Abstract:Based on the theories of Timoshenko’s beams and Vlasov’s thinwalled members, a new geometrically nonlinear beam element model is developed by placing an interior node in the element and applying independent interpolation to bending angles and warp, in which factors such as shear deformation, coupling of flexure and torsion, and second shear stress are all considered. Thereafter, geometrical nonlinear strain in TotalLagrangian is formulated and geometrical stiffness matrix is deduced. Examples manifest that the developed model is accurate and feasible in analyzing thinwalled structures.

Abstract:Based on the damage configuration and failure feature of firedamaged concrete,this paper presents studies of the stochastic evolution law of firedamaged concrete (FDC) under uniaxial tension and uniaxial compression.The stochastic damage constitutive relationship models of FDC under uniaxial tension and uniaxial compression are established with the Weibull distribution and spring damage element model by considering the damage factors such as the initial damage of concrete,the damage caused by elevated temperature and the damage healing under crack closure.Through the proposed method,four mechanical features of FDC are explained by theoretical derivation rather than test data fitting.The theoretical derivation results are compared with test data and the proposed method proves feasible in explaining the failure mechanism of FDC.

Abstract:In order to solve timedependent reliability of concrete bridges exposed to harsh environments,a computational methodology was developed with an improved response surface method and a deterministic degradation process analysis method of concrete bridges.Analysis programs named concrete bridge durability analysis system (CBDAS) and probability index by response surface method (PIRSM) were compiled by FORTRAN 95.The numerical method was implemented to a prestressed concrete simply supported bridge.The variations of various reliability indices in different limit states were analyzed.The results show that reliability index of concrete stress changes from 2.16 at completion 0.82 after 100 years.Mechanical property indices in serviceability limit state of prestressed concrete bridges may even suffer durability problems.The objective of timedependent reliability of concrete bridges is realized with the proposed computational methodology by overcoming the problem that the limit state equation of complex structure is always implicit.

Abstract:Based on the study of appropriate spans for using steel or carbon fiber reinforced polymer (CFRP) stay cables,this paper proposes a new design of CFRP and steel composite stay cables to deal with the drawback of low stiffness,especially for the cablestayed bridges with main spans of 1 400~2 800 m.More specifically,the CFRP stay cables with high strengthtoweight ratio and steel stay cables with high elastic modulus are combined together for application in cable stayed bridges,which can increase the equivalent stiffness of stay cables and then improve the entire stiffness of bridges.The design strategies for the composite cablestayed bridges are proposed in detail.Then through a parametric study concerning the equivalent stiffness and economical behavior,the proper area ratio between CFRP and steel stay cables are also proposed.Finally,the feasibility of the proposed stay cables is discussed through a case study of a cable stayed bridge with 1 400 m main span.The proposed composite stay cables demonstrate a high equivalent stiffness, which is an excellent selection for bridges with main spans of 1 400~2 800 m.

Abstract:A kind of general explicit displacement algorithm is derived and threestep explicit displacement method with secondorder precision is obtained.The acceleration is approximated by central difference and the velocity is approximated by threepoint eccentric difference.Therefore,this method is also called centraleccentric difference method,which can be looked as an improved form of central difference method because it remians as an explicit method when the damp matrix is not diagonal. The stabilization of this method is analyzed and results show that this method is superior in costs of calculation time and storage space over the other similar explicit methods.

Abstract:Based on the plane failure surface hypothesis and the limit equilibrium theory,a unified solution for the distribution,total force,location of the resultant active and passive earth pressures on retaining walls and the reacting force on failure surfaces was derived using differential slice method and graphic method.The solution was applied to the case with a battered wall,inclined ground surface,cohesive backfill and distributed surcharge on the ground surface.The Coulomb’s and Rankine’s theories of earth pressures could be considered as the special cases of the unified solution.The practical calculation model of earth pressures for stratified soils was established under the condition of battered walls and cohesive backfills.This model could be reduced to the current solution of earth pressures for stratified soils according to the Coulomb’s theory of earth pressures.By contrast with earlier methods in the literature,the validity of the present solution was verified.

Abstract:Based on MohrCoulomb yield criterion,an analytical solution of excess pore water pressure caused by shield tunneling is obtained by taking the friction angle into consideration.The formula is compared with that without considering friction angle.Results show that the yield range and excess pore water pressure will increase when friction angle being considered.The main factor of yield range and excess pore water pressure in the range is earth pressure of soil cabin.However,the maximum excess pore water pressure in elastic zone is a6ccosφ(a is Henkel coefficient,c is cohesion of soil),the value is unrelated to earth pressure of soil cabin mentioned above.A case study is made of the tunnel from Tongji Station to Guoquan Station of urban rail transit Line 10 of Shanghai,the analytical solution fits well with the monitoring results.The method of setting holes in the slab is proposed to reduce excess pore water pressure and good results are achieved.

Abstract:The Winkler foundation model is used to simulate the behaviour of the soils behind the diaphragm,the deflection of the diaphragm can be obtained using the rectangular plate model with one edge builtin and multicornered point supported,based on the interaction and the deformation compatibility between the struts,the diaphragm and the soils,a simplified method of calculating thermal stress for multilayered horizontal struts in deep excavations is deduced by considering temperature fluctuations vary linearly along the vertical direction.Numerical analysis is carried out by using the corresponding program based on the theory.The influence of diaphragm stiffness on thermal stress of horizontal struts is discussed,and the computational results are compared to that of the measured data with a good precision.Numerical results show that the thicker of the diaphragm is,the bigger the thermal stress of horizontal struts is,and temperature fluctuations have a remarkable effect on the stress state of multilayered horizontal struts in deep excavations.

Abstract:Based on an analysis of effect of the initial pore ratio,effective consolidation pressure and dynamic stress ration on the axial plastic cumulative deformation of the silty sand and a consideration of the effect of the dynamic partial stress level and the initial consolidation pressure of the silty sand, an explicit model of which parameters were of physical significance was build up to calculate the axial plastic accumulative strain of silty sands under cyclic loading. Parameters of the explicit model were determined by undrained cyclic triaxial tests on anisotropically consolidated Shanghai silty sands and validity of the model was verified by the cyclic tested data.

Abstract:By investigating into the areas in Zhejiang Province of China where wind disaster happens frequently, the geometrical parameters of the new rural lowrise buildings are obtained comprehensively. Based on the information, the windtunnel pressure tests for rigid models of such buildings are done. The law of the extreme uplift force coefficients on the roofs is studied. The effects of geometrical parameters on the most unfavorable uplift force coefficients on the gable roofs are given and then fitted as a function of roof pitches, aspect ratios and side ratios with the multiparametrical leastsquares method. The error analysis is made to assess the rationality of the result. These conclusions and the fitted function are useful references for wind loads standards and structure design of new rural lowrise buildings.

Abstract:Considering the efficiency and visualization of flood risk information management system and the difficulty in coupling gate breaking process and flood propagation, the flood propagation process at Taipu gate due to breaking can be simply computed based on water volume balance; and a coupled onedimensional and twodimensional hydrodynamic model is established to simulate flood propagation in the river channel and flooded area respectively, with one dimensional hydrodynamic model used in Taipu River channel to provide breach flow discharge at three possible embankment breach locations when Taipu Gate in failure as the boundary conditions for the two dimensional hydrodynamic model. The simulation results show that the established model, a simple model to deal with Taihu and river channel at gate breach and a coupled onetwodimensional model for river channel and flooded area respectively, is valid, efficient and practical for flood risk mapping of Taipu Gate.

Abstract:For the need a of realtime decisionmaking in safety management of road network operation, models based on Bayesian analysis (BA) for calculation of reliability of road traffic system were presented. Based on road traffic system models constructed with theories in system engineering, the concept of reliability of road traffic system was defined with reliability engineering, and reliability models of four kinds of road traffic systems were constructed respectively. To solve problems in application of the reliability models, Bayesian network (BN) was introduced to construct BNcoupled reliability models for road traffic systems. A case study was conducted to illustrate the use of the BNcoupled models.

Abstract:According to the characteristics of the spatial structure and devices inside, a UTM Station can be divided into a hieratical structure of stationfloorsareasdevices, for the sake of simulation. Based on object oriented technique, a concise and flexible modeling approach for UTM Stations is developed. All models of facilities and devices in UTM station are built by combining four geometric figure models and three facility component models, and then the simulation maps of largescale stations are generated from AutoCAD drawings easily and accurately. Besides, vctorbased animation is displayed in real time during simulation.

Abstract:Considering the percentage of eyelid closure (PERCLOS) method requires too much in equipment as a fatigue monitorig method, an outofdoor experiment was set to check out whether the PERCLOS method was feasible in real-time monitoring, and a laboratory measurement was set to test the availability of other eye states indices such as the frequency of blink and how long all blinks lasted, in order to find out more indices to monitor fatigue drive. Based on the results of the experiments, the possibility of using PERCLOS method in real-time is discussed and the relativity between the new indices and the degree of fatigue is validated.

Abstract:Phase change material (PCM) ceiling is constructed by hydrated salt CaCl2·6H2O in the underground railway tunnel.The heat dissipation of moving train is simplified as a moving heat source which generates equivalent heat.The 3D model of moving train is established to simulate numerically the dynamic range of the tunnel of the nonsteadystate thermal environment in short time.Coupled heat transfer model (CHT model) of PCM and air in the tunnel is established,in addition,solution is given and compared with that of the 3D model,which validates the CHTmodel.The CHTmodel is used to simulate the heat absorption of PCM and tunnel temperature in the long time,and the results show that the PCM ceiling can absorb 56.9% of the heat emitted by train under the simulated operating condition.

Abstract:Through the statistical meteorological conditions of Nanjing area, the temperature filed of asphalt pavement was analyzed. Based on temperature field analysis and laboratory material tests, the reasonable simulation model considering consecutively variable temperature was developed to study the effect of exterior factors (temperature and load) on rutting. The remarkable influence factors were analyzed, and then the rutting prediction model considering the climate factors was established. It is indicated that the rutting analysis close to the field condition can be simulated using the simulation method considering continuously changing temperature field; rutting usually occurs at the average daily air temperature of 20 ℃ or hgher, and the variety of daily rutting is a typical S curve. The index of rutting depth is defined and early warning method for high temperature and corresponding protective measures are also put forward.

Abstract:A new measurement method for faulting detection is proposed to overcome the shortcomings of traditional measurement methods for faulting detection on the cement concrete pavement.This method is realized by slab joints positioning based on the digital image processing and faulting calculating based on binocular vision,according to double camera’s imaging characters and the cement concrete pavement’s imaging feature.Slab joints positioning can be divided into approximate location based on the gray projection feature of whole image and accurate location based on the character of gray projection and edge projection around the slab joints image.The 3D coordinates of the points around the slab faulting which is used to calculate the faulting are obtained by the binocular vision measurement system.For the key step of this system,image matching adopts a new algorithm based on the estimated location of matching points.The experimental results show that measurement accuracy meets to the test results by ruler.

Abstract:Upon adjusting the composition of evaluating indicators and adopting percent within limits (PWL) method to measure the quality indicator,the quality evaluation model for different layers is constructed.The weight of each quality indicators in the model is calculated with analytic hierarchy process (AHP) considering pavement performance and other factors.Model practicability is verified in one experience project.

Abstract:It is a new method to clear up road snow by using electrothermal effect of the conductive concrete to melt ice.Conductive film coated aggregate (CFCA) was prepared by coating graphite on quartz sand with polymer resin and then conductive cement mortar was produced with those aggregates. The morphology of CFCA, mechanical and electro-thermal properties of CFCA mortar were measured. The SEM results show that the graphite can be uniformly coated on the aggregate surface, the thickness of coating is about 10~50 μm.The conductivity of the CFCA mortar reduces significantly with the increasing of CFCA. To achieve the electrical conductivity threshold, the CFA content is about 60%, which means that the graphite content in CFCA mortar is about 3%. Compressive strength of CFA mortar is 43 MPa. The temperature of the sample is up to 61 ℃ when heated 1h with AC25V50Hz power.

Abstract:Aiming at fundamental issues in the application of titanium dioxide on modified asphalt including dispersion and reaging performance effect on asphalt,an analysis was made of the dispersion stability of titanium dioxide in asphalt with scanning electron microscope and also the effect of titanium dioxide on the performance of asphalt by some lab tests including softening point, penetration and ductility tests.A research was then made into the effect on the reaging performance of modified asphalt by TFOT and ultraviolet radiation aging test. The results show that titanium dioxide can be effectively dispersed in the asphalt under highspeed shearing force and adding some dispersing agent can improve the dispersion ability; when the titanium dioxide content is 4%, the road performance of modified asphalt changes little, and the modified asphalt is of the best antiaging performance.

Abstract:To improve the analysis and design efficiency of McPhersonstrut suspension,a mathematical model of suspension based on force analysis and damping calculation was established.The design procedure of confirming parameters of coil spring stiffness and shock absorber damping based on designed offset frequency and relative damping ratio was put forward,and a set of special software of stiffness and damping parameter analysis and design for McPhersonstrut suspension system was designed.The test results of virtual prototype verify the accuracy of mathematical models and calculating software on stiffness and damping characteristics analysis.

Abstract:A study was made of the effect of the shape, the number, head and end shape of the turning vanes on the aerodynamic and noise elimination performances of the corner silencer in automotive aeroacoustic model wind tunnel by means of the computational flow dynamics (CFD) and the acoustic experiment. The results show that the optimization number of the turning vanes can be found by considering synthetically the pressure loss, the flow uniformity and the aerodynamic noise influence on noise elimination. Half ellipse head and tine end of the turning vane cause the lower pressure loss and aerodynamic noise than the hemicycle end. The corner silencer for the aeroacoustic model wind tunnel is better to eliminate middle and high frequency noise.

Abstract:In order to achieve the description of flow dynamics of hot asphalt in pipeline system,and to solve the accuracy problems of process control of asphalt,this paper presents a hot asphalt piping system modeling way based on the theory of bond graph.Under certain temperature in the hot asphalt pipeline system,the nonNewtonian fluid model of hot asphalt,as well as the pipeline system,pumps,valves,flow meters and other parts and components models by using bond graph theory are established.The project solution of the flow characteristics of hot asphalt in pipeline system is realized,which is easy to describe,providing a strong theoretical support for parameters design of the components matching in asphalt piping system.The effectiveness of hot asphalt pipeline system model based on the bond graph theory is proved by a comparison of the steadystate results of physical experiment and system simulation.

Abstract:A research is made on heat transfer characteristic of ground heat exchanger (GHE) with different heat imbalance rates,and then,the suggestions such as auxiliary cool and heat source,ground heat pipe adjustment are put forward for better and efficient operation of system.Furthermore,it is much better that installing ground heat exchanger in the area with high groundwater flowrate for the alleviation of soil heat imbalance problems.

Abstract:Based on the single objective robust design of injection molding process,the paper presents the biobjective robust design model based on the mean and standard deviation of the molding quality, the multiobjective robust design model with the multi quality features and the multiobjective ant colonies algorithm with crossover and mutation based on Pareto optimization.Aimed at the craft parameters of plastic injection for the top and down shell of remote controller, both the model of biobjective robust design based on the mean and standard deviation of warpage quantity, and the model of multiobjective robust design based on the maximum warpage quantity and the maximum volume shrinkage are established with an example.With the multiobjective ant colonies algorithm of crossover and mutation, the models are solved. The result shows that the partial performance of algorithm is superior to that of nondominated sorting genetic algorithms Ⅱ （NSGAⅡ）.The actual plastic injection was done by means of the parameters obtained by multi objections robust optimization. The quality of plastic parts was high, and the fluctuation was small.

Abstract:A new spectral similarity measure based on Hausdorff distance, a nonlinear operator, which measures the mismatch of the two sets, was proposed and experimented.The performance of different spectral similarity measures was compared by using real field spectrometric data. Statistical methods were also used to assess the measurement accuracy and validity.The experiment result shows that the similarity measure based on Hausdorff distance is more effective than others in spectral matching aspect.

Abstract:A mathematical model was established for pricing the new credit derivativecredit contingent interest rate swap (CCIRS),and the PDE was obtained by the hedging method under the framework of reduced form.Both explicit and implicit difference methods under the upwind scheme were used to compute the price.Finally,parameters were analyzed and properties of the product were discussed.

Abstract:Based on the sample data of knowledgebased enterprise and structural equation analysis, empirical studies reveal the micro incentive mechanism of psychological contract for knowledge transferring. The results show that the reciprocal preferences can reconstruct the psychological contract of knowledge enterprise to a certain degree of optimization, thereby contributing to the realization of knowledge transformation, but this incentive mechanism should be improved and expanded.