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Effects of Non-Uniform Needled Microstructure on Failure Mechanisms of 3d Needled C/C-Zrc-Sic composites Thick-Walled Cylinder Under Axial Compression and Internal Pressure

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SSRN 2022年

作者： Wang, Zhangwen Wang, Bing Jiang, Xinyu Wang, Xiaosong Sun, Wei Fang, Guodong Meng, Songhe Science and Technology on Advanced Composites in Special Environments Key Laboratory Harbin Institute of Technology Harbin150001 China National Key Laboratory of Precision Hot Processing of Metals Harbin Institute of Technology Harbin150001 China State Key Laboratory of Powder Metallurgy Central South University Changsha410083 China

Three dimensional (3D) needled ZrC-SiC modified C/C composites (C/C-ZrC-SiC composites) as cutting-edge materials for throat or expansion section of rocket nozzle are mainly subjected to complex loads conditions of internal pressure and axial force. The coupled axial compression and internal pressure experiments of 3D needled C/C-ZrC-SiC composites thick-walled cylinder were carried out to study the damage modes and failure mechanisms combing with the optical microscope and micro computed tomography (Micro-CT). A meso-macro finite element (FE) model considering local needling fiber regions was also established to investigate the failure process of the thick-walled cylinder under the complex loads. The predicted strength, failure strain and ultimate crack morphologies obtained by the proposed model were in good agreement with the experimental results. The effect of needled region distribution on the crack evolution and damage mechanisms was further analyzed. The non-uniform distribution of needled fiber region can induce the stress concentration of no needled regions under circumferential tension, which can trigger crack initiation and deflection. This study can be helpful of establishing the relationship between the structural behavior of ultra-high temperature ceramics modified C/C composites nozzle and the 3D needled composites design. © 2022, The Authors. All rights reserved.

关键词： Finite element method

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Workability Optimization and Microstructure Regulation for a Multi-Angular Extrusion Process of Az80 Magnesium Alloy

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SSRN 2023年

作者： Su, Zexing Sun, Chaoyang Qian, Lingyun Liu, Chengzhi Zhang, Li Liu, Yanlian School of Mechanical Engineering North University of China Taiyuan030051 China Shanxi Key Laboratory of Advanced Metal Materials for Special Environments North University of China Taiyuan030051 China School of Mechanical Engineering University of Science and Technology Beijing Beijing100083 China Beijing Key Laboratory of Lightweight Metal Forming Beijing100083 China

Engineering stability control of microstructure evolution and precision forming is a key technical issue for the high-performance manufacturing of magnesium alloy components. In this paper, a fine-grain processing window was proposed for the workability optimization and microstructure control of AZ80 magnesium alloy. The hot activation energy map (AEM) and processing map (PM) were established to analyze the hot-working properties and microstructural mechanisms, respectively. The internal state variable (ISV) based finite element (FE) model was introduced to predict the evolutions of grain size and microstructure homogeneity with processing parameters during multi-angular extrusion process. The fine-grain processing window was used to form a magnesium alloy plate. Fine microstructure and good forming performance were obtained with the optimized processing parameters at the complete DRX domain. Forming at the processing instability domain shows flow defects and microstructure heterogeneity. The above research can be applied to the processing parameter optimization and microstructure regulation during hot forming processes of magnesium alloy. © 2023, The Authors. All rights reserved.

关键词： Magnesium alloys

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Mechanical behavior and deformation mechanisms of 3D woven preforms under shear loading based on experimental and numerical approaches

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Thin-Walled Structures 2025年 215卷

作者： Yang, Tiantian Zhang, Li Hu, Jia Li, Zhixing Song, Chenyang Zheng, Tao Pan, Shidong Guo, Licheng Department of Astronautic Science and Mechanics Harbin Institute of Technology Harbin 150001 China Institute of Composite Materials and Structures Harbin Institute of Technology Harbin 150001 China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology Harbin 150001 China

In-plane shear is a dominant factor among the multiple causes of deformations in three-dimensional woven preforms (3DWPs), playing a vital role in determining the yarn distribution and the quality of final composite. However, the deformation mechanisms remain ambiguous due to the inherent complexity of woven architectures. To investigate the underlying mechanisms of shear deformation in 3DWPs, this study employs multi-scale analysis approaches to investigate their deformation behavior. At the macro-scale, picture frame experiments are performed to obtain full-field strain distributions. At the meso-scale, deformation features are captured and analyzed using high-resolution optical microscopy. Further, a digital element model is established to explore intricate micro-scale yarn deformation phenomena. The experimental results and simulation predictions exhibit strong agreement, evidenced by aligned load-displacement curve trend. This trend, together with the simulation results, suggests that the shear deformation process can be categorized into four distinct stages based on yarn motion: friction, rotation, compression, and locking. Specifically, initial yarn friction causes stress concentrations and linear shear force growth (stage I), followed by a plateau region resulting from dynamic equilibrium between internal yarn stresses and static friction forces (stage II). Subsequent yarn rotation and compression elevate internal stresses, inducing a secondary increase in shear force (stage III). Ultimately, yarn locking leads to a sharp, nonlinear increase in shear force (stage IV). The validated digital element model effectively elucidates critical 3DWPs deformation mechanisms, such as yarn morphology evolution, local compression and twisting of warp and binder yarns, and inter-yarn slippage. © 2025

关键词： 3D woven preform Deformation mechanisms Digital element Picture frame test Shear properties

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Dynamic Analysis of the Human-Machine System of a 4-Bar Gait Constraint Mechanism

Dynamic Analysis of the Human-Machine System of a 4-Bar Gait...

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IEEE International Conference on Mechatronics, Robotics and Automation (ICMRA)

作者： Lailu Li Lixun Zhang Bing Wang Da Song National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology Harbin China College of Mechanical and Electrical Engineering Harbin Engineering University Harbin China School of Mechanical Engineering Northeast Electric Power University Jilin China

Bar gait constraint mechanism has been proposed in terms of its benefits: low-cost, easy to adjust, and low weight. Aiming to analyze the interaction characteristics between the human body and the end-effector of the 4-Bar mechanism, it is necessary to conduct the dynamic analysis of the human-machine system, including the interaction force, contact force, and joint torque. First, a gait constraint mechanism based on 4-Bar was introduced. Second, the dynamic mathematical model of the human-machine system was established. Third, the dynamic simulation based on the mathematical equations was carried out. The results demonstrate that the interaction force between the machine and the human body is smooth. The human joint torques are also in a reasonable range, indicating that the 4-Bar gait constraint mechanism could assist individuals with locomotion obstacles to achieve low-limb exercises.

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Anisotropic Tensile Mechanics of Vertically Aligned Carbon Nanotube Reinforced Silicon Carbide Ceramic Nanocomposites

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SSRN 2022年

作者： Miao, Linlin Yang, Lingwei Wang, Chuanyun Zhao, Guoxin Li, Junjiao Zhao, Yushun Sui, Chao He, Xiaodong Xu, Zhonghai Wang, Chao Center for Composite Materials and Structures Harbin Institute of Technology Harbin150080 China Hypervelocity Aerodynamics Institute China Aerodynamics Research and Development Center Mianyang621000 China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology Harbin150080 China State Key Laboratory of Solidification Processing Northwestern Polytechnical Univerisity Xi’an710072 China Shenzhen STRONG Advanced Materials Research Institute Co. Ltd China

Vertically aligned carbon nanotubes (VACNTs)/silicon carbide (SiC) nanocomposites (VSNs) present remarkably anisotropic mechanical properties originated from their intrinsic heterogeneous microstructures. However, the studies related to tensile mechanical behaviors and failure mechanisms of VSNs are still suspended so far. In this work, the tensile mechanical properties of VSNs were investigated by an in-situ transmission electron microscopy (TEM) tensile test combined with classic molecular dynamics (MD) simulation. The testing results show that the fracture strength and Young’s modulus of VSNs along CNT-axis ( direction) are higher than those perpendicular to CNT-axis (⊥ direction). In addition, the fracture surface along direction is uneven whereas it is flat along ⊥ direction. The MD simulation reveals that the stronger behavior along direction is mainly benefited by the excellent tensile mechanical properties of CNTs, however, the relatively weak van der Waals interaction between CNTs and SiC matrix dominates the tensile performances of VSNs along ⊥ direction. Finally, the remarkable mechanical anisotropy of VSNs is explained by pulling-out and peeling-off failures of CNTs based on MD simulation. This work provides experimental and theoretical insights into the dominant mechanisms of mechanical anisotropy in typical VACNT/ceramic nanocomposites. © 2022, The Authors. All rights reserved.

关键词： Molecular dynamics

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Chirality tuning and reversing with resonant phase-change metasurfaces

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arXiv 2024年

作者： Sha, Xinbo Du, Kang Zeng, Yixuan Lai, Fangxing Yin, Jun Zhang, Hanxu Song, Bo Han, Jiecai Xiao, Shumin Kivshar, Yuri Song, Qinghai Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System Guangdong Provincial Key Laboratory of Semiconductor Optoelectronic Materials and Intelligent Photonic Systems Harbin Institute of Technology Shenzhen518055 China Pengcheng Laboratory Shenzhen518055 China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology Harbin150080 China Nonlinear Physics Center Research School of Physics Australian National University CanberraACT2601 Australia Collaborative Innovation Center of Extreme Optics Shanxi University Shanxi Taiyuan030006 China

Dynamic control of circular dichroism in photonic structures is critically important for compact spectrometers, stereoscopic displays, and information processing exploiting multiple degrees of freedom. Metasurfaces can help miniaturize chiral devices but only produce static and limited chiral responses. While external stimuli are able to tune resonances, their modulations are often weak, and reversing continuously the sign of circular dichroism is extremely challenging. Here, we demonstrate dynamically tunable chiral response of resonant metasurfaces supporting chiral bound states in the continuum combining them with phase-change materials. Phase transition between amorphous and crystalline phases allows to control chiral response and vary chirality rapidly from −0.947 to +0.958 backward and forward via chirality continuum. Our demonstrations underpin the rapid development of chiral photonics and its applications. © 2024, CC BY.

关键词： Chirality

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Phase Precipitation of Alloy 028 Due to Aging and the Resultant Corrosion Behavior

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SSRN 2024年

作者： An, Haoran Yu, Zhiqiang Wang, Rui Kang, Yan Zhao, Yuhong Hu, Yong Tuo, Leifeng Yan, Zhijie Eckert, Jürgen School of Materials Science and Engineering North University of China Taiyuan030051 China Shanxi Key Laboratory of Advanced Metal Materials for Special Environments North University of China Taiyuan030051 China School of Materials Science and Engineering Taiyuan University of Science and Technology Taiyuan030024 China Erich Schmid Institute of Materials Science Austrian Academy of Sciences Jahnstraße 12 LeobenA-8700 Austria Department of Materials Science Montanuniversitä€at Leoben Jahnstraße 12 LeobenA-8700 Austria

The microstructure evolution and corrosion behavior of alloy 028 after solution treatment at 1100 °C and aging at the temperatures of from 670 °C to 770 °C were systematically investigated. Experimental results indicate that the quantities of the M23C6 carbides and σ phase gradually increase as the aging temperature increases. The corrosion behavior is evaluated by potentiodynamic polarization tests and electrochemical impedance spectroscopy measurements in FeCl3 solution. The corrosion potential (Ecorr) decreases from 499 mV to 349 mV, and the self-corrosion current (Icorr) increases from 0.82 μA/cm2 to 13.35 μA/cm2 as the aging temperature increases from 670 °C to 770 °C, which reveals that the corrosion resistance of alloy 028 decreases due to aging. The precipitation of Crrich carbides and σ phase during the aging process deteriorates the corrosion resistance of alloy 028, demonstrated by the promotion of intergranular corrosion and the occurrence of pitting corrosion. Characterization of the passive films using Mott-Schottky analysis revealed that the passive film of all four samples exhibited n-p type semiconductor characteristics. The results of scanning kelvin probe force microscopy (SKPFM) show that the M23C6 carbides Manuscript File Click here to view linked References and σ phases possess the higher Volta potentials than the matrix. The corrosion originates from the potential difference between the precipitated phases and the matrix. © 2024, The Authors. All rights reserved.

关键词： Superalloys

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Photoelectrically-Excited Metasurface for Switchable and Tunable Propagation and Polarization Manipulations of Broadband Terahertz Wave

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SSRN 2022年

作者： He, Xunjun Wang, Dongjie Jiang, Jiuxing Yao, Yongtao Lu, Guangjun School of Electrical and Electronic Engineering Harbin University of Science and Technology Harbin150080 China College of Science Harbin University of Science and Technology Heilongjiang150080 China National key laboratory of science and technology on advanced composites in special environments Harbin Institute of Technology Harbin150080 China College of Electronic Engineering Guangxi Normal University Guilin541004 China

Currently, single metasurfaces with switchable and tunable multi-functional performances have arisen more and more interest. However, the existing metasurfaces usually suffer from the issues of limited functions due to the single active material used, seriously astricting their advancements and applications. Here, a photoelectrically-excited metasurface composed of two patterned graphenes (PGs) and the photosensitive silicon multilayer configuration is proposed to realize switchable and tunable propagation and polarization manipulations of broadband terahertz wave. Simulated results demonstrate that by choosing different combined ways of optical pumping silicon and electric doping patterned graphenes, the proposed metasurface can realize four working states executing broadband modulator, absorber, half-wave plate (HWP), and quarter-wave plate (QWP) respectively. Moreover, these functions can implement flexible switching and modulation by further changing the combined way and intensity of optical and electric doping individually or simultaneously. In addition, field distributions are used to discover the physical natures of broadband absorption and polarization conversion. Therefore, the reconfigurable metasurface can provide a new platform for the development of highly compact and integrated terahertz devices. © 2022, The Authors. All rights reserved.

关键词： Silicon

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High Partial Molar Volume Polymer Electrolyte for Upgraded Lithium Metal Batteries

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Angewandte Chemie 2025年第25期137卷

作者： Dongjiang Chen Wei Chen Bowen Zhang Yin Hu Shuying Wang Tianyu Lei Miao He Yuxin Fan Mingjie Zhou Yichao Yan Yuanpeng Liu Xianfu Wang Genqiang Zhang State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China 2006 Xinyuan Ave. Chengdu China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology 92 Xidazhi Street Nangang District Harbin China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments University of Science and Technology of China No. 96 Jinzhai Road Hefei China

Lithium (Li) metal batteries combined with solid electrolytes represent a highly promising technology for high-energy-density storage systems. However, their cycling performance encounters inferior stability due to the continuous growth of Li-dendrites. The initial motivation for Li-dendrite growth theoretically arises from the high chemical potential difference (∆ µ ) at the electrolyte/Li metal interface, yet the effectiveness of ∆ µ regulation lacks experimental validation. Here, we experimentally present the impact of ∆µ on the growth of Li-dendrites through manipulation of the partial molar volume of Li + ( ) in the polymer electrolyte. By weakening Li–O coordination structure, the as-produced high- polymer electrolyte (108.5 cm 3 mol −1 ) shows 83% decrease in ∆µ (289 J mol −1 ) compared with conventional counterparts, thereby enabling stable cycling for >10 months in a Li||Li cell and >2000 cycles in a Li||Cu cell with an average Coulombic efficiency (CE) of 96%. To one's delight, a practical cylindrical Li||Li[Ni 0.5 Co 0.3 Mn 0.2 ]O 2 cell with capacity of 0.62 Ah delivers excellent cycle stability with negligible capacity attenuation over 85 cycles at 0.2 C. The beneficial role of high is leveraged to introduce a new dimension in polymer electrolyte engineering, highlighting the underexplored design strategy of regulating interfacial ∆µ to rejuvenate practical lithium metal batteries.

关键词： Chemical potential difference Li deposition Li metal battery Partial molar volume Polymer electrolyte

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Correction: Effect of MXene content on the electromagnetic wave absorption performance of MXene-based composites

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Journal of Materials science 2024年第36期59卷 17293-17293页

作者： An, Boyuan Zhang, Dongjie Liu, Yuyan Fan, Zhimin Tan, Huifeng Xie, Zhimin National Key Laboratory of Science and Technology On Advanced Composites in Special Environments Center for Composite Materials and Structures Harbin Institute of Technology Harbin China MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical Engineering Harbin Institute of Technology Harbin China

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