检索结果-内蒙古大学图书馆

9th International Conference on Collision and Grounding of Ships and Offshore Structures, ICCGS 2023

作者： Sha, Yanyan Department of Mechanical and Structural Engineering and Materials Science University of Stavanger Stavanger Norway

ISBN: (纸本)9781032611303

Reinforce concrete (RC) structures have been used to construct various types of offshore structures in the past decades. Reinforce concrete has many advantages such as high strength, relatively low cost, and easy maintenance. Therefore, reinforced concrete has been used to construct the supporting structures of offshore platforms, wind turbines, and floating bridges. Nonetheless, offshore reinforced concrete structures are under the threat of collision loads from service and passing ships. Since offshore reinforced concrete structures are typically thin-walled structures, one major issue is the punching shear damage of such structures under ship collision loads. Recently, ultra-high-performance concrete (UHPC) has been increasingly used for onshore structures. UHPC has demonstrated higher impact resistance than ordinary reinforced concrete. However, research on UHPC structures under ship collision loads has seldom been conducted. In this paper, numerical simulations of ship collision with thin-walled UHPC structures are conducted using detailed finite element models. The application of different UHPC material models on ship collision simulations is discussed. The response of UHPC and normal RC structures are also compared. It is found that with calibrated parameters, the CSCM material model in LS-DYNA can be used for modelling UHPC in ship collision simulations. The results show that using UHPC material can effectively increase the ship collision resistance of offshore structures compared with ordinary reinforced concrete. © 2024 The Author(s).

关键词： Reinforced concrete

来源：评论

学校读者我要写书评

暂无评论

Ultimate and residual strength assessments of intact and collision damaged columns of the Bjørnafjorden floating bridge 9th

Ultimate and residual strength assessments of intact and col...

引用

9th International Conference on Collision and Grounding of Ships and Offshore Structures, ICCGS 2023

作者： Yu, Zhaolong Wang, Xintong Moan, Torgeir Amdahl, Jørgen Sha, Yanyan Norway Department of Mechanical and Structural Engineering and Materials Science University of Stavanger Norway

ISBN: (纸本)9781032611303

The Norwegian Public Road Administration (NPRA) has initiated an ambitious project to replace the current ferry crossing solutions with floating bridges over the wide and deep Norwegian fjords. This will substantially reduce the travelling time among major cities in Norway. It is found that ship collisions represent major critical loads to the safety and integrity of floating bridges that governs the structural design. This paper investigates the ultimate and residual strength of columns in an initial design of the Bjørnafjorden floating bridge before and after ship collisions with an initial kinetic energy of 125 MJ and 150 MJ respectively corresponding to a 10,000-year event as estimated from risk assessment. The ultimate bending and torsional capacities are assessed. Three different approaches are adopted, (1) the nonlinear finite element method using LS-DYNA;(2) A semi-analytical code PULS based on energy methods;(3) DNV rules-based formulations. The results are compared and discussed. © 2024 The Author(s).

关键词： Structural design

来源：评论

学校读者我要写书评

暂无评论

Dealloying of an amorphous TiCuRu alloy results in a nanostructured electrocatalyst for hydrogen evolution reaction

引用

Carbon Energy 2023年第8期5卷 87-97页

作者： Jinsen Tian Yuanchao Hu Wenfei Lu Jiahua Zhu Xiaodi Liu Jun Shen Gang Wang Jan Schroers College of Mechatronics and Controlling Engineering Shenzhen UniversityShenzhenChina Shenzhen Key Laboratory of High Performance Nontraditional Manufacturing College of Mechatronics and Control EngineeringShenzhen UniversityShenzhenChina Department of Mechanical Engineering&Materials Science Yale UniversityNew HavenConnecticutUSA Department of Inorganic Materials School of Materials Science and EngineeringTongji UniversityShanghaiChina Laboratory for Microstructures Institute of MaterialsShanghai UniversityShanghaiChina

Development of an electrocatalyst that is cheap and has good properties to replace conventional noble metals is important for H_(2) *** this study,dealloying of an amorphous Ti_(37)Cu_(60)Ru_(3) alloy was performed to prepare a freestanding nanostructured hydrogen evolution reaction(HER)*** effect of dealloying and addition of Ru to TiCu alloys on the microstructure and HER properties under alkaline conditions was investigated.3 at.%Ru addition in Ti_(40)Cu_(60) decreases the overpotential to reach a current density of 10mA cm^(-2) and Tafel slope of the dealloyed samples to 35 and 34mV dec−*** improvement of electrocatalytic properties was attributed to the formation of a nanostructure and the modification of the electronic structure of the ***-principles calculations based on density function theory indicate that Ru decreases the Gibbs free energy of water *** work presents a method to prepare an efficient electrocatalyst via dealloying of amorphous alloys.

关键词： amorphous alloy dealloying first-principles calculations HER TiCuRu

来源：评论

学校读者我要写书评

暂无评论

Amorphous Iridium Oxide-Integrated Anode Electrodes with Ultrahigh Material Utilization for Hydrogen Production at Industrial Current Densities

引用

Nano-Micro Letters 2024年第10期16卷 225-239页

作者： Lei Ding Kui Li Weitian Wang Zhiqiang Xie Shule Yu Haoran Yu David ACullen Alex Keane Kathy Ayers Christopher BCapuano Fangyuan Liu Pu-Xian Gao Feng-Yuan Zhang Department of Mechanical Aerospace and Biomedical EngineeringUniversity of TennesseeKnoxvilleTN 37996USA Oak Ridge National Lab Center for Nanophase Materials SciencesOak RidgeTN 37831USA Nel Hydrogen WallingfordCT 06492USA Institute of Materials Science University of ConnecticutStorrsCT 06269USA Department of Materials Science and Engineering University of ConnecticutStorrsCT 06269USA

Herein,ionomer-free amorphous iridium oxide(IrO_(x))thin electrodes are first developed as highly active anodes for proton exchange membrane electrolyzer cells(PEMECs)via low-cost,environmentally friendly,and easily scalable electrodeposition at room *** with a Nafion 117 membrane,the IrO_(x)-integrated electrode with an ultralow loading of 0.075 mg cm^(-2)delivers a high cell efficiency of about 90%,achieving more than 96%catalyst savings and 42-fold higher catalyst utilization compared to commercial catalyst-coated membrane(2 mg cm^(-2)).Additionally,the IrO_(x)electrode demonstrates superior performance,higher catalyst utilization and significantly simplified fabrication with easy scalability compared with the most previously reported ***,the remarkable performance could be mainly due to the amorphous phase property,sufficient Ir^(3+)content,and rich surface hydroxide groups in ***,due to the high activity,high cell efficiency,an economical,greatly simplified and easily scalable fabrication process,and ultrahigh material utilization,the IrO_(x)electrode shows great potential to be applied in industry and accelerates the commercialization of PEMECs and renewable energy evolution.

关键词： Ionomer-free Amorphous IrOx electrodes Ultrahigh material utilization Scalable electrodeposition Hydrogen production

来源：评论

学校读者我要写书评

暂无评论

Sensitivity study of resolution and convergence requirements for the extended overlap region in wall-bounded turbulence

引用

Physical Review Fluids 2024年第8期9卷 L082601-L082601页

作者： Sergio Hoyas Ricardo Vinuesa Peter Schmid Hassan Nagib Instituto Universitario de Matemática Pura y Aplicada Universitat Politècnica de València FLOW Engineering Mechanics KTH Royal Institute of Technology Department of Mechanical Engineering Division of Physical Sciences and Engineering (PSE) King Abdullah University of Science and Technology (KAUST) Mechanical Materials and Aerospace Engineering Armour College of Engineering ILLINOIS TECH

Direct numerical simulations (DNSs) are among the most powerful tools for studying turbulent flows. Even though the achievable Reynolds numbers are lower than those obtained through experimental means, DNS offers a clear advantage: The entire velocity field is known, allowing for the evaluation of any desired quantity. This capability includes the computation of derivatives of all relevant terms. One such derivative provides the indicator function, which is the product of the wall distance and the wall-normal derivative of the mean streamwise velocity. This derivative may depend on mesh spacing and distribution, but it is extremely affected by the convergence of the simulation. The indicator function is crucial for understanding inner and outer interactions in wall-bounded flows and describing the overlap region between them. We find a clear dependence of this indicator function on the mesh distributions we examine, raising questions about classical mesh and convergence requirements for DNS and achievable accuracy. Within the framework of the logarithmic plus linear overlap region, coupled with a parametric study of channel flows and some pipe flows, sensitivities of extracted overlap parameters are examined. This study reveals a path to establishing their high-Reτ or nearly asymptotic values at modest Reynolds numbers, but larger than the ones used in this work, accessible by high-quality DNS with reasonable cost.

关键词： Boundary layers Complex fluids Three-dimensional turbulence Turbulence Turbulent boundary layers

来源：评论

学校读者我要写书评

暂无评论

Eggshell nanoparticle reinforced recycled low-density polyethylene: A new material for automobile application

引用

Journal of King Saud University - engineering sciences 2023年第6期35卷 406-414页

作者： Bello, Sefiu Adekunle Raji, Nasirudeen Kolawole Kolawole, Maruf Yinka Adebayo, Mohammed Kayode Adebisi, Jeleel Adekunle Okunola, Kehinde Adekunle AbdulSalaam, Mustekeem Olanrewaju Department of Materials Science and Engineering Kwara State University Malete Nigeria Department of Metallurgical Engineering Yaba College of Technology Lagos Nigeria Department of Mechanical Engineering Kwara State University Malete Nigeria Department of Materials and Metallurgical Engineering University of Ilorin Ilorin Nigeria

Waste from low-density polyethylene products after lifespan accounts for 70% of solid waste in most dumpsites, contributing to environmental impacts. Eggshell foul smells are a threat to human and animal health. Before this study, there was no research documentation on transforming both wastes into green composites for engineering applications. This work developed composites using recycled low-density polyethylene (RLDPE) and eggshell Nanoparticles. They were evaluated structurally and mechanically. Straining, which affirms an improvement in the load-bearing capacity of the RLDPE due to the incorporation of eggshell Nanoparticles, was established by the composite XRD peak broadness. Structural integrities of the composites were confirmed with SEM. Maximum tensile strength was noted at 10% eggshell Nanoparticle additions to the RLDPE, equal to a 68% increase. About 52 and 19% enhancements in respective flexural strength and hardness value with a 0.85% reduction in impact energy were noted at 12% eggshell Nanoparticle additions. The probability value, 0.0481 −2 tensile strength, 21.964 Nmm−2 flexural strength, 21.69 J impact energy, and 59 VHN hardness value using sheet forming technique. Therefore, future usage of the developed RLDPE/10% eggshell Nanoparticle composite is established. © 2021 The Authors

关键词： Nanoparticles

来源：评论

学校读者我要写书评

暂无评论

Mutual promotion on the mechanical and tribological properties of the nacre-like self-lubricant film designed for demanding green tribological applications

引用

Friction 2025年第3期13卷 171-185页

作者： Hongbo Ju Jing Luan Yiping Wang Andrey Bondarev Manuel Evaristo Yaoxiang Geng Junhua Xu Albano Cavaleiro Filipe Fernandes School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Department of Mechanical Engineering ARISECEMMPREUniversity of CoimbraCoimbra 3030-788Portugal TINT-Laboratory for Tribology and Interface Nanotechnology Faculty of Mechanical EngineeringUniversity of LjubljanaAškerčeva 6Ljubljana1000Slovenia School of Engineering Bernal InstituteUniversity of LimerickLimerick V94 T9PXIreland ISEP-School of Engineering Polytechnic of PortoPorto 4200-072Portugal

The inverse relationship between the tribological and mechanical properties of environmentally friendly selflubricant films,induced by the addition of soft lubricant agents that can diffuse quickly at elevated temperatures,has hindered the widespread use of these materials in industrial *** paper took this challenge to break through the above established relationship by developing novel nacrelike multilayered Mo_(2)N–SiN_(x)/Ag–SiN_(x)self-lubricant films via an radio frequency(RF)magnetron sputtering system for real applications where harsh conditions at elevated temperatures *** multilayered films,deposited by alternating deposition of Mo_(2)N–SiN_(x)and Ag–SiN_(x)modulation layers,exhibited three phases of face-centered cubic(fcc)Mo_(2)N,fcc Ag and SiN_(x),where SiN_(x)encapsulated the nano-crystalline Mo_(2)N and Ag phases in each layer to successfully induce a“brick and mortar”nacre-like microstructure(in the area without the coherent structure).The epitaxy growth of the Ag–SiN_(x)layers with thickness below 6 nm on the Mo_(2)N template resulted in an extraordinary increase in both the hardness and elastic modulus,which was able to prevent severe degradation of the mechanical properties caused by the addition of *** room-temperature anti-friction property could be enhanced by increasing the Ag–SiN_(x)layer thickness due to the excellent lubricant nature of Ag,which acts in synergy with Mo_(2)N,while the wear rate below 4×10^(−8)mm^(3)/(N·mm)was due to the high mechanical *** tribological properties at 600℃also benefited from the interlocked multilayered architecture,which allowed an extreme low friction coefficient of~0.12 and a negligible wear rate(WR).This behavior was attributed to the synergism between the lubricant action of Ag and Mo_(2)N and the tribo-phase transformation from Ag_(2)Mo_(4)O_(13)to Ag_(2)MoO_(4).

关键词： radio frequency(RF)magnetron sputtering system Mo_(2)N-SiN_(x)/Ag-SiN_(x)self-lubricant films interlocked structure epitaxial growth lubrication synergism tribo-phase transformation

来源：评论

学校读者我要写书评

暂无评论

Developing Predictive Maintenance Framework for Wind Turbine Blade Erosion: State of the Art and Concept Analysis

Developing Predictive Maintenance Framework for Wind Turbine...

引用

2024 IEEE International Conference on Industrial engineering and engineering Management, IEEM 2024

作者： Ali, Waqar El-Thalji, Idriss Giljarhus, Knut Erik Teigen Delimitis, Andreas Department of Mechanical and Structural Engineering and Materials Science University of Stavanger Stavanger Norway

ISBN: (纸本)9798350386097

The global goal of achieving 2000 gigawatts of offshore wind power by 2050 has driven the development of the wind energy sector. This ambitious goal is facing a significant challenge in maintaining the efficiency and health of the wind turbines. Wind turbine Blade erosion is among the main critical failure modes that lead to high production losses and maintenance expenses. At present, the industry is utilizing manual or drone-based inspection, however, they are targeting more cost-effective and more informative like to predictive maintenance for erosion and severity by using data science techniques based on SCADA and sensors data. This paper reviews existing erosion blade analysis methods in wind turbines, highlighting their strengths and weaknesses. The method is based on the literature review to determine the state of the art in terms of monitoring, classification, and prediction. Moreover study will evaluate potential predictive maintenance concepts based on key performance matrix extracted from key stakeholders. It can be concluded that a combined concept of vibration, aerodynamic, acoustic, and production loss techniques supported with XGBoost, FFT, and LSTM are the most effective methods. © 2024 IEEE.

关键词： Turbomachine blades

来源：评论

学校读者我要写书评

暂无评论

Hydrogen enhanced localised plasticity of single grain α titanium verified by in-situ hydrogen microcantilever bending

引用

International Journal of Hydrogen Energy 2024年 136卷 902-913页

作者： Deconinck, Liesbet Lu, Xu Wang, Dong Johnsen, Roy Verbeken, Kim Depover, Tom Ghent University Department of Materials Textiles and Chemical Engineering Research Group of Sustainable Materials Science Technologiepark 46 Ghent9052 Belgium Department of Mechanical and Industrial Engineering Richard Birkelands vei 2B Trondheim7491 Norway

The effect of hydrogen on the micromechanical characteristics of pure grade 2 titanium was investigated by comparing prenotched microcantilever bending in air versus in-situ electrochemical hydrogen charging. The nanoscale interaction between hydrogen and the metal's defects was analysed in three different grain orientations, i.e. the top surface parallel to {101‾2}, {0001}, and {202‾1}. The subsequent high resolution post-mortem characterisation enabled to characterise the interplay between hydrogen in solid solution and the dislocations in the local deformation process. The results showed that hydrogen facilitated a localised plasticity mechanism, causing hydrogen assisted degradation at the applied low hydrogen concentration below the hydride formation threshold. Meanwhile, hydrogen provoked a reduction in defect formation energy, following the defactant concept, which was responsible for a softening effect on the yield stress and flow stress. Furthermore, due to the anisotropic characteristics of the α titanium hexagonal close packed crystal lattice, the susceptibility to hydrogen effects also depended on the grain orientation. This single grain in-situ micromechanical testing is complementing the existing macroscaled identification of hydrogen effects in α titanium. © 2024 Hydrogen Energy Publications LLC

关键词： Titanium

来源：评论

学校读者我要写书评

暂无评论

Morphable 3D architectures enabled by shear-guided approach

引用

materials Today 2025年 86卷 28-41页

作者： Li, Kan Liu, Zhi Hu, Xiaonan Xu, Zijian Zhou, Yunlei Chen, Lin Huang, Yonggang Bo, Renheng Zhang, Yihui AML Department of Engineering Mechanics State Key Laboratory of Flexible Electronics Technology Tsinghua University Beijing100084 China State Key Laboratory of Digital Manufacture Equipment and Technology Huazhong University of Science and Technology Wuhan430074 China State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and Engineering Xi'an Jiaotong University Shaanxi Xi'an710000 China Departments of Mechanical Engineering Civil and Environmental Engineering Materials Science and Engineering and Center for Bio-Integrated Electronics Northwestern University EvanstonIL60208 United States

3D structures and electronic devices assembled through mechanically guided approaches have found important applications in a wide spectrum of emerging fields, including healthcare, biomedical engineering, wearable devices, robotics, among others. To broaden the obtainable functional 3D architectures via mechanical pathways, in this work, a shear-guided assembly approach is demonstrated. A series of structures in forms of ribbon, membrane and hybrid configurations with previously inaccessible geometrical features, such as reversible local flips and centrosymmetric charity are showcased. Finite element analysis (FEA) is performed, suggesting that such shear-induced structures are capable of reversible post-assembly shape transformation among different modes. Given the above, a facile design, consisting of two ribbon-like 3D units (dual-3D-unit design), is introduced and carefully calibrated for shear sensing. Notably, such design is capable of translating the hard-to-measure shear deformation into easily-accessed vertical displacements while insensitive to finite tensile loadings. A multifunctional arrayed electronic interface is fabricated using such dual-3D-unit design, suggesting promising potentials in human–machine interactions. © 2025 Elsevier Ltd

关键词： Shear deformation

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：