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 1 篇
Design and evaluation of TPMS-inspired 3D-printed scaffolds for bone tissue engineering: enabling tailored mechanical and mass transport properties
Li Zhitong, Chen Zhaobo, Chen Xiongbiao, Zhao Runchao
doi:10.1016/j.compstruct.2023.117638
设计和评估用于骨组织工程的受 TPMS 启发的 3D 打印支架:实现量身定制的机械和质量传输特性
Bone scaffolds in tissue engineering are used to provide mechanical support and facilitate bone regeneration. For this, mechanical and mass transport properties are of critical importance, yet compromised, to scaffold performance and remain to be solved. Herein, we propose novel strut-based scaffolds and design strategies that enable independent tailoring of topological, mechanical and mass transport properties. Scaffolds with different design parameters were characterized in terms of mechanical and mass transport properties through simulation analysis, and then they were fabricated by 3D printing for experimental verification. The simulation and experimental results showed that the proposed scaffolds exhibit controllable deformation modes and mass transport characteristics. The elastic modulus (0.58-4.12 GPa) and permeability (0.96×10-7-3.47×10-7 m2) of the designed structures fully meet the range of cancellous bone in existing literature. Moreover, we demonstrated that our designs enable scaffolds to decouple and individually tailor multi-physics properties at a given porosity, thus expanding the performance regulation space and providing guidance for designing scaffolds with desired properties.
组织工程中的骨支架用于提供机械支撑和促进骨再生。为此,机械和质量传输特性对支架性能至关重要,但却受到影响,仍有待解决。在此,我们提出了基于支柱的新型支架和设计策略,可实现拓扑、机械和质量传输特性的独立定制。通过仿真分析,对不同设计参数的支架进行了力学和质量传输性能表征,然后通过三维打印制作支架并进行实验验证。模拟和实验结果表明,所提出的支架具有可控的变形模式和质量传输特性。设计结构的弹性模量(0.58-4.12 GPa)和渗透率(0.96×10-7-3.47×10-7 m2)完全符合现有文献中松质骨的范围。此外,我们还证明了我们的设计能使支架在给定孔隙率下解耦并单独定制多物理特性,从而扩大了性能调节空间,并为设计具有所需特性的支架提供指导。
Thermal-field analytical modeling of machined surface layer in high-speed-dry milling UD-CF/PEEK considering thermal anisotropy and nonlinear thermal conductivity
Liu Lei, Qu Da, Wang Jiacheng, Zhang Jin, Cao Huajun, Dong Xin
doi:10.1016/j.compositesa.2023.107864
考虑热各向异性和非线性导热性的 UD-CF/PEEK 高速干铣加工表面层热场分析模型
The high-speed-dry (HSD) machining is now recognized as a strong potential dry-cutting technique to tackle the rapidly growing productivity demand of carbon-fiber-reinforced-polyetheretherketone (CF/PEEK). The thermal-field is an essential breakthrough for eliminating the severe thermal effect of cutting temperature beyond CF/PEEK glass transition temperature Tg. However, the anisotropy and temperature-sensitive thermal conductivity of CF/PEEK lead to great challenges in thermal analytical modeling. Addressing this issue, a novel thermal-field analytical model that incorporates fiber orientation-dominated thermal anisotropy is developed to investigate the thermal field of machined surface layer for unidirectional (UD) CF/PEEK HSD milling, where the nonlinear thermal conductivity of CF/PEEK are imported into this model. With experiment verification, the thermal-field model can forecast the spatio-temporal distribution of workpiece temperature. Then, the thermal mechanisms of fiber orientations and milling parameters are clarified to restrict workpiece temperature within the Tg for limited thermal damage and reveal the feasibility essence of CF/PEEK HSD milling.
高速干式(HSD)加工是目前公认的一种潜力巨大的干式切削技术,可满足碳纤维增强聚醚醚酮(CF/PEEK)快速增长的生产率需求。热场是消除切割温度超过 CF/PEEK 玻璃转变温度 Tg 所产生的严重热效应的一个重要突破。然而,CF/PEEK 的各向异性和对温度敏感的热导率给热分析建模带来了巨大挑战。针对这一问题,我们开发了一种新型热场分析模型,该模型结合了纤维取向主导的热各向异性,用于研究单向 (UD) CF/PEEK HSD 铣削加工表面层的热场,并将 CF/PEEK 的非线性热导率导入该模型。通过实验验证,热场模型可以预测工件温度的时空分布。然后,阐明了纤维取向和铣削参数的热机理,从而将工件温度限制在 Tg 以限制热损伤,并揭示了 CF/PEEK HSD 铣削的可行性本质。
Eco-friendly, high-utilization, and easy-manufacturing bamboo units for engineered bamboo products: Processing and mechanical characterization
Huang Bin, Chen Lin, Wang Xianke, Ma Xinxin, Liu Huanrong, Zhang Xiubiao, Sun Fengbo, Fei Benhua, Fang Changhua
doi:10.1016/j.compositesb.2023.111073
用于竹制工程产品的生态友好型、高利用率和易于制造的竹单元:加工和机械特性分析
Bamboo units used for manufacturing engineered bamboo products are typically processed by breaking and planing, resulting in products with high glue content, substantial costs, and adverse environmental impacts. To address these issues, a simple and effective approach for processing standard bamboo units, based on the natural form and structure of bamboo, is proposed and tested in this study. More specifically, bamboo splits were dried at 0.05 MPa pressure and 140 °C for about 2.5 h in a pressurizing device. After drying, the bamboo splits each formed an equal-arc shaped bamboo split (EASB) in which the inner and outer radii were roughly equal. The EASB unit represents a double breakthrough of a high material utilization rate (as high as 80%) and low damage to bamboo. Additionally, the appropriate drying technique improves the dimensional stability and retains the excellent mechanical properties of natural bamboo. This work demonstrates the concept of “natural form inspired design,” and the EASB provides a basis for wider applications of sustainable engineered bamboo products.
用于制造竹制工程产品的竹材通常是通过打碎和刨削加工而成的,这导致产品含胶量高,成本高昂,并对环境造成不利影响。为解决这些问题,本研究根据竹子的自然形态和结构,提出并测试了一种简单有效的标准竹材加工方法。具体而言,竹片在 0.05 兆帕压力和 140 °C 的加压装置中干燥约 2.5 小时。干燥后,竹片各自形成一个内外半径大致相等的等弧形竹片(EASB)。等弧形竹片实现了材料利用率高(高达 80%)和竹材损坏率低的双重突破。此外,适当的干燥技术提高了尺寸稳定性,并保留了天然竹材的优良机械性能。这项工作体现了 "自然形态启发设计 "的理念,而 EASB 则为可持续工程竹制品的更广泛应用奠定了基础。
Electromechanical behavior and damage index system of 3D carbon fiber angle-interlock woven composites with FEA and data processing tools
Wu Tianwei, Li Gen, Xue Yousong, Li Zhiyong, Gu Bohong, Sun Baozhong
doi:10.1016/j.compscitech.2023.110318
利用有限元分析和数据处理工具研究三维碳纤维角交织复合材料的机电行为和损伤指标体系
The relationship between structural damage and electrical resistance change of carbon fiber reinforced composites is important to structural health monitoring. Here, we investigated the electromechanical behavior and damage index system for identification of various damage types in 3D angle-interlock woven composites under tensile loading in the warp direction. The mechanism of electrical resistance change was explored by combining current injected from both ends (Electrical current is in the plane of the laminate and goes through the entire cross section of the specimen) and current injected diagonally (Direction of electrical current between the in-plane direction and the through-thickness direction). A finite element model was established to analyze the electric potential distribution and tensile damage evolution process of composites. We found current injected from both ends can only detect with yarn damage and current injected diagonally can detect with matrix cracks, interface cracking and yarn damage. Based on the electrical resistance data of current injected diagonally, we used principal component analysis and K-means clustering methods to establish a damage index system to reflect the damage accumulation degree of different damage modes. The finite element analyses verified the rationality of the damage index system.
碳纤维增强复合材料的结构损伤与电阻变化之间的关系对于结构健康监测非常重要。在此,我们研究了三维角交错编织复合材料在经向拉伸载荷作用下的机电行为和损伤指标体系,以识别各种损伤类型。我们结合从两端注入的电流(电流在层压板的平面上,穿过试样的整个横截面)和斜向注入的电流(电流方向介于平面方向和厚度方向之间),探讨了电阻变化的机理。我们建立了一个有限元模型来分析复合材料的电动势分布和拉伸损伤演变过程。我们发现从两端注入的电流只能检测到纱线损伤,而从对角线方向注入的电流可以检测到基体裂纹、界面裂纹和纱线损伤。根据斜向注入电流的电阻数据,我们采用主成分分析和 K-means 聚类方法建立了损伤指标体系,以反映不同损伤模式的损伤累积程度。有限元分析验证了损伤指标体系的合理性。