交通运输工程学报

Analysis model of vertical vibration of high-speed train and Bögle slab track system

Xiang Jun, He Dan

Abstract: According to the structural characteristics of Bögle slab track, a new model of lateral finite strip and slab segment element was put forward, and the vertical vibration responses of high-speed train and Bögle slab track system were analyzed.In the model, the locomotive and trailer of high-speed train were regarded as multi-rigid body systems with two suspensions, based on the principle of total potential energy with stationary value in elastic system dynamics and the rule of "set-in-right-position" for formulating system matrixes, the vertical vibration equation set of the system was established, and the equation set was solved by Wilson-θ method. Computation result shows that the new model is correct and feasible, the differences between the vertical static displacements and dynamic displacements of rail and Bögle slab are 1.1×10^-2 mm and 2.0×10^-4 mm respectively, when train runs at 200 km·h^-1, the vertical vibration response waveforms and computation values of the system accord with corresponding physic concepts.More>

2007, 7(3): 1-5.

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Dynamics modeling of low-speed maglev vehicle system and simulation of its guidance mechanisms

Ye Xue-yan, Zhao Chun-fa, Zhai Wan-ming

Abstract: Low-speed maglev vehicle structures and their kinematic relationship were analyzed, a 76-DOFs virtual prototype model with active levitation control was developed by SIMPACK software, the numerical simulation of guidance mechanisms was carried out based on the model, and the kinematic rules of T-shape arm and lateral skid platform and their relationship were studied. Aiming at 300 m-radius curve and three-bogies maglev vehicle, simulation result shows that the length of frontal T-shape arm of guidance mechanism should be greater than that of the rear one, and their optimum ratio ranges from 1.50 to 2.00 in order to obtain better curve negotiation performances of low-speed maglev vehicle; the yawing amplitude of head T-shape arm relative to carbody is almost equal to that of tail T-shape arm, while their directions are opposite, and the lateral displacement responses of corresponding skids have similar curves and approximate amplitudes; the amplitude ratio of the lateral displacement of frontal skid to rear skid in the same bogie equals the length ratio of corresponding T-shape arms.More>

2007, 7(3): 6-10.

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Interval mathematics analysis method of running parameters influence on automobile fuel economy

He Ren, Zhuang Zhi-hua, Zheng Ji-ping

Abstract: In order to improve automobile fuel economy, the basic concept of interval mathematics was introduced, the mathematic model of engine universal characteristics was set up by using Matlab, the influence degrees of driving speed, loading mass and road resistance coefficient on automobile fuel economy were analyzed by using interval mathematics.Analysis result indicates that fuel wastage increases with the increase of automobile speed, but it almost changes with the variety of loading mass; the influence of road resistance coefficient is maximal, then to be loading mass and driving speed.More>

2007, 7(3): 11-15.

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Quantitative diagnosis method of engine sliding bearing failure

Wang Wei, Ma Wen-yan, Wang Yu, Wang Feng-qi

Abstract: In order to implement the quantitative diagnosis of engine sliding bearing failure, a simulation experiment on the relationship between the clearance of connecting rod bearings and their failures for EQ6100-1 model engine was conducted by using vibration monitoring technique, some characteristic parameters reflecting the failures of coupling parts were acquired from vibration signals, and a mathematic model was selected to properly describe the variation rules of the parameters with the change of coupling parts' conditions. Experiment result shows that the correlativity between failure coefficients and the clearance is prominent, their relative curves is polynomial regression curves, and their correlation coefficient approaches 1. It is obvious that the quantitative diagnosis method of engine sliding bearing failure by utilizing engine vibration signals is feasible.More>

2007, 7(3): 16-20.

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Computation model of lateral collision rate on parallel routesbased on VOR navigation

Zhang Zhao-ning, Zhang Xiao-yan, Li Dong-bin

Abstract: In order to effectively confirm the safe separation of parallel routes and evaluate collision risk, lateral collision influence factors were analyzed, Reich model and probability theory were introduced, and a computation model of lateral collision rate on parallel routes was established based on VOR navigation in continental areas. The Reich model was improved, a computation formula of lateral collision rate was deduced according to column collision slab instead of cuboid collision slab, and a computation model of lateral overlapping rate between two aircrafts was given according to event probability operation principle. Computation result shows that the computation value of lateral collision rate on gave parallel routes is less than normal value, the flight environment with gave separations is safe, which accords with real condition, so the model is feasible.More>

2007, 7(3): 21-24.

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Generalized S-transform method of rotor impact-rub fault signal of aeroengine

Zhang Zhi-yu, Lu Yan-jun, Zhang Jiu-long

Abstract: In order to effectively pick out the impact-rub fault signal of aeroengine rotor, improve fault diagnosis veracity, the impact-rub signal was transformed to phase space by using generalized S-transform, the features of fault signal were detected in phase space, and the results obtained by using generalized S-transform(GST) and continuous wavelet transform(CWT) were compared. Comparison result shows that the time-frequency localization characteristics and singular points of impact-rub signal are more distinct in GST domain than in CWT domain, the impact-rub points are easier to be detected, GST has strong capability in noise reduction, and the separation of signal and noise is also available in GST domain.More>

2007, 7(3): 25-28.

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Aeroengine scheduling method under condition-based maintenance strategy

Bai Fang, Zuo Hong-fu, Wen Zhen-hua, Rong Xiang, Zhao Hong-hua

Abstract: Based on the modeling thought of modern scheduling theory, the requirement property for aeroengines and the turnover property of aeroengine maintenance were analyzed, the concept of work note was introduced, a scheduling model of aeroengines under condition-based maintenance strategy was established, an online longest processing time (LPT) rule algorithm was improved for solving the model, and the used data of CF6 aeroengines were studied. It is pointed that aimed at aeroengine, on-wing time is longer, maintenance time is lower, guarantee rate is higher, and rental loss cost is lower when LPT rule is compared with traditional first come first serve (FCFS) rule. Analysis result indicates that LPT rule is better than FCFS rule, and the model is feasible.More>

2007, 7(3): 29-33.

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Automatic creating algorithm of route based on dynamic grid model

Li Yuan-hui, Pan Ming-yang, Wu Xian

Abstract: In order to use the abundant information of electronic chart to plan route, an automatic creating algorithm of route based on dynamic grid model was put forward. The navigability of every single square in the model was judged and classified by using a fast algorithm. A coding scheme of square connectivity was proposed, square connectivity in eight directions was expressed by using byte with eight bits, so that square connectivity corresponds to the logical operation of byte.A concept of uniformity degree of path weigh in grid was given, and a method was proposed to select the optimal path from the same distance routes. The error analysis of the shortest path was done. The path square sequence of all redirection points in route was solved by using dimidiate search algorithm. Study result shows that the route generated by the algorithm is safe and rational because of keeping away from dangerous obstacles.More>

2007, 7(3): 34-39.

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Ship motion mathematical model with six degrees of freedom in regular wave

Zhang Xiu-feng, Yin Yong, Jin Yi-cheng

Abstract: In order to improve the precision of ship-handling simulator, a ship motion mathematical model with six degrees of freedom(DOF) in regular wave was put forward by using separate modeling theory based on Froude-Krylov hypothesis. In the model, ship was regarded as trunk ship, the interferential forces and moments of regular wave were calculated, and were regarded as a part of external forces to add to the model respectively. A practice ship's data was used to create the model. The time curves of ship's turning motion at full speed under 5 kinds of sea states were simulated and analyzed. Analysis result shows that the model is feasible, simulation curves near to the result of relative reference, their trends are coincident, the precision of the model meets with the requirement of full mission ship-handling simulator; ship motion mathematical model is updated from three to six DOFs, so that simulator fidelity is improved.More>

2007, 7(3): 40-43.

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Optimization model of network distribution planning on regional container ports

Zhao Xu, Yang Zan, Jin Zhi-hong, Ji Ming-jun

Abstract: In order to avoid the repetitive construction of container ports in transportation network, and realize the optimization distribution of ports, the general interaction and decision equilibrium between container port planner and user according to Stackelberg model were considered, and an optimization model of network distribution planning on regional container ports was established. In order to effectively reflect the individual properties of port users, the choice behaviors of micro-shippers were analyzed by using disaggregation theory according to their attributes. A genetic algorithm was designed to solve the model, its initial chromosome was generated by the matrix composed with the numbers of berths and corresponding voyage densities of different container ports, and the particularity of the model restrictions was considered. Example simulation result shows that the model is feasible, the approximative optimization port network planning of example computation accords with real analysis situation, the behaviors and influence factors of shippers can be reflected, and port optimization distribution can be realized.More>

2007, 7(3): 44-49.

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Dynamic space deployment model of container storage yard

Li Jian-zhong, Ding Yi-zhong, Wang Bin

Abstract: In order to optimize the space of container storage yard and reduce vehicle travel distance, mathematics planning method was applied, the balancing quantity of container and the minimum travel distance of vehicle were considered, a dynamic space deployment model of container storage yard was set up on the base of rolling plan, and the example comparison analysis of the model and random deployment method was done. Analysis result shows that vehicle travel distance decreases by about 20%, vehicle travel efficiency improves, and container operating cost reduces, so the model is feasible.More>

2007, 7(3): 50-55.

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Structure design of asphalt pavement based on cross-anisotropy of macadam base

Li Zhen-feng, Xu Ge-ning, Guo Xiang-yun

Abstract: In order to analyze the effect of macadam cross-anisotropy on asphalt pavement structure design, and evaluate the performance of asphalt pavement with macadam base, state-space theory was used, cross-anisotropic layered elastic system theory was established, pavement structure analytical program ANISOLAYER was compiled, and asphalt pavement structure designs based on the crossanisotropy of subgrade and macadam base were analyzed. Five common asphalt pavement structures with macadam base were considered, the three-layered nomographs of thickness design for asphalt pavement structure were given, and the program design of asphalt pavement structure was carried out for a typical example. Analytic result shows that AC strains and surface deflections are close to 50% of their permitted values, the compressive strain at the top of subgrade is main critical pavement response, and the rutting is main pavement demolishing model.More>

2007, 7(3): 56-60.

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Road performance comparison of different asphalt mastics

Peng Bo, Ding Zhi-yong, Dai Jing-liang

Abstract: In order to study the road properties of different asphalt mastics, some systematic tests on penetration, cone penetration, basket drainage, adhesion quality, dynamic shear, bending beam rheometer were done, the influences of the constituters, temperature and proportion of asphalt mastic on the road properties of asphalt mixture were analyzed, and the strengthening mechanism of asphalt mastic was studied. Analysis result indicates that fiber can thicken asphalt membrane on aggregate surface, improve the viscosity, aging resistance and water stability of asphalt mastic, so that the durability and rupture resistance of asphalt mixture are improved; fiber can decrease the penetration of asphalt mastic, advance its softening point, and reinforce its elasticity comeback capacity.More>

2007, 7(3): 61-65.

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Sectioned linear fitting method of parameters for asphalt mastics viscoelastic Burgers model

Tian Li, Hu Xia-guang, Liu Yu, Sha Ai-min

Abstract: The static creep curve character of asphalt mastics was analyzed, the head section and end section of the curve were fitted by sectioned linear fitting method, the parameters of asphalt mastics viscoelastic Burgers model were solved in the condition of shear creep, and sectioned linear fitting method was compared with traditional method. It is pointed that in low temperature, the average errors of two methods are less than 5%, but the maximal error of traditional method is more than 20%, and the error of sectioned linear fitting method is more than 5% only in a small time range; under high temperature, Burgers model parameters are difficultly determined by using traditional method, but the errors from sectioned linear fitting method are less than 0.01%. Analysis result shows that the new method is feasible, its fitting error is less, and its maneuverability is better.More>

2007, 7(3): 66-69.

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Influence factors and simplified calculation of interbedded shear stress of asphalt paving on steel bridge

Gu Xing-yu, Wu Yi-ming

Abstract: In order to minish the interbedded shear stress of asphalt paving, 3-D finite element model of bridge deck was set up, the influences of load position, steel deck thickness, the open width of U shape rib, asphalt thickness, asphalt modulus, contact condition and heavy load on the longitudinal-transverse shear stresses were analyzed, and the simplified calculation formulae of the stresses were concluded. It is pointed that the shear stresses are much larger than that of road structure in same condition because of uneven deformation, the main influence factors in order are heavy load, steel deck thickness, the open width of U shape rib and paving parameters; completely smooth state between asphalt concrete and steel deck lowers the whole stiffness of deck system, but benefits to resist shear stress; controlling heavy loads, stiffening steel deck and selecting flexible interbedded sticking materials are effective method to reduce the shear stress between steel deck and asphalt paving.More>

2007, 7(3): 70-75.

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Forecast model of expressway maintenance cost

Yu Ying, Wang Qi-lin, Tian Jin-yue

Abstract: In order to decrease expressway maintenance cost, the mathematic model between maintenance cost and the factors of traffic flow and road length was established by using the management theory of marginal cost, aimed at preventive maintenance and special project maintenance for asphalt pavement on expressway, the marginal cost expression of every factor was derived by using statistical method, the concepts of marginal cost of expressway maintenance management and maintenance elastic index were first expressed, and a forecast model of expressway maintenance cost was established. With the model, the elastic indices of traffic flow and road length relating to maintenance cost were calculated, and the economic indices of expressway maintenance cost relating to traffic flow were analyzed. Computation result shows that traffic flow and road length are the primary influence factors on expressway maintenance cost, there is logarithmic change relationship between road length and expressway maintenance cost, and expressway maintenance average cost decreases with traffic flow increase.More>

2007, 7(3): 76-79.

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Application of uncertainty inference represented by credence in expert system for soft ground improvement of highway

Zhang Liu-jun, Huang Xiao-ming, Yin Li-hua

Abstract: In order to improve the scientificity of highway soft ground improvement, the characters of uncertainty, mistiness and multifactor influence for highway soft ground improvement knowledge were analyzed, uncertainty inference represented by credence was introduced into the expert system for soft ground improvement of highway, the knowledge was expressed by using production rules, and some problems, such as the identification of soft soil, the calculation method choice of embankment stability and settlement, the decision-making of soft ground improvement scheme, the analysis of problems from soft ground improvement design and construction, were solved by a mix inference method with positive direction inference and contrary direction inference. Applied result shows that uncertainty inference improves the interaction and intelligentized degree of the expert system and the scientificity of design and construction for highway soft ground improvement.More>

2007, 7(3): 80-85.

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Central angle influence of long-span curve bridge on its inner forces, displacements and stability

Wang Jun-li, He Shuan-hai

Abstract: In order to improve the safety of long-span curve bridge with high piers, the large distortion and material nonlinearity of the bridge were considered, the inner forces and displacements of piers of typical curve rigid frame bridges with different central angles of curve were computed by using finite element method, and the relations of the inner forces, displacements and nonlinear stability load coefficients to the central angle of curve were concluded. Analysis result shows that the end maximum moment of main beam during cantilever construction little decreases with the increase of the angle, but the torsion rapidly increases; the larger the angle is, the larger the transverse-vertical displacements of cantilever end and the transverse displacement at pier top are, the displacements sharply increase, their nonlinear trends are obvious; the nonlinear stability coefficient of bridge is 35% of eigenvalue stability coefficient, the stability load decreases rapidly with the augmenting of the angle; the central angle of curve can not be larger than 38° in order to ensure bridge safety.More>

2007, 7(3): 86-90.

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3-D numerical analysis of large subsoil liquefaction distortion influence resulted from earthquake on bridge pile foundation

Tong Li-yuan, Wang Bin, Liu Yi-huai

Abstract: In order to study large subsoil liquefaction distortion influence resulted from earthquake on bridge pile foundation, typical computation models in two and three soil layers were set up, the interaction nonlinearity relation between pile and soil was analyzed, the dynamic finite difference analysis of single pile and group piles was carried out by using FLAC-3D, and the characteristics of displacement and inner force of pile foundation were studied in detail. Analysis result shows that the bending moment extremum at the interface between liquefaction layer and non-liquefaction layer controls the failure of pile in the two and three soil layers, liquefaction layer has little effect on the bending moment of pile; the pile cap limits pile lateral displacement to a certain extent, and has little effect on its bending moment extremum; according to group piles, the lateral displacement and the bending moment distribution of upgrade pile are similar to that of downgrade pile, but the values of upgrade pile are larger.More>

2007, 7(3): 91-94.

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Reliability computation method of urban road network

Liu Yong, Xiang Li, Xie Jun, Yan Bao-jie

Abstract: In order to objectively reflect the reliability of urban road network, the structure and function of urban road network were analyzed, OD road network was divided into main roads and connection roads, the influence factors and the computation method of the reliability were studied, the main road reliability was amended by using OD connectivity, and the reliability of whole road network was concluded.The influence of number of the nodes on OD road network reliability was studied, and the improvement methods of OD road network reliability were discussed further. Analysis result shows that the reliability of OD road network is 0.62 when main roads are not connected effectively, the reliability is 0.70 through the connection of main roads when the continuance of main road is not affected. It is indicated that the reliability of OD road network depends on not only the continuance and the validity of main road, but also the connectivity of OD road network, so the method is feasible and effective.More>

2007, 7(3): 95-99.

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Optimal route arithmetic with multigoals in highway network based on travel decision-making

Ma Yong-feng, Lu Jian, Xiang Qiao-jun, Wei Lian-yu

Abstract: To synthetically consider the correlative influence factors of road environment and special user's desires of optimal route selection in the static optimal route search with multigoals in highway network, user-system decision-making model of optimal route search under GIS environment was studied.Based on AHP theory, the evaluation indices system of link impedance was presented involving travel time, safety, comfort and travel expenditure, and the methods of standardized process for the indices were raised. Through the synthetical evaluation process of link impedance determined by user-system, the optimal route problem was transformed into the shortest route problem, the sum of standardized values of link travel goals was taken as the evaluation index, and the optimal route could be found by using Dijkstra algorithm. Test result shows that the optimal route is different from the shortest path, its travel distance increases by 8%, its travel time decreases by 7%, its comfort and safety improve by 17%, its travel charge increases by 13%, the searched optimal route with user-aimed multigoals is better than the shortest route with single goal, so the arithmetic is feasible.More>

2007, 7(3): 100-105.

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Public transport planning of developing city based on TOD mode

Yu Jie, Yang Xiao-guang, Yin Rui, Xia Sheng-guo

Abstract: In order to realize the harmonious improvement of land use and city traffic, TOD was introduced into the public traffic planning of developing city, its public traffic development demand was analyzed, a hub-oriented planning strategy of harmonious improvement was put forward, three kinds of planning modes including terminal sort, public service subarea and public route classification were discussed, an active leading planning procedure was designed based on regarding hub-distributed planning as planning center, and the planning contents were detailed including traffic actuality investigation, traffic demand forecast, planning scheme design, planning scheme evaluation and the safeguards of planning scheme implement.Study result shows that public traffic planning method based on TOD mode benefits the layout and development of land use, embodies the feature of the planning mode for developing city.More>

2007, 7(3): 106-110.

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Trip mode transfer model by simulating quantum jump

Yao Rong-han, Wang Dian-hai

Abstract: To quantificationally describe trip mode transfer rules, the comparability between trip mode transfer and quantum jump was analyzed in detail, and a trip mode transfer model was put forward according to quantum energy level jump theory. In order to calibrate the model, the polynomial imitation equation was deduced by analyzing inhabitant trip survey data from Changchun City, the imitation coefficients were ascertained, and their correlative tests were made by using quadratic, cubic and biquadratic polynomials respectively. Data validating result shows that the function relation between distance difference and income balance fits quadratic or higher polynomial whose constant items are zero when one mode transfers to other modes; the correlative coefficients are all more than 0.900 0 when using quadratic polynomial, and they are all 1.000 0 when using cubic or biquadratic polynomial. It is obvious that the model is feasible to quantificationally describe the rules of trip mode transfer.More>

2007, 7(3): 111-115.

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Analysis of transportation behavior essence and its characteristics

Wu Qun-qi, Huang Zhi-ying

Abstract: In order to rebuild the theory system of transport economics, the essence of transportation behavior was analyzed by using basic motive mechanism in economics. It is pointed that the essence of transportation behavior is to realize resource-optimized collocation according to the move of people or goods, it has five kinds of characteristics including interaction property, relativity, main body character, subjectivity and aggregation property. Analysis result shows that the accurate understanding of transportation behavior essence and its characteristics benefits to understand the mainline of transportation economics theory, proofread transportation demand and its relative property cognition, and establish transportation distribution theory and transportation forecast theory system.More>

2007, 7(3): 116-120.

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Extended model for optimal design of remanufacturing logistics network

Ma Zu-jun, Dai Ying

Abstract: The problem on designing an appropriate integrated logistics network structure for hybrid manufacturing/remanufacturing systems was investigated, the integration of various facilities and combined transportation of forward and reverse logistics in the network was considered, the impact of scale economics on the cost of establishing those facilities was studied, an extended model for the optimal design of remanufacturing logistics network was developed based on mixed integer nonlinear programming approach. According to the model, the numbers, locations and capacities of various facilities and the allocation of corresponding goods flows in the network were ascertained, the objective was to maximize the net revenue in operation period.Finally, the model was tested and verified by a numerical example. Computation result shows that the optimal objective function and decision-making variables of the net can be gained by using the model, and logistics network and the model can be used to assist the decision-making of the network design.More>

2007, 7(3): 121-126.

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2007 Vol. 7, No. 3

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