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arXiv 2024年

作者： Chen, Fan Wang, Jinghua Duan, Huan-Feng School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai200240 China Department of Civil and Environmental Engineering The Hong Kong Polytechnic University 999077 Hong Kong

This paper presents a novel volume of fluid ghost-cell immersed boundary (IB) method for two-phase free surface flow interacting with structures. To circumvent the disturbance occurring around the intersection area of the IB and free surface when using the interpolation method for variable reconstruction, the fluid-structure interaction is firstly considered with the orthogonal IB by mimicking the imposition of boundary conditions in the body-conformal grid method. Treatments are subsequently performed to account for the non-orthogonal effect in accurately simulating the FSI, including the newly proposed flux-scaling and IB velocity re-evaluation methods. Further, a variable smoothing process and a flux correction method are adapted to handle moving boundary cases. Based on OpenFOAM, a two-phase flow solver has been developed. Both stationary and moving immersed boundary cases are used for validations. The numerical results reasonably agree with the corresponding laboratory data and other numerical simulation results, demonstrating the disturbance being effectively depressed and the solver’s accuracy in capturing fluid-structure interactions involving free surface flow. Copyright © 2024, The Authors. All rights reserved.

关键词： Two phase flow

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Digital twin driven thermal error control of linear axis for face gear grinding machine tool 20

Digital twin driven thermal error control of linear axis for...

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20th CIRP Conference on Modeling of Machining Operations in Mons, CIRP CMMO 2025

作者： Li, Mingming Ma, Chi Liu, Jialan Totis, Giovanni Academy of Aerospace Solid Propulsion Technology Xi'an710025 China College of Mechanical and Vehicle Engineering Chongqing University Chongqing400044 China State Key Laboratory of Mechanical Transmission for Advanced Equipment Chongqing University Chongqing400044 China School of Construction Machinery Chang'An University Xi'an710064 China Polytechnic Department of Engineering and Architecture University of Udine Via delle Scienze 206 Udine33100 Italy

The face gear transmission system offers advantages such as high interchangeability, strong load capacity, and effective power distribution, making it suitable for defense applications. The machining accuracy of the face gear grinding machine tool is significantly affected by the geometric and thermal errors, leading to a reduced geometric precision of the machined face gear. The real-time performance and robustness of the geometric and thermal error compensation system are the key to realize the thermal error control. So far, the real-time performance of compensation system is weak, and the robustness is poor. To address the above challenges, the effect of the temperature changes on positioning accuracy is studied. Then the thermal error prediction model is established based on the error mechanism for the linear axis of face gear grinding machine tool. Finally, the digital twin-driven thermal error control system is developed. The thermal error model is embedded into the digital twin-driven geometric and thermal error control system to realize the thermal error compensation of linear axis for face gear grinding machine tool. With the implementation of the digital twin-driven thermal error control system, the left tooth surface error decreased from 21.8 μm to 5.9 μm, and the right tooth surface error decreased from 22.9 μm to 5.7 μm, confirming the effectiveness of the proposed method. © 2025 The Author(s).

关键词： Grinding machines

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A New Field-Oriented Control for Induction Motor Drive Using a Synergetic-Super Twisting Algorithm 15

A New Field-Oriented Control for Induction Motor Drive Using...

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15th International Conference on Electronics, Computers and Artificial Intelligence, ECAI 2023

作者： Zellouma, Dalal Benbouhenni, Habib Bizon, Nicu Bekakra, Youcef University of El Oued Levres Laboratory Department of Electrical Engineering El Oued3900 Algeria Nisantasi University Faculty of Engineering and Architecture Department of Electrical & Electronics Engineering Istanbul34481742 Turkey Faculty of Electronics Communication and Computers University of Pitesti Pitesti110040 Romania National Research and Development Institute for Cryogenic and Isotopic Technologies Icsi Energy Department RamnicuValcea240050 Romania Doctoral School Polytechnic University of Bucharest Bucharest060042 Romania

ISBN: (纸本)9798350321388

In this work, a new field-oriented control (FOC) is proposed to control the induction motor drives. The FOC method stands out because of its use, simplicity, and fast dynamic speed. However, there are disadvantages to this strategy. One of its disadvantages is that there are ripples in the torque, flux, and levels at present. In addition, the current has a high total harmonic distortion value in comparison to non-linear control. The super-twisting algorithm and synergetic control are strategies of non-linear control, a novel solution is offered to address these issues and enhance the performance and effectiveness of this approach to total harmonic distortion, which is proposed and employed in the conventional FOC strategy to minimize the ripples of current, torque, and total harmonic distortion. To simulate the proposed strategy of IM drive, Matlab software has been used. Comparison results between the suggested control and a traditional FOC technique can illustrate the proposed control greatly improved performance and robustness. © 2023 IEEE.

关键词： Induction motors

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Directivity Improvement of MIMO Array Antenna using Novel Eight Element Array Configuration 3

Directivity Improvement of MIMO Array Antenna using Novel Ei...

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3rd International Conference on Advancement in Electronics and Communication engineering, AECE 2023

作者： Lafta, Alaa M. Zaboun, Abdul Razzaq T. Kosimova, Shakhlokhon Shather, Alaa. Sabah, Hawraa Ali Alchilibi, Haider National University of Science and Technology Dhi Qar Iraq Al-Esraa University College Forensic Sciences Department Baghdad Iraq Fergana Polytechnic Institute Department of Architecture Fergana Uzbekistan Al Kitab University Department of Computer Engineering Technology Altun Kopru Kirkuk00964 Iraq Al-Farahidi University Medical Laboratory Techniques Department Baghdad10022 Iraq

ISBN: (纸本)9798350330724

In this study, the Directivity of the Microstrip Patch MIMO Antenna is a Novel Eight element array configuration in comparison with its performance of a Single element patch antenna. Directivity improvement and Return loss measured for different frequencies and values are compared with a Single element patch antenna. Novel Eight element MIMO array antenna is designed and compared with a Single patch element antenna. In this work, there are two groups (Eight element patch & Single element patch) each consisting of 20 samples with pre-test power or G-power of 80%. The mean Return loss in the Novel eight element MIMO array antenna is -18.39 dB and in the Single element antenna is -15.21 dB. These results showed that the Novel eight element array exhibited a better Directivity improvement (4.483 dB) than the single element antenna (2.261 dB) with the two-tailed significance of (p © 2023 IEEE.

关键词： Microstrip antennas

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Microstructure and Properties of Ettringite with Different Al/(Fe+Al) Ratios in the C4A3-xFx$-2C$·H2 Binary Hydration System

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ACS Sustainable Chemistry and engineering 2025年第23期13卷 8671-8686页

作者： Zeng, Tian Zhang, Tingting Li, Jiangchuan Cui, Kai Chang, Jun School of Infrastructure Engineering Dalian University of Technology Dalian 116024 China School of Civil Engineering Lanzhou University of Technology Lanzhou 730050 China Department of Civil and Environmental Engineering The Hong Kong Polytechnic University Hung Hom Kowloon 999077 Hong Kong School of Civil Engineering and Architecture Hainan University Haikou 570228 China

The solid solution between Al-ettringite and Fe-ettringite (Al/Fe-ettringite), an important hydration product in Ferric-rich calcium sulfoaluminate (FR-CSA) cement, contributed to its desirable properties including excellent compact resistance and seawater erosion resistance. Previous research has given relatively little attention to this phase. Thus, the effect of Al/(Al+Fe) ratio on the crystal structure of ettringite in FR-CSA hydration products is of crucial importance to study. This paper investigates the influence of Fe³⁺ doping on the C4A3-xFx$-2C$·H2 binary hydration system by calcining Fe2O3-doped ye’elimite, and then explores the microstructure of Al/Fe-ettringite. Various analysis methods, including X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and microcalorimeter, were used to study the phases. The results indicated that the incorporation of Fe³⁺ influenced the hydration process of the C4A3-xFx$-2C$·H2 samples, with Fe2O3 content exceeding 19.10 wt % retarding hydration kinetics. C4A2.6F0.4$-2C$·H2 exhibited the highest compressive strength at 28 d, reaching 52.13 MPa. In the C4A3-xFx$-2C$·H2 samples, the introduction of Fe³⁺ decreased the crystallinity of ettringite, reduced thermal stability, and weakened the OH group binding ability;the weight loss peak temperature of ettringite decreased from 123.5 to 117.0 °C. With increasing Fe³⁺ content, the mean particle size of ettringite grew steadily from 9786 to 12132 nm. Fe³⁺ in C4A3-xFx$ preferred to generate the (A/F)H3 phase, which included a lamellar stacking morphology with very high Fe^3+<

关键词： Al/(Fe+Al) ratios calcium sulfoaluminate cement ettringite microstructure Ye’elimite

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Interpretation of Subsurface Stratigraphic Variations from Limited Boreholes Using Pixel Bi-Lstm

SSRN

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SSRN 2023年

作者： Liu, Hong-Chi Zhang, Ning Yin, Zhen-Yu Wang, Yu Department of Civil and Environmental Engineering The Hong Kong Polytechnic University Hong Kong China Department of Architecture and Civil Engineering City University of Hong Kong Hong Kong China

Site characterization provides the foundation for developing appropriate geotechnical design and construction methods, as it enables engineers to make informed decisions. However, accurately and robustly determining the spatial variations of subsurface stratigraphic formations from limited boreholes remains a significant challenge. In this paper, a deep learning-based neural network (Pixel Bi-LSTM) is proposed to interpret complex stratigraphic variations from vertical and horizontal directions using only limited borehole data. The spatial correlation between different soil deposits can be learned from the proposed method through a cross-shaped sampling system. Two encoding methods, namely ordinal encoding and one-hot encoding, are explored to express the stratigraphic features. Combining the LeaveOne-Out cross-validation and L regularization technique, the overfitting problems of the proposed neural networks can be eliminated. Meanwhile, a synthetic ground generated by the non-homogeneous Markov method is studied to illustrate the effectiveness of the Pixel Bi-LSTM model. Furthermore, the model performance is explicitly discussed from three aspects: borehole density, neighborhood scale, and sampling scheme. Additionally, the proposed method is also applied in two field projects collected from Australia and the Netherlands for engineering practice. Compared with two existing methods, the stochastic Markov random field simulation model and IG-XGBoost, the proposed model can yield a more accurate soil profile. These findings highlight the potential of the Pixel Bi-LSTM model in improving the interpretation of subsurface stratigraphic formations based on limited borehole data. © 2023, The Authors. All rights reserved.

关键词： Long short-term memory

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Rapid seismic vulnerability and risk assessment of kermanshah historic mosques

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Open Civil engineering Journal 2021年第Speacialissue1期15卷 135-148页

作者： Biglari, Mahnoosh D’amato, Michele Formisano, Antonio Department of Civil Engineering Faculty of Engineering Razi University Kermanshah Iran Department of European and Mediterranean Cultures: Architecture Environment and Cultural Heritage (DICEM) University of Basilicata Matera Italy Department of Structures for Engineering and Architecture (DIST) School of Polytechnic and Basic Sciences University of Naples “Federico II” Naples Italy

Background: In this research a rapid vulnerability and risk assessment at a territorial level is performed. Methods: The methodology used, initially proposed for ancient masonry churches, is extended and applied to ten historic masonry mosques in Kermanshah city. The method could be considered as preliminary risk assessment approach of historic structures, refers to LV0 method, since the used methodology requires simple qualitative information. It involves the application of three distinct tools;the exposure, the seismic hazard, and the seismic vulnerability. Results: The comparisons among the obtained results, by considering also the damages suffered during the last earthquakes and war blasts, validate the methodology proposed, capable of providing a seismic risk scoring at a territorial level also for ancient masonry mosques. As known, through this kind of approach, important information is obtained in order to manage and to mitigate the seismic risk of a certain territorial asset. The results show that all ten mosques has medium earthquake vulnerability condition. Emad e Doleh mosque is the most vulnerable case with vulnerability of 34. Navab mosque is located on the most hazardous place. Furthermore, the seismic vulnerability map and seismic risk indices are presented for all the investigated mosques. Conclusion: The obtained results are useful for ranking the priorities and for preliminary defining an interventions plan to be examined in detail with additional quantitative investigations carried out with more refined approaches. © 2021 Biglari et al.

关键词： Cultural heritage Index method Kermanshah historic mosque Seismic hazard Seismic risk Seismic vulnerability

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Carbon-negative cement-bonded biochar particleboards

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Biochar 2022年第1期4卷 219-227页

作者： Liang Chen Yuying Zhang Claudia Labianca Lei Wang Shaoqin Ruan Chi Sun Poon Yong Sik Ok Daniel C.W.Tsang Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou 310027China College of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China Research Centre for Resources Engineering Towards Carbon Neutrality The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Korea Biochar Research Center APRU Sustainable Waste Management Program&Division of Environmental Science and Ecological EngineeringKorea UniversitySeoul 02841Korea

Biochar from bio-waste pyrolysis presents excellent CO_(2) sequestration *** study innovated the design of cement-bonded particleboards utilizing a substantial amount of 50-70 wt.%pre-soaked biochar to render the products *** investigated the roles of biochar in magnesium oxysulfate cement(MOSC)system and demonstrated good mechanical and functional properties of biochar cement *** the presence of biochar,the amounts of hydration products were enriched in the cement systems as illustrated by the thermogravi-metric analyses(TGA)and X-ray diffraction(XRD).We further incorporated supplementary cementitious materials(SCMs)and generated 5 Mg(OH)_(2)⋅MgSO_(4)·7H_(2)O(5-1-7)phase in the MOSC *** a result,our designs of biochar particleboards satisfied the standard requirements for flexural strength(>5.5 MPa)and thickness swelling(<2%).Moreover,our biochar particleboards presented a low thermal conductivity as the biochar pores disrupted thermal bridging within *** illustrated that the high dosage ratio of biochar could significantly offset the CO_(2) emissions of the particleboards(i.e.,carbon-negative)via life cycle *** economic profits could also be accomplished for the biochar *** instance,the 50BC-MOSC bonded particleboard(with 50 wt.%pre-soaked biochar as aggregate,50 wt.%MOSC as binder)with promising mechanical properties could store 137 kg CO_(2) tonne^(−1) and yield an overall economic profit of 92 to 116 USD m^(−3) depending on the carbon prices in different *** summary,our new designs of carbon-negative biochar particleboards could curtail carbon emissions in the construction materials and promote the realization of carbon neutrality and circular economy.

关键词： Biochar-cement composite Carbon neutrality Wood waste biochar Magnesium oxysulfate cement Climate-positive construction materials

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Enhancing mechanical strength and reducing drying shrinkage in high-volume fly ash mortar: Synergistic effects of steel fibers and nano-SiO 2

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Journal of Materials Research and Technology 2025年 36卷 7351-7360页

作者： Junliang Zhao Jingjing Huang Zhongkun Wang Dongyan Wu Gengying Li College of Civil Engineering and Architecture Wenzhou University Wenzhou 325035 Zhejiang China Key Laboratory of Engineering and Technology for Soft Soil Foundation and Tideland Reclamation of Zhejiang Province Wenzhou 325035 China School of Civil Engineering & Architecture Wenzhou Polytechnic Wenzhou 325035 China Department of Civil Engineering and Smart Cities Shantou University Shantou 515063 Guangdong China College of Water Conservancy and Civil Engineering South China Agricultural University Guangzhou 510642 China

This study investigated the effects of steel fibers and nano-silica dioxide (nano-SiO 2 ) on the fluidity, capillary water absorption, mechanical properties, and drying shrinkage of mortar when 50 % of the cement was replaced by fly ash. The mechanisms by which steel fibers and nano-SiO 2 influence high-volume fly ash mortar were discussed based on macroscopic tests and microscopic structural analysis. The results show that while nano-SiO 2 and steel fibers had negligible effects on the fluidity of fly ash mortar, they significantly enhanced its mechanical properties. When the steel fiber content was 1.0 % and the nano-SiO 2 content was 2.0 %, the modified mortar exhibited increases in flexural and compressive strength by 86.4 % and 53.7 %, respectively, compared to the unmodified mortar at 28 days of age. Additionally, the incorporation of nano-SiO 2 and steel fibers significantly reduced the capillary water absorption and drying shrinkage of the mortar. The capillary absorption rate of the 1.0 % steel fibers and 2.5 % nano-SiO 2 composite mortar decreases 67.8 % compared to the fly ash mortar. At 90 days of age, the drying shrinkage of the modified mortar containing 1.0 % steel fibers and 2.5 % nano-SiO 2 was reduced by 44.4 % compared to the unmodified mortar. Microstructural characterization through scanning electron microscopy (SEM) and X-ray diffraction (XRD) demonstrated that nano-SiO 2 incorporation enhanced the hydration of both fly ash and cement, leading to a significant reduction in unhydrated fly ash particles. Furthermore, mercury intrusion porosimetry (MIP) tests demonstrated that the addition of nano-SiO 2 and steel fibers markedly decreased the average and median pore sizes in the mortar, resulting in a more optimized pore structure distribution.

关键词： High-volume fly ash mortar Nano-SiO 2 Steel fibers Fluidity Mechanical properties Drying shrinkage

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Seismic assessment of typical historical masonry churches in the Banat region, Romania - Part II

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Procedia Structural Integrity 2023年 44卷 2044-2051页

作者： Anna Lo Monaco Nicola Grillanda Iasmina Onescu Mihai Fofiu Francesco Clementi Michele D'Amato Antonio Formisano Gabriele Milani Marius Mosoarca Department of European and Mediterranean Cultures Architecture Environment and Cultural Heritage (DiCEM) University of Basilicata Via Lanera 20 Matera 75100 Italy Department of Architecture Built Environment and Construction Engineering (A. B. C.) Politecnico di Milano Piazza Leonardo da Vinci 32 Milan 20133 Italy Faculty of Architecture and Urban Planning Politehnica University Timisoara Traian Lalescu 2/A Timişoara 300223 Romania Department of Civil and Building Engineering and Architecture (DICEA) Polytechnic University of Marche Via Brecce Bianche 12 Ancona 60131 Italy Department of Structures for Engineering and Architecture School of Polytechnic and Basic Sciences University of Naples “Federico II” Piazzale Tecchio 80 Naples 80125 Italy

This work focuses on the built heritage in Romania, with particular attention to five Orthodox masonry churches located in the Banat region, whose structural configuration is characterized by a unique nave and a bell tower included into the main façade. In a companion paper the seismic numerical investigations of Romanian masonry churches according to the Romanian regulations is presented. In this paper, firstly, a seismic performance comparison of the five churches with simplified risk assessment methods is conducted. Then, the preliminary results of a case study, obtained with both a macro-elements approach and a FEM model, are illustrated and commented. The numerical results here discussed belong to on-going research campaign addressed to highlight the main characteristics of the seismic performance of the Romanian churches, also including the damage observed under seismic events, as well as to compare the results to each other.

关键词： Romanian historical masonry churches seismic assessment simplified methods local failures non-linear analyses

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