检索结果-内蒙古大学图书馆

Efects of Defect,Mean Stress and Lower Loading on High Cycle and Very High Cycle Fatigue Behavior of Ti‑6Al‑4V Alloy

引用

Acta Metallurgica Sinica(English Letters) 2025年第3期38卷 435-448页

作者： Yiyun Guo Lei Wu Yibo Shang Chengqi Sun State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China Guobiao(Beijing)Testing&Certifcation Co. Ltd.Beijing 101400China Fundamentals Department Air Force Engineering UniversityXi’an 710051China National Key Lab of Aerospace Power System and Plasma Technology Air Force Engineering UniversityXi’an 710038China

In this study,the efects of defect,mean stress and lower loading are investigated for high cycle(HCF)and very high cycle fatigue(VHCF)behavior of Ti-6Al-4V *** indicates that the S-N curve of Ti-6Al-4V alloy exhibits a linear decreasing trend or a plateau characteristic in HCF and VHCF regimes,which depends on the defect size and stress *** strength decreases with increasing the defect size,and it is irrespective of stress *** fatigue crack initiates from specimen surface at R=−1 in both HCF and VHCF *** the fatigue crack initiates from the subsurface or the interior of the specimen at R=0.1 in VHCF regime.A sequence of lower stress amplitude below the fatigue strength at 10^(9) cyc has no or negligible infuence on the fatigue life of 10^(5)-10^(9) *** lower stress amplitude in variable amplitude loadings does not afect the failure *** residual compressive stress relaxation is not observed after a large number of lower loadings under ultrasonic frequency fatigue *** formula and Goodman formula give dangerous predictions of VHCF strength for both smooth specimens and specimens with defects.

关键词： Ti-6Al-4V titanium alloy Very high cycle fatigue Defect Stress ratio Lower stress amplitude

来源：评论

学校读者我要写书评

暂无评论

Multi-Lever EarlyWarning forWind and Photovoltaic Power Ramp Events Based on Neural Network and Fuzzy Logic

引用

Energy Engineering 2024年第11期121卷 3133-3160页

作者： Huan Ma Linlin Ma Zengwei Wang Zhendong Li Yuanzhen Zhu Yutian Liu Power Grid Technology Center State Grid Shandong Electric Power Research InstituteJinan250003China Shandong Electric Power Dispatching and Control Center State Grid Shandong Electric Power CompanyJinan250012China Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong UniversityJinan250061China

With the increasing penetration of renewable energy in power system,renewable energy power ramp events(REPREs),dominated by wind power and photovoltaic power,pose significant threats to the secure and stable operation of power *** paper presents an early warning method for REPREs based on long short-term memory(LSTM)network and fuzzy ***,the warning levels of REPREs are defined by assessing the control costs of various power control ***,the next 4-h power support capability of external grid is estimated by a tie line power predictionmodel,which is constructed based on the ***,considering the risk attitudes of dispatchers,fuzzy rules are employed to address the boundary value attribution of the early warning interval,improving the rationality of power ramp event early *** results demonstrate that the proposed method can generate reasonable early warning levels for REPREs,guiding decision-making for control strategy.

关键词： Early warning machine learning power system security renewable energy power ramp event smart grid

来源：评论

学校读者我要写书评

暂无评论

Realizing high efficiency and large-area sterilization by a rotating plasma jet device

引用

Plasma Science and technology 2022年第4期24卷 133-146页

作者： Hua LI Minglei LI Hongcheng ZHU Yuhan ZHANG Xiaoxia DU Zhencheng CHEN Wenxiang XIAO Kun LIU School of Life and Environmental Sciences Guilin University of Electronic TechnologyGuilin 541004People's Republic of China The State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 400044People's Republic of China

By tilting a plasma jet and rotating 360°,a large-area can be scanned and sterilized in a short *** with the previous array device,this pipe has the significant advantages of high sterilization uniformity and low gas ***,a rotatable plasma jet device,which can control the swing and rotation of a jet pipe,is designed,and a corresponding theoretical model is established to guide the ***,with Staphylococcus aureus(***)and Escherichia coli(***)as the target bacteria,the device achieves a short sterilization time of 158 s—the minimum sterilization flow of *** and *** is 0.8 slm and 0.6 slm,*** device is compared with an array plasma sterilization device in terms of sterilization speed and gas *** results show that the device is not only better than an array plasma sterilization device with respect to scanning uniformity,but also far less than the array plasma sterilization device in gas consumption of 5 ***,the device has great potential in applications involving efficient,large-area sterilization.

关键词： low-temperature plasma sterilization rotate large area applications

来源：评论

学校读者我要写书评

暂无评论

Damage effect and progressive failure mechanism of sandstone considering different flaw angles under dynamic loading

Rock Mechanics Bulletin

引用

Rock Mechanics Bulletin 2024年第1期3卷 81-96页

作者： Dongliang Ji Hui Cheng Hongbao Zhao State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuangChina Key Laboratory of Mechanical Behavior Evolution and Control of Traffic Engineering Structures in Hebei Shijiazhuang Tiedao UniversityShijiazhuangChina School of Energy and Mining Engineering China University of Mining and Technology(Beijing)BeijingChina

In many engineering applications,it is essential to have information about rocks that inherently contain preexisting flaws under dynamic loading *** impact tests are conducted on samples with varying flaw angles using the split Hopkinson pressure bar(SHPB)test system and the Digital Image Correlation system(DIC).The characteristics of the samples after dynamic loading,including dynamic strength,energy dissipation,and fractal fracture,are compared and *** the flaw angle increases,the peak stress and strain exhibit a typical V-shaped pattern,reaching the minimum value at 30,and the initial initiation position shifts from the flaw tips to the middle of the *** modes can be divided into three modes depending on the flaw *** progressive failure process,taking into account the heterogeneity of the rock,is demonstrated by developing an elastic damage constitutive model that uses dynamic compression and tensile tests to parameterize *** the flaw angle increases,the initial damage zone also moves from the flaw tips to the middle of the *** around the hole with redistributed stress are observed,and the failure mechanisms can be explained with the aid of strain energy density(SED).Using fracture mechanics,the analytical solution of stress around the flaw is provided,and the variation of crack initiation angle,stress distribution,and energy dissipation under different flaw angles is theoretically explained,which is in good agreement with the experimental and simulated results.

关键词： Dynamic loading Damage evolution Constitutive model Flaw angle Energy dissipation

来源：评论

学校读者我要写书评

暂无评论

Active Flow Control of Hydrodynamic Characteristics around a Square Cylinder with Symmetric Synthetic Jets 34th

Active Flow Control of Hydrodynamic Characteristics around a...

引用

34th International Ocean and Polar Engineering Conference, ISOPE 2024

作者： Ding, Hao Liu, Mingyue Zhou, Jihui Zhu, Shenglong State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai China SJTU YaZhou Bay Institude of Deepsea Science and Technology Sanya China System Design Institute of Hubei Aerospace Technology Academy Wuhan China

ISBN: (纸本)9781880653784

To explore the active control method of the square cylinder wake field modification, a self-developed piston-driven synthetic jet actuator is used to generate periodic blowing and suction jets through the slits to affect the external flow field. The flow characteristics around the square cylinder controlled by synthetic jet is experimentally investigated with the force measuring system and Particle Image Velocity (PIV) technique. The statistical fluid forces, the frequency characteristics, and the time-averaged flow flied are compared with different control parameters, i.e. jet exit angle (β), the momentum coefficient (Cμ), and the excitation frequency (f*). With control, dramatic reduction in CLrms (up to 61%) is attained and the corresponding value of CD is 12% at β =45°. Narrower and longer backflow region represents a decrease in flow-induced forces. © 2024 by the International Society of Offshore and Polar Engineers (ISOPE).

关键词： Jets

来源：评论

学校读者我要写书评

暂无评论

Enhanced electrical performance in CaBi_(4)Ti_(4)O_(15)ceramics through synergistic chemical doping and texture engineering

引用

Journal of Materiomics 2024年第2期10卷 471-479页

作者： Le Zhao Guohao Li Xiao Zhai Weijie Kuai Yuzhi Zhai Gang Tian Zhigang Gai Minglei Zhao Juan Du Hongjun Zhang Limei Zheng School of Information and Automation Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan250353China School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityJinan250100China Center for Optics Research and Engineering(CORE) Key Laboratory of Laser and Infrared System of Ministry of EducationShandong UniversityQingdaoShandong266237China College of Materials Science and Engineering Liaocheng UniversityLiaocheng252059China Functional Materials and Acoustooptic Instruments Institute School of Instrumentation Science and EngineeringHarbin Institute of TechnologyHarbin150080China

High-temperature piezoelectric materials with excellent piezoelectricity,low dielectric loss and large resistivity are highly desired for many industrial sectors such as aerospace,aircraft and nuclear *** a synergistic design strategy combining microstructural texture and chemical doping is employed to optimize CaBi 4Ti 4O15(CBT)ceramics with bismuth layer *** textured microstructure with an orientation factor of 80%e82%has been successfully achieved by the spark plasma sintering ***,by doping MnO_(2),both advantages of hard doping and sintering aids are used to obtain the excellent electrical performance of d_(33)=27.3 pC/N,tandδ-0.1%,Q_(31)~2,307 and electrical re-sistivityρ~6.5×10^(10)Ω·*** to 600℃,the 0.2%(in mass)Mn doped CBT ceramics still exhibit high performance of d_(33)=26.4 pC/N,r~1.5×10^(6)Ω·cm and tandδ~15.8%,keeping at an applicable level,thus the upper-temperature limit for practical application of the CBT ceramics is greatly *** work paves a new way for developing and fabricating excellent high-temperature piezoelectric materials.

关键词： CaBi_(4)Ti_(4)O_(15) Piezoelectricity Mechanical quality factor Resistivity

来源：评论

学校读者我要写书评

暂无评论

Fused Tapered Fan-in/Fan-out Device of 6-Mode 7-Core Fiber Based On OM3 Multimode Fiber

Fused Tapered Fan-in/Fan-out Device of 6-Mode 7-Core Fiber B...

引用

2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings, ACP/POEM 2023

作者： Yang, Chen Du, Haoze Shao, Yuanhui Zhang, Fengming Liu, Zhuyixiao Zhang, Senyu Zhao, Zhiyong Tang, Ming R&d Center & Optics Valley Laboratory State Key Laboratory of Optical Fiber and Cable Manufacture Technology Wuhan China National Engineering Laboratory for Next Generation Internet Access System Wuhan China

ISBN: (纸本)9798350312614

Fused tapered Fan-in/Fan-out devices of few-mode multi-core fiber have received attentions in recent ten years. Most devices are based on special designed fibers which are called 'bridge fiber'. A low insertion loss and low-cost Fan-in/Fan-out device using OM3 fiber as the bridge fiber is fabricated and demonstrated in this paper. The insertion losses of LPOl, LPlla, LPllb, and LP2la are less than 1dB, and the insertion loss of LP2lb and LP02 are 2.02dB and 2.2dB. © 2023 IEEE.

关键词： Fan-in/Fan-out device few-mode multi-core fiber multimode fiber Spatial division multiplexing

来源：评论

学校读者我要写书评

暂无评论

Nonconvex Noise-Tolerant Neural Model for Repetitive Motion of Omnidirectional Mobile Manipulators

引用

IEEE/CAA Journal of Automatica Sinica 2023年第8期10卷 1766-1768页

作者： Zhongbo Sun Shijun Tang Jiliang Zhang Junzhi Yu the Department of Control Engineering Changchun University of TechnologyChangchun 130012China IEEE College of Information Science and Engineering Northeastern UniversityShenyang 110819China the State Key Laboratory for Turbulence and Complex Systems Department of Advanced Manufacturing and RoboticsCollege of EngineeringPeking UniversityBeijing 100871China

Dear Editor,Quadratic programming problems(QPs)receive a lot of attention in various fields of science computing and engineering applications,such as manipulator control[1].Recursive neural network(RNN)is considered t... 详细信息

关键词： directional programming hardware

来源：评论

学校读者我要写书评

暂无评论

GelPixel: A Single-Pixel-Based Tactile Sensor

GelPixel: A Single-Pixel-Based Tactile Sensor

引用

2023 IEEE International Conference on Real-Time Computing and robotics, RCAR 2023

作者： Huang, Binhua Li, Xiaoyu Sumari, Putra Ye, Chaoxiang Zhou, Zhenning Yin, Meng Yi, Zhengkun Wu, Xinyu Shenzhen Institute of Artificial Intelligence and Robotics for Society Siat Branch Shenzhen518055 China Universiti Sains Malaysia School of Computer Science 11800 Malaysia Chinese Academy of Sciences Guangdong Provincial Key Laboratory of Robotics and Intelligent System Shenzhen Institute of Advanced Technology Shenzhen518055 China

ISBN: (纸本)9798350327182

In this paper, we present the design and development of a novel optical tactile sensor that uses a single-pixel color light-to-frequency converter (TCS3200) and spectral decoding to recognize presses at different positions. This innovative approach overcomes the limitations associated with camera-based sensors, such as increased manufacturing costs and shape restrictions, enabling potential integration as a skin-like layer over a robot's body. Our proposed direct light propagation structure demonstrates enhanced sensitivity and a broader measuring range compared to traditional reflection structures. Using Ecoflex as the elastomer, the sensor's design incorporates a three-layer structure, including an LED layer, an elastomer layer, and a color sensor layer. Experimental results demonstrate that the proposed sensor performs well in localization tasks, achieving over 95% accuracy using multi-target regression for rendering poked positions. This study demonstrates the potential of single-pixel-based tactile sensors in various applications and provides a foundation for further exploration in this area. © 2023 IEEE.

关键词： Tactile sensors

来源：评论

学校读者我要写书评

暂无评论

RGBD Navigation: A 2D navigation framework for visual SLAM with pose compensation

RGBD Navigation: A 2D navigation framework for visual SLAM w...

引用

IEEE International Conference on Real-time Computing and robotics (RCAR)

作者： Teng Zhang Pengfei Wang Fusheng Zha Wei Guo Mantian Li The State Key Laboratory of Robotics Harbin Institute of Technology Harbin China

The breakthrough in SLAM(Simultaneous Localization and Mapping) technology has greatly driven the development of robot navigation. Currently, LiDAR navigation based on the development of LiDAR SLAM and ROS navigation stack is very mature. However, due to the inability of open-source vSLAM(visual Simultaneous Localization and Mapping) and VO(Visual Odometry) to establish dense maps suitable for navigation, poor adaptability of visual information to ROS navigation stack, and map positioning problems caused by sensor characteristics, the development of visual navigation faces difficulties. To address the above three issues, this work provides a framework called RGBD Navigation, which utilizes RGBD sensors to achieve vision-based navigation for robots. This framework establishes a dense point cloud map based on the pose information provided by vSLAM/VO, depth images and RGB images, and converts it into a 2D occupancy grid map. And, convert the depth image into two-dimensional laserscan information. Finally, establish a "map-to-odom" positioning node based on the pose provided by SLAM/VO to achieve robot positioning on the map. This framework solves the three main problems of visual sensor adaptation to the ROS Navigation stack, and achieves the establishment of a vision-based 2D navigation system.

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：