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Layout optimization of steel reinforcement in concrete structure using a truss-continuum model

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Frontiers of Structural and Civil Engineering 2023年第5期17卷 669-685页

作者： Anbang CHEN Xiaoshan LIN zi-long zhao Yi Min XIE Centre for Innovative Structures and Materials School of EngineeringRMIT UniversityMelbourne 3001Australia Institute of Solid Mechanics School of Aeronautic Science and EngineeringBeihang UniversityBeijing 100191China

Owing to advancement in advanced manufacturing technology,the reinforcement design of concrete structures has become an important topic in structural *** on bi-directional evolutionary structural optimization(BESO),a new approach is developed in this study to optimize the reinforcement layout in steel-reinforced concrete(SRC)*** approach combines a minimum compliance objective function with a hybrid trusscontinuum ***,a modified bi-directional evolutionary structural optimization(M-BESO)method is proposed to control the level of tensile stress in *** fully utilize the tensile strength of steel and the compressive strength of concrete,the optimization sensitivity of steel in a concrete–steel composite is integrated with the average normal stress of a neighboring *** demonstrate the effectiveness of the proposed procedures,reinforcement layout optimizations of a simply supported beam,a corbel,and a wall with a window are *** steel trajectories of SRC structures can be obtained using both *** area of critical tensile stress in concrete yielded by the M-BESO is more than 40%lower than that yielded by the uniform design and ***,the M-BESO facilitates a fully digital workflow that can be extremely effective for improving the design of steel reinforcements in concrete structures.

关键词： bi-directional evolutionary structural optimization steel-reinforced concrete concrete stress reinforcement method hybrid model

Surface effects on cylindrical indentation of a soft layer on a rigid substrate

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Acta Mechanica Sinica 2020年第2期36卷 422-429页

作者： Min Li Huan-Xin Zhang zi-long zhao Xi-Qiao Feng Institute of Biomechanics and Medical Engineering AMLDepartment of Engineering MechanicsTsinghua UniversityBeijing 100084China

In this paper,theoretical and numerical methods are combined to investigate the two-dimensional,cylindrical indentation of an elastic soft layer bonded on a rigid *** incorporating the Gurtin-Murdoch’s theory of surface elasticity into the Kerr model,we account for surface effects on the indentation behavior of a soft *** governing differential relation between the surface pressure and displacement of the film-substrate system is *** an incompressible thin layer,the explicit solutions are derived,which are simple and *** element simulations are performed using an explicit restart algorithm to study the indentation properties of the layer-substrate system and to examine the validity and accuracy of the theoretical *** work holds promise for applications in mechanical characterization of soft materials,such as biological tissues and cells.

关键词： Soft materials Indentation Surface effect Contact Kerr model

M-estimation for Periodic GARCH Model with High-frequency Data

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Acta Mathematicae Applicatae Sinica 2017年第3期33卷 717-730页

作者： Peng-ying FAN Si-xin WU zi-long zhao Min CHEN School of Economics Beijing Technology and Business University Academy of Mathematics and Systems Science Chinese Academy of Sciences

This paper studies an M-estimator of a proxy periodic GARCH （p, q） scaling model and establishes its consistency and asymptotic normality. Simulation studies are carried out to assess the performance of the estimator. The numerical results show that our M-estimator is more efficient and robust than other estimators without the use of high-frequency data.

关键词： asymptotic normality consistency high-frequency data PGARCH model M-estimator

Influence of Al-Si additions on mechanical properties and corrosion resistance of Mg-8Li dual-phase alloys

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Journal of Iron and Steel Research International 2017年第4期24卷 426-429页

作者： zi-long zhao Xue-gang Xing Yi Luo Yi-de Wang Wei Liang College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina Shanxi Key Laboratory of Advanced Magnesium based Materials Taiyuan 030024ShanxiChina Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina

Sheet samples of Mg-8Li,Mg-8Li-3Al,Mg-8Li-3AlSi and Mg-8Li-5AlSi alloys were obtained by hot *** microscope,microhardness tester,nanoindentor,X-ray diffractometer and electrochemical analyzer were adopted to investigate the microstructures,micro-mechanical properties and corrosion *** was preheated to 150°C before rolling process,and rolling reduction designed was about20% per pass with a total rolling reduction of 84%.The rolled plates were annealed at 200°C for 120 *** tensile tests were performed at room *** results showed that both the strength and corrosion resistance of theα＋βdual-phase of Mg-Li alloy were significantly improved with adding Al-Si *** strength enhancement was attributed to the solid solution of Al into theα-Mg matrix and into theβ-Li matrix as well as to the precipitation strengthening of Mg2 Si ***,the dendrite grains ofα-Mg transformed to equiaxed ones with addition of Al into alloy Mg-Li.

关键词： Mg-8Li dual-phase alloy Mechanical property Corrosion resistance Hardness Rolling

Ultrahard X-ray multifunctional application beamline at the SSRF

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Nuclear Science and Techniques 2024年第6期35卷 14-25页

作者： Ke Yang zhao-Hui Dong Chun-Yin Zhou zi-long zhao Dong-Xu Liang Sai-Chao Cao Ai-Guo Li Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China

The ultrahard X-ray multifunctional application beamline(BL12SW)is a phase-II beamline project at the Shanghai Syn-chrotron Radiation *** primary X-ray techniques used at the beamline are high-energy X-ray diffraction and imaging using white and monochromatic *** main scientific objectives of ultrahard X-ray beamlines are focused on two research *** is the study of the structural properties of Earth’s interior and new materials under extreme high-temperature and high-pressure conditions,and the other is the characterization of materials and processes in near-real service *** beamline utilizes a superconducting wiggler as the light source,with two diamond windows and SiC discs to filter out low-energy light(primarily below 30 keV)and a Cu filter assembly to control the thermal load entering the subsequent optical *** beamline is equipped with dual *** first was a meridional bending Laue monochromator cooled by liquid nitrogen,achieving a full-energy coverage of 30-162 *** second was a sagittal bending Laue monochromator installed in an external building,providing a focused beam in the horizontal direction with an energy range of 60-120 *** were four experimental hutches:two large-volume press experimental hutches(LVP1 and LVP2)and two engineering material experimental hutches(ENG1 and ENG2).Each hutch was equipped with various near-real service conditions to satisfy different *** example,LVP1 and LVP2 were equipped with a 200-ton DDIA press and a 2000-ton dual-mode(DDIA and Kawai)press,***1 and ENG2 provide in situ tensile,creep,and fatigue tests as well as high-temperature *** June 2023,the BL12SW has been in trial *** is expected to officially open to users by early 2024.

关键词： Shanghai Synchrotron Radiation Facility Ultrahard X-ray High energy diffraction High energy imaging Engineering materials Earth science

Effects of muddy water irrigation with different sediment gradations on nitrogen transformation in agricultural soil of Yellow River Basin

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Water Science and Engineering 2022年第3期15卷 228-236页

作者： Li-na Chen zi-long zhao Guo-mian Guo Jiang Li Wen-bo Wu Fang-xiu Zhang Xiang Zhang College of Agricultural Science and Engineering Hohai UniversityNanjing 211100China Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education Hohai UniversityNanjing 210098China College of Environment Hohai UniversityNanjing 210098China Key Laboratory of Lower Yellow River Channel and Estuary Regulation of Ministry of Water Resources Zhengzhou 450003China Yellow River Institute of Hydraulic Research Zhengzhou 450003China

Muddy water irrigation has been widely practiced in the Yellow River Basin for agricultural production and is an important method of economical and intensive utilization of water *** this study,the effects of sediment gradation,sand content,and soil moisture content on nitrogen(N)transformation were studied through a series of experimental *** results indicated that muddy water irrigation significantly affected agricultural soil physical and biological properties as well as N *** bulk density,total porosity,pH,and microbial enzyme activities significantly correlated with N transformation as affected by the interaction between sediment and soil *** addition generally increased the soil bulk density and reduced the soil porosity and pH significantly,and the optimum moisture for promotion of the N transformation rate was 80%of the water-filled pore ***,muddy water irrigation has a potentially long-term influence on agricultural N cycles in semi-arid regions of northwestern *** could provide a theoretical basis for scientific and rational use of muddy water for irrigation.

关键词： Yellow River Basin Muddy water irrigation Soil properties Nitrogen transformation Sediment

Picosecond time-resolved X-ray ferromagnetic resonance measurements at Shanghai synchrotron radiation facility

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Nuclear Science and Techniques 2022年第5期33卷 126-134页

作者： Xia Yang Jie-Feng Cao Jun-Qin Li Fang-Yuan Zhu Rui Yu Jian He zi-long zhao Yong Wang Ren-Zhong Tai Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China

An experimental picosecond time-resolved X-ray ferromagnetic resonance(TR-XFMR)apparatus with a time resolution of 13 ps(RMS)or 31 ps(FWHM)was constructed and demonstrated in the 07U and 08U1A soft X-ray beamlines at the Shanghai Synchrotron Radiation Facility(SSRF)using pump-probe detection and X-ray magnetic circular dichroism(XMCD)*** and time-resolved ferromagnetic resonance was excited by continuous microwave phase-locking of the bunch clock within the photon beam during synchrotron radiation and was characterized by detecting the magnetic circular dichroism signals of the elements of interest in the magnetic *** this equipment,we measured the amplitude of the element-specific moment precession during ferromagnetic resonance(FMR)at 2 GHz in a single Ni81Fe19layer.

关键词： Ferromagnetic resonance Time resolution Pump-probe Synchrotron radiation

Effect of Li content on microstructure and mechanical property of Mg-xLi-3(Al-Si) alloys

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Transactions of Nonferrous Metals Society of China 2019年第12期29卷 2506-2513页

作者： Cheng ZHANG Liang WU zi-long zhao Zhi-hui XIE Guang-sheng HUANG Lei LIU Bin JIANG Andrej ATRENS Fu-sheng PAN State Key Laboratory of Mechanical Transmission College of Materials Science and EngineeringChongqing UniversityChongqing 400044China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China College of Civil Engineering Chongqing UniversityChongqing 400045China Synthesis and Pollution Control Key Laboratory of Sichuan Province College of Chemistry and Chemical EngineeringChina West Normal UniversityNanchong 637002China Chongqing Research Center for Advanced Materials Chongqing Academy of Science and TechnologyChongqing 401123China School of Mechanical and Mining Engineering The University of QueenslandBrisbane Qld 4072Australia

Mg-4 Li-3(Al-Si),Mg-8 Li-3(Al-Si)and Mg-12 Li-3(Al-Si)alloys based on theα-Mg,α-Mg+β-Li,β-Li phases,respectively,were produced to investigate the effect of alloying with Al-Si eutectic on the microstructure and mechanical properties of the three *** with the Al-Si eutectic of Mg-xLi(x=4,8 and 12 wt.%)alloys caused the formation of different types of Al-Li precipitates:Al3Li,AlLi and Li3Al2,***,considerable quantities of Mg2Si phase particles were found in the three *** results of tensile tests showed that the Mg-4Li-3(Al-Si)alloy exhibited the highest ultimate tensile strength(UTS)of 249 MPa but the lowest elongation of 6.3%.The Mg-12Li-3(Al-Si)alloy had the highest elongation of 26%but the lowest UTS of 173 *** different mechanical properties were attributed to the different crystal structures of the three alloys and the precipitate with different type,morphology and distribution.

关键词： Mg-Li alloy Al-Si eutectic second phase tensile strength elongation

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基于子区域的结构拓扑优化并行策略

Acta Mechanica Sinica 2023年第9期39卷 114-125页

作者：赵子龙荣毅燕翌冯西桥谢亿民 Institute of Solid Mechanics School of Aeronautic Science and EngineeringBeihang UniversityBeijing 100191China Centre for Innovative Structures and Materials School of EngineeringRMIT UniversityMelbourne 300lAustralia Department of Engineering Mechanics MIIT Key Laboratory of Dynamics and Control of Complex SystemsNorthwestern Polytechnical UniversityXi'an710072China Institute of Biomechanics and Medical Engineering Department of Engineering MechanicsTsinghua UniversityBejing 100084China

结构拓扑优化在过去的三十年里经历了巨大的发展,充分利用高性能计算资源有助于拓宽拓扑优化在大规模设计问题中的应用。本文提出了一种针对一般三维拓扑优化的基于子区域的并行策略。通过子区域划分、矩阵运算、引入单元硬杀算法,优化... 详细信息

结构拓扑优化在过去的三十年里经历了巨大的发展,充分利用高性能计算资源有助于拓宽拓扑优化在大规模设计问题中的应用。本文提出了一种针对一般三维拓扑优化的基于子区域的并行策略。通过子区域划分、矩阵运算、引入单元硬杀算法,优化过程得以显著提速.将该策略整合进高效、简洁的Python代码;该代码可适用于任意形状的设计域.附录一中给出的完整代码,易于扩展,扩展后可解决多类优化问题.通过求解四个柔度最小化问题展示了该策略的高效性.本研究在机械工程、先进制造,以及建筑设计等领域有潜在的应用价值.

关键词：并行策略高性能计算子区域划分最小化问题结构拓扑优化 Python 设计域建筑设计