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Blast Protection Shelter by Using Hollow Steel Filled with Recycled Concrete

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Transactions of Tianjin university 2008年第6期14卷 426-429页

作者： li jianchun, HUANG Xin HUANG Xin ma Guowe school of civil and {2. Engineering Nanyang Technological University Singapore 639798

Under extreme loading condition,a shelter will provide a safe place to protect people from injury caused by blast wave and *** order to save resource and reuse waste materi-als,a new design concept for blast protection shelter was *** new construction was composed of I-section steel panel or C-channel steel panel filled with recycled concrete *** compaction process of the recycled concrete aggregate filled in the steel construction was ex-perimentally investigated.A single storey shelter based on the proposed design concept was nu-merically simulated by using LS-DYNA *** the 3D numerical model,three walls were de-signed using I-section steel and one wall using C-channel steel,and all of the four walls were filled with recycled concrete *** penetration analysis was done by using *** penetration tests were also carried out by using a gas *** is found that the proposed shelter based on the design concept is effective for blast protection.

关键词： hollow steel panel recycled concrete aggregate shelter LS-DYNA simulation

THREE-PHASE MEDIUM MODEL AND WAVE PROPAGATION ANALYSIS FOR FILLED ROCK JOINT

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THREE-PHASE MEDIUM MODEL AND WAVE PROPAGATION ANALYSIS FOR F...

Modeling Strain Rate Effect for Heterogeneous Brittle materials

2.09 International Symposium on Rock Mechanics:"Rock Characterisation,Modelling and Engineering Design Methods"

作者： li jianchun,ma {2. school of civil and environmental Engineering,nanyang technological university singapore,639798

The mechanical behavior of rock mass is significantly affected by the vastly existing discontinuities, primarily *** of the main tasks in the fields of rock mechanics and engineering is to well understand the mechanical properties of the discontinuities and their effects on rock mass behavior,so as to ensure the stability of the rock mass and underground structures under dynamic load,which is of great interest to mining engineers,seismologists and *** joints can be filled with materials,such as sand, clay,and other *** insight understanding and description of the dynamic properties of filled rock joints are essential for the analysis and design of rock engineering problems under dynamic loads. The filled rock joints can be considered as a complex three-phase medium consisting of rock solid particles,water and *** lower strain rates,the water and air are assumed to flow through the skeleton driven by the pore *** contrast,at higher strain rates and pressures,such as under shock and blasting loads,water and air are trapped within the pores and the deformation of the matrix is controlled by the deformation and the volume fraction of each of the three constituent *** on the multiple phase medium theory,a three-phase medium model was proposed for describing wave propagation across filled rock joints in the *** in the three-phase medium model were identified by a series of modified split Hopkinson pressure bar(SHPB) tests,where a sand or clay layer was used to represent an artificial filled rock *** granitic pressure bars with the sandwiched sand or clay layer were used to represent the filled joint to simulate longitudinal stress wave propagation across such geological *** filled joint was under different saturation and different width *** test results showed that the dynamic property of the filled rock joints was highly nonlinear and it depended on the volume ratios of th

关键词： three-phase medium model filled rock joint wave propagation modified SHPB test joint dynamic behavior

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Transactions of Tianjin university 2006年第B9期12卷 79-82页

作者： ma guowei DONG Aiai {2. school of civil and {2. Engineering Nanyang Technological University Singapore 639798

Rocks are heterogeneous from the point of dynamic failure behavior. Both the compressive and microstructure which is of significance to their tensile strength of rock-like materials is regarded different from the static strength. The present study adopts smoothed particle hydrodynamics （SPH） which is a virtual particle based meshfree method to investigate strain rate effect for heterogeneous brittle materials. The SPH method is capable of simulating rock fracture, free of the mesh constraint of the traditional FEM and FDM models. A pressure dependent J-H constitutive model involving heterogeneity is employed in the numerical modeling. The results show the compressive strength increases with the increase of strain rate as well as the tensile strength, which is important to the engineering design.

关键词： heterogeneous strain rate effect SPH method

State-of-the-art of 3D printing technology of cementitious material—An emerging technique for construction

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Science China(technological Sciences) 2018年第4期61卷 475-495页

作者： ma guowei WANG {2. JU Yang College of Architecture and civil Engineering Beijing University of Technology school of civil Environmental and Mining Engineering The University of Western Australia school of Mechanics and civil Engineering China University of Mining & Technology at Beijing State Key Laboratory of Coal Resources and Safe Mining China University of Mining & Technology at Beijing

In recent few years, significant improvement has been made in developing largescale 3 D printer to accommodate the need of industrial-scale 3 D printing. Cementitious materials that are compatible with 3 D printing promote rapid app{2.cation of this innovative technique in the construction field with advantages of cost effective, high efficiency, design flexibi{2.ty and environmental friendly. This paper firstly reviews existing 3 D printing techniques that are currently being used in commercial3 D printers. It then summarizes three latest development of largescale 3 D printing systems and identifies their relationships and {2.miting factors. Thereafter, critical factors that are used to evaluate the workabi{2.ty and printable performance of cementitious materials are specified. Easy-extrusive, easy-flowing, well-buildable, and proper setting time are significant for cementitious material to meet the critical requirements of a freeform construction process. Finally, main advantages, potential app{2.cations and the prospects of future research of 3 D printing in construction technology are suggested. The objective of this work is to review current design methodologies and operational constraints of largescale 3 D printing system and provide references for optimizing the performance of cementitious material and promote its responsible use with largescale 3 D printing technology.

关键词： 3D printing cementitious material construction automation

Effect of Foam Cladding for Blast Mitigation:Numerical Simulation

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Transactions of Tianjin university 2006年第B9期12卷 122-125页

作者： ma guowei YE Ziqing ZHANG Xingui school of civil and {2. Engineering Nanyang Technological University Singapore 639798 Singapore school of civil and Architectural Engineering Guangxi University Nanning 530004 China

Two numerical simulations were performed to investigate the protective effect of the foam cladding. One simulation is based on a previous experimental study, which is a ballistic pendulum with and without a foam cladding subjected to close-range blast loading. The other model is a steel beam with and without a foam cladding under blast loading. The overpressure due to the blast event can be calculated by the empirical function ConWep or by an arbitrary Lagrangian-Eulerian (ALE) coupling model. The first approach is relatively simple and widely used. The second approach can model the propagation of the blast wave in the air and the interaction between the air and the solid. It is found that the pendulum with the foam cladding always swings to a larger rotation angel compared to a bare pendulum. However, the steel beam with an appropriate foam cladding has a smaller deflection compared to the bare beam without a foam cladding. It is concluded that the protective effect of the foam cladding depends on the properties of the foam and the protected structure.

关键词： foam material blast mitigation ALE LS-DYNA

Simulation of viscoelastic behavior of defected rock by using numerical manifold method

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Frontiers of Structural and civil Engineering 2011年第2期5卷 199-207页

作者： Feng REN lifeng FAN guowei {2. school of civil and {2. Engineering Nanyang Technological UniversitySingapore 639798Singapore school of civil and Resource Engineering The University of Western AustraliaCrawleyWA 6009Australia

Numerical simulations of longitudinal wave propagation in a rock bar with microcracks are conducted by using the numerical manifold method which has great advantages in the simulation of ***,validation of the numerical manifold method is carried out by simulations of a longitudinal stress wave propagating through intact and cracked rock *** behavior of the stress wave traveling in a one-dimensional rock bar with randomly distributed microcracks is subsequently *** is revealed that the highly defected rock bar has significant viscoelasticity to the stress wave *** attenuation as well as time delay is affected by the length,quantity,specific stiffness of the distributed microcracks as well as the incident stress wave *** storage and loss moduli of the defected rock are also affected by the microcrack properties;however,they are independent of incident stress wave frequency.

关键词： stress wave propagation defected rock numerical manifold method viscoelastic behavior storage modulus loss modulus

Simulation of blast induced crater in jointed rock mass by discontinuous deformation analysis method

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Frontiers of Structural and civil Engineering 2010年第2期4卷 223-232页

作者： Youjun NING Jun YANG Xinmei AN guowei ma school of civil and {2. Engineering Nanyang Technological UniversitySingapore 639798Singapore State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China school of civil and Resource Engineering University of Western Australia35 Stirling HighwayCrawley WA 6009Australia

Rock blasting is a dynamic process accom panied with the propagations of shock waves and the dispersion of the explosion *** paper adopts the discontinuous deformation analysis(DDA)method to simulate the rock blasting process.A dynamic parameter adjustment and the non-reflecting boundary condition are implemented in the DDA *** sub-block DDA method to simulate fracture problems is *** blasting process in jointed rock mass is simulated by app{2.cation of the explosion gas pressure on the expanding borehole walls and induced connected fracture surfaces around the *** blast craters with different overburdens are *** whole process including the explosion gas dispersion,borehole expansion,rock mass failure and cast,and the formation of the final blasting piles in rock blasting are well reproduced *** study for different overburdens is carried out,and the results are analyzed and discussed.

关键词： blast crater jointed rock mass explosion gas pressure discontinuous deformation analysis(DDA)method

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工字形钢筋混凝土矮墙抗剪承载力研究

工程力学 2021年第4期38卷 123-135页

作者：马佳星陈柯宇王银辉李兵浙大宁波理工学院土木建筑工程学院浙江宁波315100 浙江理工大学建筑工程学院浙江杭州310018 新加坡南洋理工大学土木与环境工程学院新加坡639798

工字形钢筋混凝土(RC)矮墙在双主轴向均具有较高的强度和刚度,常用于低、中层建筑及核电站设施中。现有规范在预测工字形RC矮墙抗剪承载力时存在考虑参数不足、未考虑翼缘影响等问题,计算值于试验值相比离散性也较大。该文建立了一个包... 详细信息

工字形钢筋混凝土(RC)矮墙在双主轴向均具有较高的强度和刚度,常用于低、中层建筑及核电站设施中。现有规范在预测工字形RC矮墙抗剪承载力时存在考虑参数不足、未考虑翼缘影响等问题,计算值于试验值相比离散性也较大。该文建立了一个包含有152.试件的参数详尽的工字形RC矮墙试验数据库。并以此为基础,比对分析了多国规范的在预测此类墙抗剪承载力上的表现。同时,基于腹板裂纹分布,建立了考虑翼缘影响的工字形RC矮墙抗剪承载力计算模型,并利用力平衡推导出相应公式。结果表明:较各国规范,该文提出的公式预测精度更高,所得计算值与实测值之比的均值为1,变异系数也较小。其成果可为RC剪力墙的设计和规范公式的修订提供指导。

关键词：工字形剪力墙数据库规范抗剪承载力

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工字形钢筋混凝土剪力墙有效刚度研究

建筑结构 2022年第13期52卷 112-119页

作者：余磊马佳星王银辉李兵重庆交通大学土木工程学院重庆400074 浙大宁波理工学院土木建筑工程学院宁波315100 新加坡南洋理工大学土木与环境工程学院新加坡639798

工字形钢筋混凝土剪力墙因具有较高的承载力与刚度,被广泛运用于建筑结构抗震设计之中。有效刚度对于钢筋混凝土剪力墙的抗震性能有着重要影响。利用有限元软件DIANA对拟静力加载下工字形钢筋混凝土剪力墙进行研究,分析了翼缘宽度、轴... 详细信息

工字形钢筋混凝土剪力墙因具有较高的承载力与刚度,被广泛运用于建筑结构抗震设计之中。有效刚度对于钢筋混凝土剪力墙的抗震性能有着重要影响。利用有限元软件DIANA对拟静力加载下工字形钢筋混凝土剪力墙进行研究,分析了翼缘宽度、轴压比、剪跨比、腹板纵筋强度、翼缘纵筋配筋率对有效刚度的影响。结果表明,工字形钢筋混凝土剪力墙的有效刚度折减系数随着翼缘宽度、腹板纵筋强度的增加而减小,随着轴压比、剪跨比的增大而增大,翼缘纵筋配筋率影响不大。提出了适用于工字形钢筋混凝土剪力墙有效刚度的计算公式,其计算结果贴合试验值,说明该公式准确度较高,可用于计算工字形钢筋混凝土剪力墙的有效刚度。

关键词：工字形钢筋混凝土剪力墙有效刚度 DIANA 翼缘宽度轴压比剪跨比腹板纵筋强度翼缘纵筋配筋率