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Modified spherical cavity-expansion model for projectile penetration into concrete targets

Acta Mechanica Sinica 2019年第3期35卷 518-534页

作者： Y.Peng H.Wu Q.Fang X.Z.Kong College of Liberal Arts and Sciences National University of Defense TechnologyChangsha 410073China Key Laboratory of Performance Evolution and Control for Engineering Structures Tongji UniversityShanghai 200092China Research Institute of Structural Engineering and Disaster Reduction College of Civil EngineeringTongji UniversityShanghai 200092China State Key Laboratory for Disaster Prevention and Mitigation of Explosion and Impact PLA Amy Engineering UniversityNanjing 210007China

A modified spherical cavity-expansion model is developed in this paper.(1) We introduce a piecewise hyperbolic yield criterion suitable for pressure less than fc/3 to describe the mechanical behavior in the elastic region for the elastic-plastic response and modify the crack occurrence condition for the elastic-cracked-plastic response.(2) The hyperbolic yield criterion and a piecewise equation of state (EOS) are adopted for a better description of the plastic behavior of concrete material. Then, the modified model is validated by several projectile penetration tests in both the normal strength concrete (NSC) and ultra-high performance cement-based composite (UHPCC) targets. Finally, the hydrostatic pressure of the targets under rigid ogive-nosed projectile penetrations is found to be nearly within (0, 1.6 GPa), which usually exceeds the range that the shear strength-pressure test data covered. The influence of yield criterion on depth of penetration is discussed and it is recommended that the pressure should arrive at least 400 MPa in the related triaxial compression tests.

关键词： Dynamic cavity-expansion model Projectile Penetration Concrete Depth of penetration

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Study on the effects of low-temperature oxidation on the thermal properties and microscopic parameters of bituminous coal

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Fuel 2025年 402卷

作者： Chunlian Cheng Rongjun Si Lei Wang Quansheng Jia Zichao Huang Baisheng Nie College of Mining Engineering Guizhou University of Engineering Science Guizhou 551700 China Fire and Explosion Prevention Research Branch Chongqing Research Institute China Coal Technology and Engineering Group Chongqing 400037 China State Key Laboratory of Coal Mine Disaster Dynamics and Control School of Resources and Safety Engineering Chongqing University Chongqing 400044 China

The laser flash apparatus (LFA) and microscopic techniques were used to investigate the thermal properties and microstructural parameter of bituminous coal after low-temperature oxidation. The key factors influencing coal thermal properties and correlations were analyzed. The results indicate that as temperature increases, SHC and TC gradually increase, while TD decreases. With increasing oxidation temperature, TD, SHC, and TC exhibit a fluctuating upward trend. Meanwhile, d 002 , L a , and L c gradually rise, while the relative contents of aromatic and aliphatic structures show an overall downward trend. The contents of oxygen-containing functional groups and hydroxyl structures increase within a specific temperature range. When the oxidation temperature reaches 120 °C, significant changes occur in the functional group contents of the C and O spectra. As the oxidation temperature increases, the I D /I G exhibits a fluctuating decline, while the A D /A G and F D /F G initially decrease and then increase. The specific surface area and pore volume first increase and then decrease. The -C-O- functional group, V ad , and A ad are significantly correlated with TD, SHC, and TC, while the C-H shows a strong positive correlation with both TD and TC. These findings provide theoretical support for the study of the physicochemical properties and thermal characteristics of oxidized coal.

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Influence of initial oxidation and secondary oxidation on spontaneous combustion of lignite

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International Journal of Microstructure and Materials Properties 2019年第1期14卷 60-77页

作者： Huang, Zhi-An Zhang, Ling-Hua Wang, Jing-Jing Yang, Rui Zhang, Ying-Hua Wang, Hui Chen, Yu-Yan Gao, Yu-Kun State Key Laboratory of High-Efficient Mining Safety of Metal Mines University of Science and Technology Beijing Ministry of Education Beijing100083 China Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines Hunan University of Science and Technology Xiangtan411201 China State Key Laboratory Cultivation Base for Gas Geology and Gas Control Henan Polytechnic University Jiaozuo454000 China Beijing Research Center of Urban System Engineering Beijing Key Laboratory of Operation Safety of Gas Heating and Underground Pipelines Beijing100035 China

In order to prevent the re-ignition of residual coal, this study presents a study of initial oxidation and secondary oxidation on the spontaneous combustion characteristics of coal. Three physical experiment methods:pore volume analysis, Fourier transform infrared spectroscopy and cross point temperature method, were used to study the spontaneous combustion of lignite. The results show that the pore volume of coal increases with the increase of oxidation temperature. With the increase of temperature, different functional groups in the coal sample show different trends. Compared with initial oxidation, the tendency of the functional group changes again during the secondary oxidation. In the case of constant initial temperature of secondary oxidation, the crossing point temperature of coal samples show a decreasing trend at first and rising later. And in the case of constant initial temperature of initial oxidation, the crossing point temperature of coal samples show a trend of rising. © 2019 Inderscience Enterprises Ltd.

关键词： Spontaneous combustion

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Toughened and self-healing carbon nanotube/epoxy resin composites modified with polycaprolactone filler for coatings, adhesives and FRP

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Journal of Building Engineering 2025年 111卷

作者： Guijun Xian Xiao Qi Jiajun Shi Jingwei Tian HuiGang Xiao Key Lab of Structures Dynamic Behavior and Control (Harbin Institute of Technology) Ministry of Education Heilongjiang Harbin 150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin 150090 China School of Civil Engineering Harbin Institute of Technology Heilongjiang Harbin 150090 China Yangtze River Delta Carbon Fiber and Composite Material Innovation Center Jiangsu Changzhou 213126 China State Key Laboratory of Molecular Engineering of Polymers Fudan University Shanghai 200433 China

Aiming at the durability problem caused by micro-crack damage in polymer under complex load and hygrothermal conditions, an epoxy resin matrix composite with self-repair function was developed. The multi-damage self-healing function of epoxy resin can be realized by carbon nanotubes (CNTs) reinforcement and polycaprolactone (PCL) toughening. Based on 0.5 wt% CNTs addition, epoxy resin systems with different PCL fillers (1/5/10/15 wt%) were successfully prepared. Through the comparison of thermal and mechanical properties, the optimum formula was obtained as the epoxy resin with CNTs and 5 wt% PCL composite (EPCP5). Furthermore, the tensile strength and elongation at break of EPCP5 increased by 25.4 % and 42.3 %, respectively, compared to the control sample. This improvement was attributed to the formation of hydrogen bonds between PCL and the epoxy resin, enhancing intermolecular forces. The difference in glass transition temperature for samples with varying PCL content was minimal (less than 3.8 %), indicating excellent thermal compatibility between the PCL/CNTs fillers and the resin matrix. Before damage, the tensile and flexural strengths of EPCP5 were 47.28 MPa and 116.35 MPa, respectively. Compared with one cycle for 40 % prefabricated damage, the tensile and flexural strengths of EPCP5 increased by 15.8 % and 25.1 %, 17.4 % and 25.3 % after second and three repair cycles, demonstrating the significant self-healing effect. Under 40 % and 60 % prefabrication loads, the self-healing efficiency of EPCP5 for tensile and flexural strengths reached up to 116.1 % after the third repair cycle. This was because the PCL melt filled and bridged the damaged area, effectively healing and reinforcing the micro-cracks. Noticed, after damage repairing, the micro-morphology showed that the 2–4 μm through cracks in the resin matrix were well healed. Furthermore, the infrared spectrum of EPCP5 showed a combination of the individual spectra of CNTs, PCL, and the resin, which indic

关键词： Carbon nanotubes Damage self-healing Epoxy resin Self-healing mechanism Thermoplastic self-healing agent

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Corrigendum (Authorship Correction) to “Study on the development and dust suppression performance of a novel composite dust suppressant for metal mines” [Atmos. Pollut. Res., Available online (2024) 102336]

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Atmospheric Pollution Research 2025年第2期16卷

作者： Jiaze Ren Zhian Huang keying Meng Gang Li Abdullahi Yakubu Abdullahi Mengyang Zeng Wei Li Jinyang Li Rongxia Yu Pengfei Wang Asim Farooq State Key Laboratory of High-Efficient Mining and Safety of Metal Mines University of Science and Technology Beijing Ministry of Education Beijing 100083 China Sinosteel Maanshan General Institute of Mining Research CO. LTD. Maanshan 243000 China Guangdong Guangye Yunliu Mining Industry Co. Ltd Yunfu 527300 China Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines Hunan University of Science & Technology Xiangtan 411201 China Department of Transportation Engineering Pak-Austria Fachhochschule: Institute of Applied Sciences and Technology Haripur 22620 Pakistan

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Numerical simulation of a cinema fire based on FDS

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International Journal of Simulation and Process Modelling 2018年第3期13卷 200-209页

作者： Huang, Zhian Meng, Yaru Yang, Rui Gao, Yukun Yinghua, Zhang Wang, Shuyi State Key Laboratory of High-Efficient Mining and Safety of Metal Mines University of Science and Technology Beijing Ministry of Education Beijing10083 China Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines Hunan University of Science and Technology Xiangtan411201 China State Key Laboratory of Fire Science University of Science and Technology of China Hefei230041 China

In this paper, large-scale fire dynamics simulator (FDS) model software was used to simulate a cinema fire. The reliability of the simulation results was verified by comparison with relevant research results and some fire precaution measures were put forward. Based on the physical fire model of 1:1, full-scale simulation of a cinema fire was carried out. By studying the flue gas, temperature and variation law of the CO concentration during the fire, it is found that the mechanical air-intake damages the stratification of smoke and air in the burning room to a certain extent. The lower air in the theatre is mixed with the upper high-temperature flue gas so that the temperature of lower air is higher than that of upper air. Meanwhile, the mechanical air-intake enhances the reducing speed of visibility. The results of this research provide a reference for the fire protection design of cinemas. © 2018 Inderscience Enterprises Ltd.

关键词： Fires

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Corrigendum to “Nonlinear modeling of bamboo fiber reinforced composite materials” [Compos. Struct. 238 (2020) 111976]

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Composite Structures 2020年 244卷

作者： Zhenyu Qiu Hualin Fan State Key Laboratory for Disaster Prevention & Mitigation of Explosion & Impact Army Engineering University of PLA Nanjing 210007 China Research Center of Lightweight Structures and Intelligent Manufacturing State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

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Microscopic characteristics of the methane occurrence state in coal

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International Journal of Materials and Structural Integrity 2018年第1-3期12卷 151-178页

作者： Huang, Zhian Ma, Zhenzhen Yang, Rui Gao, Yukun Zhang, Yinghua Gong, Xuejiao State Key Laboratory of High-Efficient Mining and Safety of Metal Mines University of Science and Technology Beijing Ministry of Education Beijing100083 China Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines Hunan University of Science and Technology Xiangtan411201 China Publicity Department People's Government of Sijiqing Town of Beijing Beijing100195 China

The regulation of methane occurrence is critical for gas control. Through liquid nitrogen adsorption, isothermal adsorption/desorption of methane and electrical experiments with undeformed and deformed coal, this paper studies the microscopic characteristics of methane occurrence. The results show: the median-pore-dominant deformed coal has less specific surface area and pore volume than the undeformed coal, which has mainly micropores and small pores;the deformed coal has greater methane absorption ability than the undeformed coal, and the negative influence of temperature on the former is more notable;the resistivity of deformed coal is three to seven times that of undeformed coal, and when adsorbing the resistivity of both coals decreases before being stable, whereas their dielectric constant rises first, then slightly declines. The results of the three experiments are in good accordance. The research is basic for coalbed gas and may provide a new thought for gas control. © 2018 Inderscience Enterprises Ltd.

关键词： Pore structure

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A dual-level model predictive control scheme for multi-timescale dynamical systems-extended version

arXiv

引用

arXiv 2019年

作者： Zhang, Xinglong Jiang, Wei Yu, Shuyou Xu, Xin Li, Zhizhong College of Intelligence Science and Technology National University of Defense Technology Changsha410073 China Dipartimento di Elettronica Informazione e Bioingegneria Politecnico di Milano Milan20133 Italy State Key Laboratory of Automotive Simulation and Control Department of Control Science and Engineering Jilin University at NanLing Changchun130025 China State Key Laboratory of Disaster Prevention and Mitigation of Explosion and Impact Army Engineering University Nanjing Jiangsu210007 China

So far, many control algorithms have been developed for singularly perturbed systems. However, in many industrial processes, enforcing closed-loop fast-slow dynamics for peculiarly non-separable ones is a prior request and a crucial issue to be resolved. Aiming at the above problem, this paper presents two dual-level model predictive control (MPC) algorithms for two-timescale dynamical systems with unknown bounded disturbance and input constraint. The proposed algorithms, each one composed of two regulators working in slow and fast time scales, are designed to generate closed-loop separable dynamics at the high and low levels. As a key feature, the proposed algorithms are not only suitable for singularly perturbed systems, but also capable of imposing separable closed-loop performance for dynamics that are non-separable and strongly coupled. The recursive feasibility and convergence properties are proven under suitable assumptions. The simulation results on controlling a Boiler Turbine (BT) system, including the comparisons with other classic controllers are reported, which show the effectiveness of the proposed algorithms. © 2019, CC BY.

关键词： Model predictive control

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Means of protecting materials from spontaneous coal combustion: Current developments, mechanisms, classifications, and prospects

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International Journal of Materials and Structural Integrity 2018年第1-3期12卷 125-150页

作者： Huang, Zhian Xiao, Shanlin Lu, Wei Gao, Yukun Zhang, Yinghua Wang, Hui State Key Laboratory of High-Efficient Mining and Safety of Metal Mines University of Science and Technology Beijing Ministry of Education Beijing10083 China Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines Hunan University of Science and Technology Xiangtan411201 China School of Civil and Resource Engineering University of Science and Technology Beijing Beijing10083 China College of Mining and Safety Engineering Shandong University of Science and Technology Qingdao266590 China

Spontaneous coal combustion poses serious threats to the world and especially to China, the world's largest coal producer and user. Apart from spurring monetary losses in national exchequers and resource losses for countries, spontaneous coal combustion results in a loss of life, which cannot be measured based on costs. Innumerable researchers and scholars in China and abroad have paid considerable attention to studying means of protecting materials from spontaneous coal combustion. A variety of materials that prevent spontaneous coal combustion have been developed. The goal of this paper is reveal the academic literature on spontaneous coal combustion. In this comprehensive review, mechanisms of spontaneous coal combustion, research findings and advantages and shortcomings of materials that prevent spontaneous coal combustion are explored. In view of different coal mining conditions and material properties, materials that prevent spontaneous coal combustion are classified in accordance with material phases. The development of various coal fire extinguishing materials is discussed. Our comprehensive review can thus be used to prevent and control spontaneous coal combustion and to curtail the currently frequent disasters resulting from spontaneous coal combustion. © 2018 Inderscience Enterprises Ltd.

关键词： Coal combustion

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