检索结果-南通市图书馆

Mechanical Behavior and Shape Optimization of Lining Structure for Subsea Tunnel Excavated in Weathered Slot

China Ocean Engineering 2015年第6期29卷 875-890页

作者：李鹏飞周晓军 Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of Technology Key Laboratory of transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong University beijing collaborative innovation center for metropolitan transportation

Subsea tunnel lining structures should be designed to sustain the loads transmitted from surrounding ground and groundwater during excavation. Extremely high pore-water pressure reduces the effective strength of the country rock that surrounds a tunnel, thereby lowering the arching effect and stratum stability of the structure. In this paper, the mechanical behavior and shape optimization of the lining structure for the Xiang＇an tunnel excavated in weathered slots are examined. Eight cross sections with different geometric parameters are adopted to study the mechanical behavior and shape optimization of the lining structure. The hyperstatic reaction method is used through finite element analysis software ANSYS. The mechanical behavior of the lining structure is evidently affected by the geometric parameters of crosssectional shape. The minimum safety factor of the lining structure elements is set to be the objective function. The efficient tunnel shape to maximize the minimum safety factor is identified. The minimum safety factor increases significantly after optimization. The optimized cross section significantly improves the mechanical characteristics of the lining structure and effectively reduces its deformation. Force analyses of optimization process and program are conducted parametrically so that the method can be applied to the optimization design of other similar structures. The results obtained from this study enhance our understanding of the mechanical behavior of the lining structure for subsea tunnels. These results are also beneficial to the optimal design of lining structures in general.

关键词： subsea tunnel lining structure shape optimization safety factor hyperstatic reaction 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

Quasi-Situ Characterization of Deformation in Low-Carbon Steel with Equiaxed and Lamellar Microstructure Treated by the Quenching and Partitioning Process

引用

Acta Metallurgica Sinica(English Letters) 2020年第12期33卷 1657-1665页

作者： Pengfei Gao Weijian Chen Feng Li Beijia Ning Zhengzhi Zhao collaborative innovation center of Steel Technology University of Science and Technology BeijingBeijing 100083China beijing Laboratory of Metallic Materials and Processing for Modern transportation Beijing 100083China

The relationship between microstructure morphology and mechanical properties of the low-carbon steel(Fe-0.20 C-2.59 Mn-2.13 Si)treated by diff erent intercritical annealed quenching and partitioning(Q&P)processes was investigated through interrupted tensile tests plus quasi-situ electron backscatter diff raction *** show that size and distribution of retained austenite(RA)directly aff ect the sequence of deformation induced martensitic *** strain increases,the equiaxed RA grains wrapped by ferrite transform fi rst,followed by the equiaxed and fi lm-like RA grains adjacent to *** with traditional intercritical annealed Q&P steel with equiaxed structure,the steel with quenching pretreatment contains uniform lamellar structure and the relatively fi lm-like type of RA,leading to the higher yield strength,tensile strength,and elongation,as well as the steady increase in dislocation density upon straining.

关键词： Steel Quenching and partitioning Austenite Martensitic transformation Electron backscatter diffraction(EBSD) Tensile test

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

Extracting hand articulations from monocular depth images using curvature scale space descriptors

引用

Frontiers of Information Technology & Electronic Engineering 2016年第1期17卷 41-54页

作者： Shao-fan WANG Chun LI De-hui KONG Bao-cai YIN beijing Key Laboratory of Multimedia and Intelligent Software Technology College of Metropolitan Transportation Beijing University of Technology Beijing 100124 China School of Software Technology Dalian University of Technology Dalian 116024 China collaborative innovation center of Electric Vehicles in beijing Beijing 100081 China

We propose a framework of hand articulation detection from a monocular depth image using curvature scale space(CSS) descriptors. We extract the hand contour from an input depth image, and obtain the fingertips and finger-valleys of the contour using the local extrema of a modified CSS map of the contour. Then we recover the undetected fingertips according to the local change of depths of points in the interior of the contour. Compared with traditional appearance-based approaches using either angle detectors or convex hull detectors, the modified CSS descriptor extracts the fingertips and finger-valleys more precisely since it is more robust to noisy or corrupted data;moreover, the local extrema of depths recover the fingertips of bending fingers well while traditional appearance-based approaches hardly work without matching models of hands. Experimental results show that our method captures the hand articulations more precisely compared with three state-of-the-art appearance-based approaches.

关键词： Curvature scale space (CSS), Hand articulation, Convex hull, Hand contour

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

Cold compression deformation method for reducing residual stress and uniformizing micro-property in ferrite steel

引用

Journal of Iron and Steel Research International 2022年第3期29卷 503-511页

作者： Bo Ning Hui-bin Wu Gang Niu Xin-pan Yu collaborative innovation center of Steel Technology University of Science and Technology BeijingBeijing100083China beijing Laboratory of Metallic Materials and Processing for Modern transportation University of Science and Technology BeijingBeijing100083China

To reduce internal residual stress and homogenize micro-property of hot-rolled ferrite steel,the cold compression deformation method with small reduction rate has been performed in the hot-rolled samples,and X-ray diffraction and nanoindentation test have been used to detect the residual stress and *** samples with deformation rate of 0-5.59%or annealing at 550℃ are *** results show that,due to the coupling effect of thermal expansion and cold contraction and the volume expansion of microstructural transformation from austenite to ferrite,compressive residual stress was found inside the hot-rolled *** the increase in cold compression deformation,the dislocation density increased and the microhardness increased gradually,and there is no obvious rule for the change of mean nano-hardness in micro-zone for the center of ***,the uniformity of nano-hardness in the micro-zone increased first and then decreased,and the value of residual stress has obvious corresponding relationship with the uniformity of micro-zone *** cold compression deformation with appropriate reduction rate can reduce residual stress and improve nano-hardness uniformity of the hot-rolled samples,but more deformation(such as reduction rateε=5.59%)makes residual stress increase and makes uniformity of nano-hardness deteriorate.

关键词： Ferrite Cold compression deformation Residual stress Nano-hardness Uniformity Dislocation density

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

Effect of prior martensite on bainite transformation and microstructure of high-carbon nano-bainitic steel

引用

Journal of Iron and Steel Research International 2022年第4期29卷 647-654页

作者： Xin-pan Yu Hui-bin Wu Yang Gu Rui Yuan You-you Zhang Yu-hui Feng collaborative innovation center of Steel Technology University of Science and Technology BeijingBeijing 100083China beijing Laboratory of Metallic Materials and Processing for Modern transportation University of Science and Technology BeijingBeijing 100083China

Bainite transformation kinetics,microstructure,and mechanical properties were comparably investigated by X-ray diffraction,scanning electron microscopy,electron backscatter diffraction,transmission electron microscopy observation,and tensile and impact tests for two treatments:with and without quenching before isothermal bainite transformation at 300°*** the incubation time and growth stage of bainite transformation are accelerated by the introduction of prior martensite,especially the *** addition,the bainite microstructure around the prior martensite is refined and shows a similar orientation with the martensite due to the strain field caused by the existence of prior *** finer bainite microstructure and prior martensite improve the strength and hardness of the high-carbon nano-bainitic *** the presence of prior martensite and low misorientation relationship between the martensite and the adjacent bainite microstructure are prejudicial to impact toughness,the nanoscale bainite microstructure can inhibit the crack propagation and then improve the impact toughness of the high-carbon nano-bainitic steel.

关键词： Nano-bainitic steel Prior martensite Transformation kinetics Microstructure Mechanical property

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

Effects of Chromium,Vanadium and Austenite Deformation on Transformation Behaviors of High-strength Spring Steels

引用

Journal of Iron and Steel Research International 2016年第12期23卷 1323-1332页

作者： Gang NIU Yin-li CHEN Hui bin WU Xuan WANG Mao-fang ZUO Zhi-jun XU collaborative innovation center of Steel Technology University of Science and Technology BeijingBeijing 100083China Engineering Research Institute University of Science and Technology BeijingBeijing 100083China beijing Laboratory of Metallic Materials and Processing for Modern transportation Beijing 100083China

The phase transformation behavior during continuous cooling of high-strength spring steels containing different amounts of Cr was studied. Furthermore, the effects of combining Cr with V as well as austenite deformation on the transformation kinetics were investigated in the method of dilatometry and metallography hardness. The re suits showed that, with the increase of Cr, the pearlite transformation field was enlarged, the ferrite transformation field was narrowed, and the entire phase field shifted to the right. With the addition of V, the start transformation temperature of undercooling austenite （Ar3） was gradually increased, but the ferrite and pearlite transformation fields were not affected. Besides, the minimum critical cooling rate of martensilic transformation was also reduced. In addition, the dynamic continuous cooling transformation （CCT） curve moves to the top left compared with the static CCT curve. The transformed microstructures showed that the addition of V and the deformation not only refined the overall transformed microstructures but also reduced the lamellar spacing of pearlite. The alloying elements Cr and V promoted the Vickers hardness. However, the effect of Cr on the Vickers hardness of martensite was stronger and the influence of V on that of pearlite was stronger. Moreover, the Vickers hardness affected by the austenite deformation was more complex and strongly depended on the transformed microstructures.

关键词： spring steel phase transformation Chromium deformation microstructure

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

Accelerating the solving of mechanical equilibrium caused by lattice misfit through deep learning method

引用

Advances in Manufacturing 2024年第3期12卷 512-521页

作者： Chen-Xi Guo Hui-Ying Yang Rui-Jie Zhang collaborative innovation center of Steel Technology University of Science and Technology BeijingBeijing100083People’s Republic of China beijing Laboratory of Metallic Materials and Processing for Modern transportation University of Science and Technology BeijingBeijing100083People’s Republic of China

Precipitation is a common phenomenon that occurs during heat *** is internal stress around the precipitate owing to the lattice misfit between the precipitate and *** internal stress has a significant influence not only on the precipitation kinetics but also on the material *** misfit stress can be obtained by numerically solving the mechanical equilibrium ***,this process is complex and *** developed a new approach based on deep learning to accelerate the solution *** training data were first generated by a phase-field model coupled with elastic mechanical equilibrium equations,which were solved using the finite difference *** obtained precipitate morphologies and corresponding stress distributions were input data for training the physics-informed(PI)UNet *** well-trained PI-UNet model can then be applied to predicting stress distributions with the precipitate morphology as the *** accuracy and efficiency are discussed in this *** results showed that the PI-UNet model was an appropriate approach for quickly predicting the misfit stress between the precipitate and matrix.

关键词： Precipitate Mechanical equilibrium Heat treatment Deep learning

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

Intelligent decision support platform of new energy vehicles

引用

Journal of Systems Engineering and Electronics 2022年第4期33卷 785-791页

作者： WANG Zhenpo SUN Zhenyu LIU Peng WANG Shuo ZHANG Zhaosheng collaborative innovation center for Electric Vehicles&National Engineering Laboratory for Electric Vehicles Beijing Institute of TechnologyBeijing 100081China Chongqing innovation center Beijing Institute of TechnologyChongqing 401135China

New energy vehicles(NEVs) are gaining wider acceptance as the transportation sector is developing more environmentally friendly and sustainable technology. To solve problems of complex application scenarios and multi-sources heterogenous data for new energy vehicles and weak platform scalability,the framework of an intelligent decision support platform is proposed in this paper. The principle of software and hardware system is introduced. Hadoop is adopted as the software system architecture of the platform. Master-standby redundancy and dual-line redundancy ensure the reliability of the hardware system. In addition, the applications on the intelligent decision support platform in usage patterns recognition, energy consumption, battery state of health and battery safety analysis are also described.

关键词： new energy vehicle(NEV) intelligent decision support platform software system data platform application

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

Microstructure and mechanical properties of Cr doped WCoB based cermets by spark plasma sintering and first principle calculation

引用

Progress in Natural Science:Materials International 2020年第3期30卷 417-423页

作者： Tong Zhang Haiqing Yin Cong Zhang Xuanhui Qu beijing Advanced innovation center for Materials Genome Engineering University of Science and Technology Beijing School of Materials Science and Engineering Shandong University of Science and Technology collaborative innovation center of Steel Technology University of Science and Technology Beijing beijing Laboratory of Metallic Materials and Processing for Modern transportation University of Science and Technology Beijing

WCoB based cermet is a potential hard alloy to replace WC-Co cermets with high hardness and corrosion resistance. WCoB based cermets with different Cr doping contents were fabricated by spark plasma sintering in liquid phase sintering stage. The densification behavior, phase composition, microstructure and mechanical properties of Cr doped WCoB cermets were investigated by XRD, EDS and SEM. Due to the lower density of Cr,the density of WCoB cermets decreased with the increasing of Cr doping content. The phase composition consisted of Cr doped WCoB, unreacted W, Co–Cr binary binder phase. When the doping content exceeded11.736 wt%, the Cr enrichment zones appeared, which was harmful to the TRS. The increasing of Cr doping content contributed to the increase of unreacted W phases content and the formation of pores. The maximum value of Vickers hardness was 1751 Hv0.5 at 9.356 wt% Cr doping content. The variation trend was explained by first principle calculation, which is consistent with Hv-Zhou hardness model.

关键词： WCoB based Cermets Cr doping Microstructure Mechanical properties First principle calculation Spark plasma sintering

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Energy and environmental life-cycle assessment of passenger car electrification based on beijing driving patterns

引用

Science China(Technological Sciences) 2015年第4期58卷 659-668页

作者： WANG He Wu ZHANG Xiao Bin OUYANG Ming Gao State Key Laboratory of Automotive Safety and Energy Tsinghua University collaborative innovation center of Electric Vehicles in beijing

This paper examines the energy and environmental benefits within the whole life cycle shifting from traditional gasoline vehicles to electrified advanced vehicles under regional real-world driving behaviors. The advance vehicles focus on family passenger cars and include battery electric vehicles （BEVs）, plug-in hybrid electric vehicles （PHEVs）, and hybrid electric vehicles （HEVs）. The GREET （greenhouse gases, regulated emissions, and energy use in transportation） model is adopted with regional circumstances modifications, especially the UF （utility factors） of PHEVs. The results show that the electrified vehicles offer great benefits concerning energy consumption, greenhouse gas （GHG） emissions as well as urban Particulate Matter 2,5 （PMz.s） emissions. Compared to conventional gasoline vehicles, the life-cycle total energy reduction for advance vehicles is 51% to 57%. There is little difference on energy reduction among the HEVs, PHEVs and BEVs, with the energy mix shifting from petroleum to coal for the stronger electrification. The reductions of GHG emissions are 57% for HEV, 54% to 48% for PHEVs with 10 miles to 40 miles CD range, and 40% for BEV. The life-cycle and local PM2.5 emissions are discussed separately. The life-cycle PM2.5 emissions increase with vehicle electrification and reach a maximum for the BEV which are 5% higher than the conventional vehicle （CV）. However, electric vehicles can shift PM2.5 emissions from vehicle operation to upstream operations and help mitigate PM2.5 emissions in urban areas. The local emissions of PHEVs and BEVs can be reduced by 37% to 81% and 100% compared with CVs.

关键词： electric vehicle greenhouse gas emissions PM2.5 emissions beijing driving pattern

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：