检索结果-内蒙古大学图书馆

Test piece design, mechanical properties and fracture strain in two-step tensile testing of lightweight materials at high strain rates

引用

International Journal of Impact Engineering 2025年 206卷

作者： Da Cai Hao Jiang Peng Wang Qing Wang Weifeng Gan Junjia Cui Guangyao Li State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan University Changsha 410082 China Battery System Development Department Contemporary Amperex Technology Co. Ltd Ningde 352100 China Shenzhen Huashun Intelligent Equipment Co. Ltd Shenzhen 518119 China Shenzhen Automotive Research Institute Beijing Institute of Technology Shenzhen 518119 China

Continuous forming at high strain rates is an important research direction for future precision forming of light alloys. In this study, dynamic behavior of AA5052 aluminum alloy in two-step tensile testing at high strain rates were investigated. Special two-step tensile test piece at high strain rate was designed. The test piece of the special design contained a weak structural notch area and a dog-bone shaped area. The test piece was pre-stretched to a pre-determined strain so that the weak region broke. Then a secondary stretching was performed. The response surface equations of pre-strain and pre-strain rate were established separately to evaluate the functional relationship between the notch interval, tensile velocity and strain rate, and equivalent plastic strain. The effects of the parameters on the fracture strain were compared. The results showed that the test pieces could meet the requirements of the two-step tensile test at high strain rates. The pre-strain and pre-strain rate were affected by the size of the notch interval and the tensile velocity. The increase of tensile strength was related to pre-strain and secondary strain rate. The linear cumulative damage criterion can be used to interpret the two-step stretching at high strain rates. When the strain rate in single-step stretching is the same as the strain rate in each step of two-step stretching, the fracture strain in single-step stretching can be substituted for the fracture strain in two-step stretching. Research can help solve the problems of poor formability and early failure of lightweight alloys.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Modal Analysis of Optical Waveguide using a Novel Symplectic Compact FDTD Schemes

Modal Analysis of Optical Waveguide using a Novel Symplectic...

引用

International Conference on Numerical Electromagnetic Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO)

作者： Xiaojing Kuang Kong Meng Qi Qi Xin Zeng Zhixiang Huang Mingshen Chen The Anhui Province key laboratory of simulation & design for electronic information system Hefei Normal University Hefei China Digital circuit design east china institute of photo-electronic Suzhou China Key laboratory of intelligent & computing & signal processing Anhui University Hefei China School of Electronic Engineering Huainan Normal University Huainan China

ISBN: (数字)9781728169668

ISBN: (纸本)9781728169675

For modal analysis of longitudinally invariant optical devices, the compact-finite-difference time-domain is an efficient algorithm for alleviating the large amount of storage space and computing time under the 3D complex structure simulation. However, this algorithm needs to scale down the time step to mitigate the numerical dispersion errors while simulating optical waveguide working at high frequency. Here, a novel high-order symplectic compact FDTD scheme is proposed, which is attributed to the theory combination of the fast-spatial scheme and stable temporal scheme. The research results not only verify the effectiveness by numerical experiment on a planar dielectric waveguide with complex cross section, but also provide efficient theoretical guidance for the design and optimization of optical devices at the nanometer scale.

关键词： Electromagnetic waveguides Optical waveguide theory Adaptive optics Numerical models Time-domain analysis Optical waveguides Finite difference methods

来源：评论

学校读者我要写书评

暂无评论

Step-length optimization based on genetic algorithm for a parallel mobile robot

Step-length optimization based on genetic algorithm for a pa...

引用

International Conference on Information Science and Control Engineering (ICISCE)

作者： Shuang Liu Wei Chen Hang Wu Wenchang Zhang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Tianjin University of Technology Tianjin China Academy of Military Sciences of Chinese PLA Institute of Medical Support Technology Tianjin China

With the development of technology, parallel mobile robots have been paid more attention in various industries due to the strong load capacity, high running stability and rapid response speed. However, step-length optimization is an important but challenging task for this kind of mobile robot. Step length has dramatic effect on the stability of robot and the performance of electric cylinder. Balancing the speed characteristics and stability margin, we propose a genetic algorithm to solve this problem and design a novel fitness function that can measure the motion characteristics of parallel mobile robot. Effectiveness of our method is verified by experiments.

关键词： Industries Information science Control engineering Service robots Mobile robots Motion measurement Task analysis

来源：评论

学校读者我要写书评

暂无评论

Study on the mechanism of microcrack propagation in bentonite under confining pressure conditions

引用

Quarterly Journal of Engineering Geology and Hydrogeology 2025年

作者： Guo, Jingna Liu, Jiangfeng Liu, Daoping Zhao, Yu Lei, Min Shi, Hao School of Applied Mathematics Chengdu University of Information Technology Sichuan Chengdu610225 China State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and Technology Jiangsu Xuzhou221116 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chendu610213 China School of Civil Engineering and Architecture Anhui University of Science and Technology Huainan232001 China

For underground nuclear disposal repositories, sealing performance is crucial to ensuring long-term operational safety. Bentonite, widely employed as a sealing material, effectively reduces leakage risks owing to its self-healing capacity. However, a comprehensive investigation of gas migration mechanisms in bentonite is imperative to elucidate the underlying leakage dynamics. This study not only offers theoretical insights for the safety assessment and design optimization of disposal repositories but also holds substantial practical significance in ensuring their secure performance. To accurately model gas migration in saturated bentonite, this study systematically investigates the effects of pore pressure on soil deformation and experimentally evaluates the impact of damage evolution on permeability and elastic modulus. Building on these experimental insights, we propose a coupled fluid-solid constitutive model. This model elucidates the progressive development of microcracks within bentonite under increasing gas pressure, providing a mechanistic understanding of fracture propagation in sealing systems. By integrating experimental data from bentonite hydration and gas breakthrough tests, the study verifies that gas migration under flexible boundary conditions is primarily governed by the dilatancy effect of bentonite. Furthermore, the model's validity and applicability are demonstrated. Subsequently, the model is employed to systematically investigate the influence of confining pressure on (1) the evolution of microcracks in bentonite, (2) permeability variations, and (3) gas breakthrough pressure thresholds. Based on these analyses, theoretical mitigation strategies to prevent gas breakthrough are established for specific confining pressure ranges. © 2025 The Author(s). Published by The Geological Society of London. All rights, including for text and data mining (TDM), artificial intelligence (AI) training, and similar technologies, are reserved. For permissions:

关键词： Microcracks

来源：评论

学校读者我要写书评

暂无评论

Compound nonlinear energy sink with multiple motion types for absorbing energy from wide excitation ranges

引用

Journal of Sound and Vibration 2025年 617卷

作者： Jianen Chen Jiaqi Zhao Wei Zhang Min Sun Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin 300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin 300384 China School of Civil Engineering and Architecture Guangxi University Nanning 530004 China School of Science Tianjin Chengjian University Tianjin 300384 China

Nonlinear energy sink (NES) has garnered significant attention since its inception due to its notable broadband vibration reduction capability. However, the introduction of strong nonlinear characteristics by NESs complicates system responses, leading to a loss of effectiveness when the excitation force exceeds a specific threshold. Consequently, NESs have limited applicability in engineering because they are effective only within a constrained range of excitation amplitude. In this study, a compound NES (CNES) with multiple motion types is designed to extend the effective force range while maintaining broadband vibration reduction capability. The CNES is distinguished by its piecewise stiffness, collision mechanisms, and unique design of two-degree-of-freedom oscillators. The wide effective range of the CNES is demonstrated through slow linear sweep and fixed-frequency tests. The results indicate that the CNES effectively reduces vibrations in the primary oscillator (PO) with various resonant frequencies. Notably, the CNES achieves significant vibration reduction over a particularly wide range of excitation amplitude when controlling the PO with relatively high resonance frequencies (approximately 10.5 Hz and 19 Hz). However, a nonnegligible limitation of the CNES is its restricted effective range of excitation amplitude when the PO resonates at lower frequency (approximately 7 Hz). Moreover, five motion types of the CNES are identified and analyzed, with one motion type autonomously emerging in response to changes in excitation parameters, ensuring excellent vibration reduction performance across a wide excitation range. Finally, the performance of the CNES and a degraded single-degree-of-freedom CNES are compared to further demonstrate the extension effect of the multiple motion types on the effective range. The CNES can be used in scenarios where the parameters of protected systems and excitations vary widely, providing a thought to improve the NESs.

关键词： Compound nonlinearity Compound features Vibration reduction Vibration test Multiple motion types Effective range

来源：评论

学校读者我要写书评

暂无评论

Study on Rotating Speed Control of Dissimilar Metal Friction Stir Welding based on Fuzzy PID

引用

Journal of Physics: Conference Series 2022年第1期2206卷

作者： Yongning Liu Zhifeng Qiao Qingjian Liu Jiahao Huang Kang Fu Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin 300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education (Tianjin University of Technology)

The demand for lightweight vehicles that achieve energy conservation and emission reduction continues to grow. Aluminum alloys were commonly applied to the automotive industry to reduce the structural quality of the entire vehicle. However, the cost of aluminum alloy was higher than that of steel, so the industry considered the use of aluminum in combination with low-cost materials such as steel. Traditional welding technology was limited by the great physical difference between aluminum alloy and steel. Friction Stir Welding, a solid phase welding technology, can overcome the connection problem of aluminum and its alloys with steel, but the process parameters of FSW directly affect the welding quality. This paper established the FSW process of two different metals of DC05 and AL6061. Aimed to get a good welding joint, the error of tool speed is reduced by fuzzy PID system established in this paper, and the tool speed is controlled stably. Simulink simulation was established, and compared with the simulation results, fuzzy PID control can control the precision and stability of the tool speed of FSW, improve the welding quality, and provide a certain theoretical basis for the tool speed control.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Anionic Chemistry Modulation Enabled Environmental Self-Charging Aqueous Zinc Batteries: The Case of Carbonate Ions

引用

Angewandte Chemie 2024年第39期136卷

作者： Guangmeng Qu Lu Wang Yongzheng Zhao Dedong Wang Xixi Zhang Bin Wang Fengbo Wang Zhongxin Jing Xijin Xu Liqiang Xu Hongfei Li Key Laboratory of Colloid and Interface Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shandong University Jinan Shandong 250100 P. R. China School of Physics and Technology University of Jinan Jinan Shandong 250022 P. R. China School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen Guangdong 518055 China

Anionic chemistry modulation represents a promising avenue to enhance the electrochemical performance and unlock versatile applications in cutting-edge energy storage devices. Herein, we propose a methodology that involves anionic chemistry of carbonate anions to tailor the electrochemical oxidation-reduction reactions of bismuth (Bi) electrodes, where the conversion energy barrier for Bi (0) to Bi (III) has been significantly reduced, endowing anionic full batteries with enhanced electrochemical kinetics and chemical self-charging property. The elaborately designed batteries with an air-switch demonstrate rapid self-recharging capabilities, recovering over 80 % of the electrochemical full charging capacity within a remarkably short timeframe of 1 hour and achieving a cumulative self-charging capacity of 5 Ah g −1 . The aqueous self-charging battery strategy induced by carbonate anion, as proposed in this study, holds the potential for extending to various anionic systems, including seawater-based Cl − ion batteries. This work offers a universal framework for advancing next-generation multi-functional power sources.

关键词：

来源：评论

学校读者我要写书评

暂无评论

The Age of Generative AI and AI-Generated Everything

arXiv

引用

arXiv 2023年

作者： Du, Hongyang Niyato, Dusit Kang, Jiawen Xiong, Zehui Zhang, Ping Cui, Shuguang Shen, Xuemin Mao, Shiwen Han, Zhu Jamalipour, Abbas Vincent Poor, H. Kim, Dong In School of Computer Science and Engineering Nanyang Technological University Singapore639798 Singapore School of Automation Guangdong University of Technology Key Laboratory of Intelligent Information Processing and System Integration of IoT Ministry of Education Guangzhou510006 China Guangdong-HongKong-Macao Joint Laboratory for Smart Discrete Manufacturing Guangzhou510006 China Pillar of Information Systems Technology and Design Singapore University of Technology and Design Singapore487372 Singapore State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications China Chinese University of Hong Kong Shenzhen China Department of Electrical and Computer Engineering University of Waterloo WaterlooONN2L 3G1 Canada Department of Electrical and Computer Engineering Auburn University AuburnAL36849-5201 United States Department of Electrical and Computer Engineering University of Houston HoustonTX77004 United States Department of Computer Science and Engineering Kyung Hee University Seoul446-701 Korea Republic of School of Electrical and Information Engineering University of Sydney SydneyNSW2006 Australia Department of Electrical and Computer Engineering Princeton University PrincetonNJ08544 United States Department of Electrical and Computer Engineering Sungkyunkwan University Suwon16419 Korea Republic of

Generative AI (GAI) has emerged as a significant advancement in artificial intelligence, renowned for its language and image generation capabilities. This paper presents "AIGenerated Everything" (AIGX), a concept that extends GAI beyond mere content creation to real-time adaptation and control across diverse technological domains. In networking, AIGX collaborates closely with physical, data link, network, and application layers to enhance real-time network management that responds to various system and service settings as well as application and user requirements. Networks, in return, serve as crucial components in further AIGX capability optimization through the AIGX lifecycle, i.e., data collection, distributed pre-training, and rapid decision-making, thereby establishing a mutually enhancing interplay. Moreover, we offer an in-depth case study focused on power allocation to illustrate the interdependence between AIGX and networking systems. Through this exploration, the article analyzes the significant role of GAI for networking, clarifies the ways networks augment AIGX functionalities, and underscores the virtuous interactive cycle they form. This article paves the way for subsequent future research aimed at fully unlocking the potential of GAI and networks. © 2023, CC BY.

关键词： Decision making

来源：评论

学校读者我要写书评

暂无评论

Influence of vibration on mechanical polishing micro-structured surface using discrete element method

引用

International Journal of Machining and Machinability of Materials 2020年第1期22卷 24-46页

作者： Wang, Guilian Lv, Bingrui Liu, Li Liu, Bin Zhou, Haibo Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China Tianjin Laboratory of Control Theory and Applications in Complicated System Tianjin300384 China School of Electrical and Electronic Engineering Tianjin University of Technology Tianjin300384 China

A model using discrete element method (DEM) was conducted to simulate vibration assisted mechanical polishing micro-structured surface process by particle flow code in three dimensions (PFC3D). The effect laws of vibration frequency and amplitude on abrasive grains and polishing force were researched in detail according to the simulation results. The effects of vibration on the particles average motion velocity in one fluid cell were researched, and the simulation results show that average velocity increases with increase of vibration frequency and amplitude on the whole. The effects of vibration on the unbalanced force acting on the workpiece surface were quantified at first. The changes of average unbalanced force obviously increase for low feed rate with increase of frequency and increase approximately linearly with increase of amplitude. It is concluded that vibration with high frequency and great amplitude can significantly increase machining efficiency and improve surface quality in micro-structured surface polishing. Copyright © 2019 Inderscience Enterprises Ltd.

关键词： Finite difference method

来源：评论

学校读者我要写书评

暂无评论

Analysis of Anchor-Based and Anchor-Free Object Detection Methods Based on Deep Learning

Analysis of Anchor-Based and Anchor-Free Object Detection Me...

引用

IEEE International Conference on Mechatronics and Automation

作者： Shujian Liu Haibo Zhou Chenming Li Shuo Wang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin China

ISBN: (数字)9781728164168

ISBN: (纸本)9781728164175

As one of the core mission of computer vision, object detection has been widely applied with the rapid development of computer technology, especially in the fields of face detection, behavior detection, auto driving, and intelligent monitoring. Aiming at the shortcomings of the traditional object detection, such as low detection accuracy, low efficiency and poor robustness, this article summarizes deep learning-based detectors of two kinds of modules: Anchor-Based and Anchor-Free. The performance of each detector is compared and analyzed in this paper as well. In addition, we summarize the development of object detection's key technologies from the aspect of improvement of Backbone, the optimization of NMS, imbalance of positive and negative samples' solution etc. Finally, the development trend of object detection is discussed from the prospect of lightweight detection model, weakly supervision detection and small object detection etc.

关键词：

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：