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【新文速递】2024年4月16日复合材料SCI期刊最新文章

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今日更新:Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 3 篇

Composites Part A: Applied Science and Manufacturing

In-situ infrared annealing for laser-assisted automated fiber placement to enhance interlaminar properties without sacrificing laydown efficiency

Xukang Wang, Cheng Chen, Shirui Hu, Zhikun Chen, Wei Jiang, Guancheng Shen, Zhigao Huang, Huamin Zhou

doi:10.1016/j.compositesa.2024.108214

 

激光辅助自动铺放光纤的原位红外退火,在不牺牲铺放效率的情况下提高层间性能

Laser-assisted automated fiber placement (LAFP) in-situ consolidation (ISC) of thermoplastic composites suffers from poor interlaminar bonding. Repass treatment improves interlaminar bonding but sacrifices laydown efficiency. Here we propose an in-situ infrared annealing (IIA) strategy that combines infrared heat treatment with a second pressure roller immediately following the LAFP ISC process. This approach causes repeated interlaminar melting and slower cooling, reducing the porosity by 57.9% and increasing crystallinity by 89.2% compared to LAFP-manufactured carbon fiber-reinforced polyether-ether-ketone composites. Moreover, it completes the crystallization process with only a single placement rather than multiple placements by repass treatment. Interlaminar shear strength and mode I interlaminar fracture toughness are improved by 239.7% and 292.4%, respectively. These improvements are comparable to those achieved by repass treatment with a near-infrared laser. Overall, the IIA strategy offers a promising alternative to traditional post-consolidation processes while maintaining laydown efficiency.

热塑性复合材料的激光辅助自动铺放(laff)原位固结(ISC)存在层间键合差的问题。重传处理改善了层间键合,但牺牲了铺层效率。在这里,我们提出了一种原位红外退火(IIA)策略,将红外热处理与第二个压力辊结合在LAFP ISC工艺之后。与lafp制造的碳纤维增强聚醚-醚-酮复合材料相比,这种方法 会导致层间反复熔化,冷却速度较慢,孔隙率降低57.9%,结晶度提高89.2%。此外,它完成结晶过程,只有一个放置,而不是多次放置通过再传递处理。层间剪切强度和I型层间断裂韧性分别提高了239.7%和292.4%。这些改进可与用近红外激光进行重传治疗所取得的效果相媲美。总体而言,IIA战略在保持布局效率的同时,为传统的整合后流程提供了一个有希望的替代方案。


Composites Part B: Engineering

Validation and verification of a novel higher-order FE Framework for process modeling of thermoset composites

M.H. Nagaraj, S. Shah, A. Sabato, M. Maiaru

doi:10.1016/j.compositesb.2024.111447

热固性复合材料过程建模的新型高阶有限元框架的验证与验证

Uncontrolled curing-induced residual stress is a significant limitation to the efficient design of thermoset composite structures, and a sufficiently high post-cure stress state can compromise their performance, durability, and geometrical tolerance. Experimentally validated multiscale process models aid in quantitatively describing the relation between process parameters and residual stress development across composite length scales, thereby allowing for an optimized manufacturing process and improved part performance. This work presents a novel numerical approach for the process modeling of fiber-reinforced thermosets, and is based on higher-order finite elements derived from the Carrera Unified Formulation. The process framework is experimentally validated at the macro-scale using cure-induced warpage data of fabricated cross-ply laminates. Micromechanical process analysis is performed to predict residual stress evolution at the micro-scale, and a comparison with reference 3D-FEA provides a verification of the proposed approach. The predicted laminate-level cure-induced warpage is found to be within 9% of experimental measurements, thereby validating the presented process model, while comparing the micromechanical analysis costs with conventional 3D-FEA demonstrates an order-of-magnitude improvement in computational efficiency. The performance of the proposed computational models constitutes a milestone towards enabling practically feasible multiscale process modeling for composites structures.

不受控制的固化引起的残余应力是热固性复合材料结构有效设计的一个重要限制,足够高的固化后应力状态会损害其性能、耐久性和几何公差。实验验证的多尺度工艺模型有助于定量描述工艺参数与复合材料长度尺度上残余应力发展之间的关系,从而允许优化制造工艺并改善零件性能。这项工作提出了一种新的数值方法,用于纤维增强热固性材料的过程建模,并基于源自Carrera统一公式的高阶有限元。该工艺框架在宏观尺度上利用制备的交叉层合板的固化引起的翘曲数据进行了实验验证。通过微力学过程分析来预测微尺度下的残余应力演化,并与参考的三维有限元分析进行了比较,验证了所提出方法的有效性。预测的层压层固化引起的翘曲在实验测量值的9%以内,从而验证了所提出的工艺模型,同时将微观力学分析成本与传统的3D-FEA进行比较,表明计算效率有了数量级的提高。所提出的计算模型的性能是实现复合材料结构实际可行的多尺度过程建模的里程碑。


Unlocking Anti-Aging Potential: Flame Retardants Thrive Without Added Antioxidants

Pengfei Sun, Pengfei Jia, Wei Wang, Ningning Hong, Fuhao Yu, Dayong Chen, Bibo Wang, Zhou Gui, Yuan Hu

doi:10.1016/j.compositesb.2024.111450

 

开启抗衰老潜能:阻燃剂无需添加抗氧化剂即可茁壮成长

A synergistic flame retardant with a core-shell structure utilizes the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative as the outer shell and ammonium polyphosphate (APP) as the inner core. Three derivatives of DOPO (DOPO-GY, DOPO-DH and DOPO-GD) are synthesized by reacting DOPO with glyoxal, paraformaldehyde and diethanolamine, and glutaraldehyde, respectively. DOPO-GY@APP, DOPO-DH@APP and DOPO-GD@APP exhibit good radical scavenging activities. The oxidation induction time for EVA/DOPO-GY@APP is exceptionally high at 19.04 minutes, in contrast to EVA alone, which has an induction time of only 5.51 minutes. Simultaneously, after aging at 180 °C and 165 °C for 7 days, the retention rates of elongation at break for EVA/DOPO-GY@APP are 34.67% and 55.50%, respectively. These findings demonstrate the long-term anti-aging properties of EVA/DOPO-GY@APP without the need for additional antioxidants. Moreover, EVA/DOPO-GY@APP, EVA/DOPO-DH@APP and EVA/DOPO-GD@APP all achieve V-0 rating with 25% addition of flame retardant. In comparison to pure EVA, their peak heat release rates and maximum smoke density decrease by 52% and 47%, 43% and 54%, and 51% and 44%, respectively. Additionally, compared to EVA/APP, their mechanical properties have been improved. Therefore, these microencapsulated flame retardants with DOPO derivatives as the shell effectively enhance the mechanical properties and fire safety of EVA composites.

以9,10-二氢-9-氧-10-磷菲-10-氧化物(DOPO)衍生物为外壳,聚磷酸铵(APP)为内核的核-壳结构协同阻燃剂。将DOPO分别与乙二醛、多聚甲醛和二乙醇胺、戊二醛反应,合成了DOPO的三个衍生物DOPO- gy、DOPO- dh和DOPO- gd。DOPO-GY@APP、DOPO-DH@APP和DOPO-GD@APP具有良好的自由基清除活性。EVA/DOPO-GY@APP的氧化诱导时间异常高,为19.04分钟,而单独EVA的氧化诱导时间仅为5.51分钟。同时,在180℃和165℃时效7 d后,EVA/DOPO-GY@APP的断裂伸长率分别为34.67%和55.50%。这些发现证明了EVA/DOPO-GY@APP的长期抗衰老特性,而不需要额外的抗氧化剂。此外,EVA/DOPO-GY@APP, EVA/DOPO-DH@APP和EVA/DOPO-GD@APP在添加25%阻燃剂的情况下均达到V-0等级。与纯EVA相比,它们的峰值放热率和最大烟密度分别降低了52%和47%,43%和54%,51%和44%。此外,与EVA/APP相比,它们的力学性能得到了改善。因此,这些以DOPO衍生物为外壳的微胶囊化阻燃剂有效地提高了EVA复合材料的力学性能和防火安全性。


Formulation of O-carboxymethyl chitosan with magnesium phosphate cement promotes in vitro/in vivo angiogenesis and osteogenesis related to the TRPM7 channel in bone regeneration

Changtian Gong, Jian Yang, Di Zheng, Bin Zhou, Xiping Zhang, Xingyu Wang, Xinghan Huang, Qingsong Ye, Weichun Guo

doi:10.1016/j.compositesb.2024.111451

o -羧甲基壳聚糖与磷酸镁水泥的配制促进体外/体内血管生成和骨再生中与TRPM7通道相关的成骨

Despite the abundant evidence on the biodegradability of K-struvite (KMgPO4·6H2O) that promotes bone regeneration, the cell-related surface bioactivity still stays low owing to the absence of organic components. O-Carboxymethyl chitosan (O-CMC) is a glycosaminoglycan-mimetic with outstanding biocompatibility, biodegradability and solubility, which has been successfully used in tissue engineering and regenerative medicine (TERM). In this study, we incorporated O-CMC into K-struvite to prepare hybrid scaffolds (OMPCs) with increasing biphasic contents. we found that O-CMC improved the physicochemical properties, in vitro/vivo biocompatibility, and enzymatic biodegradability of K-struvite, resulting in enhanced in vitro/vivo angiogenesis and osteogenesis via the proper release of Mg2+. In addition, we found differential expression of transient receptor potential cation channel member 7 (TRPM7) within the endothelial and osteoblast lineages, triggering the phosphorylation of the PI3K/Akt and MEK/ERK signaling pathways, respectively. In summary, it can be concluded that the biphasic addition of O-CMC is a viable method for improving the surface bioactivity of K-struvite to accelerate bone regeneration.

尽管有大量证据表明k -鸟粪石(KMgPO4·6H2O)具有促进骨再生的生物可降解性,但由于缺乏有机成分,其与细胞相关的表面生物活性仍然很低。o -羧甲基壳聚糖(O-CMC)是一种具有良好生物相容性、生物可降解性和溶解性的糖胺聚糖模拟物,已成功应用于组织工程和再生医学(TERM)。在本研究中,我们将O-CMC掺入k -鸟粪石中,制备了增加双相含量的杂交支架(OMPCs)。我们发现O-CMC改善了k -鸟粪石的理化性质、体外/体内生物相容性和酶促生物降解性,从而通过适当释放Mg2+促进体外/体内血管生成和成骨。此外,我们发现瞬时受体电位阳离子通道成员7 (TRPM7)在内皮细胞和成骨细胞谱系中的差异表达,分别触发PI3K/Akt和MEK/ERK信号通路的磷酸化。综上所述,双相添加O-CMC是提高鸟粪石表面生物活性,促进骨再生的可行方法。



来源:复合材料力学仿真Composites FEM
ACTMechanicalGENESIS断裂复合材料UGUM材料多尺度控制
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首次发布时间:2024-11-14
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【新文速递】2024年4月19日复合材料SCI期刊最新文章

今日更新:Composite Structures 6 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 1 篇Composite StructuresRapid prediction of the cure-induced distortion of newly developed composite parts via transfer learningJiawei Guo, Shuting Liu, Yingguang Li, Qinlu Meng, Xu Liu, Xiaozhong Haodoi:10.1016/j.compstruct.2024.118139基于迁移学习的复合材料零件固化变形快速预测Accurately predicting Cure-Induced Distortion (CID) is paramount to ensuring manufacturing precision. Existing prediction models heavily rely on material parameters associated with the CID, which presents challenges for newly developed composites due to the time-consuming, expensive, and limited accuracy of parameter characterization processes. With recognizing the shared curing mechanism across various composites, this paper introduces a transfer learning-based approach that leverages a small dataset of practical CID data from the newly developed composite and historical knowledge from existing composites to achieve rapid and accurate CID predictions. This approach was validated for two typical CID prediction cases by implementing a transfer learning framework, and various sampling methods were explored to assess the stability and repeatability of prediction results. The results indicate that the proposed method can predict the CID within a 5% margin of error. This paper offers a promising approach for predicting CID in the design and manufacturing processes.准确预测固化诱发变形(CID)对保证制造精度至关重要。现有的预测模型严重依赖于与CID相关的材料参数,由于参数表征过程耗时、昂贵且精度有限,这给新开发的复合材料带来了挑战。在认识到各种复合材料之间的共享固化机制后,本文引入了一种基于迁移学习的方法,该方法利用来自新开发复合材料的实际CID数据的小数据集和来自现有复合材料的历史知识来实现快速准确的CID预测。通过迁移学习框架对两个典型的CID预测案例进行了验证,并探索了各种采样方法来评估预测结果的稳定性和可重复性。结果表明,该方法可以在5%的误差范围内预测CID。本文为设计和制造过程中CID的预测提供了一种有前途的方法。Characterization of a two-step laser paint stripping process on CFRPMan Xu, Sen Yang, Xinyi Liu, Lin Li, Yu Wan, Chenzhuo Wang, Meng Wu, Youdong Gao, Mian Zhong, Biyi Wang, Yong Jiangdoi:10.1016/j.compstruct.2024.118140CFRP两步激光脱漆工艺的表征This work presents a two-step non-destructive method for cleaning the surface paint of CFRP. The method combines ablation and vibration, using a pulsed laser with a wavelength of 1064 nm. The effects of laser power, beam and path overlap rate on the removal of paints are investigated. The analysis focuses on the cleaning and the damage threshold of the paints and fibers. Additionally, the study analyzed the thermal accumulation effect and fiber damage resulting from various laser parameters. The cleaned samples were analyzed for micro-morphology, elemental composition, surface roughness, three-dimensional morphology, and contact angle to demonstrate the modulation of derivatization phenomena of CFRP surface paints under different cleaning states using this method. This points to the reliability and feasibility of the relevant treatment parameters and provides a reference for the subsequent research on the practical application of laser cleaning.本文提出了一种两步法无损清洗CFRP表面涂料的方法。该方法结合了烧蚀和振动,使用波长为1064 nm的脉冲激光器。研究了激光功率、光束和路径重叠率对涂料去除的影响。重点分析了涂料和纤维的清洗和损伤阈值。此外,研究还分析了不同激光参数对光纤的热积累效应和损伤。对清洗后的样品进行微观形貌、元素组成、表面粗糙度、三维形貌和接触角分析,验证了该方法对CFRP表面涂料在不同清洗状态下衍生化现象的调节作用。这指出了相关处理参数的可靠性和可行性,为后续激光清洗实际应用的研究提供了参考。Double shooting method for FRCM reinforced systems in debonding problemsYu Yuan, Gabriele Milanidoi:10.1016/j.compstruct.2024.118136钢筋混凝土加固体系脱粘问题的双射法研究The debonding process in FRCM (Fiber Reinforced Cementitious Matrix) strengthened brittle substrates, such as concrete and masonry, is characterized by complex failure modes that include debonding at both the external and internal interfaces of the composite, as well as damage to the mortar matrix. This study addresses this problem classically as a mode-II fracture process by accounting for the one-dimensional non-linear interfacial shear stress-slip relationship combined with matrix axial non-linearity. The approach employed considers the longitudinal displacements of both the inner and outer layers of mortar, along with that of the fiber textile, as unknowns, and analytically solves the second-order ordinary differential equation (ODE) system that governs the debonding problem. Then, the boundary value problem (BVP) is transformed into an initial value problem (IVP) and a double shooting method is proposed to find displacements and stresses along the bonded length in the presence of non-linearity. The appropriate initial values of matrix layer displacements, satisfying the required boundary conditions, are efficiently determined through a two-dimensional bisection method working on rectangular and triangular patches. The softening behavior of both mortar layers and interfaces between mortar and fiber are taken into account using jagged constitutive relationships to enhance convergence. The numerical calculation speed, robustness, and key simulation parameters are thoroughly discussed. Moreover, the proposed numerical approach is compared with existing experimental data and models, on both concrete and masonry FRCM-reinforced specimens. The influence of mortar failure and interfacial strength is also explored. The model demonstrates its ability to effectively reproduce the global bond behavior observed in experimental studies, while capturing the local behavior and simulating various failure modes observed in the tests.FRCM(纤维增强胶凝基质)增强脆性基体(如混凝土和砌体)的脱粘过程具有复杂的破坏模式,包括复合材料外部和内部界面的脱粘以及砂浆基体的破坏。考虑到一维非线性界面剪应力-滑移关系和基体轴向非线性,本研究将该问题经典地描述为ii型断裂过程。所采用的方法考虑了砂浆内层和外层的纵向位移,以及纤维织物的纵向位移,作为未知数,并解析地解决了控制脱粘问题的二阶常微分方程(ODE)系统。然后,将边值问题(BVP)转化为初值问题(IVP),提出了在非线性条件下沿键长方向求位移和应力的双射击方法。通过对矩形块和三角形块进行二维平分的方法,有效地确定了满足边界条件的矩阵层位移初始值。采用锯齿状本构关系,考虑砂浆层和砂浆与纤维界面的软化行为,增强收敛性。详细讨论了数值计算速度、鲁棒性和关键仿真参数。此外,将本文提出的数值方法与现有的混凝土和砌体frcm加筋试件的实验数据和模型进行了比较。探讨了砂浆破坏和界面强度的影响。该模型能够有效地再现实验研究中观察到的整体键行为,同时捕获局部行为并模拟试验中观察到的各种破坏模式。A multi-responsive actuator with sensing capability based on poly (N-isopropyl acrylamide)/poly (sodium acrylate) Janus hydrogelsJinkun Lin, Jialei Li, Weiheng Gong, Yongjia Liu, Yuxuan Ai, Aihua He, Huarong Niedoi:10.1016/j.compstruct.2024.118141 基于聚(n -异丙基丙烯酰胺)/聚(丙烯酸钠)Janus水凝胶的具有传感能力的多响应驱动器A Janus hydrogel composed of temperature-responsive poly (N-isopropyl acrylamide) (PNIPAM) and pH-responsive poly (sodium acrylate) (PSA) was fabricated from inexpensive monomers using a facile synthesis route. The asymmetric swelling between PNIPAM and PSA in different media and at different temperatures makes the Janus hydrogels have a multi-stimuli response, meanwhile, the interpenetrating layer between PNIPAM and PSA indicated a good interfacial adhesion for easy transfer of internal stress and deformation. Thus, the Janus hydrogels exhibited excellent advantages in actuator/sensor engineering, demonstrating the potential to grip and release objects in toxic media, encrypt, monitor and control safety in chemical production, and alert temperature of flammable and explosive solvents. In addition, the features of the Janus hydrogels incorporated with carbon nanotubes, such as the high sensitivity, large stretchability, and rapid and linear response, enabled their application as strain sensors for wearable technologies in the recognition of body movement and health detection.以廉价单体为原料,采用简便的合成方法制备了温度响应型聚n -异丙基丙烯酰胺(PNIPAM)和ph响应型聚丙烯酸钠(PSA)的Janus水凝胶。PNIPAM和PSA在不同介质和温度下的不对称膨胀使Janus水凝胶具有多刺 激响应,同时PNIPAM和PSA之间的互穿层具有良好的界面附着力,易于传递内应力和变形。因此,Janus水凝胶在执行器/传感器工程中表现出优异的优势,展示了在有毒介质中抓取和释放物体的潜力,加密,监测和控制化学生产中的安全,以及易燃易爆溶剂的温度警报。此外,Janus水凝胶与碳纳米管结合的特点,如高灵敏度、大拉伸性、快速线性响应等,使其能够作为可穿戴技术的应变传感器应用于身体运动识别和健康检测。Influence of Oxygen/Argon/Nitrogen multi-component plasma modification on interlayer toughening of UHMWPE fiber reinforced compositesYuwei Zhao, Chunyue Fang, Lixia Jia, Bao Shi, Zhenhong Chen, Xiayun Zhang, Sainan Wei, Yuefen Han, Zixuan Liu, Ruosi Yandoi:10.1016/j.compstruct.2024.118142氧/氩/氮多组分等离子体改性对超高分子量聚乙烯纤维增强复合材料层间增韧的影响The study reveals the influence of glow discharged three gas sources of Oxygen/Argon/Nitrogen plasma modification on interlayer toughening of ultra-high molecular weight polyethylene (UHMWPE) fiber reinforced composite. The failure modes under bending, tensile and interlayer fracture toughness testing were analyzed through acoustic emission (AE) technology. The results showed that Oxygen/Argon/Nitrogen multi-component plasma modified fiber introduced more hydrophilic groups such as hydrogen and hydroxyl groups, and significantly enhanced the binding of fiber and matrix. The GⅠC (Mode-I interlaminar fracture toughness) of multi-component plasma modified composites exhibited increased by 61.67%, 40.88% and 18.01% compared to untreated, Oxygen and Oxygen/Argon plasma, respectively, while GⅡC (Mode-Ⅱ interlaminar fracture toughness) increased by 38.57%, 25.57% and 23.09%. AE cluster analysis exhibited that multi-component plasma modified composites formed an energy dissipation mechanism dominated by fiber breakage. Additionally, the oxygen, argon, and nitrogen plasma modification have a synergistic effect on interlayer toughening.研究了放电氧/氩/氮三种气源等离子体改性对超高分子量聚乙烯(UHMWPE)纤维增强复合材料层间增韧的影响。利用声发射(AE)技术分析了材料在弯曲、拉伸和层间断裂韧性测试下的破坏模式。结果表明,氧/氩/氮多组分等离子体改性纤维引入了更多的氢、羟基等亲水性基团,显著增强了纤维与基体的结合。多组分等离子体改性复合材料的i型层间断裂韧性(GⅠC)比未处理、氧和氧/氩等离子体分别提高了61.67%、40.88%和18.01%,而GⅡC (Mode-Ⅱ)层间断裂韧性分别提高了38.57%、25.57%和23.09%。声发射聚类分析表明,多组分等离子体改性复合材料形成了以纤维断裂为主的能量耗散机制。此外,氧、氩、氮等离子体改性对层间增韧有协同作用。Compression after impact (CAI) failure mechanisms and damage evolution in large composite laminates: High-fidelity simulation and experimental studyPeyman Shabani, Lucy Li, Jeremy Laliberte, Gang Qidoi:10.1016/j.compstruct.2024.118143大型复合材料层合板冲击后压缩(CAI)破坏机制与损伤演化:高保真模拟与实验研究This study focuses on developing and validating a high-fidelity finite element model for predicting damage evolution and residual strength in fiber-reinforced composite panels. Impact and compression after impact (CAI) tests were conducted at both barely visible impact damage (BVID) and clearly visible impact damage (CVID) levels. The ASTM D7137 standard 100 mm × 150 mm CAI coupons were inadequate to cover the range of experimental studies required for model validation. Therefore, larger 254 mm × 304.8 mm laminates were investigated under two CAI testing conditions: one a scaled-up version of ASTM standard coupon, and the other with additional anti-buckling support plates to reduce unsupported areas to 127 mm × 177.8 mm. The model captured inter- and intra-laminar failure modes, including fiber breakage, splitting, kinking, pull-out, and crushing as well as matrix cracking, delamination, and their interactions. This was achieved by cohesive zone modeling technique and enhancing the LaRC05 failure criteria through modeling the fiber damage evolution and utilizing an efficient search algorithm to determine the matrix fracture plane and fiber kink band angle. This study underscores the efficacy of the high-fidelity modeling approach in accurately predicting both impact damage and CAI strength in typical aircraft impact damage scenarios. Additionally, it provides insights into complex CAI failure mechanisms and energy release associated with various damage modes and highlights the effect of global buckling on the failure behavior and compressive strength of composite laminates. Furthermore, it shows that the proposed fixture with support plates is suitable for testing a broader range of impact scenarios without experiencing global buckling.本研究的重点是开发和验证高保真有限元模型,用于预测纤维增强复合材料板的损伤演变和剩余强度。在几乎不可见的冲击损伤(BVID)和清晰可见的冲击损伤(CVID)水平下进行冲击和冲击后压缩(CAI)试验。ASTM D7137标准100 mm × 150 mm CAI券不足以涵盖模型验证所需的实验研究范围。因此,在两种CAI测试条件下,研究了较大的254 mm × 304.8 mm层压板:一种是ASTM标准券的放大版本,另一种是额外的抗屈曲支撑板,以减少不受支撑的面积到127 mm × 177.8 mm。该模型捕获了层间和层内的破坏模式,包括纤维断裂、劈裂、扭结、拔出和破碎,以及基体开裂、分层及其相互作用。采用内聚区建模技术,通过模拟纤维损伤演化,利用高效搜索算法确定基体断裂面和纤维扭结带角,增强了LaRC05失效准则。该研究强调了高保真建模方法在准确预测典型飞机冲击损伤场景中的冲击损伤和CAI强度方面的有效性。此外,它还提供了与各种损伤模式相关的复杂CAI破坏机制和能量释放的见解,并强调了整体屈曲对复合材料层合板破坏行为和抗压强度的影响。此外,它表明,所提出的夹具与支撑板适用于测试更广泛的冲击场景,而不会经历整体屈曲。Composites Part A: Applied Science and ManufacturingRandom modeling of hemp fibers mechanical propertiesChiara Pepi, Maria Eleonora Pipistrelli, Massimiliano Gioffrèdoi:10.1016/j.compositesa.2024.108203麻纤维力学性能的随机建模The growing interest in vegetal fiber-based composite materials for reinforcing structural elements is prompting researchers to consider the inherent randomness, arising from various factors which are complex to model. For this reason a general probabilistic approach seems more appropriate to model all uncertainties regardless where they come from. In this paper, factory produced hemp ropes, and their components, are tested to obtain their tensile mechanical properties. In particular, 120 fibers with four different lengths, 55 yarns, 33 strands and 64 ropes are used to obtain a first statistical characterization of tensile strength, strain and Young modulus. These results are used to calibrate two commonly used random models such as Gaussian and three-parameters Weibull distributions and to give both qualitative and quantitative complete random characterization of the tensile properties of each hemp rope components. The obtained results are crucial to estimate vegetal fiber-based composite materials structural response.人们对植物纤维基复合材料增强结构构件的兴趣日益浓厚,这促使研究人员考虑其固有的随机性,这些随机性由各种复杂的因素引起,难以建模。由于这个原因,一般的概率方法似乎更适合于对所有不确定性进行建模,而不管它们来自哪里。本文对工厂生产的麻绳及其组成部分进行了拉伸力学性能测试。特别地,使用了四种不同长度的120根纤维,55根纱线,33股和64根绳索,以获得抗拉强度,应变和杨氏模量的首次统计特性。这些结果被用来校准两种常用的随机模型,如高斯分布和三参数威布尔分布,并给出了定性和定量的完全随机表征麻绳各组分的拉伸性能。所得结果对于估计植物纤维基复合材料的结构响应具有重要意义。Composites Part B: EngineeringSelf-standing and compressible SiCnw/SiCnf composite aerogel via free carbon in-situ transformation mechanism: towards thermal and electromagnetic wave protectionTiansheng Wang, Menghang Feng, Zichen Xiang, Zhi Song, Hualiang Lv, Yi Hou, Lixi Wang, Qitu Zhangdoi:10.1016/j.compositesb.2024.111454 独立可压缩SiCnw/SiCnf复合气凝胶通过自由碳原位转化机理:对热和电磁波的保护SiC nanofiber-based composite aerogel represents a promising lightweight, high-temperature-resistant, and broadband-absorbing material. However, the residual carbon phase during the pyrolysis process would threaten the high-temperature oxidation tolerance. Herein, a free carbon in-situ transformation (FCIT) strategy was proposed to convert the amorphous free carbon on the surface of SiC nanofibers into SiC nanowires, constructing a multi-scale SiC nanowire/SiC nanofiber (SiCnw/SiCnf) composite aerogel. The SiCnw great broaden the inner fibrous framework, and the hierarchical network offers great enhancement for EM attenuation, compression resistance and thermal insulation. The self-standing composite aerogel possesses excellent flexibility (1500 cycles in 180°-bending test) and compression resistance (100 cycles at 40% strain). With only 10 wt% filler content, the SiCnw/SiCnf sample displays an effective absorption bandwidth (EAB) of 8.81 GHz (9.19-18.00 GHz) at a thickness of 2.94 mm. Even after enduring oxidation at 800 °C, the EAB still remains substantial at 6.92 GHz (11.08-18.00 GHz). Moreover, the outstanding mechanical performance were also retained under high temperature and oxidation environment due the reduced density and thermal conductivity. Therefore, the multifunctional SiCnw/SiCnf composite aerogel prepared by FCIT strategy could be served as efficient thermal and EMW protection candidate.碳化硅纳米纤维基复合气凝胶是一种很有前途的轻质、耐高温、宽带吸收材料。然而,热解过程中残留的碳相会对高温耐氧化性造成威胁。本文提出了自由碳原位转化(FCIT)策略,将SiC纳米纤维表面的非晶态自由碳转化为SiC纳米线,构建了多尺度SiC纳米线/SiC纳米纤维(SiCnw/SiCnf)复合气凝胶。SiCnw极大地扩大了内部纤维框架,分层网络对电磁衰减、抗压缩和隔热有很大的增强。自立式复合气凝胶具有优异的柔韧性(在180°弯曲试验中可循环1500次)和抗压性(在40%应变下可循环100次)。当填料含量仅为10 wt%时,SiCnw/SiCnf样品在厚度为2.94 mm时的有效吸收带宽(EAB)为8.81 GHz (9.19-18.00 GHz)。即使经过800°C的持久氧化,EAB在6.92 GHz (11.08-18.00 GHz)时仍然保持可观。此外,由于密度和导热系数降低,在高温氧化环境下仍能保持优异的力学性能。因此,采用FCIT策略制备的多功能SiCnw/SiCnf复合气凝胶可以作为高效的热防护和EMW防护的候选材料。An integrative warning-protection shear thickened composite sponge towards sensing performance and impact resistance with excellent flame retardantYucheng Pan, Min Sang, Junshuo Zhang, Zimu Li, Shuai Liu, Zhentao Zhang, Qian Ma, Xinglong Gongdoi:10.1016/j.compositesb.2024.111466 一种具有传感性能、抗冲击性能和优异阻燃性能的综合预警保护剪切增厚复合海绵The mechanical shock and thermal damage generally exist together in hazardous environment, whereas traditional single protective materials are difficult to achieve all-round protection under extreme environment. Herein, to realize the integration of multifunctional abilities about impact resistance, flame-retardant and sensing performance, a “solid-liquid host-guest” structural shear thickened composite sponge is proposed, which flame-retardant shear thickening fluids with an extraordinary thickening ratio of 2183.95 % continuously disperse in 3D sponge matrix. The resulting composite sponge effectively attenuates the impact force by nearly 80% with the thickness of only 4 mm via a cooperation between the effect of shear hardening and structure densification. Meanwhile, after burning on the alcohol flame for 12 s, the composite sponge with 7 wt.% fire-retardant additive maintains a complete morphology and realizes self-extinguishing with a reliable flame-retardant ability. Attributed to the good electrical conductivity of shear thickening fluid, the composite sponge serves favorably in human body monitoring, impact sensing and fire warning. In a word, this multifunctional lightweight composite sponge is expected to realize the integration of early warning and protection, which is a competitive candidate material for the intelligent protection in complex environments.在危险环境下,机械冲击和热损伤一般同时存在,传统的单一防护材料难以在极端环境下实现全方位防护。为实现抗冲击、阻燃、传感等多功能性能的集成,提出了一种“固-液主客”结构剪切增稠复合海绵,其阻燃剪切增稠流体在三维海绵基体中连续分散,增稠比达到2183.95%。通过剪切硬化和组织致密化的共同作用,得到的复合海绵在厚度仅为4 mm的情况下,有效地衰减了近80%的冲击力。同时,添加7 wt.%阻燃剂的复合海绵在酒精火焰上燃烧12s后,形态保持完整,实现自熄,阻燃能力可靠。由于剪切增稠流体具有良好的导电性,复合海绵在人体监测、冲击传感、火灾报警等方面具有良好的应用前景。总之,该多功能轻量化复合海绵有望实现预警与防护一体化,是复杂环境下智能防护的极具竞争力的候选材料。Composites Science and TechnologyTranslaminar-envelope ply for CFRP mechanical enhancementJiahe Ma, Qiang Xu, Haowei Zhang, Lei Miao, Weidong Zhu, Yinglin Kedoi:10.1016/j.compscitech.2024.110594 跨层包络层用于CFRP机械增强Pursuing the trend of ply-level innovation in the field of high-performance CFRP composites, a pseudo-woven layup configuration has been developed by interlacing a thin-ply prepreg in the translaminar-envelope manner space-orthogonally inside a homogenized 4-ply sub-laminate to acquire mechanical superiorities for the global multidirectional laminate. This evolved layup structure possesses the stiffening feedbacks on in-plane principal properties by the locally-regulated 0° ply amount, and exerts the multi-interface synergy on shear-driven interlaminar fractures by the long-acting binding action. Further, the high robustness of structural performances has been revealed by resistance and tolerance against severe low-velocity impact damage, achieving up to 60% decrease in the projected delamination area and over 60% increase in the post-impact compressive strength. The translaminar-envelope layup configuration is expected to enhance the service capability of CFRP laminates.在高性能CFRP复合材料领域,追求层序创新的趋势,通过在均匀的4层亚层压板中以跨层包覆的方式空间正交地交错薄层预浸料,开发了一种伪编织层压板结构,以获得全局多向层压板的力学优势。这种演化的铺层结构通过局部调节的0°铺层量对面内主要性能产生强化反馈,并通过长效结合作用对剪切驱动的层间裂缝发挥多界面协同作用。此外,对严重低速冲击损伤的抵抗力和容忍度显示了结构性能的高鲁棒性,预计分层面积减少60%,冲击后抗压强度增加60%以上。跨层包络层合结构有望提高碳纤维复合材料层合板的使用性能。来源:复合材料力学仿真Composites FEM

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