Abstract:Based on the features of shear failure of concrete,the shear damage element,which comprises the elastic part and the plastic part,is introduced.Furthermore,a new kind of idealized mesoscopic damage model,which the material is represented by a set of the elements of equal stiffness that are joined in parallal,is developed for concrete under monotonic axial compressive loading.The model can well explain the experimentallyobserved nonlinearity of stressstrain curve,stiffness degradation and strain softening,etc..The constitutional law for concrete under axial compression is established.Also,a simple analysis method for plastic strain is put forward.With damage and elasticity modulus as random variables,stochastic equations of damage growth and stressstrain are presented.With the help of stochastic structural modeling and optimization methods,coefficients in the model,for example,the distribution parameter of the random field of failure strain,can be easily determined by the full stressstrain curves of concrete specimens under axial loading.Comparison with the test results shows that the analytical values agree well with the test.

Abstract:This paper investigates behaviors of the restrained column under axial load in fire through using a calibrated finite element method model.Presented results include the column axial force-temperature evolution curve,column bending moment-temperature evolution curve,failure temperature of restrained column,difference between failure temperature of unrestrained and restrainedcolumn,and difference between failure and bucklingtemperature of restrained column.Results of parametric study show that:①before the column buckles,the axial force in column increases linearly and bending moment only varies a little;②after the column buckles,the bending moment in column increase suddenly,and the column is loaded under combined axial force and bending moment;③the axial restraint reduces failure temperature of restrained column;and the reduction in failure temperature increases with increasing of axial restraint stiffness.However,there is a critical restraint stiffness ratio,above which no further reduction in column failure temperature occurs.

Abstract:According to a series of wind pressure measurement wind tunnel tests,the effects of area densities of surrounding buildings on distributions of wind loads on a flatroof building are studied.The test results indicate that when the area densities of the surrounding buildings increase,the conical vortices on the flat roof of the surrounded building for oblique wind directions will disappear gradually and the extreme values of suction pressures on different locations of the flat roof will decrease and become uniform.The maximum values of negative wind pressure on the flat roof of the surrounded building become 80%,30% and 20% of those of isolated buildings when it is surrounded by the buildings with the same geometric parameters but with different area densities of 0.1,0.3 and 0.6,respectively.

Abstract:This paper presents an experimental study on mechanical properties of a new type of metal plate,in which its teeth are orthogonal oriented.Experiment was designed to investigate the loaddeformation relationship,ultimate lateral capacity of teeth and ultimate lateral slip capacity of teeth for this type of metal plate connected joints.40 specimens were tested under tension loading paralleltograin.Experimental data of loaddeformation were fitted to Foschi model with the leastsquare method,the goodness of fit was verified by classic statistical method,and the Foschi model being adopted to represent the loaddeformation relationship of woodbased connections had been widely accepted and extensively verified by experimental study.Then the probability distribution model for load carrying capacity was determined by goodness of fit test.Based on reliability theory,characteristic values for ultimate lateral resistance and ultimate lateral slip resistance were determined on the basis of the probability distribution model.Analytical results indicate that this kind of joints exhibit high ductility and low variability.

Abstract:Based on tests of 9 recycled concrete specimens confined by glass fiber reinforced plastics (GFRP) tube with different recycled coarse aggregate replacement percentages under axial compression,an investigation was made into the failure properties under compression,axial forcelongitudinal displacement relationship,lateral strain development and variation rule of lateral deformation ratio of the test specimens.It is found that the stressstrain relationship of GFRP confined recycled concrete can be divided into four branches, i.e., the elastic ascending branch,the elastoplastic ascending branch,the descending branch and strainstrengthening branch.The strength and deformation ability of confined recycled concrete are obviously improved than those of unconfined recycled concrete.The slip between the inner recycled concrete and the GFRP tube is negligible,and the lateral deformation ratio of specimens containing recycled aggregates is lower than those without recycled aggregates.

Abstract:The shear tests of CFRPConcrete interface specimens were executed at different temperatures,4,40,60,80,100,120,140,160,180 ℃,to investigate the changing regulation of the interface strength with temperature,the failure type and the influence of the temperature on the adhesive and carbon fiber reinforced polymer(CFRP).The relationship between the bond stress and slip was preliminarily established at different temperatures.The test results show that the interface bond strength at 40 ℃ is the maximum,and the interface strength decreases when the temperature is over 40 ℃,and then remains stable when the temperature is over 100 ℃.

Abstract:In this study,the mercury intrusion porosimetry(MIP)tests were performed on the natural marine clay to investigate the relationship between the change in entrance pore size distribution and the applied stress level.Quantitative analysis was made on clay mineral content of Zhuhai clay through Xray diffraction tests(XRD).In addition,the measured data was compared to the experimental data obtained Regina clay,Canada.The results show that the entrance pore size distribution of marine clay in Zhuhai demonstrate a continuous unimodal distribution.And the entrance pore size distribution varies little when the stress level is smaller than the gross yielding stress,but changes significantly when the applied stress is in the vicinity of the gross yielding stress.In the latter case,the large pores(r>2 000 nm)and the medium pores(2 000 nm>r>200 nm)become smaller while the micropores(200 nm>r>20 nm)vary little.When the applied stress is larger than the gross yielding stress,micropores space volume decreases rapidly,and the pore size gradually becomes uniform with the increase in applied stress level.Finally,the differences in pore size distribution between Zhuhai clay and Regina clay can be attributed to different clay content and mineral.

Abstract:With the GDS 10 Hz/20 kN dynamic triaxial system,undrained tests on the saturated sands during liquefaction process were performed.Development of dynamic pore water pressure of saturated sands during liquefaction process was studied and its evolution mechanism was represented.Based on the results,a practical strain model of dynamic pore water pressure under isotropic consolidation was proposed.The model relates with the strain amplitude in dynamic analysis directly,which can make up for the deficiency of stress pore water pressure model and has better applicability.There is little effect on the relationship between dynamic pore water pressure ratio and dynamic strain ratio from the variation of dynamic stress and confining pressure under isotropic consolidation and the law of dynamic pore water pressure can be described by the same model.The test constant can adopt an identical value when the characteristics of dynamic pore water pressure is described by dynamic pore water pressure model under isotropic consolidation proposed by Seed in different dynamic stresses and confining pressures.

Abstract:According to AASHTO TP8 in American standard specification,threepointbendingfatigueloading test method was modified to evaluate the fatigue performance of asphalt rubber(AR)gapgraded mixture.Material test system(MTS)and straincontrol mode were used to evaluate influence factors of fatigue performance of AR mixture.According to the research,the fatigue life of AR mixture increases with the asphalt content when the asphalt content is between 7.0%~8.5%.The decrease of air voids will also improve the fatigue performance if VFA is within a reasonable extent.The best fatigue performance comes out when the crape rubber modifier(CRM)content in AR is 19%.Air voids have the greatest influence on fatigue property of AR mixture and VFA(voids filled with asphalt),asphalt content and CRM content also influence the property obviously.When AR mixture based on fatigue performance is designed,lower air voids first be confirmed according to the engineering requirement and then higher asphalt content and higher CRM content is advised.

Abstract:he combined travel demand model (CTDM) combines the traveldestinationmoderoute choice based on the random utility theory.This model avoids the limitation of the conventional sequential fourstep procedure,and can be formulated as a nonlinear programming problem.By analyzing the partial linearization algorithm of CTDM,a quadratic interpolation method is proposed to obtain the approximated optimal step size.Comparison of the proposed algorithm with method of successive averages and bisection line search method in the classic Sioux Falls network confirms that the quadratic interpolation can converge faster and get better solution than the other two methods.

Abstract:Relationship between freeflow speed and lane width is analyzed by studying characteristics of freeflow speed of urban road sections and exit lane at intersections.Field data of speed are collected from 9 roads with similar facility and different lane width in the urban area of Hangzhou by using video detection and recognition technology.The data show that the freeflow speeds obey the normal distribution, and the characteristic speed increases with the lane width.A model is established to describe the relationship between lane width and the speed discreteness.According to this model,the trend of speed discreteness is presented.The conclusion shows that reasonable value of lane width is beneficial to restricting running speed and improving road safety.This research also contributes in urban traffic flow modeling and traffic management.

Abstract:The safety perception characteristics of pedestrian crossing the urban road was defined according to the critical theory.Based on a study of the microscopic mechanism of pedestrianvehicle traffic conflict and collision,the probabilistic microscopic models for pedestrianvehicle traffic conflict and collision were established.Then, the probability value was calculated by the formula of Bayesian statistics and Monte Carlo simulation for an analysis of the influence of safety perception,reaction time, traffic volumes and vehicle speed on pedestrians. Finally,the indicator of risk evaluation was established on the basis of 90% confidence level of probability. The results can provide the best foundation for the implementation of traffic regulation.

Abstract:A study was made of the influence of chloramination on DBPs formation from different organics based on the grading and clssification of organics.The experimental results show that the formation of CHCl2Br and CHClBr2 are restricted by chloramine disinfection for the hydrophilieity and strong hydrophobicity organics.For the weak hydrophobicity organics,formation of DBAA and CHCl3 is affected.Chloramine disinfection reduces the THMs and HAAs formation from the organics whose molecularities are less than 10 ku,and the influence is weakened to some certain extent with the increase of molecular weight in chloramination.

Abstract:The tensile mechanical properties of the armchair and zigzag single graphene sheets at different temperatures (0~3 000 K) were investigated based on molecular dynamics simulation with Tersoff bondorder interatomic potential.The dependence of the tensile mechanical properties of the sheets on the temperature was predicted and analyzed.A study was also made of the difference of the tensile mechanical properties between armchair and zigzag sheets at different temperatures.Simulation results indicate that the tensile mechanical properties and deformation mechanism of the sheets are strongly dependent on the temperature.The Young’s modulus,tensile strength and limit tensile strain of the two chiral sheets all decrease significantly with the increasing temperature.It is also found that the mechanical anisotropy of the sheets is also affected by the temperature.When the temperature is less than 600K,the mechanical properties of armchair sheets are superior to those of the zigzag ones.However, when the temperature is over 600 K,this superiority diminishes gradually and even turns into inferiority,especially at a high temperature.

Abstract:Development history and research status of continuously variable transmission (CVT) is explicated.From technique aspect,the basic structure of metal vbelt CVT is introduced,then the structure and principle of the metal belt and chain is compared.The paper presents the principle and performance of the mechanicalhydraulic control system and electrohydraulic control system,especially the slip control strategy developed recently.CVT advantages are presented.From application aspect,CVT key manufacturers are enumerated,and CVT automobiles in China market are summarized.Future CVT market potential and its development trend are predicted.

Abstract:Line segment Hausdorff distance (LHD) is used to measure the degree of matching effect to improve fitting quality and the conception of Points Hausdorff Distance fitting is developed.New panel fitting model is presented and Genetic Algorithm is used for parallel searching fitting parameters.A case study of autobody engine hood fitting design shows that the proposed method can effectively improve fitting quality.

Abstract:The geometry filter phenomenon is analyzed with a simplified vertical railway vehicle.Then the relationship between geometry filter phenomenon and the resonant vibration of flexible carbody is studied with a full vehicle model.It is found that geometry filter phenomenon consists of “wheelbase filter” effects and “bogie center filter” effects.It is called wheelbase filter effect when there is neither car body bounce nor pitch responses at some wavelengths.And it is called bogie center filter effects when there is no car body bounce or pitch response at some track wavelengths.Near the null pitch response frequencies,the acceleration transmissibility from track unevenness to carbody bounce will reach local maximum.So if the carbody first bending frequency coincides with the frequencies which have the peak values of acceleration transmissibility,resonant vibration of flexible carbody will happen.

Abstract:Wire electrochemical micromachining(WEMM)is proposed as a new method of precision machining.Because of no electrode wear in this process the micrometer scale metal wire can be used as the wire electrode in WEMM,and the micrometer or tens micrometer structure can be fabricated.Base on the principle of electrochemical,the mechanism of wire electrochemical micromachining is investigated,the theoretical model of the method is founded and the top limit of feed speed of the micron scale wire electrode is studied.Effects of process parameters on the machining accuracy in the electrochemical micromachining have been studied theoretically and experimentally,and micro blades with the slit width of 20 μm are machined.It is proved experimentally that WEMM can provide a new effective manufacturing method for machining highperformance materials.

Abstract:This paper presents a performance analysis approach of embedded systems based on the randomized complete block designs.A case study is made of this approach in performance testing of automatic gate machines used in the automatic fare collection system of Shanghai Metro.Embedded systems based on ReWorks,Linux or Windows XPE are used in automatic gate machines.The assessment results show that the approach is helpful and effective.

Abstract:According to theory of photogrammetry image matching, registration problems about multistation point clouds are analyzed.Then,error propagation rules are discussed in detail and error propagation model for point clouds registration is established.By experiments,the quantitative relationship between precision of point clouds and model accumulation errors is verified,and which can be used to evaluate registration quality of point clouds.

Abstract:A new method is proposed for speckle noise suppression and water objects extracting from synthetic aperture radar(SAR)imagery based on morphology and independent component analysis(ICA)blind source separation(BSS).The distribution of SAR image data with multiplicative speckle noise is nonGausssian and its parameters are unknown.Logarithmic Quantification is utilized to transform multiplicative speckle noise to independent additive noise.Speckle noise and image data are separated from multipolarimetric imagery,and the components with the least speckle index are chosen as the object component automatically by means of ICA while the specific distribution of SAR imagery is unnecessary.Water objects are extracted from the separated component imagery based on Morphology Open Reconstruction according to their lightness and region shape features.Experimental results for ENVISAT ASAR show that the method can extract water objects from the multipolarimetric imagery with high accuracy and fast speed.

Abstract:Sorption of soluble organic matter(OM)to clay minerals occurs ubiquitously in sediments and sedimentary rocks.Soluble and insoluble OM associate with clay minerals closely in hydrocarbon source rocks,and the former holds the great proportion.The formation of soluble OMclay complexes runs through out the whole process of aggregation,deposition,preservation and diagenesis,and may be one important nature parent material of hydrocarbon.Soluble OM occurs in the micropores and on the external and internal surface of clay minerals,forming organoclay complexes via multiple interaction mechanism,which is quite different from insoluble macromolecularkerogen.The amounts of soluble OM by various organic solvent extractions are different,and its emergence and amounts vary with types and nature of the clay minerals,showing a rather complicated associations of soluble OM with clay minerals in hydrocarbon source rocks.Study from soluble OMclay interaction,therefore,explores a new way for hydrocarbon source rocks research,which has a great significance in the study of mechanism of hydrocarbon generation and calculation of oil and gas resource extent.

Abstract:The paper presents a selfadaptive regularization inversion method to improve the resolution and stability of 2D inversion for vertical induced polarization sounding(VIPS) data.The choice of regularization factor can be completely selfadaptively adjusted during the global inversion by taking no human effort.First,the generalized linear inversion method is introduced that total smooth constraint is imposed,and studies are made of the construction of initial model,the computation of partial derivative matrix and the choice of selfadaptive regularization factor of VIPS inversion.Then, the practical and effective 2D inversion software of vertical induced polarization sounding is programmed.Finally,it is verified through inverting the simulated and measured VIPS data that the method is feasible and effective,and the inversion software can be applied to the practical work.

Abstract:Based on the stratigraphic distribution,the geologic structure and hydrogeologic conditions of Sanmenxia bauxite,the hydrogeologic conceptual model of karstfracture aquifer system of water enrichment CambrianOrdovirian Period limestone was generalized,and the numerical model of groundwater flow was established with the finite difference method of Visual MODFLOW to simulate variation of groundwater level and to predict water discharging.The groundwater flow mathematical model was corrected and the hydrogeolocical parameters were inversed in combination with the observation value of groundwater level of group drilling pumping tests in mining area boreholes,and then the corrected mathematical model and parameters were adopted to predict the groundwater level distribution and mine discharge changes at different designed mining drainage level in well.The reliable basis is provided for controlling groundwater effectively and safe rational mining bauxite.

Abstract:The optimal portfolio is investigated based on the semiinvariance model.A solution is given to the optimal portfoli by means of the feedback optimal control of an linearquadratic optimal control problem.

Abstract:The paper presents an efficient Monte Carlo method on the basis of the Control Variate technique for valuation of the Variance Swap derivatives under the stochastic volatility assumption.The result shows that the method can reduce variance efficiently and improve precision obviously by choosing an efficient control variate testified with the computation results.Finally,a study is also made of the factors affecting the price of the Variance Swap.The method can also be applied to the other valuation of Variance Swaps,such as Corridor Variance Swap,Gamma Variance Swap,Conditional Variance Swap and other products with multifactor models.

Abstract:The strategic object of an enterprise stakeholder management is to maximize performance under resource constraints.Based on a linear programming model of resource constraints，a quantitative analysis is made of the improvement of the performance indicators and the levels of performance improvement are presented.An analysis of the relationship between performance indicators and stakeholders reveals the stakeholders are closely related to the performance indicator.The study results offer a strategic basis for stakeholder management.

Abstract:Employees affiliated to occupational pension schemes have to choose between lumpsum,phased withdraw and annuitization after retirement.The recursive preference was introduced to eliminate intertemporal substitution,and an intertemporal utility function with unique uncertainty of lifetime was set up to explore the employees’ decisions without bequest motive.Results show that longevity risk and ephemerality risk have different effect: the lumpsum way and phased withdraw help to aversion to longevity risk while annuitization helps to aversion to ephemerality risk.In general,the utility of annuitization decreases and the lumpsum way is more attractive as risk aversion increases.