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Journal of Wuhan University of Technology(Materials Science) 2009年第6期24卷 940-944页

作者：张武满 School of transportation Science and engineering Beihang University Jiangsu Key Laboratory of Construction Materials Southeast University

Hardened cement paste was subjected to the flexural loading and wet-dry cycles in sea water. The degradation of microstructures was obtained using scanning electron microscope （SEM）, and the energy dispersive spectrum （EDS） analysis was carried to analyze the local composition. Mercury intrusion porosimetry （Poremaster GT-60） was used to analyze the degradation of pore structures. The experimental results show that the synergistic action of the flexural loading, wet-dry cycles and sea water leads to significant deterioration of hardened cement paste. The degradation of microstructures in the tensile region is more serious than that in the compressive region. The flexural loading and wet-dry cycles accelerate the chemical attack of sea water.

关键词： hardened cement paste pore structure microstructures flexural loading wet-dry cycles sea water

A new method for particle manipulation by combination of dielectrophoresis and field-modulated electroosmotic vortex

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Applied Mathematics and Mechanics(English Edition) 2018年第3期39卷 409-422页

作者： Chuanchuan XIE Bo CHEN Bing YAN Jiankang WU School of civil engineering and Mechanics Huazhong University of Science and Technology Department of Mechanical and Electrical engineering Wenhua College

A field-modulated electroosmotic flow （FMEOF） in a microchannel can be obtained by applying modulating electric fields in a direction perpendicular to the channel wall. Micro-vortexes are generated around the electrodes along with an EOF due to the surface charge on the modulated wall. When polarizable particles are suspended near the electrodes, they experience dielectrophoretic forces due to a non-uniform electric field. In this paper, micro-vortexes and dielectrophoretic forces are combined to achieve separation and trap different sized particles in a continuous flow. Numerical results indicate that by adjusting the driving electric field parallel to the channel wall and the modulating electric field, the ratio of dielectrophoretic and hydrodynamic forces can be altered. One type of particles can be trapped by micro-vortexes （negative dielectrophoresis （DEP））, and the other particles are transported to the downstream so that the particles are separated. The influence of the electrode length and the channel height on the trapping rate is investigated.

关键词： electroosmotic dielectrophoretic micro-vortex particle separation

Numerical simulation of wheel wear evolution for heavy haul railway

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Journal of Central South University 2015年第1期22卷 196-207页

作者：王璞高亮 School of civil engineering Beijing Jiaotong University Key Laboratory of Beijing for Railway engineering (Beijing Jiaotong University)

The prediction of the wheel wear is a fundamental problem in heavy haul railway. A numerical methodology is introduced to simulate the wheel wear evolution of heavy haul freight car. The methodology includes the spatial coupling dynamics of vehicle and track, the three-dimensional rolling contact analysis of wheel-rail, the Specht's material wear model, and the strategy for reproducing the actual operation conditions of railway. The freight vehicle is treated as a full 3D rigid multi-body model. Every component is built detailedly and various contact interactions between parts are accurately simulated, taking into account the real clearances. The wheel-rail rolling contact calculation is carried out based on Hertz's theory and Kalker's FASTSIM algorithm. The track model is built based on field measurements. The material loss due to wear is evaluated according to the Specht's model in which the wear coefficient varies with the wear intensity. In order to exactly reproduce the actual operating conditions of railway,dynamic simulations are performed separately for all possible track conditions and running velocities in each iterative *** weight coefficients are introduced that determine the ratios of different cases and are obtained through site survey. For the wheel profile updating, an adaptive step strategy based on the wear depth is introduced, which can effectively improve the reliability and stability of numerical calculation. At last, the wear evolution laws are studied by the numerical model for different wheels of heavy haul freight vehicle running in curves. The results show that the wear of the front wheelset is more serious than that of the rear wheelset for one bogie, and the difference is more obvious for the outer wheels. The wear of the outer wheels is severer than that of the inner wheels. The wear of outer wheels mainly distributes near the flange and the root; while the wear of inner wheels mainly distributes around the nominal rolling

关键词： heavy haul railway wheel wear evolution wheel-rail rolling contact vehicle-track coupling dynamics profile updating

A comparative study on using meta-heuristic algorithms for road maintenance planning:Insights from field study in a developing country

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Journal of Traffic and transportation engineering(English Edition) 2017年第5期4卷 477-486页

作者： Ali Gerami Matin Reza Vatani Nezafat Amir Golroo Department of civil and Enuironmental engineering The George Washington UniversityWashington DC 20052USA transportation Research Institute Old Dominion UniversityNorfolkVA 23529USA Department of civil and Environmental engineering Amirkabir University of Technology(Tehran Polytechnic)TehranIran

Optimized road maintenance planning seeks for solutions that can minimize the life-cycle cost of a road network and concurrently maximize pavement condition. Aiming at pro- posing an optimal set of road maintenance solutions, robust meta-heuristic algorithms are used in research. Two main optimization techniques are applied including single-objective and multi-objective optimization. Genetic algorithms （GA）, particle swarm optimization （PSO）, and combination of genetic algorithm and particle swarm optimization （GAPSO） as single-objective techniques are used, while the non-domination sorting genetic algorithm II （NSGAII） and multi-objective particle swarm optimization （MOPSO） which are sufficient for solving computationally complex large-size optimization problems as multi-objective techniques are applied and compared. A real case study from the rural transportation network of Iran is employed to illustrate the sufficiency of the optimum algorithm. The formulation of the optimization model is carried out in such a way that a cost-effective maintenance strategy is reached by preserving the performance level of the road network at a desirable level. So, the objective functions are pavement performance maximization and maintenance cost minimization. It is concluded that multi-objective algorithms including non-domination sorting genetic algorithm II （NSGAII） and multi-objective particle swarm optimization performed better than the single objective algorithms due to the capability to balance between both objectives. And between multi-objective algorithms the NSGAII provides the optimum solution for the road maintenance planning.

关键词： Meta-heuristic algorithms Particle swarm optimization Non-domination sorting geneticalgorithm Ⅱ Multi-objective particle swarmoptimization

Development of the Construction Classification System in Japan(JCCS)

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Tsinghua Science and Technology 2008年第S1期13卷 199-204页

作者： Tatsuo Terai Department of Architecture and civil engineering Faculty of Engineering Chiba Institute of Technology

This paper deals with the intermediate results of the development of a national standardized classification system called JCCS to ensure harmonized use of various kinds of information to be processed through the whole life cycle of construction projects in a nation-wide Japanese CALS/EC scheme. JCCS is planned to be a Japanese IFD and developped on the technical basis of ISO 12006-2 and 12006-3. Japan has currently no such an IFD-like library of terminologies which is to be an essential tool for the multiple and harmonized information processing, so that JCCS should be a key technology for the successful CALS/EC. First, the development concepts and related technologies are described. Second, evaluation of the current situation of information process in the construction industry is clarified, and followed by the requirements of the development of JCCS. In the main part, the current version of JCCS is outlined, major contents of which are the basic architecture of JCCS, JCCS schema, JCCS basic tables and the usage of JCCS in practice. Finally, future develoment in plan is briefly explained.

关键词： CALS/EC concept definition schema classification IFD information harmonization

Criteria of limiting temperature and parametric analysis of the large deflection behavior for fully restrained steel beams in fire

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Science China(Technological Sciences) 2012年第1期55卷 264-275页

作者： XI Feng LUAN YanPing Shandong Provincial Key Laboratory of Structural engineering School of Civil Engineering Shandong Jianzhu University Jinan 250101 China School of civil engineering Shandong Jianzhu University Jinan 250101 China

This paper mainly involve 3 parts:1) To apply the minimum principle of acceleration in dynamics of elastic-plastic continua at finite deformation to the statics problems,a computing model is presented for the restrained steel beams exposed to the *** this model,both effects of large deflection and thermal expansion deformation are taken into account,and the constitutive equations with the temperature effects are *** a dynamic finite difference(DFD) method is presented by using the dis-crete technique,which can be used in simulating the response of the steel beams at elevated temperature,and the large deflec-tion behavior and catenary action effects of the beams can be adequately *** primary numerical results show that the method is valid and *** with other methods,this technique is very simple,and it can also be further devel-oped to simulate the behavior of steel beams subjected to the coupling loading of explosion and fire when both effects of strain rate and inertia are considered.2) By using this DFD method,detailed parametric analysis are presented so as to check the consistency of response results for several different formulas of thermal expansion deformation and retention factors of steel at elevated temperature,the influence of these parameters on the critical temperature is examined.3) Based on the analysis for the curves of temperature-generalized yield function comprised by the axial force and bending moment,both criteria to determine the limiting temperature(or failure temperature) of large deflection steel beams are presented more explicitly,that is,both lim-iting temperatures can be determined by if the catenary force begins to appear or arrives at the maximum value,*** is shown by numerical results that both limiting temperatures are close to the both critical temperatures which are correspond-ing to the maximum deflections equal to span/20 and span/10,*** conclusion may be helpful to make r

关键词： steel beam fire DFD method large deflection parametric analysis limiting temperature criteria yield function

Experimental Study on Magnetorheological Damper for Semi-Active Vibration Control of civil Infrastructures

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Transactions of Tianjin University 2004年第1期10卷 19-23页

作者：李忠献徐龙河 School of civil engineering Tianjin University

Magnetorheological (MR) fluid is a kind of smart material whose rheological properties can be rapidly varied in magnetic field. To make full use of the advantages of MR fluid to devices, a model of double ended, shear combined and valve typed MR damper is designed and manufactured, and the dynamic properties under sinusoidal excitations are experimentally studied. The experiment results show that the maximum damping force of the MR damper at the full magnetic intensity reaches about 20 kN while the maximum power required is less than 50 W, which predicts that the MR damper will be a powerful measurement for semi active vibration control of civil infrastructures.

关键词： civil infrastructure semi active vibration control magnetorheological (MR) damper dynamic behavior magnetic intensity

Bus passengers’anger scale and expression in anger-provoking situations

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transportation Safety and Environment 2023年第1期5卷 18-30页

作者： Zhili Yuan Qun Chen Shi Ye School of Traffic and transportation engineering Central South UniversityChangsha 410075HunanChina.

This paper investigates the scale and expression of passengers’anger arising from disputes between drivers and passengers,and between passengers,by surveying a sample of 757 undergraduate *** bus passengers’anger scale and expression inventory(BPASX),a newly-designed questionnaire battery,is used to analyse the anger levels and resulting behaviour expression of passengers in 6-item anger-provoking *** analysis shows that a positive correlation exists between the frequency or duration of bus rides and anger levels/external anger expression,while self-adaptive expression is only correlated with *** differs only in the violent external expression,where males display a greater ***,the correlations of anger levels between anger-provoking situations are significantly ***,anger expression patterns gradually shift from self-adaptation to external expression as anger levels grow in general,but the variation rules of expression frequency are ***,this study provides a newly effective tool to explore characteristics of the anger expression of bus passengers in different anger-provoking scenarios and demonstrates its variation features when anger levels change.

关键词： anger bus passengers expression bus passengers’anger and expression inventory(BPASX)

Theoretical Calculation and Analysis of Slip and Deformation for Concrete Sandwich Panels

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Transactions of Tianjin University 2007年第2期13卷 121-125页

作者：李砚波章少华夏宝阳 School of civil engineering Tianjin University

Slip and deformation of concrete sandwich panels under uniformly distributed loads is concerned. The effect of slip on the deformation of concrete sandwich panels are studied,and the analytical expressions of slip and deformation for concrete sandwich panels is obtained. These formulae can describe the slip distribution and account for its effect on deformation. In order to restrict the bound of formula, the formula of crack moment is obtained. The results of theoretical calculation are compared with those of tests and finite element methods. The comparison shows that the results of theoretical calculation are in accord with those of tests and finite element methods. So the theoretical calculation can be used to calculate slip and deformation of concrete sandwich panels in practical projects.

关键词： concrete sandwich panels slip deformation deflection crack moment finite element method

A new hybrid algorithm for global optimization and slope stability evaluation

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Journal of Central South University 2013年第11期20卷 3265-3273页

作者： Taha Mohd Raihan Khajehzadeh Mohammad Eslami Mahdiyeh civil and Structural engineering Department National University of Malaysia civil engineering Department Anar BranchIslamic Azad University Electrical engineering Department Science and Research BranchIslamic Azad University

A new hybrid optimization algorithm was presented by integrating the gravitational search algorithm （GSA） with the sequential quadratic programming （SQP）, namely GSA-SQP, for solving global optimization problems and minimization of factor of safety in slope stability analysis. The new algorithm combines the global exploration ability of the GSA to converge rapidly to a near optimum solution. In addition, it uses the accurate local exploitation ability of the SQP to accelerate the search process and find an accurate solution. A set of five well-known benchmark optimization problems was used to validate the performance of the GSA-SQP as a global optimization algorithm and facilitate comparison with the classical GSA. In addition, the effectiveness of the proposed method for slope stability analysis was investigated using three ease studies of slope stability problems from the literature. The factor of safety of earth slopes was evaluated using the Morgenstern-Price method. The numerical experiments demonstrate that the hybrid algorithm converges faster to a significantly more accurate final solution for a variety of benchmark test functions and slope stability problems.

关键词： gravitational search algorithm sequential quadratic programming hybrid algorithm global optimization slope stability