trends, while explaining the relationship between compression load and deformation. Specifically, the average load capacity of bio-inspired scapus re-entrant structures and double-crank re-entrant structures exceeds that of their original designs by at least 55% and 13.2%, respectively. Moreover, specific energy absorption increases by a minimum of 8.6% and 3.4%, accompanied by improved heat dissipation performance in these structures. Finally, battery pack impact resistance models as well as thermal conductivity models for electric-powered vehicles are presented as examples to validate the potential application prospects of this novel bio-inspired re-entrant structure in engineering.提出了一种新的结构部件装配设计方法。受具有消能效应的灰鹤羽毛的启发，提出了新型重入式肩胛组件和新型重入式双曲柄组件。新型重入式结构由蜂窝结构（HS）、泊松结构（PS）和手性结构（CS）组装而成。激光粉末床熔融技术（LPBF）被用于制造生物启发结构。并通过实验、数值和理论方法全面分析了结构装配对力学性能的影响。采用欧拉理论预测仿生组件对结构载荷趋势的影响，同时解释压缩载荷与变形之间的关系。具体来说，受生物启发的肩胛骨再入式结构和双曲柄再入式结构的平均承载能力分别比原始设计高出至少 55% 和 13.2%。此外，这些结构的比能量吸收至少增加了 8.6% 和 3.4%，同时散热性能也得到了改善。最后，以电动汽车的电池组抗冲击模型和导热模型为例，验证了这种新型生物启发再入式结构在工程中的潜在应用前景。Design, FDM printing, FE and Theoretical Analysis of ABS Auxetic Structures Consisting of Arc-shaped and Dumbell-shaped Struts under Quasi-Static LoadingEtemadi Ehsan, Hosseinabadi Mahbubeh, Scarpa Fabrizio, Hu Hongdoi:10.1016/j.compstruct.2023.117602准静态载荷下由弧形和哑铃形支柱组成的 ABS 辅助结构的设计、FDM 印刷、有限元分析和理论分析This paper presents the design, 3D printing, and testing of this novel type of auxetic structure formed with arc-shaped unit-cells (UCs). The mechanical behavior of two different re-entrant Dumbell (RED) and Multiple-Arc structures are evaluated. The metamaterials are fabricated using 3D printing via Fused Deposition Modeling (FDM) techniques. Quasi-static compressive loading tests are performed on these metamaterials, and the results are verified using Finite Element (FE) simulation and theoretical analysis. The results of the study reveal that the RED configuration, which includes Dumbell-shaped struts that exhibit negative Poisson’s ratio (NPR) themselves, outperforms the Multiple-Arc, the traditional re-entrant circular (REC), and conventional re-entrant auxetic structures in terms of specific stiffness (Es) specific energy absorption (SEA) and NPR values. In addition, the effects of the geometry parameters, including strut thickness to height ratio, length to height ratio, and angle of Dumbell strut on the SEA and NPR values of the RED structure, are investigated. The findings indicated that the SEA values improved as the thickness-to-height ratio and Dumbell strut angle increased, and the length-to-height ratio decreased. Additionally, the NPR value showed enhancement with increased thickness-to-height ratio and Dumbell strut angle. However, the thickness-to-height ratio did not significantly influence the NPR value.本文介绍了这种由弧形单元（UC）形成的新型辅助结构的设计、三维打印和测试。本文评估了两种不同的再入哑铃（RED）和多弧结构的机械行为。超材料是通过熔融沉积建模（FDM）技术使用三维打印技术制造的。对这些超材料进行了准静态压缩加载测试，并使用有限元（FE）模拟和理论分析对结果进行了验证。研究结果表明，RED 配置（包括本身表现出负泊松比 (NPR) 的 Dumbell 形支柱）在比刚度 (Es) 比能量吸收 (SEA) 方面优于多重弧形结构、传统重入圆形结构 (REC) 和传统重入辅助结构的比刚度（Es）、比能量吸收（SEA）和 NPR 值均优于多弧形结构、传统重入式圆形结构（REC）和传统重入式辅助结构。此外，还研究了几何参数（包括支柱厚度与高度比、长度与高度比以及 Dumbell 支柱角度）对 RED 结构的 SEA 值和 NPR 值的影响。研究结果表明，随着厚度与高度比和 Dumbell 支杆角度的增加，SEA 值有所提高，而长度与高度比则有所降低。此外，NPR 值随着厚度-高度比和 Dumbell 支杆角度的增加而增加。然而，厚度-高度比对 NPR 值没有明显影响。Practical application of multi-material topology optimization to performance-based architectural design of an iconic buildingLi Yu, Ding Jiemin, Zhang Zheng, Zhou Xinjie, Makvandi Mehdi, Yuan Philip F., Min Xie Yidoi:10.1016/j.compstruct.2023.117603多材料拓扑优化在标志性建筑性能建筑设计中的实际应用With the rapid development of architectural design methods and structural analysis techniques, structural performance-based design approaches have become increasingly important in architectural design. Among these approaches, topology optimization is a significant design method. However, most existing topology optimization research and related applications are based on single-material topology optimization techniques, which have limitations when applied to the design of complex and challenging structures. Building upon our previously proposed multi-material bi-directional evolutionary structural optimization (multi-material BESO) method, this paper presents the approaches for achieving diverse and competitive structural designs and then presents a practical application of the multi-material BESO method to the structural design of the core structure of a long-cantilevered building project called “Xiong’an Wings”. After an evolutionary design process based on the multi-material BESO method, an efficient frame with lower overall material costs, better static and dynamic performance compared to the initial design by experienced engineers is achieved. As the first practical application of the multi-material BESO method to a large-scale architectural design, the example of the “Xiong’an Wings” building demonstrates the tremendous prospects for the application of multi-material topology optimization technology to the generative design of innovative and efficient building structures.随着建筑设计方法和结构分析技术的快速发展，基于结构性能的设计方法在建筑设计中变得越来越重要。在这些方法中，拓扑优化是一种重要的设计方法。然而，现有的拓扑优化研究和相关应用大多基于单一材料拓扑优化技术，在应用于复杂和具有挑战性的结构设计时存在局限性。本文以我们之前提出的多材料双向进化结构优化（multi-material BESO）方法为基础，介绍了实现多样化和有竞争力的结构设计的方法，并将多材料双向进化结构优化方法实际应用于一个名为 "雄安之翼 "的长悬臂建筑项目的核心结构设计中。经过基于多材料 BESO 方法的演化设计过程，与经验丰富的工程师的初始设计相比，实现了总体材料成本更低、静态和动态性能更好的高效框架。作为多材料 BESO 方法在大型建筑设计中的首次实际应用，"雄安之翼 "建筑的实例展示了多材料拓扑优化技术在创新和高效建筑结构生成设计中的巨大应用前景。Composites Part A: Applied Science and ManufacturingTemperature-dependent cutting physics in orthogonal cutting of carbon fibre reinforced thermoplastic (CFRTP) compositeGe Jia, Tan Wei, Ahmad Shahzad, Falzon Brian G., Catalanotti Giuseppe, Higgins Colm, Jin Yan, Sun Dandoi:10.1016/j.compositesa.2023.107820碳纤维增强热塑性塑料 (CFRTP) 复合材料正交切削中与温度相关的切削物理现象The global commitment towards reducing carbon emissions drives the implementation of sustainable carbon-fibre-reinforced-thermoplastic composites (CFRTPs). However, the machining of CFRTPs presents challenges due to the material’s ductile-brittle composition and sensitivity to machining-induced high temperatures. For the first time, we conducted temperature-controlled orthogonal cutting of CFRTP (using CF/PEKK as a demonstrator) to unveil its temperature-dependent cutting physics. Three representative cutting temperatures, 23 ℃ (ambient temperature),100 ℃ (< PEKK’s glass transition temperature (Tg)) and 200 ℃ (>Tg) and four typical fibre cutting orientations (0°, 45°, 90°, and 135°) have been investigated. The evolution of chip microstructural morphology and surface/subsurface damage have been analysed by advanced microscopy to reveal temperature-dependent material removal mechanisms. The experimental results were elucidated through a novel microscale finite-element-analysis (FEA) model considering thermal softening of the matrix and interface. Results show the transition of the cutting physics with increasing temperature is associated to the degradation of the thermoplastic matrix stiffness/ultimate strength and interface bonding strength and fracture toughness, especially when >Tg.全球致力于减少碳排放，这推动了可持续碳纤维增强热塑性复合材料（CFRTP）的应用。然而，由于碳纤维增强热塑性复合材料具有韧性-脆性成分，并且对加工引起的高温非常敏感，因此加工这种材料面临着挑战。我们首次对 CFRTP 进行了温控正交切削（使用 CF/PEKK 作为示范材料），以揭示其与温度相关的切削物理特性。我们研究了三种代表性的切割温度：23 ℃（环境温度）、100 ℃（< PEKK 的玻璃化转变温度 (Tg)）和 200 ℃（>Tg），以及四种典型的纤维切割方向（0°、45°、90° 和 135°）。通过先进的显微镜分析了切屑微观结构形态和表面/次表面损伤的演变，揭示了与温度相关的材料去除机制。实验结果通过一个考虑到基体和界面热软化的新型微尺度有限元分析（FEA）模型进行了阐释。结果表明，随着温度的升高，切削物理效应的转变与热塑性基体刚度/最终强度、界面结合强度和断裂韧性的下降有关，尤其是当温度大于 Tg 时。Estimation of axial compressive strength of unidirectional carbon fiber-reinforced plastic considering the variability of fiber misalignmentUeda Masahito, Suzuki Yuki, Pinho Silvestre Tdoi:10.1016/j.compositesa.2023.107821考虑纤维错位变化的单向碳纤维增强塑料轴向抗压强度估算The analytical method to calculate the axial compressive stress-strain relation of a unidirectional carbon fiber-reinforced plastic (UD CFRP) was presented considering the variability of the fiber misalignment angle. Because the compressive load-bearing capability of fibers surrounded by a matrix was different depending on the fiber misalignment angle, fibers were grouped based on the misalignment angle. The contribution to the load bearing was calculated and summed based on the area ratio of the fiber groups. All fibers supported a compressive load in the initial loading. However, with increased loading, the load-bearing capabilities of the different fiber groups decreased more dramatically with greater misalignment angles. The fibers with a misalignment angle of 0.5° showed a large load drop after their maximum loading, which triggered the ultimate failure. The variability of the fiber misalignment angle was indispensable to determining the axial compressive strength under the assumption of zero mean fiber misalignment angle.考虑到纤维错位角的变化，提出了计算单向碳纤维增强塑料（UD CFRP）轴向压缩应力-应变关系的分析方法。由于纤维错位角不同，被基体包围的纤维的压缩承载能力也不同，因此根据错位角对纤维进行了分组。根据纤维组的面积比计算出纤维对承重的贡献并求和。在初始加载时，所有纤维都能承受压缩载荷。然而，随着荷载的增加，不Composites Part B: EngineeringThree-dimensional modeling of frontal polymerization for rapid, efficient, and uniform thermoset composites manufacturingTarafdar Amirreza, Jia Chen, Hu Weifei, Hosein Ian D., Fu Kun (Kelvin), Wang Yeqingdoi:10.1016/j.compositesb.2023.111029正面聚合的三维建模，实现快速、高效和均匀的热固性复合材料制造Due to the incapability of one-dimensional (1D) and two-dimensional (2D) models in simulating the frontal polymerization (FP) process in laminated composites with multiple fiber angles (e.g., cross-ply, angle-ply), modeling a three-dimensional (3D) domain, which is more representative of practical applications, provides critical guidance in the control and optimization of the FP process. In this paper, subroutines are developed to achieve the 3D modeling of FP in unidirectional and cross-ply carbon fiber laminates with finite element analysis, which are validated against the experimental data. The 3D model is employed to study the effect of triggering direction in relevance to the fiber direction on the FP process, which cannot be studied using traditional 1D/2D models. Our findings suggest that triggering in the fiber direction leads to a higher front velocity, in comparison to cases where front was triggered in the direction perpendicular to the fiber. Moreover, the average front velocity in cross-ply laminates is on average 20–25% lower than that in unidirectional laminates. When triggered using two opposite fronts in the in-plane direction, the maximum temperature of the thermal spike in the cross-ply laminate, when two fronts merge, is about 100 °C lower than that in the unidirectional laminate. In cross-ply laminates, a sloped pattern forms across the thickness direction as the front propagates in the in-plane direction, as opposed to the traditionally observed uniform propagation pattern in unidirectional cases. Furthermore, the effect of thermal conductivity is studied using two additional composite laminates with glass (1.14 W/m·K) and Kevlar fibers (0.04 W/m·K). It is shown that the frontal velocity, degree of cure, and the thermal spike temperature decrease as the thermal conductivity reduces.由于一维（1D）和二维（2D）模型无法模拟多角度纤维（如交叉层、角层）层压复合材料的正面聚合（FP）过程，因此建立更能代表实际应用的三维（3D）域模型可为 FP 过程的控制和优化提供重要指导。本文开发了子程序，通过有限元分析实现了单向和交叉层碳纤维层压板中 FP 的三维建模，并与实验数据进行了验证。三维模型用于研究触发方向与纤维方向的相关性对 FP 过程的影响，而传统的一维/二维模型无法研究这些影响。我们的研究结果表明，与在垂直于纤维的方向上触发前沿相比，在纤维方向上触发前沿会导致更高的前沿速度。此外，交叉层压板的平均前沿速度比单向层压板平均低 20-25%。在平面方向上使用两个相反的锋面触发时，当两个锋面合并时，交叉层压板中热尖峰的最高温度比单向层压板低约 100 °C。在交叉层压板中，锋面沿平面方向传播时，在整个厚度方向上会形成一个倾斜的图案，而在单向层压板中，传统上观察到的是均匀的传播图案。此外，我们还使用玻璃纤维（1.14 W/m-K）和凯夫拉纤维（0.04 W/m-K）两种额外的复合层压板研究了导热系数的影响。结果表明，随着导热系数的降低，正面速度、固化程度和热尖峰温度都会降低。Excellent thermal stability of nanostructured Al2O3–Y3Al5O12–ZrO2 eutectic ceramic composites by high-speed directional solidificationZhao Di, Su Haijun, Hao Shuqi, Shen Zhonglin, Liu Yuan, Guo Yinuo, Yang Peixin, Zhang Zhuo, Guo Mindoi:10.1016/j.compositesb.2023.111035通过高速定向凝固获得热稳定性极佳的纳米结构 Al2O3-Y3Al5O12-ZrO2 共晶陶瓷复合材料The contradiction between the nanostructure and thermal stability is the major obstacle on the way of the practical applications of nanomaterials. Here we demonstrated a simple solution for reconciling this contradiction, i.e., the high-speed directional solidification of a ternary eutectic ceramic composite. Its highly textured lamellar and rod-like nanostructures and low-energy interfaces contributed to an outstanding thermal stability that the nanostructure was maintained after being heated at 1573 K for 100 h. It was uncovered that the high solidification rate of 1080 mm/h had an evident restriction on the growth orientation of the faceted crystals during the solidification process, forming a highly textured nanostructure. Combining with the interface energy minimization mechanism, the low-energy interfaces were simultaneously obtained. The evolution of microstructure and interface characteristics during the coarsening process at the higher temperature was further studied. The lamellar structure presented a better thermal stability than that of the rod-like structure since the former had a constraint on the diffusion dimensions. Moreover, a novel structural evolution pattern in the coarsening process was revealed, which was completely different from that of traditional sintered ceramics. The solidified specimens could further keep stable in density, homogeneity of structure and size of internal pores during heat treatment, contributing to a better stability in hardness than that of traditional sintered specimens.纳米结构与热稳定性之间的矛盾是纳米材料实际应用道路上的主要障碍。在这里，我们展示了调和这一矛盾的简单解决方案，即三元共晶陶瓷复合材料的高速定向凝固。它的高纹理片状和棒状纳米结构以及低能界面使其具有出色的热稳定性，在 1573 K 下加热 100 小时后，纳米结构仍能保持稳定。研究发现，在凝固过程中，1080 mm/h 的高凝固速率明显限制了面状晶体的生长取向，从而形成了高纹理纳米结构。结合界面能量最小化机制，同时获得了低能量界面。研究人员进一步研究了在较高温度下粗化过程中微观结构和界面特征的演变。片状结构的热稳定性优于棒状结构，因为前者对扩散尺寸有限制。此外，在粗化过程中还发现了一种新的结构演变模式，与传统的烧结陶瓷完全不同。固化试样在热处理过程中能进一步保持密度、结构均匀性和内部孔隙大小的稳定，从而使其硬度稳定性优于传统烧结试样。Experiment and numerical Investigation of the intra-ply shear behaviour of unidirectional prepreg forming through picture-frame testYuan Hao, Khan Muhammad, Qian Connie, Reynolds Neil, Kendall Kennethdoi:10.1016/j.compositesb.2023.111036通过画框试验对单向预浸料成型层内剪切行为的实验和数值研究Intra-ply shear behaviour of uncured composite plies strongly influences component quality in advanced manufacturing processes such as prepreg compression moulding (PCM) and double diaphragm forming (DDF). This study investigates a straightforward method to characterise the intra-ply shear behaviour of a carbon fibre/epoxy UD prepreg using a specially designed picture-frame rig, by which specimens can be tested without involving inter-ply shear as would normally be observed in cross-plied UD prepreg stacks. Applying the proposed method, it is seen that specimens tend to suffer transverse buckling/wrinkling and local fibre-splitting at large shear strains. 3D digital image correlation (DIC) and a non-contacting video extensometer were utilised to determine the shear strain distribution throughout the test and particularly to determine the onset of out-of-plane deformations such that the trellis shear deformation portion of the test can be identified. The obtained shear stress-strain results show a temperature- and rate-dependent viscoelastic response, with the greatest influence from the temperature. The obtained in-plane shear properties were applied in the numerical simulation of the picture frame test based on a hypoelastic law. Although the predicted reaction forces are greater than experimental results at high strains due several factors including local fibre-splitting, a good agreement overall between physical test data and simulation results is seen for all test conditions. Finally, it is demonstrated that major advantages of the proposed test with respect to the conventional picture-frame test are that only load-extension data are required from the trellis shear experiment to calculate accurately the intra-ply shear stress-strain relationship and that the deformation rate can be easily controlled.在预浸料压缩成型（PCM）和双隔膜成型（DDF）等先进制造工艺中，未固化复合材料层的层内剪切行为对部件质量有很大影响。本研究使用专门设计的画框钻机，研究了一种表征碳纤维/环氧 UD 预浸料层内剪切行为的直接方法，通过这种方法可以对试样进行测试，而无需像通常在交叉层 UD 预浸料堆栈中观察到的那样进行层间剪切。应用所提出的方法可以发现，试样在受到较大剪切应变时往往会出现横向屈曲/皱缩和局部纤维断裂。利用三维数字图像相关（DIC）和非接触式视频拉伸计确定了整个试验过程中的剪切应变分布，特别是确定了平面外变形的起始点，从而确定了试验中的大棚剪切变形部分。所获得的剪应力-应变结果显示了与温度和速率相关的粘弹性响应，其中温度的影响最大。所获得的平面内剪切特性被应用于基于低弹性定律的画框试验数值模拟。虽然在高应变时，由于包括局部纤维分裂在内的一些因素，预测的反作用力大于实验结果，但在所有试验条件下，物理试验数据与模拟结果之间的总体一致性都很好。最后，实验证明，与传统的画框试验相比，所提议的试验的主要优点是：只需要从棚架剪切实验中获得载荷-拉伸数据，就能准确计算层内剪切应力-应变关系，而且变形速率易于控制。Formability, densification behavior and hierarchical grain structure of laser-directed energy deposition of TiB reinforced titanium matrix compositesLiu Huaqiang, Han Junzhu, Han Yuanfei, Fang Minhan, Wang Xiaoyan, Huang Guangfa, Lu Weijiedoi:10.1016/j.compositesb.2023.111039激光定向能沉积 TiB 增强钛基复合材料的成型性、致密化行为和分层晶粒结构Achieving the homogenous microstructural features and the high strength-ductility is significant considerations for the additively manufactured titanium alloys, but it was still limited to its huge columnar β grains (>1 mm). Designing equiaxed grain is still a critical method to overcome these challenges. This work successfully in-situ developed 5 vol% TiB reinforced titanium matrix composites (TMCs) with tailorable columnar to equiaxed grain transition (CET) and network structures through controlling laser energy densities (Ev) of the laser-directed energy deposition (L-DED) process. The deposited TMCs (230.8 J/mm3) showed the highest relative density of 97.683%. The sufficient Ev (∼250.0 J/mm3) induced the significant CET and the large hierarchical networks (41 μm). The 5 vol%TiB dramatically reduced the β grain by 153 μm, obtaining a refined grain size of 29.8–42.5 μm. TiB/α-Ti interfaces exhibited the favorable bonding and presented the uniform strain distribution without noticeable strain gradient. This work obtained the highest ultimate tensile strength of 1138 MPa (176.4 J/mm3) and remained an acceptable ductility. The good strength-ductility synergy was achieved at the Ev of 230.8 J/mm3 due to the high densification and the CET. The grain refinement was mainly responsible for the excellent strength of TMCs. The CET coupled with hierarchical coarsening networks were advantageous for improving ductility at high level of Ev (≥230.8 J/mm3). This study confirmed that changing solidification condition could further induce the significant CET of the additively manufactured TiB/Ti6Al4V composites.实现均匀的微观结构特征和高强度-电导率是添加剂制造钛合金的重要考虑因素，但它仍然受限于巨大的柱状 β 晶粒（大于 1 毫米）。设计等轴晶粒仍然是克服这些挑战的关键方法。这项研究通过控制激光能量密度（Ev）。沉积的 TMCs（230.8 J/mm3）相对密度最高，达到 97.683%。足够的 Ev（∼250.0 J/mm3）产生了显著的 CET 和大的分层网络（41 μm）。5 vol%TiB 显著减少了 153 μm 的 β 晶粒，获得了 29.8-42.5 μm 的细化晶粒尺寸。TiB/α-Ti 界面表现出良好的结合，应变分布均匀，没有明显的应变梯度。这项研究获得了 1138 兆帕（176.4 焦耳/立方毫米）的最高极限拉伸强度，并保持了可接受的延展性。在 Ev 为 230.8 J/mm3 时实现了良好的强度-电导率协同作用，这归功于高密度化和 CET。晶粒细化是 TMCs 具有优异强度的主要原因。CET 与分层粗化网络的结合有利于在高 Ev (≥230.8 J/mm3)时对提高延展性具有优势。这项研究证实，改变凝固条件可进一步诱导添加制造的 TiB/Ti6Al4V 复合材料产生显著的 CET。Composites Science and TechnologySustainable green composite of yam and agricultural waste corn stalk fiber with good mechanical, thermal, optical, aging performance and excellent biodegradabilityPoudel Raghav, Karak Niranjandoi:10.1016/j.compscitech.2023.110276 具有良好机械、热、光、老化性能和优异生物降解性的山药和农业废弃物玉米秆纤维可持续绿色复合材料Sustainable green composites with safe biodegradability produced using environmentally benign materials are required as modern-day alternatives for harmful synthetic materials. Agricultural waste such as corn stalks and underutilized natural polymer sources such as yam are significant potential candidates in this regard. In our work, a green composite of yam and alkali-treated corn stalk fiber was prepared through a simple solution casting and oven-drying method. The successfully prepared green composites displayed good mechanical and thermal properties as the corn stalk fibers effectively reinforced the yam bioplastic matrix. Spectral studies such as FTIR, SEM, and p-XRD confirmed the probable structural changes and formation of the composites. Prepared green composites possessed high resistance and good thermal (−2 °C and 70 °C), UV (254 nm for 180 h), and chemical aging properties along with low moisture absorption behavior. Further, the green composites showed excellent biodegradable nature under normal environmental conditions. Thus, potentially capable green composite for applications in packaging, biomedical, automobile, and construction sectors was reported here.作为有害合成材料的现代替代品，需要使用对环境无害的材料生产出具有安全生物降解性的可持续绿色复合材料。在这方面，玉米秸秆等农业废弃物和山药等未充分利用的天然聚合物资源是重要的潜在候选材料。在我们的工作中，通过简单的溶液浇铸和烘箱干燥法制备了山药和碱处理过的玉米秸秆纤维的绿色复合材料。由于玉米秸秆纤维有效地增强了山药生物塑料基体，因此成功制备的绿色复合材料显示出良好的机械和热性能。傅立叶变换红外光谱、扫描电子显微镜和 p-XRD 等光谱研究证实了复合材料的可能结构变化和形成。制备的绿色复合材料具有较高的抗性和良好的耐热（-2 °C和70 °C）、耐紫外线（254 纳米，180 小时）和化学老化性能，同时吸湿性较低。此外，绿色复合材料在正常环境条件下具有极佳的生物降解性。因此，这种绿色复合材料有望应用于包装、生物医学、汽车和建筑领域。High mechanical performance short carbon fiber reinforced polyetherimide composites via solution mixing processLiu Quan-Xiu, Zhang Yuan-Yuan, Sun Zheng, Li Yuan-Qing, Guan Bo-Wen, Guan Tao, Fu Yu-Tong, Mo Xiao-Long, Fu Shao-Yundoi:10.1016/j.compscitech.2023.110296 通过溶液混合工艺实现高机械性能短碳纤维增强聚醚酰亚胺复合材料Proper preparation processes of short fiber reinforced thermoplastics are critical to achieving high residual fiber lengths in final composites, which in turn greatly influences the mechanical properties of short fiber reinforced polymers. In this work, the injection molding process was respectively combined with conventional extrusion compounding and a newly developed solution mixing process to fabricate short carbon fiber (SCF) reinforced polyetherimide (PEI) composites. Carbon fiber-filled PEI master batches were prepared for injection molding respectively by conventional extrusion compounding (denoted by CE-MB) and solution mixing process (denoted by SM-MB) diluted with PEI powders. Afterwards, the corresponding two types of composites (SCF/PEIE and SCF/PEIS + D) were prepared by injection molding. Compared with the SCF/PEIE composites, the SCF/PEIS + D composites exhibit significantly enhanced mechanical performances due to greatly higher residual fiber lengths in final composites. As a result, the 20 vol fraction (vol%) SCF/PEIS + D composite obtained shows a record high tensile strength of 239.6 MPa for injection molded PEI composites. Moreover, it is worth mentioning that the tensile strength of the SCF/PEIS + D composite with only 5 vol% SCFs is even higher than that of the SCF/PEIE composite with 25 vol% SCFs. Consequently, the injection molding process combined with the newly proposed solution mixing process is promising to replace the conventional extrusion process for developing high mechanical performance short fiber reinforced high-performance thermoplastic composites, particularly for the cases with low to medium fiber contents (≤25 vol%).短纤维增强热塑性塑料的适当制备工艺对于在最终复合材料中获得较高的残余纤维长度至关重要，而残余纤维长度反过来又会极大地影响短纤维增强聚合物的机械性能。在这项工作中，注塑成型工艺分别与传统的挤出复合工艺和新开发的溶液混合工艺相结合，制造出短碳纤维（SCF）增强聚醚酰亚胺（PEI）复合材料。碳纤维填充聚醚酰亚胺（PEI）母料分别采用传统的挤出共混工艺（CE-MB）和溶液混合工艺（SM-MB）制备，并用聚醚酰亚胺（PEI）粉末稀释后注塑成型。然后，通过注射成型制备出相应的两种复合材料（SCF/PEIE 和 SCF/PEIS + D）。与 SCF/PEIE 复合材料相比，SCF/PEIS + D 复合材料由于最终复合材料中的残余纤维长度大大增加，因此机械性能显著提高。因此，20 体积分数（vol%）的 SCF/PEIS + D 复合材料的拉伸强度达到了注塑成型 PEI 复合材料的最高纪录 239.6 MPa。此外，值得一提的是，仅含有 5 Vol% SCFs 的 SCF/PEIS + D 复合材料的拉伸强度甚至高于含有 25 Vol% SCFs 的 SCF/PEIE 复合材料。因此，在开发高机械性能的短纤维增强高性能热塑性复合材料时，注塑成型工艺结合新提出的溶液混合工艺有望取代传统的挤出工艺，特别是在中低纤维含量（≤25 vol%）的情况下。Quantification of damage expansion influence on frequency response function of plate for structural health monitoring with integral differential methodWen Tao, Narita Fumio, Kurita Hiroki, Jia Yu, Shi Yudoi:10.1016/j.compscitech.2023.110298 利用积分微分法量化损伤扩展对板材频率响应函数的影响，用于结构健康监测This paper presents a feasibility study on damage size quantification throughout the damage expansion procedure using the integral differential method based on the developed frequency response function (FRF) programme. A designed pattern of piezoelectric Micro Fibre Composite (MFC) transducers was integrated with three composite panels for a real time monitoring testing by swept sine vibration input signals under three varied frequency bandwidths ranged from 10–1kHz, 1k-3kHz and 3k-5kHz, respectively. The composite panels under pristine stage without any impact damages were tested and documented as a cross-reference for subsequent quantification estimation. The damages were introduced around transducers array, and its expansion process is equivalently simulated by a repetitive impact test procedure. A modified damage index, difference of response (DoR), was derived through integral differential method to assess the FRF outcome change of damaged composite plate relative to the pristine state. Combined with damage geometrical dimensions measured by thermography imaging technology, a quantification formula is derived reversely through numerical analysis, which showed a segmentation linear relation between the DoR and damage size governed by the power and logarithmic functions. The damages under different severity subjected to an additional composite plate were successfully quantified by the segmentation formula, which validate the feasibility of quantification with DoR.本文基于开发的频率响应函数（FRF）程序，采用积分微分法对整个损伤扩展过程中的损伤大小量化进行了可行性研究。设计的压电微纤维复合材料（MFC）传感器图案与三块复合板集成在一起，分别在 10-1kHz、1k-3kHz 和 3k-5kHz 三种不同频率带宽下通过正弦振动扫频输入信号进行实时监测测试。复合材料板在原始状态下没有受到任何撞击损坏，我们对其进行了测试和记录，作为后续量化估算的交叉参考。在传感器阵列周围引入损伤，并通过重复冲击测试程序模拟其扩展过程。通过积分微分法得出了修正的损伤指数--响应差异（DoR），以评估受损复合板相对于原始状态的 FRF 结果变化。结合热成像技术测量的损伤几何尺寸，通过数值分析反向推导出量化公式，结果表明 DoR 与损伤大小之间存在幂函数和对数函数支配的分段线性关系。利用分段公式成功量化了附加复合板上不同严重程度的损伤，验证了利用 DoR 进行量化的可行性。同纤维组的承载能力随着错位角度的增大而急剧下降。错位角为 0.5°的纤维在承受最大荷载后，荷载下降幅度较大，从而导致最终失效。在平均纤维错位角为零的假设条件下，纤维错位角的变化对于确定轴向抗压强度是不可或缺的。来源：复合材料力学仿真Composites FEM