2011, 39(8):1099-1104. DOI: 10.3969/j.issn.0253-374x.2011.08.001 CSTR:
Abstract:The paper presents a summary of the experience of metropolitan development both international and domestic,and an analysis of Shanghai’s international status,regional background and development opportunities as well as a review of the effectiveness and the problems of suburban development in the past 10 years.Based on a comparison and an analysis,the paper puts forward a new spatial pattern of Shanghai’s suburban development with a nuclear,twoaxises and multicores.The adjustment content of urban development is proposed to be focusing on new towns and major townships. Finally,the paper presents the specific approaches including legislation and institutional building,public facility provision and railtransportationoriented development and so on.
2011, 39(8):1105-1112. DOI: 10.3969/j.issn.0253-374x.2011.08.002 CSTR:
Abstract:A probabilisticand finite elementbased lifetime performance assessment method is proposed.A durability analysis program named concrete bridge durability analysis system(CBDAS) is written based on the numerical simulation methods relating to the deterioration of materials properties,reduction of sectional areas,and variation of structural performance.Then the statistical parameters of the random variables involved in the assessment of structural lifetime performance are recommended according to the present studies.Thus,the timevariant system reliability assessment method of reinforced concrete bridges is set up based on CBDAS and MonteCarlo simulations.Finally,the lifetime performance of a reinforced concrete continuous bridge under chloride penetration is investigated by means of the timevariant system reliability.
2011, 39(8):1113-1119. DOI: 10.3969/j.issn.0253-374x.2011.08.003 CSTR:
Abstract:Based on Goodman model,which is used for simulating the contact surface between beams,this paper presents an analysis of the relationship interfacial slip of composite beam,internal force,deflection and load in elastic state.For the simplysupported and cantilever beams subjected to variety of loads,the impacts on deformation due to the interfacial slip are considered through the “additional slip bending moment”.This theoretical formula can describe the law of slip,deflection and sectional stress distribution.The closedform solutions are then validated by means of finite element analysis.All the theoretical formula in the paper which reflects the structural mechanism can simplify calculation of interfacial slip effects of composite beam.
2011, 39(8):1120-1125. DOI: 10.3969/j.issn.0253-374x.2011.08.004 CSTR:
Abstract:Based on a summary and an analysis of the configuration in composite cablepylons,the expression for calculating the horizontal force burdened by the main members of composite cablepylon was deduced according to the deformation compatibility principle;and the expression for calculating the inner force of the main members in composite cablepylon was deduced too.The full scale model tests were made to analyze the horizontal mechanical behavior of composite cablepylon according to an actual project and the stress distribution patterns of main members were obtained.Comparing to the tests results,the proposed accurate of the method was testified.
2011, 39(8):1126-1131. DOI: 10.3969/j.issn.0253-374x.2011.08.005 CSTR:
Abstract:he developed cablesliding friction aseismic bearing was designed by using the concept of friction energy dissipation and displacement restriction device.Numerical model of this bearing was simulated based on experimental results.Different continuous beam bridge models with different support restraints were established.The effects of seismic mitigation were compared.Some parameters including the initial free movement and the friction coefficient in the bearing model were analyzed.The results show that application of the cablesliding friction aseismic bearing can reduce the earthquake internal force of fixed pier.The initial free movement and the friction coefficient can be properly increased to improve the effect of seismic mitigation.
KE Shitang , GE Yaojun , ZHAO Lin , ZHANG Junfeng
2011, 39(8):1132-1137. DOI: 10.3969/j.issn.0253-374x.2011.08.006 CSTR:
Abstract:A new procedure is presented to calculate the equivalent static wind loads (ESWL) for the large cooling tower.Based on the synchronous multipressure measurement on the rigid building model,the generalized resonant modal displacement covariance matrix is obtained from structural equation of motion; then based on inertial wind loading(IML) method,covariance matrix of elastic restoring force containing the resonant components is obtained; the resonant response and equivalent static wind loads are calculated with loadsresponse correlation method.At last the total ESWL is obtained with linearity combination of background and resonant components.The proposed procedure avoids the integration process of calculating elastic restoring force with a full consideration of the modal coupling effects,which can be used to calculate the ESWL for any complex structures.The calculation of ESWL of the super large cooling tower of Ninghai Power Plant demonstrates the effectiveness of the present approach.
HOU Gang , TONG Lewei , CHEN Yiyi
2011, 39(8):1138-1144. DOI: 10.3969/j.issn.0253-374x.2011.08.007 CSTR:
Abstract:Finite element numerical technique is used in the paper to simulate the longitudinal residual stress (LRS) distirbution in a coldformed square hollow section (CFSHS) which is produced during its rollforming and springback process,and then to investigate the effects of CFSHS’s width,wall thickness and yield strength on the LRS ditribution.It is concluded that LRS along the CFSHS’s wall thickness presents a feature of a nonlinear distribution,tension at the outside surface but compression at the inside surface,and mostly the same amplitude at the both surface.The LRSs at the corner and at the flat side come to 50% and 45% of CFSHS’s yield strength respectively.The LRS for a smaller width increses,whereas the LRS for a larger width does not show such the trend,as the wall thickness increases.The LRS decreases,as the width increases.The ratio of LRS to yield strength does not change significantly,as the yield strength varies.
LI Zhiyi , LIU Zhong , ZHAO Yanfei , ZHANG Huidong
2011, 39(8):1145-1149. DOI: 10.3969/j.issn.0253-374x.2011.08.008 CSTR:
Abstract:Based on ADINA,a 3D augersoil FEM model was developed to study the impact of pattern of the drill auger,screwpitch and the soil parameter on the required torque.Secondly,the model tests of auger squeezing into cementsoil mixture were done to get the optimized drill auger with least torque.At last,onsite test result of drill auger squeezed into ground verified the correctness of the numerical analysis and model test.The conclusions in this paper can provide a basis for optimal design of drill auger.
LU Siwen , ZHANG Lanfang , FANG Shouen
2011, 39(8):1150-1154. DOI: 10.3969/j.issn.0253-374x.2011.08.009 CSTR:
Abstract:In terms of carfollowing critical condition,the characteristics of freeway rearend mechanism was analyzed.The four kinds of situation of freeway rearend collision were studied and the quantified index of rearend collision risk was inferred according to the rearend collision kinetic theory.Considering the random effect of driver’s reaction time,brake deceleration,the Monte Carlo method was used to calculate the value of rearend collision risk.The scope of threshold value was then obtained by fuzzy clustering method.The results can provide the theoretical foundation for early warning of freeway driving safety.
2011, 39(8):1155-1160. DOI: 10.3969/j.issn.0253-374x.2011.08.010 CSTR:
Abstract:Based on the numerical algorithm of a threedimensional flexible joint element to furnish the stiffness and damping in transverse,vertical and rotational directions,a calculation model under wheel load drop according to the finiteelement method is built,and,the dynamic responses in time and frequency domain are studied respectively for a whole turnout structure with articulated or integral switch sleepers impacted by a falling wheelset,considering the nonlinear characteristic of the ballast’s support under the sleepers as well as the special construction of the articulated joints.Compared with the normal integral sleeper design,the track with articulated switch sleepers has a lower rigidity,which changes more evenly along the track and improves its dynamic performance.Furthermore,by modifying the switch sleepers’ vibration behaviour,the articulated joints effectively reduce the impact loading of the ballast at the end of the sleeper under the turnout branch track when the vehicles are running on the main turnout route.This will extend the life of the ballast bed.Finally,in combination with the articulated switch sleepers,high elastic fastenings,whose rational parameters are proposed,are employed to make up the elastic track foundation,the vibration characteristics of highspeed turnout are optimized .
WEI Li , ZHANG Yicheng , DA Shipeng , SHEN Xiaojun
2011, 39(8):1161-1166. DOI: 10.3969/j.issn.0253-374x.2011.08.011 CSTR:
Abstract:This paper first reviews the development status of domestic and international simulation technology for urban rail transit system,and describes in detail the shortcomings of existing simulation systems such as less accurate models and incomprehensive consideration of the interaction between train and traction power system,leading to large deviation of simulation result compared with practical experiment.Simulation of electrical interaction between train and traction system shows that the traction performance of the train is influenced by the variation of overhead line’s voltage.Finally,in order to have a fullscale reflection on the characteristics of urban rail transit system that dynamic simulation which combines multitrain with multiworking mode is demanded,and the study of a general simulation platform should also be carried out.It is proposed that the integration of PSCAD/EMTDC and Matlab can be used for developing the platform.
WU Jiaorong , HU Shanchuan , CHEN Zhenwu
2011, 39(8):1167-1172. DOI: 10.3969/j.issn.0253-374x.2011.08.012 CSTR:
Abstract:Convex polygon partitioning was adopted to divide the railway station’s space and every divided space was described with depth value and integration value.Finally a quantitative method was given to evaluate the navigation signs’ distribution,which concerned the spatial awareness,the ken of pedestrian,streamlines and their flow.Application of this method with examples was finally given.
HE Pinjing , YU Chun , ZHANG Chunyan , WANG Ke
2011, 39(8):1173-1176. DOI: 10.3969/j.issn.0253-374x.2011.08.013 CSTR:
Abstract:To investigate the relation between the mass loading and the improvement of incineration properties,four trials of municipal solid waste (MSW) stacking and fermentation under different mass loadings (0,3.20,8.00,12.7 kPa) were carried out in the laboratory for 3 days.The results show that water removal mainly occurs in the first 36 hours,and it has a nonlinear relationship with the mass loading.The water removal efficiency decreases when the mass loading is higher than the optimal value (8.00 kPa in these experiments).Although the concentrations of combustible Cl,S,and heavy metals in the pretreated waste increase,which are positively correlated with the quantity of the water removed,the decline of the total amount of these pollutants and their concentrations per unit of lower heating value is observed.Therefore,the incineration pollution potential improves greatly after the MSW stacking and fermentation process.
AN Na , GAO Naiyun , CHU Wenhai , XIE Huihui
2011, 39(8):1177-1180. DOI: 10.3969/j.issn.0253-374x.2011.08.014 CSTR:
Abstract:An analytical method used for the detection of odorants——2methoxy33isopropyl pyrazine (IPMP) and 2methoxy33isobutyl pyrazine (IBMP) in drinking water with liquidliquid extraction (LLE) by gas chromatographymass spectrometry(GC/MS)was developed.The LLE was carried out in a solution of pH 4 with a dosage of 0.2 and 60 g·L -1NaCl,respectively.The extraction lasted for 4 min.Good relativity (r>0.995 4) was obtained when the linear range was 20~500 μg·L -1.The recoveries of IPMP and IBMP were 72.0%~103.6%.The relative standard deviations were less than 8%.
ZHAO Ming , ZHANG Xiong , ZHANG Yongjuan , LIN Maosong
2011, 39(8):1181-1184. DOI: 10.3969/j.issn.0253-374x.2011.08.015 CSTR:
Abstract:The resistance of blended cement paste to sulfuric acid attack was investigated.Two groups of mixtures were tested,cement with slag only,cement with both slag and silica fume.Mass loss,acid consumption and corrosion depth were measured to analyze the deterioration of blended cement paste in sulfuric acid solution.The results show that the porous corroded layer acts as a protective barrier against the direct contact of the inner cement paste with the acid solution.Kinetic equations of sulfuric acid attack were established in form of d=Ktn ,where d is corrosion depth,t is corrosion time,K and n are fitting coefficients,to predict their corrosion depth at a specific age.It provides a reference for construction design,maintenance and protection.
WEI Hengyong , LIN Jian , LI Dongwei , FENG Zhaobin
2011, 39(8):1185-1192. DOI: 10.3969/j.issn.0253-374x.2011.08.016 CSTR:
Abstract:TeO2 thin films were prepared by nonhydrolytic solgel method with tellurium 1,2propylene diglycollate and tellurium tetrachloride as raw materials,respectively.The nonhydrolytic solgel polymerization mechanism and the microstructure transformation process of the gel films during calcining were studied.The results show that tellurium 1,2propylene diglycollate can form chainlike polymeric molecules,and the nonhydrolytic condensation reaction proceeds between the associated molecular clusters through ether elimination.When tellurium tetrachloride was used as raw materials,the intermediate products tellurium chloride ethoxide were firstly generated by the partly substitution reaction of TeCl4 and C2H5OH.And then the nonhydrolytic condensation reaction took place between these intermediate products via alkyl chloride elimination.The results show that metallic Te formed by different way in the gel films during the films are annealed,which is relative to the amount and position of residual organic component in the gel thin films.When the gel thin films prepared through alkyl chloride elimination nonhydrolytic solgel process,there are more nonbridging oxygen and the crystal of Te2O5 in the films,which is attributing to the residual chloride ion in the network structure of gel thin films.With the increasing of annealing temperature,metallic Te and Te2O5 were reoxidised and decomposed into TeO2,respectively,and the crystal ofβTeO2 and α TeO2 sequentially formed in the thin films.
ZHENG Junsheng , ZHANG Xinsheng , LI Ping , YUAN Weikang
2011, 39(8):1193-1197. DOI: 10.3969/j.issn.0253-374x.2011.08.017 CSTR:
Abstract:Microstructures controllable carbon nanofibers (CNFs),i.e.platelet CNFs (pCNFs),fishbone CNFs (fCNFs) and tube CNFs (tCNFs),were synthesized and the microstructure effect on oxygen reduction reaction (ORR) performance was investigated.The physicochemical and electrochemical properties of the CNFs and Pt/CNFs were characterized by high resolution transmission electron microscope (HRTEM),Xray diffraction (XRD) and cyclic voltammetry.Platinum electrocatalysts supported on CNFs and activated carbons were synthesized,too.Pt/p-CNFs exhibits more positive ORR onset reduction potential than the electrocatalyst supported on other CNFs and activated carbon.
2011, 39(8):1198-1203. DOI: 10.3969/j.issn.0253-374x.2011.08.018 CSTR:
Abstract:The thickness thinning,residual stress and effective plastic strain resulted from sheet metal forming process were introduced into the crashworthiness simulation of a front side rail assembly in this work.Influences of these forming effects on the energy absorption and reaction force were analyzed in detail.The main factors determining the calculation precision and its efficiency were discussed.Results show that the internal energy with a consideration of the forming history is larger than that neglecting the forming history.And the peak force is larger and late.Among the thickness,the residual stress and the effective plastic strain,the thickness is the most significant factor for the energy absorption and the residual stress and effective plastic strain are important factors for the reaction force.
LI Qiliang , YANG Zhigang , WANG Yigang
2011, 39(8):1204-1207. DOI: 10.3969/j.issn.0253-374x.2011.08.019 CSTR:
Abstract:The profile of generic rear view mirror is taken as the basic model,and three shape parameters and two angle parameters,the possible parameters that affect the noise characteristics of rear view mirror,are chosen respectively.The aerodynamic noise generated by mirror is predicted by using large eddy simulation and FWH equation and the influence parameters are analyzed.The agreement of aerodynamic noise generated by generic rear view mirror between full scale automotive wind tunnel test results and numerical computation results indicates that hybrid method is feasible to predict the aerodynamic noise generated by mirror.When aerodynamic noise generated by all kinds of mirrors was analyzed,it is found that the sound source intensity radiated from the support surface of the mirror is stronger than it is at mirror surfaces.A trapezium region based on high sound pressure level is found at the support surface of generic rear view mirror and it is independent of the shape of front face and rear face,but it becomes the rectangular region when a root is mounted at the bottom of mirror.The increase of all parameters except rotate angle can be applied to reduce aerodynamic noise generated by mirror.
MA Liying , ZHOU Hong , PENG Xiaojun
2011, 39(8):1208-1211. DOI: 10.3969/j.issn.0253-374x.2011.08.020 CSTR:
Abstract:Curvature mode theory was introduced to the damage identification of a rear axle of a car.The modal test analysis of rear axle was done.Results shows that the change of curvature mode shape has an obvious effect on identifing the local damage.The study results provide a practicable research method for structure damage identification of automobile components .
WANG Anlin , YUE Binnan , ZHOU Pengju , LIU He
2011, 39(8):1212-1215. DOI: 10.3969/j.issn.0253-374x.2011.08.021 CSTR:
Abstract:Improved nonlinear bond graph models and the parameter optimization algorithms are established.With these optimization algorithms,model parameters can be determined based on the experimental efficiency data of samples.Taking a motor product sample for example,the distribution chart of operating conditions efficiency of the improved model is much closer to the experimental results than that of the traditional model.Compared to sample experimental results,the mean value of percentage error for traditional model is 3.55% and for improved model is 1.18%,and the variance value of the improved model is much smaller than that of the traditional model.The error analysis proves that the improved model is much more suitable for description of device modeling in complex operating conditions.
ZHANG Yongquan , XU Kelin , SUN Yu
2011, 39(8):1216-1221. DOI: 10.3969/j.issn.0253-374x.2011.08.022 CSTR:
Abstract:Due to the multiple objectives of steel plate distribution from suppliers with uncertainty to computer numerical control cutters,the supplydistribution system was modeled by dependentchance goal programming (DCGP).This model revised the disposal process of goals in the same priority and minimized the deviation from the target with certain preemptive priorities.It was solved by a hybrid intelligent algorithm which integrated stochastic simulation,neural network and genetic algorithm(GA).The calculating result shows that the chance of crucial cutters to achieve the supreme cutting lengths is maximized.The drawnout amount of steel plates increases while the sequence of the distribution retains.The multiple objectives of the production can be satisfied.It proves that DCGP can eliminate and control the effect on the production because of suppliers’ uncertainty in distribution system with multisuppliers.
2011, 39(8):1222-1226. DOI: 10.3969/j.issn.0253-374x.2011.08.023 CSTR:
Abstract:The paper presents a dynamical topology multiobjective particle swarm optimization(DMPSO)algorithm and a definition of the degree of domain and congestion and discrepancy of particles as well as a strategy of renewing archives which depends on the degree of domain and congestion around neighborhood.So the diversity and uniformity of solution are enhanced.In order to overcome the premature convergence,a new imitating small world dynamical topology strategy based on congestion degree and discrepancy degree is applied to balancing the ability of global searching and local searching.In the end,the application successfully to engineering shows that the DMPSO is feasible and effective.
LIU Junhao , ZHANG Hao , CHEN Qijun
2011, 39(8):1227-1232. DOI: 10.3969/j.issn.0253-374x.2011.08.024 CSTR:
Abstract:Networked control systems(NCS)with continuous plant and a shorter delay than one sampling period was described by a discrete model.A sufficient condition of stability for NCS neglected the quantization error was derived by Lyapunov method and linear matrix inequality approach.Moreover,a state feedback controller was designed to ensure the NCS with uniform quantizer to be uniformly bounded,and the upper bound of NCS was obtained by accommodating the quantizer error.Quantized level and code length could be obtained in practice.At last,a matlab simulation example was given to illustrate the effectiveness of the proposed method,and the effect of quantized error was analyzed.
XIE Weida , ZHOU Yuheng , KOU Ruolan
2011, 39(8):1233-1237. DOI: 10.3969/j.issn.0253-374x.2011.08.025 CSTR:
Abstract:Some improvements were made for normalized cross correlation based on two criterions according to the characteristics of template and image and the interrelationship between them.The autocorrelation of the template was calculated at first,and the cross correlation between template and image was gained based on fast Fourier transform.Then the first criterion was used to shrink the range of the possible solutions, which could shorten the matching time;and the second criterion was applied to generating a more miniature set,in which the solution with the maximal normalized cross correlation was the global optimal solution.Experiments show that the normalized cross correlation based on the given criteria can speed the computing with an enhanced matching precision.
SHI Renghui , ZHAO Xiaoqun , LI Lizhi
2011, 39(8):1238-1242. DOI: 10.3969/j.issn.0253-374x.2011.08.026 CSTR:
Abstract:Pseudorandom punctured sequence pairs were applied to the construction of low correlation zone(LCZ)sequence pairs set; a new construction method for LCZ punctured sequence pairs set was presented.According to different shift sequences and orthogonal matrix,LCZ punctured sequence pairs set with a certain length,sequence pairs number,and low correlation zone could be generated through interleaved technique based on pseudorandom punctured sequence pairs.The construction method was theoretically proved and some examples were given.This method could also be used for constructing LCZ punctured sequence pairs set based on generalized pseudorandom punctured binary sequence pairs.There were more choices for engineering application because the LCZ sequence pairs exist in a larger scope.
LI Weixiao , SHEN Yunzhong , LI Bofeng
2011, 39(8):1243-1246. DOI: 10.3969/j.issn.0253-374x.2011.08.027 CSTR:
Abstract:The paper presents a new coordinate transformation model with a consideration of the coordinate errors in both coordinate systems.The computation formulae of transformation parameters are derived based on the minimization of weighted sum of coordinate corrections in two systems.In addition, the coordinate corrections of transformed points are computed according to the covariance matrix of coordinates between public and transformed points with the leastsquares collocation method.The experiments show that the new model can significantly improve the precision of the coordinate transformation especially in case that the strong correlation exists between public and transformed coordinates.
LIN Yi , PAN Chen , CHEN Yingying , REN Wenwei
2011, 39(8):1247-1252. DOI: 10.3969/j.issn.0253-374x.2011.08.028 CSTR:
Abstract:Based on the analysis of spectral curve and features of cyanobacteria bloom and other typical ground object,the normalized difference cyanobacteria bloom index(NDI_CB)was constructed to distinguish between cyanobacteria bloom and turbid water with the Landsat7 ETM+ image in Lake Dianshan.In this study two other different vegetation indexes,normalized difference vegetation index(NDVI)and ratio vegetation index(RVI),together with NDI_CB,were applied to extracting the cyanobacteria bloom information from the same image via unsupervised classification method(kmeans).The results show that NDI_CB is the best one for lowdensity cyanobacteria bloom extraction.In order to recognize the cyanobacteria bloom better,support vector machine(SVM)classification method was used to classify the image based on spectral features and NDI_CB,and to obtain the spatial distribution and the area of cyanobacteria bloom in Lake Dianshan.Through studying the laws of the cyanobacteria bloom distribution at a particular time,a sound,efficient and objective basis has been achieved for the ecological analysis of the prevention and the treatment of cyanobacteria bloom.
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