Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 27

年份

2021 1

2020 2

2019 2

2017 3

2016 1

2014 1

2013 3

2012 2

2011 2

2010 1

2009 1

2008 5

2007 2

2004 1

展开︾

关键词

LoRa 1

NB-IoT 1

N∶P比值 1

β-粒子的横向振动 1

“∞”形 1

两弹一星 1

共赢博弈 1

关键技术创新 1

分解水 1

南京长江第四大桥 1

变化 1

地下连续墙 1

复杂地质条件 1

广域低功耗网络 1

应力场 1

建设管理 1

开发太空 1

李雅普诺夫能量函数 1

横向台阶分布 1

展开︾

检索范围：

排序：展示方式：

Cyclic behavior of stiffened joints between concrete-filled steel tubular column and steel beam with narrowouter diaphragm and partial joint penetration welds

Chunyan QUAN,Wei WANG,Jian ZHOU,Rong WANG

《结构与土木工程前沿（英文）》 2016年第10卷第3期页码 333-344 doi: 10.1007/s11709-016-0357-7

摘要： This paper presented an investigation on a stiffened joint in practical engineering which was between concrete-filled steel tubular column and steel beam with narrow outer diaphragm and partial joint penetration welds. Through the low-frequency cyclic loading test, the cyclic behavior and failure mode of the specimen were investigated. The results of the test indicated the failure mode and bearing capacity of the specimen which were influenced by the axial compression ratio of the concrete-filled tubular column. On the contrary, the inner diaphragm and inner stiffeners had limited impacts on the hysteretic behavior of the joint. There was no hysteresis damage fracture on the narrow outer diaphragm connected to the concrete-filled steel tubular column with partial joint penetration welds. Due to the excellent ductility and energy dissipating capacity, the proposed joint could be applied to the seismic design of high-rise buildings in highly intensive seismic region, but axial compression ratio should be controlled to avoid unfavorable failure modes.

关键词： narrow outer diaphragm concrete-filled tubular column joint inner and outer stiffening cyclic behavior

HTML PDF 收藏

Flow characteristics of single-phase flow in narrow annular channels

ZENG Heyi, SU Guanghui, JIA Dounan

《能源前沿（英文）》 2008年第2卷第4期页码 466-470 doi: 10.1007/s11708-008-0101-7

摘要： The characteristics of single-phase flow in narrow annular channels were analyzed and theoretical model was proposed. Based on the present model, the theoretical calculation was performed to predict the flow characteristics for the developed flow in narrow annuli with the gap sizes of 1.0, 1.5 and 2.0 mm, respectively. The results were in good agreement with the experimental data. In addition, the gap size of narrow annuli has great impact upon the flow characteristics. The decrease of gap size reduces friction factor. The higher the Reynolds number, the more remarkable the effect of gap size upon friction coefficient during single-phase flowing through narrow annular channels. The effect of gap size upon friction coefficient is dependent on the Reynolds number, and will decrease with the decrease of the Reynolds number.

关键词： narrow annuli remarkable mm developed friction

HTML PDF 收藏

Finite element modeling of thermo-active diaphragm walls

Yi RUI, Mei YIN

《结构与土木工程前沿（英文）》 2020年第14卷第3期页码 646-663 doi: 10.1007/s11709-020-0584-9

摘要： There are two major challenges faced by modern society: energy security, and lowering carbon dioxide gas emissions. Thermo-active diaphragm walls have a large potential to remedy one of these problems, since they are a renewable energy technology that uses underground infrastructure as a heat exchange medium. However, extensive research is required to determine the effects of cyclic heating and cooling on their geotechnical and structural performance. In this paper, a series of detailed finite element analyses are carried out to capture the fully coupled thermo-hydro-mechanical response of the ground and diaphragm wall. It is demonstrated that the thermal operation of the diaphragm wall causes changes in soil temperature, thermal expansion/shrinkage of pore water, and total stress applied on the diaphragm wall. These, in turn, cause displacements of the diaphragm wall and variations of the bending moments. However, these effects on the performance of diaphragm wall are not significant. The thermally induced bending strain is mainly governed by the temperature differential and uneven thermal expansion/shrinkage across the wall.

关键词： thermo-active diaphragm wall finite element analysis thermo-hydro-mechanical coupling ground source heat pump

HTML PDF 收藏

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gasesusing line-by-line and statistical narrow-band models

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

《能源前沿（英文）》 2014年第8卷第1期页码 41-48 doi: 10.1007/s11708-013-0292-4

摘要： Narrow-band transmissivities in the spectral range of 150 to 9300 cm and at a uniform resolution of 25 cm were calculated using the statistical narrow-band (SNB) model with the band parameters of Soufiani and Taine, the more recent parameters of André and Vaillon, and the line-by-line (LBL) method along with the HITEMP-2010 spectroscopic database. Calculations of narrow-band transmissivity were conducted for gas columns of different lengths and containing different isothermal and non-isothermal CO -H O-N mixtures at 1 atm. Narrow-band transmissivities calculated by the SNB model are in large relative error at many bands. The more recent SNB model parameters of André and Vaillon are more accurate than the earlier parameters of Soufiani and Taine. The Planck mean absorption coefficients of CO , H O, CO, and CH in the temperature range of 300 to 2500 K were calculated using the LBL method and different versions of the high resolution transmission (HITRAN) and high-temperature spectroscopic absorption parameters (HITEMP) spectroscopic databases. The SNB model was also used to calculate the Planck mean absorption coefficients of these four radiating gases. The LBL results of the Planck mean absorption coefficient were compared with the classical results of Tien and those from the SNB model.

关键词： transimissity HITEMP HITRAN Planck mean absorption coefficients

HTML PDF 收藏

Nucleate boiling in two types of vertical narrow channels

Lei GUO, Shusheng ZHANG, Lin CHENG

《能源前沿（英文）》 2011年第5卷第3期页码 250-256 doi: 10.1007/s11708-010-0128-4

摘要： To explore the mechanism of boiling bubble dynamics in narrow channels, we investigate 2-mm wide I- and Z-shaped channels. The influence of wall contact angle on bubble generation and growth is studied using numerical simulation. The relationships between different channel shapes and the pressure drop are also examined, taking into account the effects of gravity, surface tension, and wall adhesion. The wall contact angle imposes considerable influence over the morphology of bubbles. The smaller the wall contact angle, the rounder the bubbles, and the less time the bubbles take to depart from the wall. Otherwise, the bubbles experience more difficulty in departure. Variations in the contact angle also affect the heat transfer coefficient. The greater the wall contact angle, the larger the bubble-covered area. Therefore, wall thermal resistance increases, bubble nucleation is suppressed, and the heat transfer coefficient is lowered. The role of surface tension in boiling heat transfer is considerably more important than that of gravity in narrow channels. The generation of bubbles dramatically disturbs the boundary layer, and the bubble bottom micro-layer can enhance heat transfer. The heat transfer coefficient of Z-shaped channels is larger than that of the I-shaped type, and the pressure drop of the former is clearly higher.

关键词： nucleate boiling narrow channel numerical simulation bubble dynamics

HTML PDF 收藏

Parametric sensitivity analysis of cellular diaphragm wall

Xi CHEN, Wei XU

《结构与土木工程前沿（英文）》 2012年第6卷第4期页码 358-364 doi: 10.1007/s11709-012-0177-3

摘要： The deformation law of the cellular diaphragm wall in deep foundation pits was studied through numerical simulation. Based on the example of the dock wall in engineering, the full three-dimensional finite element model was used to simulate the excavation of the foundation pit. Interaction between the cellular diaphragm wall and the soil was also taken into account in the calculation. The results indicated that the maximum lateral displacement, which is the evaluation index of sensitivity analysis, appeared on the top of the interior longitudinal wall with an excavation depth of 10 m. The centrifuge model test was carried out to study the deformation regulation for a cellular diaphragm wall. The most sensitive factor was found by adjusting the length of the partition wall, the spacing of the partition wall and the thickness of the wall. In the end, a suggestion was proposed to optimize the cellular diaphragm by adjusting the length of the partition wall.

关键词： cellular diaphragm wall sensitivity analysis optimization centrifuge model test

HTML PDF 收藏

Diaphragm wall-soil-cap interaction in rectangular-closed- diaphragm-wall bridge foundations

Hua WEN, Qiangong CHENG, Fanchao MENG, Xiaodong CHEN

《结构与土木工程前沿（英文）》 2009年第3卷第1期页码 93-100 doi: 10.1007/s11709-009-0015-4

摘要： Rectangular-closed-diaphragm-wall foundation is a new type of bridge foundation. Diaphragm wall-soil-cap interaction was studied using a model test. It was observed that the distribution of soil resistance under the cap is not homogeneous. The soil resistance in the corner under the cap is larger than that in the border; and that in the center is the smallest. The distribution of soil resistance under the cap will be more uniform, if the sectional area of soil core is enlarged within a certain range. Due to the existence of cap, there is a “weakening effect” in inner shaft resistance of the upper wall segments, and there is “enhancement effect” in the lower wall segments and in toe resistance. The load shearing percentage of soil resistance under the cap is 10%-20%. It is unreasonable to ignore the effects of the cap and the soil resistance under the cap in bearing capacity calculations.

关键词： diaphragm wall bridge foundation low cap interaction

HTML PDF 收藏

Power performance of circular piezoelectric diaphragm generators

TANG Kehong, KAN Junwu, YANG Zhigang, CHENG Guangming, PENG Taijiang

《机械工程前沿（英文）》 2008年第3卷第4期页码 434-440 doi: 10.1007/s11465-008-0069-3

摘要： Energy generation performance of a piezoelectric generator depends mainly on several elements such as the structural style, boundary conditions, geometry parameters, materials, vibration-source frequency, and external load. To obtain the optimal energy-harvesting device, the Raleigh method is used to establish the analysis model of circular piezoelectric composite diaphragms. Simply supported and clamped boundary conditions were considered. The relationships between the output power and the structural parameters of piezoelectric composite diaphragms, and the external load resistance and frequency were shown. Given the correlative material parameters and boundary conditions, the output power, using structural parameters, external load, or vibrating frequency as variables, can be calculated. Simulation results show that there are optimal structural parameters and load for a composite diaphragm to achieve the maximum output power. A piezoelectric diaphragm generator with given dimensions tends to achieve higher output power under clamped boundary conditions than that under simply supported boundary conditions.

关键词： clamped boundary energy-harvesting composite diaphragm piezoelectric composite maximum

HTML PDF 收藏

Dielectric barrier micro-plasma reactor with segmented outer electrode for decomposition of pure CO

Baowei Wang, Xiaoxi Wang, Bo Zhang

《化学科学与工程前沿（英文）》 2021年第15卷第3期页码 687-697 doi: 10.1007/s11705-020-1974-1

摘要： Four coaxial cylinder dielectric barrier discharge micro-plasma reactors were designed for the non-catalytic decomposition of pure CO into CO and O at low temperature and ambient pressure. The influence of segmented outer electrodes on the electrical characteristics and the reaction performance was investigated. Experimental results indicated that the introduction of segmented outer electrodes can significantly promote the decomposition of CO . Encouragingly, the highest conversion of 13.1% was obtained at an applied voltage of 18 kV, which was a substantial increase of 39.4% compared to the traditional device. Compared with other types of dielectric barrier discharge plasma reactors, the proposed segmented outer electrode micro-plasma reactor can give a higher CO conversion and acceptable energy efficiency. The increase in conversion can be attributed mainly to the enhanced corona discharge caused by the fringe effect at electrode edges, the increase in energy density and the increase in the number of micro-discharges. In addition, detailed electrical characterization was performed to reveal some trends in the electrical behavior of proposed reactors.

关键词： CO₂ decomposition dielectric barrier discharge segmented outer electrodes electrical analysis reactor design

HTML PDF 收藏

β-粒子在穿越铜狭缝中的横向台阶分布

朱永强,郝建宇

《中国工程科学》 2008年第10卷第8期页码 81-86

摘要：

文章研究了电子高速运动时所产生的横向振动。实验方法是利用半圆聚焦β-谱仪上90Sr源β-粒子在不同磁场下对于相同弯曲半径下β-粒子具有不同的能量和动量的特性，研究这些β-粒子在通过不同宽度的铜狭缝（厚8 mm）时的粒子数n和铜狭缝宽度δ的函数关系，发现不管β-粒子具有什么能量和动量，都具有横向运动的趋势和在铜狭缝中出现了台阶分布。其原因可能是β-粒子本身具有横向振幅A和周围真空起伏能量的相互作用。

关键词： β-粒子的横向振动铜狭缝宽度横向台阶分布

HTML PDF 收藏

The behavior of a rectangular closed diaphragm wall when used as a bridge foundation

Qiangong CHENG, Jiujiang WU, Zhang SONG, Hua WEN

《结构与土木工程前沿（英文）》 2012年第6卷第4期页码 398-420 doi: 10.1007/s11709-012-0175-5

摘要： The rectangular closed diaphragm (RCD) wall is a new type of bridge foundation. Compared to barrette foundation, measuring the performance of RCD walls is relatively complicated because of their incorporation of a soil core. Using the FLAC3D software, this paper investigates the deformation properties, soil resistance and skin friction of a laterally loaded RCD wall as well as the settlement, axial force and load-sharing ratio of a vertically loaded RCD wall. Special attention is given to the analysis of factors that influence the performance of the soil core. It was found that under lateral loading, the RCD wall behaves as an end-bearing friction wall during the entire loading process. The relative displacement between the wall body and the soil core primarily occurs below the rotation point, and the horizontal displacement of the soil core is greater than that of the wall body. Under vertical loading, the degree of inner skin friction around the bottom of the soil core and the proportion of the loading supported by the soil core increase with increased cross-section size. The wall depth is directly proportional to the loading supported by the outer skin friction and the tip resistance of the wall body and is inversely proportional to the loading borne by the soil core.

关键词： diaphragm wall soil core bridge foundation FLAC3D bearing behavior

HTML PDF 收藏

Soil arching effect of Lattice-Shaped Diaphragm Wall as bridge foundation

Jiujiang WU, Lingjuan WANG, Qiangong CHENG

《结构与土木工程前沿（英文）》 2017年第11卷第4期页码 446-454 doi: 10.1007/s11709-017-0397-7

摘要： As a new type of bridge foundation, Lattice-Shaped Diaphragm Wall (hereinafter for LSDW) is highly concerned in relevant construction area but its research is far from achievement. Based on PFC , the soil arching effect of LSDWs is studied thoroughly in this paper and the special attention is given to its influencing factors. It turns out to be that a differential wall-soil settlement can be found at the lower location of soil core of an LSDW which is one of the trigger factors of soil arching; meanwhile, the differential settlement degree can reflect the exertion degree of soil arching; the shape of soil arching is basically a hemisphere which can be explained by the theory proposed by Hewlett and Randolph; normally, the chamber number is a negative factor for the development of soil arching; the soil arching effect is significantly influenced by the distance of two adjacent wall elements and the foundation depth, and a relatively large or small value of these factors is disadvantageous to the exertion of soil arching; in addition, the soil arching effect increase with the growth of stiffness and friction coefficient of particles and the friction coefficient of particles has insignificant influence on the development of soil arching effect compared with particle stiffness.

关键词： LSDW soil arching PFC^2D shape of soil arching influencing factors

HTML PDF 收藏

Numerical investigation on the dryout point of annular flow in the upward narrow annuli with bilateral

SU Guanghui, QIU Suizheng, DUAN Feng, XIAO Zejun, HUANG Yanping

《能源前沿（英文）》 2007年第1卷第3期页码 264-272 doi: 10.1007/s11708-007-0037-3

摘要： Based on the fundamental conservation principles—the mass, momentum, and energy conservation equtions of liquid films and the momentum conservation equation of vapor core, a theoretical three-fluid model has been developed to predict the dryout point of upward annular flow in vertical narrow annuli with bilateral heating. The range of the parameters are: pressure from 0.5 to 5.0 MPa; mass flow rate from 30 to 150 kg/(m · s); gap size from 1.2 to 2.0 mm. Through numerically solving the model, the relationships among the parameters of the critical quality (), critical heat flux (), mass flow rate, system pressure, and the ratio of heat flux on the inner wall of the outer tube to that on the outer wall of the inner tube (/) are obtained and analyzed. The predicted results accurately match with the experimental data. For a fixed , will increase with the decreases in the gap size and the tube curvature when the dryout point occurs on the outer wall of the inner tube. However, for a fixed , when the dryout point occurs on the inner wall of the outer tube, the parametric trend is reverse. When the dryout point on the inner and outer walls occurs simultaneously, reaches a peak value, and the ratio of / at this position changes with the gap size and the tube curvature.

HTML PDF 收藏

Nongray radiation from gas and soot mixtures in planar plates based on statistical narrow-band spectral

Huaqiang CHU, Qiang CHENG, Huaichun ZHOU, Fengshan LIU

《能源前沿（英文）》 2011年第5卷第2期页码 149-158 doi: 10.1007/s11708-010-0124-8

摘要： The nongray behavior of combustion products plays an important role in various areas of engineering. Based on the statistical narrow-band (SNB) spectral model with an exponential-tailed inverse intensity distribution and the ray-tracing method, a comprehensive investigation of the influence of soot on nongray radiation from mixtures containing H O/N +soot, CO /N +soot, or H O/CO /N +soot was conducted in this paper. In combustion applications, radiation transfer is significantly enhanced by soot due to its spectrally continuous emission. The effect of soot volume fraction up to 1×10 on the source term, the narrow-band radiation intensities along a line-of-sight, and the net wall heat fluxes were investigated for a wide range of temperature. The effect of soot was significant and became increasingly drastic with the increase of soot loading.

关键词： soot combustion SNB model nongray radiation

HTML PDF 收藏

Controlling nested wrinkle morphology through the boundary effect on narrow-band thin films

Hanyang XU, Tielin SHI, Guanglan LIAO, Qi XIA

《机械工程前沿（英文）》 2019年第14卷第2期页码 235-240 doi: 10.1007/s11465-017-0458-6

摘要： We describe the formation of nested wrinkles created by the thermal mismatch between a narrow-band thin film and a compliant substrate. When a film is described as “narrow-band”, it literally means that the film band width is much shorter than its length; more precisely, it means that the width is comparable with the wavelength of the wrinkles. A silicon mask was used during film sputtering to create narrow-band films on poly (dimethylsiloxane) substrate, thus creating regular boundaries to steer local stresses and control wrinkle morphology. Disordered nano-scale wrinkles were found nested within highly ordered micro-scale sinusoidal wrinkles. The formation of nested wrinkles was explained through the amplitude and wavelength saturation of nano-scale wrinkles. The disordered morphology of nano-scale wrinkles and the highly ordered morphology of micro-scale wrinkles were explained by using the boundary effect.

关键词： nested and hierarchical wrinkles morphology amplitude saturation boundary effect

HTML PDF 收藏

标题作者时间类型操作

Cyclic behavior of stiffened joints between concrete-filled steel tubular column and steel beam with narrowouter diaphragm and partial joint penetration welds

Chunyan QUAN,Wei WANG,Jian ZHOU,Rong WANG

期刊论文

Flow characteristics of single-phase flow in narrow annular channels

ZENG Heyi, SU Guanghui, JIA Dounan

期刊论文

Finite element modeling of thermo-active diaphragm walls

Yi RUI, Mei YIN

期刊论文

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gasesusing line-by-line and statistical narrow-band models

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

期刊论文

Nucleate boiling in two types of vertical narrow channels

Lei GUO, Shusheng ZHANG, Lin CHENG

期刊论文

Parametric sensitivity analysis of cellular diaphragm wall

Xi CHEN, Wei XU

期刊论文

Diaphragm wall-soil-cap interaction in rectangular-closed- diaphragm-wall bridge foundations

Hua WEN, Qiangong CHENG, Fanchao MENG, Xiaodong CHEN

期刊论文

Power performance of circular piezoelectric diaphragm generators