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 331

会议视频 2

年份

2024 2

2023 35

2022 26

2021 34

2020 27

2019 20

2018 16

2017 11

2016 14

2015 15

2014 11

2013 8

2012 11

2011 17

2010 6

2009 11

2008 13

2007 18

2006 10

2005 4

展开︾

关键词

力学性能 8

力学模型 2

微机电系统 2

数值模拟 2

斜拉桥 2

机械结构 2

燃耗 2

现场监测 2

2021全球工程前沿 1

700 MW级水电机组 1

ANSYS 1

DNA结构 1

EBSD 1

FRP 聚合物 1

G蛋白偶联受体 1

IHNI-1 1

MCNP 1

Maxwell方程组 1

ORIGEN2 1

展开︾

检索范围：

排序：展示方式：

Uncertainty assessment in hydro-mechanical-coupled analysis of saturated porous medium applying fuzzy

Farhoud KALATEH, Farideh HOSSEINEJAD

《结构与土木工程前沿（英文）》 2020年第14卷第2期页码 387-410 doi: 10.1007/s11709-019-0601-z

摘要： The purpose of the present study was to develop a fuzzy finite element method, for uncertainty quantification of saturated soil properties on dynamic response of porous media, and also to discrete the coupled dynamic equations known as - hydro-mechanical equations. Input parameters included fuzzy numbers of Poisson’s ratio, Young’s modulus, and permeability coefficient as uncertain material of soil properties. Triangular membership functions were applied to obtain the intervals of input parameters in five membership grades, followed up by a minute examination of the effects of input parameters uncertainty on dynamic behavior of porous media. Calculations were for the optimized combinations of upper and lower bounds of input parameters to reveal soil response including displacement and pore water pressure via fuzzy numbers. Fuzzy analysis procedure was verified, and several numerical examples were analyzed by the developed method, including a dynamic analysis of elastic soil column and elastic foundation under ramp loading. Results indicated that the range of calculated displacements and pore pressure were dependent upon the number of fuzzy parameters and uncertainty of parameters within equations. Moreover, it was revealed that for the input variations looser sands were more sensitive than dense ones.

关键词： fuzzy finite element method saturated soil hydro-mechanical coupled equations coupled analysis uncertainty analysis

HTML PDF 收藏

Investigation of the hydro-mechanical behaviour of compacted expansive clay

Yujun CUI, An Ninh TA, Anh Minh TANG, Yingfa LU,

《结构与土木工程前沿（英文）》 2010年第4卷第2期页码 154-164 doi: 10.1007/s11709-010-0019-0

摘要： The hydro-mechanical behaviour of compacted expansive Romainville clay was investigated. The soil was air-dried, crushed, and passed through a 2 mm sieve before being statically compacted to a dry density of 1.35 Mg/m. The mechanical behaviour was investigated by tests in oedometer with controlled suction using the vapor equilibrium technique (suction = 0, 9, 39, and 110 MPa). The vertical stress was applied in the range of 0–800 kPa. The experimental results are shown as follows: 1) wetting-induced swelling was higher at lower vertical stresses; 2) the vertical stress under which no swelling occurred during water flooding was estimated at 60 kPa, which can be considered as the swelling pressure of the soil tested; 3) the soil compressibility (changes of volume upon stress increases) was strongly influenced by the soil suction: the lower the suction, the higher the compressibility. The hydraulic behaviour was investigated using a large-scale infiltration chamber (800 mm × 1000 mm in section and 1000 mm high). The large size of the soil column allowed burying the volumetric water content sensors (ThetaProbe) without significantly affecting the water transfer and the soil swelling during infiltration. The soil suction was monitored along the soil height (every 100 mm) using various relative humidity sensors and psychrometers. In the infiltration test, water was kept on the soil surface and changes in suction and volumetric water content were monitored for 338 d. The wetting front has reached the bottom of the soil column at the end of the test. The data from the simultaneous monitoring of suction and water content were used to determine the water retention curve and the unsaturated hydraulic conductivity using the instantaneous profile method. It has been observed that the soil water retention curve depends on the soil depth; that is to be related to the soil depth-dependent swelling. The unsaturated hydraulic conductivity was found to be quite low, comprised between 3 × 10 m/s (at saturated state) and 10 m/s (at about 100 MPa suction).

关键词： Romainville clay suction control oedometer test large infiltration task hydro-mechanical behaviour

HTML PDF 收藏

Effect of land-use management systems on coupled physical and mechanical, chemical and biological soil

Rainer HORN, Winfried E. H. BLUM

《农业科学与工程前沿（英文）》 2020年第7卷第3期页码 243-245 doi: 10.15302/J-FASE-2020334

HTML PDF 收藏

基于有限变形理论的齿轮楔横轧制坯热力耦合模拟

应富强,潘孝勇,李敏

《中国工程科学》 2007年第9卷第7期页码 47-52

摘要：

楔横轧齿轮轧制成形是一个全新的课题，在轧制过程中轧件的变形、温度场及力能参数都有待研究。将楔横轧技术与齿轮范成加工原理相结合，设计了楔横轧齿轮轧制的模具，给出了楔横轧齿轮轧制成形热力耦合本构模型，并在SuperForm平台对轧制成形过程进行了有限元模拟，获得了轧件在成形过程中的变形规律、温度场分布及力能参数变化等数据，详细分析了数值模拟结果，为进一步研究齿轮楔横轧制坯提供参考。

关键词：楔横轧齿轮热力耦合有限元

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

An extended thermo-mechanically coupled algorithm for simulation of superelasticity and shape memory

S. HASHEMI,H. AHMADIAN,S. MOHAMMADI

《结构与土木工程前沿（英文）》 2015年第9卷第4期页码 466-477 doi: 10.1007/s11709-015-0300-3

摘要： Thermo-mechanical coupling in shape memory alloys is a very complicated phenomenon. The heat generation/absorption during forward/reverse transformation can lead to temperature-dependent variation of its mechanical behavior in the forms of superelasticity and shape memory effect. However, unlike the usual assumption, slow loading rate cannot guarantee an isothermal process. A two-dimensional thermo-mechanically coupled algorithm is proposed based on the original model of Lagoudas to efficiently model both superelasticity and shape memory effects and the influence of various strain rates, aspect ratios and boundary conditions. To implement the coupled model into a finite element code, a numerical staggered algorithm is employed. A number of simulations are performed to verify the proposed approach with available experimental and numerical data and to assess its efficiency in solving complex SMA problems.

关键词： shape memory alloy thermo-mechanical coupling superplasticity shape memory effect

HTML PDF 收藏

Prediction of hydro-suction dredging depth using data-driven methods

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 652-664 doi: 10.1007/s11709-021-0719-7

摘要： In this study, data-driven methods (DDMs) including different kinds of group method of data handling (GMDH) hybrid models with particle swarm optimization (PSO) and Henry gas solubility optimization (HGSO) methods, and simple equations methods were applied to simulate the maximum hydro-suction dredging depth (h_s). Sixty-seven experiments were conducted under different hydraulic conditions to measure the h_s. Also, 33 data samples from three previous studies were used. The model input variables consisted of pipeline diameter (d), the distance between the pipe inlet and sediment level (Z), the velocity of flow passing through the pipeline (u₀), the water head (H), and the medium size of particles (D₅₀). Data-driven simulation results indicated that the HGSO algorithm accurately trains the GMDH methods better than the PSO algorithm, whereas the PSO algorithm trained simple simulation equations more precisely. Among all used DDMs, the integrative GMDH-HGSO algorithm provided the highest accuracy (RMSE = 7.086 mm). The results also showed that the integrative GMDHs enhance the accuracy of polynomial GMDHs by ~14.65% (based on the RMSE).

关键词： sedimentation water resources dam engineering machine learning heuristic

HTML PDF 收藏

A review on membrane distillation in process engineering: design and exergy equations, materials and

《化学科学与工程前沿（英文）》 2022年第16卷第5期页码 592-613 doi: 10.1007/s11705-021-2105-3

摘要： One of the problems that most afflicts humanity is the lack of clean water. Water stress, which is the pressure on the quantity and quality of water resources, exists in many places throughout the World. Desalination represents a valid solution to the scarcity of fresh water and several technologies are already well applied and successful (such as reverse osmosis), producing about 100 million m³·d⁻¹ of fresh water. Further advances in the field of desalination can be provided by innovative processes such as membrane distillation. The latter is of particular interest for the treatment of waste currents from conventional desalination processes (for example the retentate of reverse osmosis) as it allows to desalt highly concentrated currents as it is not limited by concentration polarization phenomena. New perspectives have enhanced research activities and allowed a deeper understanding of mass and heat transport phenomena, membrane wetting, polarization phenomena and have encouraged the use of materials particularly suitable for membrane distillation applications. This work summarizes recent developments in the field of membrane distillation, studies for module length optimization, commercial membrane modules developed, recent patents and advancement of membrane material.

关键词： membrane distillation recent developments heat and mass transfer wetting membrane material

HTML PDF 收藏

Design of damping valve for vehicle hydro pneumatic suspension

DONG Mingming, HUANG Hua, GU Lian

《机械工程前沿（英文）》 2008年第3卷第1期页码 97-100 doi: 10.1007/s11465-008-0014-5

摘要： According to the design features of a hydro pneumatic spring, the necessity of a separate damping valve is proposed. Based on a 1/4 vehicle linear suspension model, the optimum damping coefficient is worked out and the parameters of the damping valve are determined with the equivalent linearization method. A practical structure of the damping valve is proposed having a small size, high flowrate when the valve opens, and the ability of enduring high back pressure. Based on bench tests, the damping valve has been found to properly work and be suitable. The design method and damping valve structure are useful guides for hydro pneumatic suspension, especially for the design of heavy-duty vehicles.

关键词： ability pneumatic necessity flowrate equivalent linearization

HTML PDF 收藏

Hydro-pyrolysis of lignocellulosic biomass over alumina supported Platinum, Mo

Songbo He, Jeffrey Boom, Rolf van der Gaast, K. Seshan

《化学科学与工程前沿（英文）》 2018年第12卷第1期页码 155-161 doi: 10.1007/s11705-017-1655-x

摘要： In-line hydro-treatment of bio-oil vapor from fast pyrolysis of lignocellulosic biomass (hydro-pyrolysis of biomass) is studied as a method of upgrading the liquefied bio-oil for a possible precursor to green fuels. The nobel metal (Pt) and non-noble metal catalysts (Mo C and WC) were compared at 500 °C and atmospheric pressure which are same as the reaction conditions for fast pyrolysis of biomass. Results indicated that under the pyrolysis conditions, the major components, such as acids and carbonyls, of the fast pyrolysis bio-oil can be completely and partially hydrogenated to form hydrocarbons, an ideal fossil fuel blend, in the hydro-treated bio-oil. The carbide catalysts perform equally well as the Pt catalyst regarding to the aliphatic and aromatic hydrocarbon formation (ca. 60%), showing the feasibility of using the cheap non-noble catalysts for hydro-pyrolysis of biomass.

关键词： bio-oil pyrolysis hydro-deoxygenation (HDO) non-noble metal catalysts hydro-treatment

HTML PDF 收藏

Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 595-608 doi: 10.1007/s11709-021-0720-1

摘要： The effective notch stress approach for evaluating the fatigue strength of rib–deck welds requires notch stress concentration factors obtained from complex finite element analysis. To improve the efficiency of the approach, the notch stress concentration factors for three typical fatigue-cracking modes (i.e., root–toe, root–deck, and toe–deck cracking modes) were thoroughly investigated in this study. First, we developed a model for investigating the effective notch stress in rib–deck welds. Then, we performed a parametric analysis to investigate the effects of multiple geometric parameters of a rib–deck weld on the notch stress concentration factors. On this basis, the multiple linear stepwise regression analysis was performed to obtain the optimal regression functions for predicting the notch stress concentration factors. Finally, we employed the proposed formulas in a case study. The notch stress concentration factors estimated from the developed formulas show agree well with the finite element analysis results. The results of the case study demonstrate the feasibility and reliability of the proposed formulas. It also shows that the fatigue design curve of FAT225 seems to be conservative for evaluating the fatigue strength of rib–deck welds.

关键词： notch stress concentration factor rib–deck weld parametric analysis regression analysis parametric equation

HTML PDF 收藏

Solving nonlinear differential equations of Vanderpol, Rayleigh and Duffing by AGM

null

《机械工程前沿（英文）》 2014年第9卷第2期页码 177-190 doi: 10.1007/s11465-014-0288-8

摘要：

In the present paper, three complicated nonlinear differential equations in the field of vibration, which are Vanderpol, Rayleigh and Duffing equations, have been analyzed and solved completely by Algebraic Method (AGM). Investigating this kind of equations is a very hard task to do and the obtained solution is not accurate and reliable. This issue will be emerged after comparing the achieved solutions by numerical method (Runge-Kutte 4th). Based on the comparisons which have been made between the gained solutions by AGM and numerical method, it is possible to indicate that AGM can be successfully applied for various differential equations particularly for difficult ones. The results reveal that this method is not only very effective and simple, but also reliable, and can be applied for other complicated nonlinear problems.

关键词： Algebraic Method (AGM) Angular Frequency Vanderpol Rayleigh Duffing

HTML PDF 收藏

Optimal dynamic emergency reserve activation using spinning, hydro and demand-side reserves

S. Surender REDDY,P. R. BIJWE,A. R. ABHYANKAR

《能源前沿（英文）》 2016年第10卷第4期页码 409-423 doi: 10.1007/s11708-016-0431-9

摘要： This paper proposes an optimal dynamic reserve activation plan after the occurrence of an emergency situation (generator/transmission line outage, load increase or both). An optimal plan is developed to handle the emergency, using the coordinated action of fast and slow reserves, for secure operation with minimum overall cost. It considers the reserves supplied by the conventional thermal generators (spinning reserves), hydro power units and load demands (demand-side reserves). The optimal backing down of costly/fast reserves and bringing up of slow reserves in each sub-interval in an integrated manner is proposed. The proposed reserve activation approaches are solved using the genetic algorithm, and some of the simulation results are also compared using the Matlab optimization toolbox and the general algebraic modeling system (GAMS) software. The simulation studies are performed on the IEEE 30, 57 and 300 bus test systems. These results demonstrate the advantage of the proposed integrated/dynamic reserve activation plan over the conventional/sequential approach.

关键词： demand-side reserves dynamic reserve activation approach hydro power units post contingency sequential reserve activation approach spinning reserves

HTML PDF 收藏

Proca电磁理论的若干问题

黄志洵

《中国工程科学》 2005年第7卷第3期页码 6-12

摘要：

2004年6月，位于西非Oklo的美国Los Alamos实验室的核工业反应堆对实验数据做再分析后得出结论说，近20亿年内精细结构常数减小了4.5×10^-8。常数不常，意味着光速有很小的变化。这是最新的与狭义相对论不符的实验报告。另一方面，光子如有质量，Maxwell方程组将被Proca方程组所取代，而磁矢位（势）A将成为可观测量。而过去和现在都有许多方法测量光子的质量。

文章的主要目的是在Proca理论框架内研究电磁波波速，发现即使在自由空间（真空）条件下也会出现超光速传播；同时又对波导与Proca波的截止现象做了比较，给出了相应的结果。

关键词：狭义相对论 Maxwell方程组 Proca方程组电磁波波速光子的静止质量

HTML PDF 收藏

Load shedding scheme for an interconnected hydro-thermal hybrid system with SMES

D. TYAGI, Ashwani KUMAR, Saurabh CHANANA

《能源前沿（英文）》 2012年第6卷第3期页码 227-236 doi: 10.1007/s11708-012-0198-6

摘要： The frequency of the power system varies based on the load pattern of the consumers. With continuous increase in the load, the frequency of the system keeps decreasing and may reach its minimum allowable limits. Further increase in the load will result in more frequency drop leading to the need of load shedding, if excess generation is not available to cater the need. This paper proposed a methodology in a hybrid thermal-hydro system for finding the required amount of load to be shed for setting the frequency of the system within its minimum allowable limits. The load shedding steps were obtained based on the rate of change of frequency with the increase in the load in both areas. The impact of superconducting magnetic energy storage (SMES) was obtained on load shedding scheme. The comparison of the results was presented on the two-area system.

关键词： critical load frequency response load shedding multi-area system rate of change of frequency superconducting magnetic energy storage (SMES) device