Abstract:Without considering the correlation in time and space for environmental actions, the features of time of environmental actions such as temperature and relative humidity were analyzed in detail on the basis of the characteristics of the “time calculation scale” for the representative value of environmental actions and the variation of environmental actions with time as well as an example about the carbonation of concrete due to the main environmental actions. It was found that the mean annual value and the adjusted mean annual value can be regarded as the representative value of environmental actions for the calculation of carbonation of concrete, and the Holt Winters method can be used to describe the variation of the environmental actions well. Determining the appropriate “time calculation scale” and the variation of environmental actions with time, the carbonation depth of concrete structures can be predicted easily and precisely.

Abstract:The principle and the procedure of bi directional evolutionary structural optimization (BESO), which is the later version of evolutionary structural optimization (ESO), are stated in detail. A stream of ANSYS Parametric Design Language (APDL) commends based on BESO is programmed. An exploratory research is carried out by applying this program to solving 2D topology optimization problems whose boundary conditions are set according to real bridge structures. The topology optimizations for arch bridges with different rise to span ratios, main cable of suspension bridge and main tower of cable stayed bridge are achieved. The procedures provide several different topological forms and the results show rational structures with well distributed stress and smooth force transmission, which demonstrate the efficiency of the program. The program is then expanded from 2D plane to 3D space and the conceptual design of a canyon bridge is achieved on the basis of topology optimization result. The research indicates structural topology optimization is an effective tool which can be used to draw a reasonable and heuristic layout of a bridge structure in conceptual design phase.

Abstract:Near fault ground motion with characteristics of fling step and forward directivity is significantly different from far fault ground motion, during which fling step with permanent static displacement offset resulting in one sided velocity pulses could be very effective in causing damage to longer period structures. The record with fling step was selected from the 1999 Turkey earthquake at station SKR. Based on the elastic and elastoplastic response spectrum, a single degree of freedom system with different linear fundamental periods and yield strengths was used to investigate the fling effects. At the same time, a typical reiforced concrete shear wall high rise building was adopted to assess the seismic performance subjected to near fault groud motion with fling effects. Results show that near fault ground motion with fling step significantly affects the performance of high risen structure with longer period, at the same time, for the shorter period structure, fling effects can not be ignored once structure goes to remarkable nonlinear state.

Abstract:A moving thunderstorm downburst is a sort of non stationary flow field. In order to study the effects of inlet velocity, translational velocity of a storm, jet height, and the angle of downburst flow with the ground to the field, an experiment was conducted by an impinging jet device. A phenomenon model was proposed based on the experimental results. Under different parameters of downburst, this model is capable of obtaining various time histories of horizontal wind velocity. Finally, according to the different wind speed profiles, time histories of horizontal wind speed produced by combining vector summation method, were compared with those by phenomenological model. In the duration before the arrival of the downbursts, the comparison states a good agreement between them except the Holmes & Oliver model, whereas it is found that the phenomenological model proposed herein has a stronger capacity of characterizing the variation of horizontal wind velocity in the duration of the departure of the downbursts.

Abstract:Based on an analysis of the advantages and the disadvantages of event trees (ET), fault trees (FT) and Bayesian networks (BN) respectively, a conclusion is drawn that the three methods should be applied jointly, and the way to construct a BN is improved. This way consists of three steps. First, the FT whose top event and middle events are the output event and the event sequence of the ET respectively is built. Then, the constructed FT is transformed into a BN directly. Finally, with the advantages of the calculation and analysis, the BN is used to make predictions as well as diagnostics. When there is any failure in the non root node event in BN, the corresponding root node events should be controlled by the descending order of their posterior probability values. By applying the proposed method to the soil cement mixing wall in a deep excavation, the failure probability of the top event and the main cause are figured out easily and the practicability of this method is proved.

Abstract:According to Mohr Coulumb Criterion and the elastic theory for circular distribution pressure, the critical bearing capacity can be determined, which is the pressure when the maximums depth in plastic zone is upto one fourth of the diameter. Based on a comparison with strip foundation, the critical bearing capacity factors and shape factors are presented. The shape factors of the critical bearing capacity for circular foundation are compared with those of several ultimate bearing capacity. Similarity is found for the shape factors in relation with cohesion and embedded depth of foundation, but inconsistency is found for the shape factor in relation with width of foundation, which is advised to adopt Meyerhof’s shape factor for safety. The safety factor of the ultimate capacity divided by the critical one for circular foundation is consistent with that for strip foundation.

Abstract:A 2D numerical model to simulate tidal flow and salinity in complex estuaries is developed. The grid module is designed under unstructured triangular grid with second order accuracy by cell reconstruction using multiple least square methods to remove stability limitations associated with surface gravity wave. The circulation module is based on semi implicit Eulerian Lagrangian method and free from CFL condition constraint, and the wetting and drying are addressed by movable boundary techniques. The salinity module is designed in the frame work of finite volume method with a second order resolution in coordination with the discreted continuity equation, through the cell face concentration reconstructed from surrounding cell averaged by complex interpolation combined with a mono tonicity criterion. The model has been tested by a pure advection case and a pure diffusion case, which demonstrates that the model has a high accuracy. Finally, this model has been applied to simulating the saline intrusion in the Yangtze (Changjiang)River Estuary and the results show that the simulated tidal levels, velocities and salinities agree well with the measured ones.

Abstract:To obtain the effect of change in design elements of curves on vehicle’ track and speed while driving in curve cutting, two indexes were established to measure cutting effectiveness, i.e. speed increment and track radii increment at mid curve. Then, process of a car driving in curve cutting and lane keeping pattern on test curves was simulated by a “roadway - driver - vehicle” virtual driving system. And the relationships among curve radii R, deflection angle ΔA, roadway width WR, curve length Lh and cutting effectiveness were analyzed. The results show that cutting effectiveness reaches maximum at ΔA= 20deg, and it would decline as ΔA increase. For curves with ΔA less than 10deg, track radii in curve areas is larger than the curve radii even from lane following pattern. And only when ΔA exceeds 20deg, track radii can be in accordance with curve radii. There exists a critical angle ΔA0C, widening the pavement can result in an increase in cutting effectiveness only when ΔA <ΔA0C. Cutting effectiveness would decline as curve radii increase, and the larger ΔA, the faster in decline. For curves with 30 m radii, no matter how a ΔA and WR it has, an obvious speed increment can be gained by cutting. Cutting effectiveness would decrease as Lh increase, when Lh exceeds a critical length, the effectiveness being zero.

Abstract:This study first defines two new indicators to describe the characteristics of road network structure, one is road network concentration degree, which describes the extent to which the network has a centralized structure, another is structure index of road network layout, which describes comprehensive structure properties from the aspects of road network density and network topology. Then the influencing factors and mechanism which impact on density of public transportation network by road network layout are analyzed. Finally, based on the regression analysis of field data, this study points out that the density of public transportation network is influenced by density of road network and road network concentration degree, there is a significantly positive linear correlation between density of public transportation network and structure index of road network layout.

Abstract:In order to investigate the actual stress state of waterproof adhesive layer of SMA pavement on concrete box girder bridge, the finite element method and laboratory test method were both used to analyze the interlayer bonding properties. The composite structure model of two spans of the whole bridge was established, and the influence of braking, overloading, random dynamic loading on the mechanical response of waterproof adhesive layer was analyzed. The lab shear strength and drawing strength between adhesive layer and bridge deck were carried out. Research results show that the influence of braking and overloading on mechanical response of adhesive layer is larger than that of random dynamic loading caused by bridge deck roughness. The max tensile stress appears when the load move on the pavement surface above the pier, and the max shear stress appears when the load move on the pavement surface at the center of a span. Compared the calculated results with test results, laboratory test results can meet the theoretical requirements, and the SBS modified asphalt and rubber asphalt can be considered as the material of waterproof adhesive layer.

Abstract:Based on a case study of the joint faulting evaluation criteria in Chongqing, a new method was proposed for rating the joint faulting with a consideration of the level of ride quality. Two representative cement concrete pavement sections were chosen, then the joint faulting values and localized roughness index（LRI） of those pavement sections were detected. The relationship between joint faulting and LRI was revealed by the regression analysis. Then the joint faulting evaluation criteria were obtained based on the relationship between localized roughness and ride quality.

Abstract:Based on the investigation and analysis of different sleeper types at home and abroad, primary schemes of sleeper type on bridge in high speed railway were determined according to the structure characteristics of ballast track on bridge in high speed railway of China. The sleeper types proposed in the primary schemes including type Ⅲ sleeper, wide sleeper, ladder sleeper and frame sleeper. Then a vehicle track bridge coupling system dynamic analysis model was established, with which the dynamic performances of the primary selected sleeper types were compared and analyzed to select the suitable sleeper type for bridge. The selected sleeper type was optimized, and the wide sleeper is recommended for high speed railway in China. Based on a comprehensive consideration of the track maintenance, type Ⅲ sleeper was proposed for sleeper scheme. The dynamic analysis results show that the widening sleeper with 2~4 cm type Ⅲ sleeper can well reduce ballast stress and be easy to maintain. Study results are helpful for the design of new sleeper structures on bridge.

Abstract:Copper indium diselenide nanopowders were hydrothermallly synthesized (200℃, 18h)by using water as the solvent, CuCl2, InCl3and Se powder as the starting materials, sodium borohydride as the reductant repectively. X ray powder diffraction (XRD), X ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM)were used to characterize the obtained nanopowders. The results demonstrate that the average diameter of the as synthesized nanoparticles is around 100 nm; the reaction temperature is important for the formation of CuInSe2, the powders prepared under the temperature above 200 ℃ is pure CuInSe2 with chalcopyrite structure; time has a great effect on the morphologies of the as prepared powders, the particle size increases as the reaction time is prolonged. Furthermore, a possible formation mechanism for product was also proposed.

Abstract:The model of cylinder shape surface contact was applied to the investigation of fretting fatigue failure characters of 35CrMoA under multi axial cyclic loading. And the fretting wear scar and fracture morphology were examined by optical microscope and scanning electronic microscope. The effect of fretting wear on material fatigue failure was discussed, too. Results of this study indicate that the oxide debris produced in the wear scar play important roles to surface material damage; fretting wear can accelerate the initiation of fretting fatigue crack and lead to material failure at the boundary of fretting and non fretting area.

Abstract:Intelligent control strategy for cooperative launching of dual cclutch transmission (DCT) based on the fuzzy control and neural network is presented, which comprehensively considers driver intention, vehicle load, road gradient and clutch engagement state. The driver intention is identified in real time according to the accelerator pedal opening and its change rate. Fuzzy control rules of the driver intention are designed based on operating experience of the skilled driver. In implementation of the adaptive control strategy based on people vehicle road, the input parameters of neural network are denoted by the driver intention, vehicle load, road gradient, and the control parameters of neural network are denoted by the ratio of the rotating speed difference between driving and driven disc to the driving disc rotating speed, which control the engagement and disengagement of dual clutch. Finally, the merits of the launching strategy are validated in some typical modes including conditions of fast launching, slow launching and variable driver intention.

Abstract:Analysis was done to find out the main factors to the radiation noise of a plate structure. Results show that the distribution shape of the vibration velocity can be the main factor when the frequency is low; while in the high frequency domain, the sound power almost only depends on the amplitude of the vibration velocity. Hereby, ‘shape optimization’ and ‘amplitude optimization’ were proposed to optimize the thickness distribution of the plate, so that the sound power could be reduced. Then, a rectangle plate was used to verify and evaluate these two optimization methods. Numeric results show the shape optimization method has a good performance when the frequency is not very high, and the amplitude optimization method brings a steady improvement of the sound radiation when the frequency is high.

Abstract:The drum surface method was proposed to fit the dual curvature glass. The drum surface was obtained from the automotive body cloudy data with the motion equation by using line element geometry and KLocalRANSAC algorithm. Based on the drum line principle, the proportional function method was used to obtain the guide rail curve. At the same time, the motion deviation was analyzed and the max motion deviation was not more than 0.6 mm. The results fully achieve the engineering requirements. It is proved that the drum surface fitting method and the guide rail design are correct and reasonable.

Abstract:Three dimensional hot wire was used to test the unsteady characteristic of the flow inside the test section of an 1:15 scaled wind tunnel under different situations. By analyzing the power spectrum density (PSD) data of the test points, conclusions were drawn that when nozzle speed was lower than 37 m·s-1 the turbulent density concentrates at the frequency of about 20 Hz. At the speed of 25 m·s-1 the PSD value was max. When nozzle speed was higher than 37 m·s-1 the turbulent density was concentrate at the frequency of about 43Hz. At the speed of 41 m·s-1 the PSD value was max. Under both low speed and high speed situations the peak of the velocity fluctuations were all enlarged along with the flow from nozzle to collectors. And the amplification was larger under the situation of high speed. From test we also found that when the angle of the collectors was 0 degree the velocity fluctuations were much lower than that of 15 degree collectors.

Abstract:To support the match, selection and composition of manufacturing service during the networked collaborative manufacturing process, as well as to improve the recall ratio & precision ratio of manufacturing services, a manufacturing service construction method based on semantic was proposed. At first, formal presentations combined with corresponding case examples were given to the manufacturing service from the aspects of basic information, category, function, resource, related manufacturing task, accessing, status, quality of service and so on. Secondly, web ontology language for service (OWLS) was extended by XML document to describe the dynamic information of manufacturing service in the process. Then manufacturing service model was realized by the description of the designed extended OWLS method. Based on the above research, the prototype of collaborative manufacturing platform and running process were presented. The application production example of collaborative manufacturing platform in a certain textile machinery manufacturing enterprise verified the feasibility of the methods proposed.

Abstract:This study focuses on the modeling of the multi vehicle route searching with soft time windows for medical rescue. First of all, the hybrid genetic algorithm (HGA) is initialized by nearest neighbor heuristic algorithm and the new chromosomes are generated through iterated swap procedure. Secondly, the roulette wheel selection is adopted to choose fitter chromosomes to undergo genetic operations and the offspring can be improved through order crossover, heuristic mutation and inversion mutation. And thereby the optimal route for medical rescue is obtained under the minimum total cost as well as the travel time of vehicles is shorthed effectively. Eventually, a medical rescue example under unconventional sudden onset disaster is provided to demonstrate the validity and feasibility of this model and algorithm.

Abstract:The accurate analysis of the inverter direct current (DC) link current is the key to the assessment of the electromagnetic interference and computation and selection of the DC link capacitance. Aiming at the mathematical expression and solving method to the inverter DC link current for permannet magnet synchronous motor (PMSM) based on vector control, the paper presents an analysis of the corresponding equivalent inductances for the fundamental wave and the high order harmonics of the phase voltage. The results show that the equivalent inductances for all the harmonic waves of the salient pole PMSM are equal and constant, the equivalent inductances for the high order harmonics of non salient PMSM are changeable with the rotator position, and the fundamental wave can be decomposed on the d axis and q axis by phasor synthesis and the corresponding inductances are d axis inductance and q axis inductance. In the theoretical computation, the high order inductances can be regarded as a constant through averaging method or the high order harmonics can be abandoned. The correctness and effects are verified through the simulation and experiment.

Abstract:A theoretical inference was made on the DC side current contents of traction inverter and DC supply network based on the analysis of electric traction system of urban metro vehicles. Then the function of line filter was analyzed in detail. Finally, DC supply network current harmonics were quantitatively analyzed under the typical square wave mode with the MATLAB simulation software. Simulation results show that the theoretical analysis is valid and the derived formula provides a method to assess the current harmonics and power loss of DC supply network.

Abstract:According to the complex situation of modern urban transportation network, a new T GIS data model for urban complex road network (UCRN) was esfablished to describe its complex characteristics. First, the complex network theory was introduced to validate the complexity of road network. Then on the basis of three aspects such as the comprehensive description of UCRN, the attribute expression, and the internal logical relationship of UCRN, T GIS data model was constructed. Finally, T-GIS data model proved to be effective in applications, and clearly represented spatial information and internal logic relations of UCRN. The study provides desired data for road congestion and traffic flow analysis, route induction and road network evolution.

Abstract:Shrinkage deformation of light cured composite resin is a major cause of the failure of dental restoration. Based on the electronic speckle pattern interferometry method (ESPI), the shrinkage deformation of light cured composite resins (Type R1 and Type R2) are measured under the different conditions. The ESPI patterns are obtained during shrinkage of the Type R1 and Type R2 According to these experimental results, the relative curves of the max out of plane displacement and time are plotted. The results show that the shrinkage deformation of light cured composite resin is connected with the width of the hole in the tooth. When the width increase, the shrinkage deformation increase as well, but there was no linear relation between them. The results also show that Type R1 is more suitable for clinical application.

Abstract:Considering the cell subdivision method and the modified velocityVerlet algorithm, the implementation of LeesEdwards boundary conditions for DPD method was investigated. The simulated results show that the profiles of velocities, densities, temperatures, pressures and stresses agree well with the expected. Furthermore, when dissipative coefficient γ was increased to 100, the velocity profile in the system was homogeneous, indicating that the LE boundary conditions still valid for higher dissipation rate. Viewpoints different from Ref ［21］ are proposed.

Abstract:Chitosan was coated and modified by calix［8］arene, calix［6］arene and calix［4］arene, and the adsorption properties of neodymium ion were studied. The study show that calixarene is coated on the surface of chitosan mostly depending on the effect between hydrogen bond and chitosan.Adsorbance of neodymium ion by chitosan coated with calix［6］arene or calix［8］arene is far more than that of chitosan,while adsorbance of neodymium ion by chitosan coated with calix［4］arene is smaller. However, when the equilibrium concentration of neodymium ion is lower, the adsorbance of neodymium ion by chitosan coated with calix［4］arene is still more than that of chitosan. At the same time the relationship of adsorption capacity of calixarene coated chitosan and pH value was studied.

Abstract:Based on the analysis and an induction of project management models and the former research,the project protfolio management ability(PPMA) index system is constructed initially. The evidence theory is applied to evaluating PPMA, By building the recognition framework, determining the credibility function and fusing the evidences, the procedure of PPMA evaluation is specified. Finally, an example proves the index system and evaluating method to be both effective and practical.

Abstract:A management model is first established under complete information, and then a contract is made to expose the farmers’ production type under incomplete information by incentive theory. An incentive model with government’s auditing is presented, which improves the compensation model. A discussion is held on the model’s result, as a result,the compensation mechanism of non point source pollution is obtained. The new mechanism can realize the management goal by farmers’ self declaration. At last, a numerical example validates the approach.