检索结果-南通市图书馆

A critical review of preparation design and workability measurement of concrete material for largescale 3D printing

Frontiers of Structural and Civil Engineering 2018年第3期12卷 382-400页

作者： guowei ma Li WANG College of Architecture and Civil Engineering Beijing University of Technology Beijing 100124 China School of Civil Environmental and Mining Engineering The University of Western Australia Crawley WA 6009 Australia School of Mechanics and Civil engineering China University of Mining & Technology at Beijing Beijing 100083 China

In recent few years, significant improvement has been made in developing largescale 3D printers to accommodate the need of industrial-scale 3D printing. It is of great feasibility to construct structural components and buildings by means of 3D concrete printing. The major issues of this innovative technique focus on the preparation and optimization of concrete materials which possess favourable printable properties as well as the measurement and evaluation methods of their workability. This paper firstly introduces three largescale 3D printing systems that have been successfully applied in construction industry. It then summarizes the commonly used raw materials in concrete manufacturing. Critical factors that should be particularly controlled in material preparation are specified. Easy-extrusive, easy-flowing, well-buildable, proper setting time and low shrinkage are significant for concrete mixture to meet the critical requirements of a freeform construction process. Thereafter, measuring methods that can be employed to assess the fresh and hardened properties of concrete at early stages are suggested. Finally, a few of evaluation methods are presented which may offer certain assistance for optimizing material preparation. The objective of this work is to review current design methodologies and experimental measurement and evaluation methods for 3D printable concrete materials and promote its responsible use with largescale 3D printing technology.

关键词： 3D printing concrete material printable property workability measurement construction automation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

3D simulation of image-defined complex internal features using the numerical manifold method

引用

Science China(Technological Sciences) 2024年第4期67卷 1023-1039页

作者： WU Jie ma guowei School of Civil and Transportation Engineering Hebei University of TechnologyTianjin 300401China Tianjin Key Laboratory for Prefabricated Building and Intelligent Construction Tianjin 300401China

The numerical simulation of internal features,such as inclusions and voids,is important to analyze their impact on the performance of composite ***,the complex geometries of internal features and the induced continuous-discontinuous(C-D)deformation fields are challenges to their numerical *** this study,a 3D approach using a simple mesh to simulate irregular internal geometries is developed for the first *** the help of a developed voxel crack model,image models that are efficient when recording complex geometries are directly imported into the *** reconstructions,which are usually labor-intensive,are excluded from this ***,using image models as the geometric input,image processing techniques are applied to detect material interfaces and develop contact ***,the C-D deformations of the complex internal features are directly calculated based on the numerical manifold *** accuracy and convergence of the developed3D approach are examined based on multiple *** 3D C-D simulation of sandstones with naturally formed complex microfeatures demonstrates the capability of the developed approach.

关键词： 3D continuous-discontinuous simulation image-based simulation complex internal features numerical manifold method voxel crack model structured mesh

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dual reciprocity boundary element based block model for discontinuous deformation analysis

引用

Science China(Technological Sciences) 2015年第9期58卷 1575-1586页

作者： FU GuoYang ma guowei QU XiaoLei School of Civil Environmental and Mining Engineering University of Western Australia School of Civil Environmental and Chemical Engineering RMIT University College of Architecture and Civil Engineering Beijing University of Technology

This paper presents a further development of the dual reciprocity boundary element method(DRBEM) with stepwise updating to pave the way for the introduction of boundary element mesh into the discontinuous deformation analysis(DDA). The advantage of the proposed method lies in its adoption of static fundamental solutions and reduction in the size of the governing equations by transforming the inertial term domain integrals to boundary integrals in the dynamic large displacement analysis. The unconditionally stable Newmark-β time integration method involving numerical damping to enhance the numerical stability is implemented for the dynamic analysis. In order to be coupled with the DDA to improve the deformability of the DDA block domains, a stepwise updating algorithm of the system variables is introduced. The stress updating in the analysis involved in the calculation of a domain integral and internal cells are used for the integration of the initial stress term. Several examples are used to verify the geometry-updated DRBEM model and satisfactory results have been obtained.

关键词： boundary element method stepwise updating initial stress large displacement

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experimental investigation on the cracking behavior of 3D printed kinked fissure

引用

Science China(Technological Sciences) 2018年第12期61卷 1872-1881页

作者： ma guowei DONG QianQian WANG Li College of Architecture and Civil Engineering Beijing University of Technology School of Civil and Transportation Engineering Hebei University of Technology

Uniaxial compression tests were carried out for 3 D printed samples having various types of kinked fissures by using the rock mechanics servo-controlled testing system. Photo-elastic technique is adopted to characterize and visualize the stress distribution and evolution of 3 D printed models subjected to vertical compression. The stress field in the loading process can clearly be captured via a high-speed camera. The results showed that fringes around the kinked fissure tips formed a central symmetrical interference fringe pattern, and failure firstly occurred at interference fringe of highest order. Two failure types i.e. tip-cracking and non-tip-cracking are categorized on the basis of crack propagation pattern of 3 D printed samples. Tensile crack propagation of wing cracks is the main form of failure of the antisymmetric kinked fissures, but the inclination of the branch fissures also played a key role on the location of initial fracture. The finite element method was applied to numerically simulate the process of crack propagation. The isochromatic fringe patterns are in good agreement with the experimental investigation. The current work gives an insight for implication of advanced technique to quantify and visualize the distribution of stress field, and provides further understanding of kinked fissure behavior at failure.

关键词： kinked fissure 3D printing cracking behavior stress field non-tip-cracking photo-elasticity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

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

引用

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

作者： ma guowei WANG Li 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 application of this innovative technique in the construction field with advantages of cost effective, high efficiency, design flexibility 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 limiting factors. Thereafter, critical factors that are used to evaluate the workability 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 applications 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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Inner damage identification and residual strength assessment of a 3D printed tunnel with marble-like cementitious materials using piezoelectric transducers

引用

Journal of Rock Mechanics and Geotechnical Engineering 2023年第4期15卷 838-851页

作者： guowei ma Chen Huang Junfei Zhang School of Civil and Transportation Engineering Hebei University of TechnologyTianjin300401China College of Architecture and Civil Engineering Beijing University of TechnologyBeijing100124China

Quantitative damage identification of surrounding rock is important to assess the current condition and residual strength of underground *** this work,an underground tunnel model with marble-like cementitious materials was first fabricated using the three-dimensional(3D)printing technique and then loaded to simulate its failure mode in the *** zirconate titanate piezoelectric(PZT)transducers were embedded in the surrounding rock around the tunnel in the process of 3D printing.A 3D monitoring network was formed to locate damage areas and evaluate damage extent during *** show that as the load increased,main cracks firstly appeared above the tunnel roof and below the floor,and then they coalesced into the tunnel ***,the tunnel model was broken into several *** resonant frequency and the peak of the conductance signature firstly shifted rightwards with loading due to the sealing of microcracks,and then shifted backwards after new cracks *** overall increase in the root-mean-square deviation(RMSD)calculated from conductance signatures of all the PZT transducers was observed as the load(damage)***-dependent equivalent stiffness parameters(ESPs)were calculated from the real and imaginary signatures of each PZT at different damage *** agreement between equivalent and experimental ESP values was ***,the relationship between the change of the ESP and the residual strength was *** method paves the way for damage identification and residual strength estimation of other 3D printed structures in civil engineering.

关键词： Piezoelectric(PZT)transducers Three-dimensional(3D)printed tunnel Electro-mechanical impedance(EMI) method Equivalent stiffness parameter(ESP) Residual strength

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transient electromagnetic detection method in water-sealed underground storage caverns

引用

Underground Space 2016年第1期1卷 44-61页

作者： Fang Lin Shougen Chen guowei ma MOE Key Laboratory of Transportation Tunnel Engineering Southwest Jiaotong UniversityChengdu 610031SichuanChina School of Civil Environmental and Mining EngineeringThe University of Western AustraliaPerth 6009Western AustraliaAustralia

Taking advantage of the water sensitivity of the transient electromagnetic method(TEM),this study assesses the effectiveness of the water curtain system for underground LPG storage caverns during the excavation *** also detects fracture water flow during the excavation process in light of the practice of two pilot large underground LPG storage caverns in *** maps of apparent resistivity derived from TEM measurements before and after water-filling during the excavation process have been discussed to improve the quality of the water curtain *** is the first case to apply TEM to detect the quality of the water curtain system during the construction of underground LPG storage cavern projects,and it is found to be practical,more visualized and worth popularizing.

关键词： LPG storage Transient electromagnetic method Underground caverns Water curtain system Fracture flow

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A review on effects of different factors on gas explosions in underground structures

引用

Underground Space 2020年第4期5卷 298-314页

作者： Ying Xu Yimiao Huang guowei ma School of Civil and Transportation Engineering Hebei University of Technology5340 Xiping RoadBeichen DistrictTianjinChina Department of Civil Environmental and Mining EngineeringUniversity of Western Australia35 Stirling HighwayCrawleyWAAustralia

Underground structures are normally located in highly-confined and congested spaces,which may lead to severe gas explosion accidents,with significant human and economic *** accurately evaluating the consequences of these explosions,a variety of influencing factors need to be considered,including concentrations of gas mixtures,vent conditions,obstacles,and ignition ***,a good review on these influencing factors is important for a better understanding of explosion behavior,e.g.,the deflagration to detonation *** this study,some critical influencing factors for gas explosions in underground or confined spaces are investigated,and the effects of the factors on such gas explosions are *** results are discussed,along with findings from *** present study provides a reference for future studies on safety management and consequence mitigation for underground gas explosions.

关键词： Gas explosion Gas concentration Ventilation Obstacle Ignition feature Detonation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modeling Strain Rate Effect for Heterogeneous Brittle materials

引用

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

作者： ma guowei DONG Aiai LI Jianchun School of Civil and Environmental 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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analysis of Penetration Model for Geo-material by Rigid Projectile

引用

Transactions of Tianjin University 2006年第B9期12卷 188-192页

作者： LI Jianchun ma guowei YU maohong Nanyang Technological University Singapore 639798 Xi＇an Jiaotong University Xi＇an 710049 China

Based on the cylindrical cavity expansion theory, a plastic-damage-elastic model is proposed for the penetration problem of geo-material. In the model, the unified strength criterion (Yu, 1991) is adopted as the failure criterion. The distributions of the radial stress and velocity are analyzed. According to the Newton's second law, a series results of the final penetration depth and the impedance load are obtained to different parameter b, when a rigid projectile normally impacts and penetrates a semi-infinite geo-material target with an impact velocity of 300-1200 m/s. By comparing with the test data available, it appears that the method can be used in analyzing the final depth and the impedance load of a rigid projectile penetrating into a semi-infinite target with different impact velocities.

关键词： penetration rigid projectile geo-material plastic-damage-elastic unified strength criterion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：