交通运输工程学报

Study Evolvement of Train Aerodynamics in China

TIAN Hong-qi

Abstract: The research methods of train aerodynamics, such as numerical simulation computation, wind tunnel tests, moving model tests and full-scale train tests, were dissertated.The research works of the aerodynamic performances of China representative train, China-star high-speed train, double deck container freight train, maglev train (magnetically levitated train) were introduced.Five important theorization formulas were put out, with the emphasis on the relations of streamline shapes and train aerodynamic performances, including streamline train head shape, car body section figuration, train configuration and car surface, the important car components that influence train aerodynamic performances enormously were discoursed, such as flow guide mantle of pantograph, outside vestibule diaphragm, car bottom with mantle structure, skirt baffle structure and flow guide plate.The whole set technology on the manufacture of streamline car shape and its applications in China were introduced.The main characteristics of tunnel-train aerodynamics were recommended.The topic concentrated upon the running safety influenced by train aerodynamic in improving speeds of five times in China and Lanzhou-Xinjiang railway suffered windstorm on more than hundred kilometers was discoursed.More>

2006, 6(1): 1-9.

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Influence of Rail Fastener Failure on Vehicle Dynamic Derailment

XIAO Xin-biao, JIN Xue-song, WEN Ze-feng

Abstract: In order to investigate the effect of disabled fastener system on railway vehicle derailment, a non-symmetrical vehicle-track coupling dynamics model was established.The abrupt change of track stiffness along the track was assumed to simulate the failure situation of rail fastener system.The effect of discrete sleeper support on the coupling dynamics of vehicle and track was taken into consideration.The creepage formulas of wheel/rail rolling contact were deduced, in which the lateral, vertical and torsional motions of rail were taken into account, the normal forces of wheel/rail were calculated by Hertzian contact theory, the creep forces of wheel/rail rolling contact were decided by the nonlinear creep theory of Shen.The motion equations of vehicle/track coupling system were solved with new explicit integration method.The effect of five seriate fasteners' system in different failure situations on railway vehicle derailment was analyzed and evaluated.The ratio of lateral force and vertical force on wheel and rail, wheel load reduction ratio, vehicle derailment time and the variations of contact points on wheel treads were computed.Numerical computation result indicates that when the failure index increases from 0.8 to 1.0, that is to say, rail fasteners experience a process from almost looseness to complete looseness, the influence of rail fastener failure on vehicle dynamic derailment shows an exponential rule.More>

2006, 6(1): 10-15.

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Construction and Application of DKQ Bending Element

YAO Song, TIAN Hong-qi

Abstract: In order to analyze the states of thin-walled structures under complicated loads by discrete Kirchhoff principle, the strain matrix of triangle bending element and explicit area coordinate integral method were discussed in detail.According to variant principle, DKQ (Discrete Kirchhoff Quadrilateral) bending element was constructed.By introducing symmetric and antisymmetric mesh distortion modes, mesh distortion sensitivity analysis was carried out.Through combining DKQ element with planar stress element, quadrilateral plate element used for general thin-walled structures analysis was implemented by finite element program.Numerical test result indicates that when relative offset value varies from-0.18 to 0.18, the deflection maximum errors of antisymmetric and symmetric modes are 1.83% and 0.99% respectively.For a car-body of some subway vehicle, the differences between the analysis values and those obtained by ANSYS are less than 3.5%.The result shows that DKQ bending element is insensitive to mesh distortion and has good convergence capability and accuracy for displacement field.More>

2006, 6(1): 16-19.

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Motion Analysis Method of Series Images for Train Component Crash

XU Ping, YAO Shu-guang

Abstract: In order to analyze the crash process of vehicle component, a motion analysis method of sequence images of train component crash was developed on the basis of the characteristic recognition of crash mark point in matching course and the prognostication of motion orientation and motion velocity in searched area by alterable template matching technique, the dynamic deformation process and final remain deformation could be showed, the special marked objects or dynamically selected objects by mouse could be recognized and tracked, and their displacements, velocities and accelerations could be worked out, which were exported by curves, tables and data.Test result shows that the deformation of aluminum alloy circle pipe part is processed in lengthways order from impact end to restraint end, all seven corrugations are shaped and its planform assumes hexagon, its max compressed length is 230.9 mm, the course of plastic deformation takes 64 ms, which indicates that the aluminum alloy component has good plastic fluidity, is fine energy-absorbed component of car-body, the analysis method is feasible.More>

2006, 6(1): 20-24.

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Probabilistic Models of Random Fatigue Crack Propagation Based on Forman Equation

YANG Bing, ZHAO Yong-xiang, ZHANG Wei-hua

Abstract: In order to improve the prediction precision of random fatigue crack propagation, its probabilistic models based on Forman equation and the estimation method of its parameters were developed, the effect of test data scattering regularity and sampling size on probabilistic assessment was taken into account, the models consisted of survival probability-based curves, confidence-based curves and survival-probability-and-confidence-based curves, their parameters of were measured by linear regression technique and maximum likelihood method.The prediction data of LZ50 axle steel indicate that the models show the effect of material rupture temper on long crack propagation, over come the non-conservative prediction of conventional models based on Paris-Erdogan equation in high intensity factor range, which shows that the models are reasonable and feasible.More>

2006, 6(1): 25-28.

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Numerical Simulation Methods of Railway Track Irregularities

LIU Yin-hua, LI Fei, HUANG Yun-hua

Abstract: In order to improve the reliability that the power spectrum densities of railway track were transformed into time domain samples by numerical simulation methods, the principles and steps of the methods were analyzed, some simulation samples in time domain were achieved by simulating programs respectively, the samples were taken as the inputting disturbances of a vehicle vertical dynamics model, the time response courses of vehicle system were obtained by numerical simulation.The comparison of simulation results show that each simulated sample in time domain is true, the samples simulated by trigonometric series and IFFT method have little discretenesses, but the samples simulated by white noise filter and secondary filter method have greater discretenesses and are not feasible to act as the track disturbances of studying non-linear system time response.More>

2006, 6(1): 29-33.

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Calculation of Longitudinal Force and Displacement of Seamless Turnout on Continuous Beam Bridge

CENG Zhi-ping, CHEN Xiu-fang, ZHAO Guo-fan

Abstract: Rail and beam were regarded as bar elements, sleeper was regarded as beam element, fastening resistance, ballast resistance and pier stiffness were considered as spring elements, a finite element mechanics model was proposed to calculate the longitudinal force and displacement of seamless turnout on continuous beam bridge, the nonlinear equations of the model were established by variational principle and "set-in-right-position" rule, the influences of turnout design parameters on the longitudinal force and displacement were analyzed. Calculation result shows that the longitudinal force on the fixed pier of continuous beam decreases by 43.2% when the expansion joints are laid in the back of seamless turnouts, the longitudinal stiffness increase of the fixed pier leads to the decrease of rail displacement, the fixed support location of continuous beam should be taken into consideration in the system design because it influences the longitudinal force and displacement of the system.More>

2006, 6(1): 34-38.

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Fatigue Characteristic of Asphalt Concrete Pavement on Cement Concrete Bridge Deck

GAO Ying, HUANG Xiao-ming, XU Tao

Abstract: In order to improve the life of cement concrete bridge deck pavement, compound beam test was used to research the fatigue characteristics of hot mixed asphalt (HMA) courses on bridge deck, finite element analysis (FEA) method was employed to make the mechanical response of compound beam accord with that of actual bridge deck under the same load, the fatigue test was done for compound beams with different pavement structures.Test result shows that the destroy process of compound beam is similar with that of actual bridge deck, the structure with waterproof and cohesive course has a fatigue life, which is 8 times longer than that of the structure without the course, the addition of fiber in the HMA can increase at least 20% of its fatigue life, the combination structure of stone matrix asphalt (SMA) and fiber reinforced asphalt concrete (AC) is the best pavement structure in the test.More>

2006, 6(1): 39-43.

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Joint Sealant Fatigue Property of Airport Concrete Pavement

LIU Xiao-xi, WANG Shuo-tai

Abstract: In order to improve the waterproof performance of airport pavement by fatigue loading method, the property of joint sealant was evaluated, the effects of joint width, tension and compression, freezing and thawing on the fatigue property of joint sealant were considered.In the test, the sealant was suffered from normal stress and shear stress at the same time, the material stress status in expansion joint and transverse contract joint was simulated.Some specimens were exposed to 50 cycles of rapid freezing and thawing prior to testing, which reduced the number of loading cycles that caused sealant failure, and experienced a high rate of stress reduction.The fatigue behaviors of the polysulfide are better than the polyurethane, so polysulfide should be used in freezing airport, the conclusion shows a good agreement with survey result.More>

2006, 6(1): 44-47.

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Road Performance of Cement-Stabilized Aggregate Mixture with Expansion Agent

YANG Hong-hui, HAO Pei-wen, DAI Jing-liang

Abstract: In order to low the shrinkage of cement-stabilized aggregate, appropriate expansion agent was added to cement-stabilized aggregate, its close-grained degree could be improved, its shrinkage could be decreased when the micro-expansion of expansion agent came into being.Test result show that cement-stabilized aggregate mixture with expansion agent has good character, its resisting shrinkage ability is increased by 50%, so cement-stabilized aggregate mixture with expansion agent has favorable road-applied capability.More>

2006, 6(1): 48-51.

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Static Analysis of Semi-Integral Abutment Jointless Bridge

HU Da-lin, WANG Tian-li, CHEN Feng, TONG Shen-jia

Abstract: To overcome the damage of bridge expansion joint, a static analysis model of semi-integral abutment jointless bridge was presented, the interactions among the superstructure, substructure and soil foundation of bridge were analyzed, a 100 m PC continuous box beam bridge with semi-integral abutment was studied by nonlinear geometric finite element method, the forces and deformations of the bridge undergoing dead load, vehicle load and temperature change load were obtained, the computation results of corresponding bridge with joint and integral abutment were compared.Analysis result indicates that the bending moment, shear force and deflection of the main girder and the axial force of the substructure for jointless bridge with semi-integral abutment are close to that of joint bridge, axial force appears in the main girder of jointless bridge, the bending moment and shear force of its substructure are bigger than that of joint bridge.As the damage of bridge joint is eliminated and the global stiffness of bridge structure is increased, semi-integral abutment jointless bridge is worth of application and popularization.More>

2006, 6(1): 52-56.

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Anti-Seismic Performance Calculation of Luohe Bridge

LIU Jian-xin, ZHANG Wei, ZHANG Qian

Abstract: In order to calculate the seismic response of Luohe bridge exactly, three computation models were put forward based on long-span bridge seismic analysis method.In whole-pile model, pile-soil interaction was considered.In incomplete-pile model, longer piles in soil were cut when their wave speeds were greater than 500 m·s^-1, pile-soil interaction was considered.In big mass model, the multi-support excitations of different site soils and the traveling-wave effect resulted from limit transmitting earthquake wave were analyzed.Bridge 3-D earthquake wave was studied by finite element program ANSYS.The result shows that the displacement and axial force of longer pier are greater, the shorter pier is, the bigger its transverse and lognitudinal shearing forces and its flexural torque in lognitudinal are, the most deviations of displacement responses for incomplete-pier model and whole-pier model are 7.4% and 8.2% respectively, therefore, incomplete-pile model is adaptively used for the simplified analysis of bridge response when its piles are too long, big-mass model is greatly affected by the capacity of mass block and the length of bridge pier, the bridge is insensitive to traveling-wave effect when its span is below 160 m and its length is below 660 m, shorter pier sectional resisting force design and longer pier ductility design must be strengthened in the seismic design of continuous rigid-framed bridge with high piers and long spans based on considering pile-soil interaction.More>

2006, 6(1): 57-62.

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Pure Bending Properties of Self-Compacting Concrete Filled Circular Steel Tube

DING Fa-xing, YU Zhi-wu

Abstract: Based on appropriate numerical constitutive model of concrete filled steel tube, layered method was adopted to calculate the complete moment-curvature curves of concrete filled circular steel tube (CFST) subjected to pure bending, the practical composite flexural stiffness, practical flexural capacity and practical moment-curvature relationships of composite element for CFST beams were presented, the tests of three self-compacting concrete filled circular steel tubes and one normal concrete filled circular steel tube subjected to pure bending were carried out, the influences of concrete strength and steel ratio on the pure bending properties of the specimens were discussed.Experimental result shows that the confinement effect between steel tube and concrete happens in compressive side, but the steel tube is in biaxial tensile stress conditions in tensile side, with the strength increase of concrete, the flexural capacities of the specimens are hardly influenced, but with steel ratio increase, the flexural capacities are enhanced significantly.More>

2006, 6(1): 63-68.

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Time-Dependent Reliability Index Calculation of Existed Highway Bridge

SUO Qing-hui, QIAN Yong-jiu

Abstract: In order to effectively evaluate existed bridge reliability, the effect of bridge service time on bridge reliability was considered, some simplified formulas for calculating bridge reliability index were deduced based on the dispersed stochastic resistance and load effect of bridge, the effects of its resistance degradation model, load increasing tendency and service life on bridge reliability index were studied.Calculation result shows that bridge reliability index decreases with the increase of bridge service life, and it is sensitive to the resistance degradation mode and load increasing tendency of bridge.More>

2006, 6(1): 69-71.

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Probability Statistic Rule of C25 Shotcrete-Strength

CHEN Jian-xun, LUO Yan-bin

Abstract: In order to analyzing the distributation rule of shotcrete-strength, the expenimental data of shotcrete-strength were studied by Normal distribuation, logarithm Normal distributation and extremum Ⅰ distributation, the distributations were examined by χ² mothed, statistical standard values were calculated by the rule. Computation result shows that the C25 shotcrete-strength distribution submits Normal distribution, C25 shotcrete-strength's standard deviation is 6.91~7.15 MPa, its variation coefficient is 0.24~0.26, C25 moulded concrete strength's standard deviation is 5.43 MPa, its variation coefficient is 0.16, the homogeneity of shotcrete-strength construction is worse, the divergence index of shotcrete-strength is larger, the standard value of shotcrete-strength is 16~18 MPa, it is near to the strength 17 MPa of moulded concrete.More>

2006, 6(1): 72-75.

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Effect of Fuel Oil Sulfur on Marine Engine Emissions

WEI Hai-jun, SUN Pei-ting

Abstract: In order to study engine burning conditions and the harmful matters of engine exhaust gas when diesel oil has different sulfur contents, the harmful matters, such as NO_x, SO_x, CO_x, DS and SOF, were measured by chemiluminescence detector, electro chemical cell, magnetic type, galvanic cell type, filtration and weight method when the sulphur contents of fuel oil were 1%, 1.5%, 3.0% and 5.0% respectively.Test result shows that the different sulfur contents of diesel oil have obvious effect on the burning condition and exhaust gas temperature of marine engine, the fuel oil consume ratio increases with sulfur content increase, and it reaches the maximum value when sulfur content is within 3.5%, CO content increases with sulfur content increase, but CO₂ content is invariable, SOF content and NO_x content decrease with sulfur content increase, but DS content increases.More>

2006, 6(1): 76-79.

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Dynamic Identification of Ship Diesel Engine Based on T-S Fuzzy Model

XIAO Jian-mei, WANG Xi-huai, LI Shun-lin

Abstract: Considering the nonlinear of ship diesel engine model and the uncertainty of its loads, the paper investigated a T-S fuzzy identification algorithm to build ship diesel engine dynamic model.The number of fuzzy rules and the parameters of membership functions in the antecedent of T-S model were generated by fuzzy clustering method, the linear parameters of identification consequent in each rule were separately identified by weighted least square method.The output data of diesel speeds and turbocharger speeds under different throttle scales and loads were gained from some experimentations, when diesel engine was disturbed by a small deviation signal in its steady running state, the data were used to build a T-S fuzzy model of ship diesel engine, which could express the dynamic characteristic of diesel engine.Simulation result shows that the method is effective to identify the models of diesel engine speed, turbocharger speed, turbocharger pressure and air condenser pressure under small deviations.More>

2006, 6(1): 80-83.

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Adaptive Triangular Mesh Generation of Ship Hull Surface Based on NURBS

SHI Guo-you, JIA Chuan-ying

Abstract: Aimed at the calculation of 3-D ship hull property and display of real image, an innovative arithmetic for adaptive triangular mesh generation of ship hull surface based on NURBS was put forward by NURBS curve and surface theories, combining quadrangle coding method and improved surface evenness checking method were proposed, which were capable of subdividing quadrangle grids quickly and effectively when the NURBS surface of ship hull was recursively subdivided for satisfying the gave precision requirements in the height direction and on the boundary of the surface, a quadrangle grid was divided into two or more triangle grids by cut corner arithmetic.Applied result indicates that the triangle hull surface created by the arithmetic approximates real ship hull, none of cracks appears among grids, the quadrangle coding method distinctly saves time and space compared with binary-tree method and quard-tree method, improves the efficiency of the arithmetic.More>

2006, 6(1): 84-88.

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Fuzzy Control of Fuel Flow Rate on Small Aviation Gasoline Engine

LI Yu-zhen, ZHAO Yang-xu, GUO Lu

Abstract: In order to accurately control the fuel flow rate of small aviation engine, based on fuzzy control theory, an electronic injection system was designed, a delaminated fuzzy logic construct was used for designing the MISO control law of electronic injection system in order to decrease fuzzy rules and predigest reasoning process.The fuzzy rules of electronic injection system were designed by fuzzy consequence synthesization, the test data of carburetor engine were taken as input and output data to make the fuzzy control rules represent the fuelling law of the engine in reason.Test trial result shows that the engine rated power increases by 6.8%, its fuel consumption decreases by 11.3%.More>

2006, 6(1): 89-92.

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Maintainability Assessment and Verification Technologies of Civil Aircraft in Virtual Environment

SUN You-chao, DENG Hua-wei

Abstract: Based on CATIA and DELMIA 3-D CAD modelling tool, the basic methods of virtual assessment and verification technologies on the maintainability of civil aircraft were studied by virtual reality technology and concurrent engineering thought.The elements of virtual maintainability environment were described, the implement and combination methods of maintenance scenes, maintenance objects, maintenance tools and human models in virtual environment were analyzed, the methods and process of creating virtual maintainability environment were put forward.The basic principle and procedure of virtual assessment and verification for civil aircraft maintainability were researched, the qualitative and quantitative methods of accessibility analysis, collision and interference analysis and personnel body posture analysis were proposed.The result of assessment and verification indicates that the total optimization of aircraft life cycle is effectively implemented by the methods, they are feasible for the concurrent optimization design of aircraft maintainability.More>

2006, 6(1): 93-97.

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Network Communication Technology of Vehicle Inspection Control System

ZHAO Xiang-mo, GUO Xiao-fen, XU Zhi-gang, MA Jian

Abstract: In order to improve the quality and efficiency of network communication in vehicle inspection control system, several traditional communication methods that are RS-232, shared file and network database were contrasted, a new communication method based on Winscoket was brought out.By using Winsocket technology, two message structures of data frame and command frame were defined.The vehicle schedule and real time data transfer of vehicle inspection control system are solved under C/S mode, the running process stability of the system, the real-time property and dependability of inspection data transmission are improved.More>

2006, 6(1): 98-102.

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Traffic Flow Characteristics and Short-Term Prediction Model of Urban Intersection

WENG Xiao-xiong, TAN Guo-xian, YAO Shu-shen, HUANG Zheng

Abstract: The long-term prediction models (time scale is larger than 15 min) of traffic flow did not satisfy the demands of traffic signal control and traveler information real-time dissemination.After observing and measuring actual intersection traffic flow in Guangzhou city center area for long time, the paper analyzed the characteristics of varied-time-scale traffic flow, and proposed an ARIMA (p, d, q) model, in which signal periods were taken as time intervals, and the flow rates of green phase were taken as model variables for predicting the short-term traffic flow of urban intersection.By the case study of traffic flow modeling and predicting with different time-sections separately in 1 signal period and 3 signal periods, it is validated that the ARIMA (p, d, q) prediction model construction is stable, its arithmetic is simple, the prediction model in 3 signal periods can well keep the characteristics of short-term traffic flow, its accuracy is quite satisfied, its root-mean-squareerror is 0.0159.More>

2006, 6(1): 103-107.

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Traffic Organization of Urban Arterial Road Intersected by Multi-Inferior Roads at T-Intersections

WANG Hao, WANG Wei, CHEN Jun

Abstract: In order to rationally organize the traffic in the area of urban arterial road intersected by multi-inferior roads at T-intersection, a traffic organization method with channelized traffic design and signal coordinated control was presented, based on the investigation and analysis of the characteristics of the above area.It is pointed that the average delay decreases of major-stream vehicles are 56.4% at T-intersections and 28.4% for overall arterial road segments respectively.The result indicates that the method is effective and convenient for the traffic organization in such areas.More>

2006, 6(1): 108-112.

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Technological Methods of Environmental Evaluation for Highway Network Planning

YANG Yun-feng

Abstract: There are not perfect theory system and mature technological methods in China for environmental analysis in highway network planning.Based on sustained development thought, the technological methods of environmental analysis in highway network planning were analyzed to explore the theories and methods of environmental evaluation, the environmental characteristics of ecological effect industries were studied.From the macro angles of resoure, ecology and environmental bearing capacity, the analysis principles of sensitive problems in environmental evaluation, the analysis indices of environmental effect evaluation and the evaluation methods of environmental reason in highway network planning were pointed out to give technological references for environmental evaluation.More>

2006, 6(1): 113-117.

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Relationship Analysis of Port Traffic Accidents and Port Environment Factors

ZHENG Zhong-yi, HUANG Zhong-guo, WU Zhao-lin

Abstract: In order to evaluate the safety of port traffic environment and determine the weighting of each environment factor, the environment factors data of nine ports were analyzed by factor analysis method, the relationship of port integrated factor scores and port traffic accident numbers was studied, their regression equation was deduced, each factor effect degree on port traffic accidents were determined by each factor coefficient in regression equation.Analysis result indicates that visibility, navigational aids, VTS management degree and traffic separation degree have greater effect on traffic safety, the length of channel and the number of turning points have less effect on traffic safety, which basically reflects the effect degrees of environment factors on port traffic accidents.It is shown that factor analysis method can quantitatively determine the effect degree of each environment factor on traffic accidents, it can be applied to the relationship analysis and assessment of port traffic accidents.More>

2006, 6(1): 118-121.

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Grey Verhulst Predictive Model of Road Traffic Accidents

WANG Fu-jian, LI Tie-qiang, YU Chuan-zheng

Abstract: In order to improve the predictive precisions of grey predictive models for road traffic accidents, the properties of GM (1, 1) model and grey Verhulst model were analyzed.GM (1, 1) model adapted to the sequences with good exponent law, only described monotonous change process, Verhulst model adapted swinging sequences or saturated S-shape sequences.Recently, road traffic accidents in China developed as saturated S-shape sequences, so a Verhulst predictive model of road traffic accidents was put forward.The predictive values of grey Verhulst model and GM (1, 1) model for the death people numbers of road traffic accidents in 2004 in China are (108 700) and 117 200 respectively, their predictive precisions are 1.49% and 9.43% respectively, which shows that the predictive precision of the presented model is better than that of GM (1, 1) model.More>

2006, 6(1): 122-126.

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