资源类型

期刊论文 27

年份

2022 2

2020 1

2018 2

2016 2

2015 1

2013 2

2012 5

2011 1

2010 2

2009 2

2007 3

2002 1

1999 1

展开 ︾

关键词

悬索桥 2

PPWS 1

S型钢丝研制 1

主缆 1

余度 1

修正方法 1

分子二极管 1

分子导线 1

分子晶体管 1

分子电子学 1

分子电容器 1

切割效率 1

功率电传 1

压力盒 1

双张紧 1

变压力 1

大直径盾构 1

干空气除湿 1

应力监测 1

展开 ︾

检索范围:

排序: 展示方式:

Development of a new wear resistant coating by arc spraying of a steel-based cored wire

Lidong ZHAO, Pia KUTSCHMANN, Binyou FU, Dingyong HE

《机械工程前沿(英文)》 2009年 第4卷 第1期   页码 1-4 doi: 10.1007/s11465-009-0012-2

摘要: In the present study, a cored wire of 304 L stainless steel as sheath material and NiB and WC-12Co as filler materials was designed and deposited to produce a new wear resistant coating containing amorphous phase by arc spraying. The microstructure of the coating was investigated. The porosity and hardness of the coating were determined. The wear performance of the coating was evaluated. The XRD and TEM analyses showed that there are high volume of amorphous phase and very fine crystalline grains in the coating. DTA measurements revealed that the crystallization of the amorphous phase occurred at 579.2°C. Because metallurgical processes for single droplets were non-homogenous during spraying, the lamellae in the coating have different hardness values, which lie between about 700 and 1250 HV . The abrasive wear test showed that the new Fe-based coating was very wear resistant.

关键词: amorphous phase     arc spraying     microstructure     wear     cored wire    

Three-dimensional modeling of borehole data cored from engineering rock mass

HE Manchao, LI Xueyuan, LIU Bin, XU Nengxiong

《结构与土木工程前沿(英文)》 2007年 第1卷 第3期   页码 334-339 doi: 10.1007/s11709-007-0044-9

摘要: Vast data from the drilling and geophysical prospecting are reliable original information to describe the space state of engineering rock mass, and one of the main difficulties in three-dimensional (3D) modeling of engineering rock mass is the processing of the primary data. From the viewpoint of 3D modeling, the engineering rock masses are classified as four basic types according to their geometric characteristics of geologic structure: (1) continuum rock mass; (2) discontinuous rock mass; (3) overturned fold rock mass and (4) intrusive rock mass. Because drilling data are very important to describe the characters of multi-scale of the spatial data for rock mass, the rule of how to process drilling data is developed to help appropriately display them in the viewpoint of 3D space. According to the characteristics of rock mass layers, the processing method of drilling data for 3D modeling of engineering rock masses, along with the layer thicknesses, is also proposed, including the evaluation rules and the extensive direction for original borehole data. By this method, the typical 3D data modeled is completed and the model form of the engineering rock mass is developed. By this example, it is finally verified that the method presented is successful and feasible to process 3D engineering rock mass.

关键词: three-dimensional     discontinuous     primary     extensive direction     engineering    

Elevated temperature creep model of parallel wire strands

《结构与土木工程前沿(英文)》   页码 1060-1071 doi: 10.1007/s11709-023-0981-y

摘要: Parallel wire strands (PWSs), which are widely used in prestressed steel structures, are typically in high-stress states. Under fire conditions, significant creep effects occur, reducing the prestress and influencing the mechanical behavior of PWSs. As there is no existing approach to analyze their creep behavior, this study experimentally investigated the elevated temperature creep model of PWSs. A charge-coupled camera system was incorporated to accurately obtain the deformation of the specimen during the elevated temperature creep test. It was concluded that the temperature level had a more significant effect on the creep strain than the stress level, and 450 °C was the key segment point where the creep rate varied significantly. By comparing the elevated temperature creep test results for PWSs and steel strands, it was found that the creep strain of PWSs was lower than that of steel strands at the same temperature and stress levels. The parameters in the general empirical formula, the Bailey–Norton model, and the composite time-hardening model were fitted based on the experimental results. By evaluating the accuracy and form of the models, the composite time-hardening model, which can simultaneously consider temperature, stress, and time, is recommended for use in the fire-resistance design of pre-tensioned structures with PWSs.

关键词: parallel wire strands     experimental study     elevated temperature creep model    

Preconcentration of trace elements by adsorption onto a niobium wire for electrothermal atomization atomic

Satoshi KANECO, Hiroaki KITANAGA, Hideyuki KATSUMATA, Tohru SUZUKI

《化学科学与工程前沿(英文)》 2012年 第6卷 第4期   页码 432-435 doi: 10.1007/s11705-012-1219-z

摘要: In the present work, a new preconcentration method of trace elements by adsorption onto a niobium wire has been developed for electrothermal atomization atomic absorption spectrometry (ETAAS) with a tungsten tube atomizer. Detection limits (pg·mL ) by this method combined with ETAAS were 45 for bismuth, 7.0 for cadmium, 20 for copper, 1.3 for gold, 36 for lead, 65 for manganese, 9.5 for rhodium and 19 for silver.

关键词: preconcentration     adsorption onto niobium wire     electrothermal atomization atomic absorption spectrometry     tungsten tube atomizer     trace elements    

Numerical studies of dynamic behavior of liquid film on single-layer wire mesh with different wettabilities

《化学科学与工程前沿(英文)》   页码 1672-1680 doi: 10.1007/s11705-022-2205-8

摘要: Droplet impacting on the stainless steel wire mesh is very common in chemical devices, like a rotating packed bed. Surface wettability of wire mesh significantly affects the liquid flow pattern and liquid dispersion performance. However, the effect of surface wettability on the impaction phenomena at microscale such as liquid film is still unknown. In this work, the dynamic behavior of liquid film on the surface of wire mesh was analyzed by computational fluid dynamics simulation. The dynamic behavior of liquid film on the surface of wire mesh can be divided into the following three steps: (1) spreading step; (2) shrinkage process; (3) stabilizing or disappearing step. Effects of surface wettability, as well as operating conditions, on wetting area and liquid film thickness were studied. Compared to the hydrophilic wire mesh, the final wetting area of hydrophobic wire mesh is zero in most cases. The average liquid film thickness on the surface of hydrophilic wire mesh is 30.02–77.29 μm, and that of hydrophobic wire mesh is 41.76–237.37 μm. This work provided a basic understanding of liquid film flow at microscale on the surface with various surface wettabilities, which can be guiding the packing optimization and design.

关键词: stainless steel wire mesh     computational fluid dynamics     surface wettability     liquid film     impacting    

Experimental study on wire breakage detection by acoustic emission

Limin SUN, Ji QIAN

《结构与土木工程前沿(英文)》 2011年 第5卷 第4期   页码 503-509 doi: 10.1007/s11709-011-0132-8

摘要: This paper experimentally investigated wire breakage detection in a steel cable by acoustic emission (AE) waveform. In the experiments, the attenuation laws of waveform amplitudes were discussed based on stress wave propagation in the wire, which was generated by kNocking and wire breakage. Then the wave velocity was calculated based on the reach time of the stress wave from each sensor. Finally, based on the waveform attenuation laws and the linear position method, the amplitude and energy of the source were confirmed through the measured waveform to identify the source category. The experimental results illustrated that the stress wave from different sources has a different frequency spectrum, and the amplitude attenuation factor varied with the stress wave frequency; high frequency waves had a greater attenuation factor. Compared with the other source, the wire breakage source contained a much higher energy, and thus, the wire breakage signal can be distinguished from the other source by comparing the non-attenuation energy at the source position.

关键词: acoustic emission (AE)     waveform     wire breakage     attenuation factor     wave velocity    

游离磨料多股线线锯切割实验研究

王金生,姚春燕,彭伟,金鑫, 陈世杰

《中国工程科学》 2012年 第14卷 第11期   页码 94-98

摘要:

游离磨料线锯切割是将磨浆中的磨粒通过一定速度的细钢丝线带入切割区域,达到去除工件材料的目的。多股线由多根细金属线绕制而成,表面具有很多凹槽,与钢丝线光滑表面相比,可以输送更多的磨粒进入切割区域,从而提高切割效率。应用0.25 mm的多股线和0.25 mm的钢丝线对光学玻璃K9进行切割对比实验,结果表明,在相同工艺条件下,多股线的切割效率和表面粗糙度均优于钢丝线,但切缝宽度大于钢丝线。

关键词: 线锯     游离磨料加工     切割效率    

evaluation methodology for masonry building and retrofitting using splint and bandage technique with wire

Pravin Kumar Venkat Rao PADALU; Yogendra SINGH

《结构与土木工程前沿(英文)》 2022年 第16卷 第4期   页码 478-505 doi: 10.1007/s11709-022-0817-1

摘要: The paper presents a seismic safety assessment of unreinforced masonry (URM) building using two approaches. The first approach uses the ‘Pier Analysis’ method, based on the concept of equivalent lateral stiffness, where in-plane and out-of-plane actions are considered independently. The second approach is developed with the program SAP2000, where the linear response is evaluated using continuum ‘finite element modelling’ (FEM). Both methods are compared to evaluate the safety of wall piers and the differences in the outcomes under combined gravitational and lateral seismic forces. The analysis results showed that few wall elements are unsafe in in-plane and out-of-plane tension. It is also observed that the pier analysis method is conservative compared to FEM, but can be used as a simplified and quick tool in design offices for safety assessment, with reasonable accuracy. To safeguard the URM wall piers under lateral loads, a retrofitting technique is adopted by providing vertical and horizontal belts called splints and bandages, respectively, using welded wire mesh (WWM) reinforcement. The study using the ‘Pier Analysis’ shows that the lateral load capacity of unsafe URM piers can be enhanced up to 3.67 times and made safe using the applied retrofitting technique. Further, the retrofitting design methodology and recommendations for application procedures to on-site URM buildings are discussed in detail.

关键词: unreinforced masonry     seismic in-plane and out-of-plane forces     pier analysis     finite element modelling     splint and bandage technique with wire mesh    

Process improvement in laser hot wire cladding for martensitic stainless steel based on the Taguchi method

Zilin HUANG,Gang WANG,Shaopeng WEI,Changhong LI,Yiming RONG

《机械工程前沿(英文)》 2016年 第11卷 第3期   页码 242-249 doi: 10.1007/s11465-016-0397-7

摘要:

Laser hot wire cladding, with the prominent features of low heat input, high energy efficiency, and high precision, is widely used for remanufacturing metal parts. The cladding process, however, needs to be improved by using a quantitative method. In this work, volumetric defect ratio was proposed as the criterion to describe the integrity of forming quality for cladding layers. Laser deposition experiments with FV520B, one of martensitic stainless steels, were designed by using the Taguchi method. Four process variables, namely, laser power (P), scanning speed (Vs), wire feed rate (Vf), and wire current (I), were optimized based on the analysis of signal-to-noise (S/N) ratio. Metallurgic observation of cladding layer was conducted to compare the forming quality and to validate the analysis method. A stable and continuous process with the optimum parameter combination produced uniform microstructure with minimal defects and cracks, which resulted in a good metallurgical bonding interface.

关键词: process optimization     Taguchi method     signal-to-noise (S/N) ratio     volumetric defect ratio     laser hot wire cladding    

Experimental research on the mechanical property of prestressing steel wire during and after heating

ZHENG Wenzhong, HU Qiong, ZHANG Haoyu

《结构与土木工程前沿(英文)》 2007年 第1卷 第2期   页码 247-254 doi: 10.1007/s11709-007-0031-1

摘要: The mechanical property of prestressing steel wire during and after heating is the key factor in the design of fire resistance and after-fire damage evaluation of prestressed structures. Tensile experiment of 16 prestressing steel wires ( = 1770 N/mm, = 5 mm, low relaxation of stress) at high temperature and tensile experiment of 14 prestressed steel wires after heating are carried out. According to the experiment, the shapes of stress-strain curves of steel wire at high temperature go smooth and the mechanical property indexes of the steel wire such as strength, modulus of elasticity, etc., degenerate continuously as temperature increased. According to the experiment after heating, the mechanical property of steel wire varies little when the highest temperature that the steel wire has ever been heated to is lower than 300vH; while the stress-strain curves of steel wire become more ductile and the mechanical property indexes of the steel wire degenerate gradually when the highest temperature is higher than 300vH. By applying the theory of viscoelastic mechanics, stress-strain curves of steel wire at high temperatures without loading rate influence are obtained. The law of mechanical property indexes of the wire is presented. The mathematical models of the stress-strain relationship of the pre-stressed steel wire are established. All can serve as basic data for the analysis of fire resistance and after-fire damage evaluation of pre-stressed structures.

Modification of premixed combustion in shear layers by grid turbulence

MU Kejin, WANG Yue, ZHANG Zhedian, NIE Chaoqun

《能源前沿(英文)》 2007年 第1卷 第2期   页码 245-250 doi: 10.1007/s11708-007-0034-6

摘要: The influence of grid turbulence on the shear layer of a jet and the premixed flames embedded in it was investigated in the present study. The velocity field of the jet was measured by using hot-wire anemometry. It was found that grid turbulence reduced turbulence intensities in the shear layer and suppressed low frequency fluctuation. Moreover, the energy contained in small-scale fluctuation was increased and turbulence became homogeneous. The results indicate that grid turbulence inhibits the formation of a large-scale coherent structure in the shear layer. Flame temperature was measured by using a compensated fine-wire thermocouple. It was found that grid turbulence reduced low frequency fluctuation of the flame fronts, increased the small-scale wrinkles and elevated the mean temperature of the flame zone. The results show that grid turbulence can enhance and stabilize premixed flames in shear flow.

关键词: homogeneous     fine-wire thermocouple     temperature     hot-wire anemometry     premixed    

A wind tunnel study on control methods for cable dry-galloping

Hung D. VO,Hiroshi KATSUCHI,Hitoshi YAMADA,Mayuko NISHIO

《结构与土木工程前沿(英文)》 2016年 第10卷 第1期   页码 72-80 doi: 10.1007/s11709-015-0309-7

摘要: The common vibration of cable caused by rain-wind combination has been known as most typical type and a lot kind of its countermeasures has been proposed for suppressing this phenomenon. Recently, stayed-cables were also proved that they could be excited in dry state (without rain), which is called dry-galloping. Recently, its mechanisms have been explained by axial flow, Reynolds number and so on. To clarify the characteristics of this galloping, wind tunnel test of a cable model with various kinds of wind angle was conducted. Then, three types of countermeasure were examined to suppress dry- galloping of bridge cable. The tests confirmed that the occurrence of dry-galloping depends on relative wind attacked angles and onset reduced wind speed. Furthermore, single spiral wire, double spiral wire and circular ring were found to have high effectiveness in mitigating this galloping when those are installed properly.

关键词: dry-galloping     wind-relative angle     single spiral wire     double spiral wire     circular rings    

国产桥梁拉索用1 770 MPa 镀锌钢丝制造技术的研究

丁峰,桑春明,周代义,白柄东

《中国工程科学》 2009年 第11卷 第3期   页码 57-64

摘要:

重点介绍了宝钢集团公司在苏通大桥斜拉索用高强度镀锌钢丝的研制实践中,通过制造技术研究和技术创新,形成了“双张紧 + 限径模”工艺、“主导工艺 + 微调”整体优化、“三度控制”热镀锌操作等三大关键技术,生产制造出了高强度、低松弛、具有良好扭转性能的国产桥梁斜拉索用高强度(1 770 MPa 级)镀锌钢丝。

关键词: 镀锌钢丝     扭转     双张紧     限径模     沙砾抹拭    

A novel shape memory alloy actuated soft gripper imitated hand behavior

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0700-8

摘要: The limited length shrinkage of shape memory alloy (SMA) wire seriously limits the motion range of SMA-based gripper. In this paper, a new soft finger without silicone gel was designed based on pre bent SMA wire, and the finger was back to its original shape by heating SMA wire, rather than relying only on heat exchange with the environment. Through imitating palm movement, a structure with adjustable spacing between fingers was made using SMA spring and rigid spring. The hook structure design at the fingertip can form self-locking to further improve the load capacity of gripper. Through the long thin rod model, the relationship of the initial pre bent angle on the bending angle and output force of the finger was analyzed. The stress-strain model of SMA spring was established for the selection of rigid spring. Three grasping modes were proposed to adapt to the weight of the objects. Through the test of the gripper, it was proved that the gripper had large bending amplitude, bending force, and response rate. The design provides a new idea for the lightweight design and convenient design of soft gripper based on SMA.

关键词: shape memory alloy (SMA)     pre bent     wire     gripper     grasping mode     lightweight    

未来飞机液压系统的特点

王占林,陈斌

《中国工程科学》 1999年 第1卷 第3期   页码 5-10

摘要:

现代飞机舵面操纵系统与动力收放系统几乎都是液压驱动的。随着飞机特别是军用飞机的发展,对机载液压系统提出了更高的要求。文章对飞机特别是军用飞机液压系统的主要发展趋势进行了综述,并对国内外的飞机液压系统的研究工作进行了一定的介绍。指出:质量轻、体积小、高压化、大功率、变压力、智能化、集成化、余度技术等是未来飞机液压系统的主要发展趋势,尤其是高压变压力泵源系统对未来飞机的发展尤为重要。

关键词: 机载液压系统     高压化     变压力     余度     功率电传    

标题 作者 时间 类型 操作

Development of a new wear resistant coating by arc spraying of a steel-based cored wire

Lidong ZHAO, Pia KUTSCHMANN, Binyou FU, Dingyong HE

期刊论文

Three-dimensional modeling of borehole data cored from engineering rock mass

HE Manchao, LI Xueyuan, LIU Bin, XU Nengxiong

期刊论文

Elevated temperature creep model of parallel wire strands

期刊论文

Preconcentration of trace elements by adsorption onto a niobium wire for electrothermal atomization atomic

Satoshi KANECO, Hiroaki KITANAGA, Hideyuki KATSUMATA, Tohru SUZUKI

期刊论文

Numerical studies of dynamic behavior of liquid film on single-layer wire mesh with different wettabilities

期刊论文

Experimental study on wire breakage detection by acoustic emission

Limin SUN, Ji QIAN

期刊论文

游离磨料多股线线锯切割实验研究

王金生,姚春燕,彭伟,金鑫, 陈世杰

期刊论文

evaluation methodology for masonry building and retrofitting using splint and bandage technique with wire

Pravin Kumar Venkat Rao PADALU; Yogendra SINGH

期刊论文

Process improvement in laser hot wire cladding for martensitic stainless steel based on the Taguchi method

Zilin HUANG,Gang WANG,Shaopeng WEI,Changhong LI,Yiming RONG

期刊论文

Experimental research on the mechanical property of prestressing steel wire during and after heating

ZHENG Wenzhong, HU Qiong, ZHANG Haoyu

期刊论文

Modification of premixed combustion in shear layers by grid turbulence

MU Kejin, WANG Yue, ZHANG Zhedian, NIE Chaoqun

期刊论文

A wind tunnel study on control methods for cable dry-galloping

Hung D. VO,Hiroshi KATSUCHI,Hitoshi YAMADA,Mayuko NISHIO

期刊论文

国产桥梁拉索用1 770 MPa 镀锌钢丝制造技术的研究

丁峰,桑春明,周代义,白柄东

期刊论文

A novel shape memory alloy actuated soft gripper imitated hand behavior

期刊论文

未来飞机液压系统的特点

王占林,陈斌

期刊论文