作者：
Bin Chen;Guo He;Feng Zhou;Hao Huang;Wei Liu;...
期刊：
2023 IEEE Intl Conf on Parallel & Distributed Processing with Applications, Big Data & Cloud Computing, Sustainable Computing & Communications, Social Computing & Networking (ISPA/BDCloud/SocialCom/SustainCom),2023年:846-853
作者机构：
[Bin Chen; Guo He; Hao Huang; Wei Liu; Ronghua Du] College of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha, China;[Feng Zhou] College of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha, China
摘要：
For electric vehicles (EVs) equipped with hybrid energy storage systems (HESS), a challenge is reasonably distributing and optimizing load power. To optimize the performances of the vehicle power and battery capacity, This paper introduces an innovative data-driven Energy Management Strategy (EMS) designed for HESS, which combines a hierarchical strategy of fuzzy neural network (FNN) and data-enabled predictive control (DeePC). At the driving level, FNN predicts load power demand by collecting historical speed and acceleration information along with current data. At the energy management level, the EMS adopts a novel data-enabled model, which collects the load power predicted by an upper layer. The DeePC achieves power distribution by controlling the supercapacitor current while maintaining the state of charge (SoC) within the expected range. The simulation results verify the effectiveness of the developed EMS. Compared with long-short term memory (LSTM), artificial neural network (ANN), and support vector regression (SVR), FNN demonstrates the best-fitting performance, while the prediction results are closer to the actual load power. Compared with model predictive control (MPC), the proposed DeePC approximately reduces battery capacity loss by 0.15% and demonstrates well control performance.
摘要：
A torsional buckling model of cylindrical shells with asymmetric local thickness defect is established based on the Hamiltonian system. The critical load and torsional buckling mode of cylindrical shells with defects are obtained by the symplectic eigensolution expansion method, which overcomes the difficulty of constructing the deflection function of the traditional semi-inverse method. Local buckling modes can be captured by this new analytical model with the superposition of symplectic eigensolutions. To ensure accuracy and validity of the symplectic method, the analytical solution with torsional buckling of a cylindrical shell is compared with the classical solution and the finite element method (FEM) solution. The results show that the most detrimental position of the defect is only related to the width of the defect, not to the depth. The local defect changes the circumferential buckling wave number of the cylindrical shell and concentrates the torsional corrugation on the side containing the defect. Torque symmetry is broken due to the asymmetric defect, and the most detrimental defect direction for buckling is the same as the direction of torsional buckling wavelet.
摘要：
Rotor-stator axial clearance is a crucial design parameter affecting rotating machines’ efficiency and safety. To accurately measure the dynamic axial clearance in high-speed machinery, a precise method based on time division multiplexing with frequency domain interferometry has been proposed. This method has proven robust and accurate through simulations and experiments. The inclusion of an optical switch enables the utilization of dispersive interferometry(DPI) and time division multiplexing for multiple channels of the light source. It achieves a static accuracy of 1.5 µm for a 15 mm range and a dynamic accuracy of 9 µm at 3000 rpm.
摘要：
Nonequilibirum vacancy concentration widely appears in crystals under many extreme loading conditions, but receives relatively few attentions. In this work, we systematically explore the influence of a serial of different vacancy concentrations on the edge dislocation motion in copper using molecular dynamics (MD) simulations. Our result shows that the vacancy would hinder the dislocation motion, but the mechanism depends on the detailed dislocation motion regions. In thermally activated region, its influence is mainly reflected by modifying the dynamic and static threshold stresses required for edge dislocation initiation and continuous motion. In the linear region, the hindering mechanism is gradually transformed from phonon damping to vacancy pinning with the increasing vacancy concentration. In contrasts, the dislocation structure is almost unchanged under different vacancy concentrations in the non-linear region. Under high applied stress, high vacancy concentration will cause the dislocation velocity to jump back and forth between transonic and subsonic velocities more frequently. It has been attributed to the reactions between the dislocation and vacancies. The latter may result in dislocation local constriction and climbing. Moreover, a mobility equation suitable for describing edge dislocations at different non-equilibrium vacancy concentrations is proposed, which fits the MD results well. Finally, the roles of the nonequilibirum vacancy concentration on the edge dislocation motion is interpreted using the degrading elastic property and stacking fault energy.
通讯机构：
[Kai Gao] C;College of Automotive and Mechanical Engineering, Changsha University of Science & Technology, Changsha 410114, China<&wdkj&>Hunan Key Laboratory of Smart Roadway and Cooperative Vehicle-Infrastructure Systems, Changsha 410114, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
battery thermal management system;liquid cooling;structure optimization;thermal performance;high power dissipation
摘要：
Electrochemical discharge machining (ECDM) is an effective and promising technology for the micro-hole drilling of hard and brittle insulating materials such as glass, quartz and ceramics. Hole exit quality is an important part of through-hole machining quality in ECDM. The hole exit quality is influenced by two different machining states before and after the hole breakout. Therefore, it is necessary to identify hole breakout occurrence to provide a basis for achieving a machining strategy that matches the changing machining state and thus improves the hole exit quality. However, currently, there is no effective method to detect the hole breakout in the ECDM of micro-holes. In this paper, a self-adaptive micro-hole breakout detection method based on CNN- BiLSTM was proposed. The hole breakout detection can be expressed as a binary classification problem according to the analysis of the current signals collected before and after the hole breakout. The sufficiency of the raw current signal information was discussed. A CNN-BiLSTM model was established to detect hole breakout using the current signals as the training dataset. The CNN-BiLSTM model showed better performance compared to CNN, LSTM, BiLSTM and CNN-LSTM by comprehensive considering of accuracy, F1 score, AUC value, training time, predict time, breakout detection results and Dunn test results. Furthermore, the length of current signals used for each single detection and the threshold value used for breakout detection were discussed. An optimal threshold value was calculated, and the delay of detection was within 66 ms. The proposed method was successfully applied to the hole breakout detection in the through-hole drilling experiments and the success rate was 100 %. The hole exit area just after breakout were measured and compared to the hole exit area after hole completion, the average ratios of the former to the latter were 11.69 %, 27.29 %, 38.43 % and 44.41 % for the voltage of 39 V, 41 V, 43 V and 45 V respectively.
通讯机构：
[Changhe Li] S;[Zafar Said] C;School of Mechanical and Automotive Engineering, Qingdao University of Technology, Qingdao, China<&wdkj&>College of Engineering, University of Sharjah, Sharjah, United Arab Emirates
摘要：
Double hat-beams (DB) made of high-strength steel are widely used in automobile body for their excellent impact resistance. To further improve the crashworthiness of DB, the concept of hierarchy is first introduced into the design of DBs to obtain the so-called hierarchical double-hat beams (HDBs). The finite element model of DB is validated by impact tests. It is found that the hierarchical structures exhibit better energy absorption characteristics and deformation stability compared with DB. Among them, the mean crushing force (MCF) values of DBT and STT exceed DB 70.63% and 49.47% separately, and their specific mean crushing force (SMCF) values exceed DB 32.34% and 45.06% respectively. The triangular hierarchical structures perform better than quadrangular and hexagonal models. The effects of substructure size and geometry on the impact resistance of HDBs are further investigated, and the impact resistance of HDBs can be effectively improved by increasing H1 value and adding microstructure to the substructures. The SMCF values of DBT-8, DBT-10, DBQ-8, DBQ-10 and DBT-III are 116.31, 109.61, 45.36, 79.59 and 66.50% higher than that of DB. In addition, these HDBs show novel deformation patterns that resemble the letter "T", the symbol "+" and the mushroom. In summary, the hierarchy of structure can significantly improve the crashworthiness of DB. & COPY; 2023 Elsevier Masson SAS. All rights reserved.
通讯机构：
[Haibin Yin] H;Hubei Key Laboratory of Digital Manufacturing, School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan 430070, China
摘要：
High chromium superalloy K648, additive-manufactured by extreme high-speed laser metal deposition (EHLMD) process, was heat treated by solution and then cooled at different cooling rates achieved by different conditions in this study. The investigation focused on the impact of solution cooling rates (water-cooling (WC), air-cooling (AC) and furnace-cooling (FC)) on the microstructure and mechanical properties of EHLMD K648 superalloy. As the solution cooling rates decrease, it was observed that grain sizes, carbide, and a-Cr grew larger. Simultaneously, the carbides at the grain boundary evolved from a discontinuous granular shape to a chain-like shape, while a-Cr transformed from short needle to a short rod shape. Concurrently, the quantities of secondary g' phase diminished, but the size of secondary g' phases enlarged as the cooling rate decreased. Additionally, a significant amount of small granular tertiary g' phase emerged in the FC superalloy. The microhardness of the EHLMD superalloy exhibited a substantial increase with the decrease of the solution cooling rate, to the point that the microhardness of FC superalloy reached 429 HV. The ultimate tensile strength and yield strength increase, but the elongation de-creases significantly, with the ultimate tensile strength of FC superalloy reaching 1058.3 MPa. The fracture of EHLMD K648 superalloy gradually transformed into ductile fracture to ductile and brittle mixed fracture as solution cooling rates decreased.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
