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Experimental and mesoscopic investigation on the dynamic properties of coral aggregate concrete in compression

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Science China(Technological Sciences) 2021年第6期64卷 1153-1166页

作者： WU Zhang Yu ZHANG JinHua YU HongFa FANG Qin CHEN Li yue chengjun Department of Civil and Airport Engineering Civil Aviation CollegeNanjing University of Aeronautics and AstronauticsNanjing 210016China School of Civil Engineering Southeast UniversityNanjing 210096China Engineering Research Center of Safety and Protection of Explosion&Impact of Ministry of Education(ERCSPEIME) Southeast UniversityNanjing 211189China Department of Civil Engineering Army Engineering University of PLANanjing 210007China

To investigate the dynamic responses and comprehending the damage mechanism of coral aggregate concrete(CAC) in compression, both the experimental and numerical investigations were implemented in the present work. Firstly, the dynamic mechanical properties of CAC at different strain rates were tested through the Split-Hopkinson pressure bar(SHPB) ***, the effects of concrete strength grade and strain rate on CAC were discussed and analyzed. Subsequently, we developed the three-dimensional(3D) random mesoscale model considering the randomness of aggregate shape, size and distribution at meso-level, which was validated and employed in the numerical simulation of CAC in compression. The results indicate that the splitting failure passing through the coral aggregate is CAC’S primary failure mode. It has been found that the failure pattern, deformation process, and dynamic increasing factor of CAC are associated with both the strain rate and concrete strength grade. Furthermore, by comparing the experimental and mesoscopic results, it has been proven to be reliable to employ the developed 3D mesoscale modelling method to simulate CAC’s dynamic performances, which has enormous potential in future research of CAC under intense dynamic loadings.

关键词： coral aggregate concrete 3D mesoscopic modelling SHPB strain rate DIF

Service Life Design for Concrete Engineering in Marine Environments of Northern China Based on a Modified Theoretical Model of Chloride Diffusion and Large Datasets of Ocean Parameters

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Engineering 2022年第10期17卷 123-139页

作者： Taotao Feng Hongfa Yu Yongshan Tan Haiyan Ma Mei Xu chengjun yue Department of Civil and Airport Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China School of Materials Science and Engineering Southeast UniversityNanjing 211189China College of Civil Science and Engineering Yangzhou UniversityYangzhou 225127China

In this study,through experimental research and an investigation on large datasets of the durability parameters in ocean engineering,the values,ranges,and types of distribution of the durability parameters employed for the durability design in ocean engineering in northern China were *** on a modified theoretical model of chloride diffusion and the reliability theory,the service lives of concrete structures exposed to the splash,tidal,and underwater zones were *** concrete proportions meeting the requirement of a service life of 100 or 120 years were designed,and a cover thickness requirement was *** addition,the effects of the different time-varying relationships of the boundary condition(Cs)and diffusion coefficient(Df)on the service life were compared;the results showed that the time-varying relationships used in this study(i.e.,Cscontinuously increased and then remained stable,and Dfcontinuously decreased and then remained stable)were beneficial for the durability design of concrete structures in marine environment.

关键词： Large datasets Modified theoretical model Reliability theory Service life Boundary condition Diffusion coefficient

聚脲加固砖填充墙抗爆性能的试验和分析方法研究

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爆炸与冲击 2022年第7期42卷 124-135页

作者：许林峰陈力李展岳承军东南大学爆炸安全防护教育部工程研究中心江苏南京211189 陆军工程大学江苏南京210007

为了掌握聚脲喷涂加固砖填充墙的抗爆特性,基于一种改进的大型爆炸试验装置,开展了聚脲加固框架砖填充墙的原型爆炸试验,分析了爆炸荷载作用下加固砖墙的动力响应特征和破坏过程及模式,揭示了其失效破坏机理。研究结果表明,聚脲加固可... 详细信息

为了掌握聚脲喷涂加固砖填充墙的抗爆特性,基于一种改进的大型爆炸试验装置,开展了聚脲加固框架砖填充墙的原型爆炸试验,分析了爆炸荷载作用下加固砖墙的动力响应特征和破坏过程及模式,揭示了其失效破坏机理。研究结果表明,聚脲加固可大幅提升填充墙构件的抗爆性能,显著增加填充墙构件的变形延性;加固砖墙受爆炸荷载作用发生振动的过程其体系刚度不断变化,最高相差133%;随着比例距离降低,加固砖墙的破坏模式逐渐由弯曲破坏转为剪切破坏,聚脲厚度超过6 mm可以有效限制局部剪切破坏现象;基于砖墙和聚脲涂层的抗力函数建立的理论计算模型,可以较为准确地预测爆炸作用下背爆面加固双向砖墙的正向位移响应过程。

关键词：聚脲砖墙抗爆试验体系刚度抗力函数

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全珊瑚海水混凝土冲击压缩性能试验研究与数值模拟

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建筑材料学报 2021年第2期24卷 283-290页

作者：岳承军余红发麻海燕梅其泉刘婷南京航空航天大学民航学院江苏南京211100

采用直径为75 mm的霍普金森压杆对强度等级为C30和C50的全珊瑚海水混凝土(CASC)以及剑麻纤维增强全珊瑚海水混凝土(SFCASC)进行了冲击压缩试验,并使用LS-DYNA软件对CASC的冲击性能进行了模拟.结果表明:CASC与SFCASC的动态增强因子DIF与... 详细信息

采用直径为75 mm的霍普金森压杆对强度等级为C30和C50的全珊瑚海水混凝土(CASC)以及剑麻纤维增强全珊瑚海水混凝土(SFCASC)进行了冲击压缩试验,并使用LS-DYNA软件对CASC的冲击性能进行了模拟.结果表明:CASC与SFCASC的动态增强因子DIF与应变率ε·s、立方体抗压强度f cu有关,建立了DIF关于ε·s与f cu的二元函数模型;通过试件的破坏形态分析可知剑麻纤维能够有效增强CASC的抗冲击性能,当应变率为52.4 s^(-1)时,CASC-C50试件破坏较为严重,而SFCASC-C50试件在应变率为56.9 s^(-1)时仍能保持完整的形态,只在边缘处出现少量裂缝;采用LS-DYNA软件对CASC-50的冲击压缩过程进行数值模拟,通过试验数据确定了HJC模型参数,模拟的动态抗压强度与试验值的误差在1.0%~4.9%,模拟动态临界应变与试验值的误差在4.3%~18.3%.

关键词：全珊瑚海水混凝土霍普金森压杆剑麻纤维应变率效应数值模拟

Solving the Problem of the Link Optimizing and Delayconstrained Multicast Routing Based on GA

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Solving the Problem of the Link Optimizing and Delayconstrai...

第25届中国控制会议

作者： yue chengjun,Jing Yuanwei College of Information Science and Engineering, Northeastern University, shenyang 110004 College of Information and Science,Liaoning University,shenyang,110036

＜正＞In this paper, we investigate the problem of multicast routing in IP network with the link cost and delay-constrained. For the limitation of OSPF（Open Short Path First） net protocol, the unbalance use of link often results in the congestion in the larger scale network. Our contribution is that we consider the multicast routing problem taking into consideration the congestion due to the unbalance use of link, and we present a improved genetic algorithm to solving the problem of the multicast routing. The genetic algorithm begins from a least-delay tree, then iteratively replaces expensive tree links with cheaper links during the crossover, and gets final multicast tree satisfied delay constraint. Through extensive simulation experiments,we result show that the proposed genetic algorithm can perform better in terms of delay an running time, and construct optimal delay-constrained multicast tree efficiently.

关键词： multicast routing delay constraint link optimizing

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全珊瑚海水混凝土动态冲击性能试验研究

材料导报 2019年第16期33卷 2697-2703页

作者：岳承军余红发麻海燕章艳梅其泉达波南京航空航天大学土木工程系南京210016 南京工程学院建筑工程学院南京210009

通过掺加剑麻纤维和使用碱式硫酸镁水泥(Basic magnesium sulfate cement,BMSC)两种方法提高全珊瑚海水混凝土(Coral aggregate seawater concrete,CASC)的冲击强度和韧性。试验采用直径为75 mm的分离式霍普金森压杆(Split Hopkinson pressure bar,SHPB)得到CASC在四个应变率下的冲击压缩力学性能。结果表明:CASC具有明显的应变率硬化效应,当应变率在56~137 s^-1范围内时,综合应用碱式硫酸镁水泥和剑麻纤维的CASC的动态增强因子(DIF)是普通硅酸盐水泥CASC的1.19~1.29倍;剑麻纤维和BMSC对CASC均具有增韧作用,综合应用两者后在四个应变率下CASC的韧性指数分别提高了2.24倍、1.86倍、1.35倍、1.18倍;在掺加剑麻纤维(含量3 kg/m^3)或使用BMSC后,CASC的冲击抗裂性能均有增强,综合应用剑麻纤维和BMSC比单独使用其中一种增强效果更佳。

关键词：全珊瑚海水混凝土(CASC) 霍普金森压杆(SHPB) 剑麻纤维碱式硫酸镁水泥(BMSC) 应变率效应动态增强因子(DIF)

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TDS-MD常见故障的分析及处理

辽宁大学学报（自然科学版） 2000年第2期27卷 149-150页

作者：岳承君辽宁大学信息科学与技术学院辽宁沈阳110036

主要针对西安唐都教学仪器厂研制的实验设备TDS

关键词： TDS-MD 实验设备故障分析故障处理教学实验

Preparation of FeCoNi medium entropy alloy from Fe^(3+)-Co^(2+)-Ni^(2+)solution system

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 92-101页

作者： Zongyou Cheng Qing Zhao Mengjie Tao Jijun Du Xingxi Huang chengjun Liu Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819China School of Metallurgy Northeastern UniversityShenyang 110819China Engineering Research Center of Frontier Technologies for Low-carbon Steelmaking(Ministry of Education) Shenyang 110819China

In recent years,medium entropy alloys have become a research hotspot due to their excellent physical and chemical *** controlling reasonable elemental composition and processing parameters,the medium entropy alloys can exhibit similar properties to high entropy alloys and have lower *** this paper,a FeCoNi medium entropy alloy precursor was prepared via sol-gel and coprecipitation methods,respectively,and FeCoNi medium entropy alloys were prepared by carbothermal and hydrogen *** phases and magnetic properties of FeCoNi medium entropy alloy were *** showed that FeCoNi medium entropy alloy was produced by carbothermal and hydrogen reduction at 1500℃.Some carbon was detected in the FeCoNi medium entropy alloy prepared by carbothermal *** alloy prepared by hydrogen reduction was uniform and showed a relatively high ***,the hydrogen reduction product exhibited better saturation magnetization and lower coercivity.

关键词： medium entropy alloy sol-gel co-precipitation carbothermal hydrogen reduction

C45珊瑚混凝土的冲击压缩性能试验及数值模拟

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东南大学学报（自然科学版） 2020年第3期50卷 488-495页

作者：吴彰钰余红发麻海燕张锦华岳承军刘婷章艳南京航空航天大学民航学院南京211100 东南大学土木工程学院南京211189 南京工程学院建筑工程学院南京210009

为了研究珊瑚混凝土(CAC)的动态力学性能,采用试验研究和数值模拟相结合的方法对强度等级为C45的CAC冲击压缩性能及破坏特征进行了分析.首先,通过实验得到了CAC的压缩强度、应力应变曲线和破坏特征;然后,采用HJC模型对其冲击实验进行数... 详细信息

为了研究珊瑚混凝土(CAC)的动态力学性能,采用试验研究和数值模拟相结合的方法对强度等级为C45的CAC冲击压缩性能及破坏特征进行了分析.首先,通过实验得到了CAC的压缩强度、应力应变曲线和破坏特征;然后,采用HJC模型对其冲击实验进行数值模拟,并将模拟结果与试验结果进行对比,分析HJC模型及其参数的可靠性.结果表明:冲击压缩荷载作用下的CAC呈典型脆性破坏形态,其抗压强度具有明显的应变率效应;可以采用欧洲混凝土委员会推荐的计算模型来分析预测CAC的动态增强因子;动态屈服强度试验值与模拟值的误差(1.76%~7.71%)在允许范围内,说明HJC模型及其模型参数在C45 CAC的冲击力学性能分析方面具有较高的可靠性.

关键词：珊瑚混凝土冲击压缩荷载霍普金森压杆数值模拟 HJC模型