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Development of carbon fibre reinforced polymer matrix composites and optimization of the process parameters for railcar applications

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Materials Today: Proceedings 2021年 38卷 628-634页

作者： I.A. Daniyan K. Mpofu A.O. Adeodu O. Adesina Department of Industrial Engineering Tshwane University of Technology Pretoria South Africa Department of Mechanical and Mechatronics Engineering Afe Babalola University Ado Ekiti Nigeria Department of Mechanical and Automation Engineering Tshwane University of Technology Pretoria South Africa

The potential use of carbon fibre for railcar application stems from its excellent properties such as high strength to weight ratio and fire retarding abilities. This work studies the development of carbon fibre reinforced epoxy matrix composites and the optimization of the process parameters for railcar applications. Using the transfer moulding process, the composite comprising of mixture of double layers of polyacrylonitrile (PAN) based carbon fibre as reinforcement, epoxy resin which serves as the binder to form the matrix and silica additives were prepared and cured in a mould. The numerical experiment was performed using the Response Surface Methodology (RSM) and central composite design (CCD) comprising of two factors namely; the curing temperature (100–180 °C) and curing time (6–24 h). The statistical analysis of the numerical and physical experimentations were used to obtain a predictive model that correlates the tensile strength as a function of the curing temperature and curing time. There is a high degree of correlation between the results obtained from both the numerical and physical experimentations which implies that the developed model is suitable for predictive and correlative purposes. In addition, the results of the mechanical properties of the developed composite material indicate high tensile strength under varying loading conditions. This is an indication that the material possesses good strength and stiffness which makes the composite suitable for railcar applications. This work bring about the development of carbon fibre reinforced polymer and the determination of its mechanical properties for railcar applications.

关键词： Carbon fibre Curing RSM Reinforcement Railcar

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Improved Method of Multi-objective Particle Swarm Algorithm Learning Factor Based on Fitness Change

Improved Method of Multi-objective Particle Swarm Algorithm ...

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Artificial Intelligence and Computer engineering (ICAICE), International Conference on

作者： Jingchen Xie Guoxin Luo Hanlin Yin Chenyao Li Jiayang Pu Xueli Zhang Suyu Wang Unit: China University of Mining and Technology (Beijing) School of Mechatronics and Information Engineering Beijing China

ISBN: (纸本)9781665421874

Aiming at the problem that the inertial component of particles could not guide the particle to the right direction when the fitness became poor, a multi-objective particle swarm algorithm learning factor improvement method based on the fitness change was proposed. The large learning factor improved the multi-objective particle swarm algorithm. In the simulation experiment, the improved algorithm PSO-AIC1C2 and the PSO-S, PSO-AIC1 and PSO-AIC2 with c 1 and c 2 obtained by splitting this algorithm were fixed with c 1 and c 2 changed separately, and then compared with other PSO improvements. The algorithms MOPSO, SMPSO, and dMOPSO are compared. Experiments showed that increasing c 1 could improve the performance of the algorithm, and increasing c 2 would cause the convergence of the algorithm to deteriorate. In most test functions, PSO-AIC1C2 had obvious advantages in convergence and distribution indicators. The improved method proposed had certain guiding significance for the study of learning factors of particle swarm optimization in the future.

关键词： Learning (artificial intelligence) Particle swarm optimization Convergence

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A systematic review of reliability issues in rf-mems switches

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Micro and Nanosystems 2019年第1期11卷 11-33页

作者： Saleem, Muhammad Mubasher Nawaz, Hamid Department of Mechatronics Engineering National University of Sciences and Technology Islamabad Pakistan

The main challenge in the commercialization of the RF-MEMS switches is their reliability, related to both the electrical and mechanical domains. The development of test standards and understanding the underlying physics of different failure modes has always been of major concern for the RF-MEMS designers. This paper reviews the different failure modes in the RF-MEMS switches like stiction, residual stress, cyclic fatigue, creep, wear and packaging in detail. The origin of these failure modes, their characterization procedure and respective solutions presented in the literature are presented to get a better understanding of the state of the art work done in the field RF-MEMS reliability for nearly past two decades. © 2019 Bentham Science Publishers.

关键词： Fatigue of materials

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Bidirectional DC Circuit Breaker with Improved Performance during Commissioning and Reclosing

Bidirectional DC Circuit Breaker with Improved Performance d...

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European Conference on Power Electronics and Applications

作者： Aditya Pogulaguntla Venkata Raghavendra I Satish Naik Banavath Andrii Chub T Sreekanth Harish Sarma Krishnamoorthy Department of Electrical Engineering Indian Institute of Technology Dharwad Dharwad Karnataka India Department of Electrical Power Engineering and Mechatronics Tallinn University of Technology Tallinn Estonia Department of Electrical and Computer Engineering University of Minnesota Twin Cities MN USA Department of Electrical and Computer Engineering University of Houston Houston TX USA

ISBN: (数字)9789075815399

ISBN: (纸本)9781665487009

DC circuit breakers play a major role in developing and expanding electric power system networks by protecting the network elements from short circuits and overloads. This paper proposes a modified bidirectional z-source dc circuit breaker (MBZSDCCB) by retaining features such as common ground between source and load side terminals, low pass filtering, minimised reflected fault current, and in-corporates the features of reduced starting current, elimination of negative current flow during starting and reclosing, and bidirectional power flow capability. The sizing of the components used in the pro-posed dc circuit breaker is analysed in detail. The MBZSDCCB operation during a short circuit, and commissioning/reclosing instances is demonstrated in SPICE simulation. The issues with the existing z-source circuit breaker are identified by an experimental prototype with a system rating of 120V/3.5A. The performance testing of the proposed MBZSDCCB is validated using simulations in spice and also by developing an experimental prototype of a system rating 400V /10A.

关键词： Thyristors Circuit breakers Simulation Prototypes Surge protection Switches Topology

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Time Series Diffusion Method: A Denoising Diffusion Probabilistic Model for Vibration Signal Generation

arXiv

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arXiv 2023年

作者： Yi, Haiming Hou, Lei Jin, Yuhong Saeed, Nasser A. Kandil, Ali Duan, Hao School of Astronautics Harbin Institute of Technology Harbin150001 China Department of Physics and Engineering Mathematics Faculty of Electronic Engineering Menoufia University Menouf32952 Egypt Department of Automation Biomechanics and Mechatronics Department of Mechanical Engineering Lodz University of Technology Lodz90924 Poland Mathematics Department Faculty of Science Galala University Galala City43511 Egypt Shenyang Blower Works Group Corporation Shenyang110869 China

Diffusion models have demonstrated powerful data generation capabilities in various research fields such as image generation. However, in the field of vibration signal generation, the criteria for evaluating the quality of the generated signal are different from that of image generation and there is a fundamental difference between them. At present, there is no research on the ability of diffusion model to generate vibration signal. In this paper, a Time Series Diffusion Method (TSDM) is proposed for vibration signal generation, leveraging the foundational principles of diffusion models. The TSDM uses an improved U-net architecture with attention block, ResBlock and TimeEmbedding to effectively segment and extract features from one-dimensional time series data. It operates based on forward diffusion and reverse denoising processes for time-series generation. Experimental validation is conducted using single-frequency, multi-frequency datasets, and bearing fault datasets. The results show that TSDM can accurately generate the single-frequency and multi-frequency features in the time series and retain the basic frequency features for the diffusion generation results of the bearing fault series. It is also found that the original DDPM could not generate high quality vibration signals, but the improved U-net in TSDM, which applied the combination of attention block and ResBlock, could effectively improve the quality of vibration signal generation. Finally, TSDM is applied to the small sample fault diagnosis of three public bearing fault datasets, and the results show that the accuracy of small sample fault diagnosis of the three datasets is improved by 32.380%, 18.355% and 9.298% at most, respectively. © 2023, CC BY.

关键词： Time series

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Wood-derived biochar as thick electrodes for high-rate performance supercapacitors

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Biochar 2022年第1期4卷 358-376页

作者： Bing Yan Jiaojiao Zheng Li Feng Cheng Du Shaoju Jian Weisen Yang Yimin A.Wu Shaohua Jiang Shuijian He Wei Chen International Innovation Center for Forest Chemicals and Materials Co-Innovation Center of Efficient Processing and Utilization of Forest ResourcesCollege of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinPeople’s Republic of China Department of Mechanical and Mechatronics Engineering Waterloo Institute of Nanotechnology University of WaterlooWaterlooON N2L 3G1Canada Fujian Key Laboratory of Eco-Industrial Green Technology College of Ecology and ResourcesEngineeringWuyi UniversityWuyishan 354300China University of Science and Technology of China Hefei 230026People’s Republic of China

Developing effective electrodes with commercial-level active mass-loading(>10 mg cm^(−2))is vital for the practical application of ***,high active mass-loading usually requires thick active mass layer,which severely hinders the ion/electron transport and results in poor capacitive ***,a self-standing biochar electrode with active mass-loading of ca.40 mg cm^(−2) and thickness of 800μm has been developed from *** basswood was treated with formamide to incorporate N/O in the carbon structure,followed by mild KOH activation to ameliorate the pore size and introduce more O species in the carbon *** as-prepared carbon monoliths possess well conductive carbon skeleton,abundant N/O dopant and 3D porous structure,which are favorable for the ion/electron transport and promoting capacitance *** self-standing carbon electrode not only exhibits the maximum areal/mass/volumetric specific capacitance of 5037.5 mF cm^(−2)/172.5 F g^(−1)/63.0 F cm^(−3) at 2 mA cm^(−2)(0.05 A g^(−1)),but also displays excellent rate performance with 76%capacitance retention at 500 mA cm^(−2)(12.5 A g^(−1))in a symmetric supercapacitor,surpassing the state-of-art biomass-based thick carbon *** assembled model can power typical electron devices including a fan,a digital watch and a logo made up of 34 light-emitting diodes for a proper period,revealing its practical application *** study not only puts forward a commercial-level high active mass-loading electrode from biomass for supercapacitor,but also bridges the gap between the experimental research and practical application.

关键词： Biochar High mass-loading Heteroatom doping Self-standing electrodes Supercapacitor

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An automatic bolt segregation based on thread detection and dot matrix marking system

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AIP Conference Proceedings 2024年第1期2937卷

作者： S. Ramkumar R. Kishore P. Vinoth Kumar A. Eswaran M. Santhanakrishnan Department of Mechatronics Engineering Rajalakshmi Engineering College Chennai-6021051 Tamilnadu India. Department of Mechanical Engineering Chennai Institute of Technology Chennai-600069 Tamilnadu India. Department of Mechatronics Engineering Chennai Institute of Technology Chennai-600069 Tamilnadu India.

The rearmost stage for any mass production of component is packaging. This is of key importance in threaded components fabrication. In this process the bolts are to be segregated based on the length and the presence of threads on it. Based on this segregation and presence of thread the bolts are to be punched with their respective length number. Which is currently being carried out manually, eventually giving roots for many errors while packaging. For performing this process with more accuracy and impeccability, with at most care we have proposed this work of digital segregation of bolts using an electronic control module. This module being kept in-between an assembly line can divide the bolts based on the lengths and thread existence without any manual intervention, thereby reducing all the human prone errors. By fitting this kind of mechatronics system, we can obtain a more precise, more accurate punching on bolts with their size and thereby high quality of packaging of bolts can be obtained based on several segregation factors.

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Development of robust participation strategies for an aggregator of electric vehicles in multiple types of electricity markets

Energy Conversion and Economics

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Energy Conversion and Economics 2020年第2期1卷 104-123页

作者： Liu, Weijia Wen, Fushuan Dong, Zhaoyang Palu, Ivo School of Electrical Engineering Zhejiang University Hangzhou China Department of Electrical Power Engineering and Mechatronics Tallinn University of Technology Tallinn Estonia School of Electrical Engineering and Telecommunications University of New South Wales SydneyNSW Australia

The flexible charging and discharging behaviours of electric vehicles (EVs) can provide a promising profit opportunity for EV owners or aggregators in deregulated market. However, a major barrier to overcome is the uncertain market prices. In this context, this study aims to establish a novel and robust model for EV aggregators to optimally participate in multiple types of electricity markets while considering the uncertainty of the prices in various markets. First, the electricity market framework and the obligation of an EV aggregator are introduced, and each EVaggregator is entitled to participate in day-ahead, real-time, and regulation service markets. To cope with forecasting errors of market prices and other uncertainties, a robust optimisation model is developed to schedule the charging/discharging of EVs in different markets. A stepwise bidding strategy is then proposed to formulate robust market bids, offering more flexibility in handling volatile market prices in actual electricity markets. After the clearing of multiple types of electricity markets, a real-time dispatch model for EV aggregators is proposed for allocating the settlements and regulation orders to each EV. Finally, scenario-based simulation is employed to demonstrate the effectiveness of the proposed bidding strategy using actual market data and regulation signals. © 2020 The Authors. Energy Conversion and Economics published by John Wiley & Sons Ltd on behalf of The Institution of engineering and technology and the State Grid of China Economic & Technological Research Institute Co Ltd.

关键词： Power markets

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Info-Gap-Based Optimization of Microgrids Integrated with Power, Cooling and Hydrogen Generation Units

Info-Gap-Based Optimization of Microgrids Integrated with Po...

引用

Compatibility in Power Electronics (CPE)

作者： Fayezeh Mahmoudnezhad Mohammad Amin Mirzaei Freddy Plaum Roya Ahmadiahangar Jako Kilter Argo Rosin Smart City Center of Excellence (Finest Twins) Tallinn Estonia Department of Electrical Power Engineering and Mechatronics Tallinn University of Technology Tallinn Estonia Faculty of Electrical and Computer Engineering University of Tabriz Tabriz Iran

ISBN: (数字)9781665496780

ISBN: (纸本)9781665496797

The emerging concept of integrated demand response (IDR) is a promising platform for promoting the utilization of renewable energy sources (RES) and improving energy efficiency in multi-energy systems. In this paper, a robust scheduling model for a power, cool, and hydrogen-based islanded microgrid (MG) in the presence of hydrogen fueling stations (HFSs) and EV parking lots (EVPLs) is proposed. Additionally, the impact of power and cooling-based IDR is investigated in reducing the operating cost of the proposed system. The proposed multi-energy MG is equipped with power generation, wind turbine, electrical, cooling and hydrogen storage systems, power to hydrogen (P2H) facility and an electrical chiller to meet power, cooling, and hydrogen demands simultaneously. In order to deal with wind power generation uncertainty, a robust optimization approach is employed without the need for probability density function (PDF) or scenario generation, which strengthens the optimal operation of the proposed multi-energy MG against the wind power uncertainty and allows the operator to apply a risk-averse approach. Numerical results demonstrate that the establishment of IDR in the presence of storage systems reduces the total operating costs by 5.6%.

关键词： Costs Uncertainty Hydrogen storage Cooling Hydrogen Optimal scheduling Microgrids

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Tribological Properties of Laser-Cladded Fe-Based Amorphous Composite Coatings Under Dry and Lubricated Sliding

SSRN

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SSRN 2023年

作者： Yu, Jing Qiao, Chenfeng Zhang, Shuai Liu, Zhengda Wróblewski, Piotr Marine Engineering College Dalian Maritime University Dalian116026 China Department of Materials Science and Engineering Dalian Maritime University Dalian116026 China Faculty of Mechatronics Armament and Aerospace The Military University of Technology Institute of Aviation Technology Division of Aircraft Construction and Operation ul. gen. Sylwestra Kaliskiego 2 Warsaw 46 00-908 Poland

Fe-based amorphous composite coatings are promising surface coating materials, because of their low cost, high hardness, and superior wear resistance. In the present study, Fe-based composite coatings with various amorphous contents (35.9–59.3%) were deposited onto 1045 steel via laser cladding, and the influence of laser-cladding parameters on the amorphous content was analysed. The cross sections of the coating layer and ground coating surface were then characterised in terms of the microstructure, phase composition, amorphous content, grain size, and microhardness. Importantly, the tribological properties of coatings with various amorphous contents under both dry and lubricated sliding conditions with light and heavy loads were systematically investigated. The microstructure of the crystalline/amorphous mixture was found to be a function of the temperature gradient, cooling rate, and chemical composition. The high microhardness was related to the amorphous content and grain size. The tribological properties were found to be insensitive to the amorphous content under both dry and lubricated conditions under light and heavy loads. The manifold morphologies of the wear tracks and the transition of the wear mechanism were the result of the combined effects of the amorphous content, phase composition, and size and distribution of the crystalline phase. © 2023, The Authors. All rights reserved.

关键词： Laser cladding

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