交通运输工程学报

Characteristic and control method of early-age temperature field for cement concrete pavement

HU Chang-bin, SUN Zeng-hua, WANG Li-juan

Abstract: The control principles of early-age temperature field were put forward based on the temperature stress, built-in basic temperature, built-in temperature difference and curing temperature of cement concrete pavement.The specialized early-age temperature field numerical simulation program of cement concrete pavement was used, the sensitivities and influencing characteristics of pavement early-age temperature field parameters were researched, and the effectivenesses of pavement early-age temperature field control measures were evaluated.Analysis result shows that compared with material parameters, environment construction parameters are major factors effecting pavement early-age temperature characteristics.Appropriate paving time and environment condition may change the temperature difference between the top and the bottom of slab more than 20℃.Proper curing methods and curing materials may reduce the temperature of pavement more than 12 ℃.Concrete paving temperature, water cement ratio and cement content significantly effect built-in basic temperature.For specific temperature control target, the sensitivities of influencing parameters are not the same, field pavement early-age temperature simulation should be combined to balance the effects of control measures.More>

2013, 13(5): 1-9.

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Analysis of heat-reflective coating property for asphalt pavement based on cooling function

ZHENG Mu-lian, HE Li-tao, GAO Xuan, WANG Fei, CHENG Cheng

Abstract: In order to improve asphalt pavement high temperature stability in summer and mitigate urban heat island effect, a new type of heat-reflective coating was applyed on the surface of asphalt pavement.The working principle of heat-reflective coating was analyzed, the thermalphysical environment performance comprehensive test device of heat-reflective asphalt pavement was developed, and the cooling effects of asphalt mixtures with different color coatings were studied by using the device.The skid resistance performances of coatings with different thicknesses were evaluated based on pendulum type friction coefficient measuring instrument.Analysis result shows that the cooling effect of white heat-reflective coating is better than grey coating, white heat-reflective coating on specimen can cool 18 ℃-25 ℃ within door test, the temperature of 2.5 cm place inside specimen reduces by 9.4 ℃, and the temperature of grey coating surface reduces by 12 ℃.The cooling ability of heat-reflective coating increases with the increase of coating thickness, but it will tend to be constant while reaching certain thickness.The sensible dosage of heat-reflective coating is 0.6 kg·m^-2 comprehensively considering cooling effect and cost.With the increase of coating thickness, the surface skid resistance performance of pavement reduces, and it is recommended to spread antiskid particles in the coating to meet traffic safety requirements.More>

2013, 13(5): 10-16.

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Analyses of structural damage and parameter sensitivity for CRCP+AC composite pavement

WANG Bin, HUANG Wei, YANG Jun, ZHANG Lei

Abstract: The structural plasticity damage of continuous reinforcement concrete pavement (CRCP) and asphalt concrete (AC) composite pavement was analyzed, the spatial distribution laws of structural stresses and damages under different loading conditions were studied.Orthogonal test method was used, the structural tensile damage was taken as an index, the parameter sensitivity analyses with a variety of complex structural and environmental factors were employed to obtain factor influencing laws.Based on the results of variance and range analyses, the primary and secondary factors were distinguished and ordered with their various influencing effects under temperature changing or temperature-load coupling conditions.Analysis result shows that there are differences in the distribution of structural damage along the depth range of CRCP slab, which lead to the difference distribution of tension stress.When repeated traffic loading is applied, the trend of structural damage steps up in the initial stage and is steady growth in the later stage with the intensification of structural stress softening.The normal direction of structural crack plane can be judged by the vector direction of maximum plasticity principal strain.Based on the comprehensive consideration of analysis results under different loading conditions, the thickness of asphalt layer, the linear expansion coefficient of concrete and the support state under CRCP slab are the most important influencing factors associated with the structural damage of CRCP.More>

2013, 13(5): 17-26.

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Analysis of longitudinal force regulation for CWR on railway cable-stayed bridge

WANG Ping, LIU Hao, WEI Xian-kui, XIAO Jie-ling

Abstract: Based on the theory of track-bridge interaction, the calculation model of longitudinal force for continuous welded rail (CWR) on cable-stayed bridge was established, and the related calculation software was compiled.Taking a double-tower steel truss cable-stayed bridge commonly used in the railway as an example, the longitudinal force regulations of CWR were analyzed.Analysis result shows that the cable-stayed bridge can be simplified as a continuous beam with fixed bearing in the middle to calculate rail expansion forces.Rail bending forces can be calculated under the conditions of loads laid on main span and its adjacent span or the separate main span, and the direction change of train needn't be considered.Speed locking devices should be set on railway cable-stayed bridge to effectively limit the main beam longitudinal displacement under train braking force, and rail deformation decreases simultaneously.The method of trackbridge interaction should be used for cable-stayed bridge with CWR to calculate rail broken gap value accurately.More>

2013, 13(5): 27-32.

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Control strategy of maglev on elastic track

WANG Hui, ZHONG Xiao-bo, SHEN Gang

Abstract: In order to effectively control maglev-guideway coupling vibration, maglev-guideway coupling vibration system was simplified as electromagnet-elastic-track model.A full-state feedback optimum controller was developed.The guideway vibration information was introduced into the control system by state observer.A small-scale elastic-track magnetic levitation test rig was built using dSPACE.Compared with the traditional controller, the proposed control strategy can always keep the system stable, even the guideway is rather soft and no damping effect exists.Step response tested from the test rig indicates that the developed controller can stabilize the system in 0.3 swith a overshot of 4%.Analysis result shows that the control strategy is able to effectively restrain the coupling vibration.Moreover, it reduces the over-dependence of the system stability on the guideway beam properties based on satisfying maglev stability.More>

2013, 13(5): 33-38.

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Low track force dynamic performance and connection reliability of new type radial bogie for freight car

LI Heng-li, LI Fei, PAN Shu-ping, FU Kai, WANG Yong

Abstract: In order to realize wheel-rail low track force performance of bogie for heavy haul feight car, a new low track force radial bogie configuration was given based on the heavy haul transportation state of Chinese railway and the running experience of ZK7 type radial bogie.The improvement focused on sub-frame structure: comparing to the holistic prototype, each axle-box had an independent adapter mounted on sub-frame by tow rivets.The vehicle-track coupling dynamics model with C70EF type gondola and standard Chinese track parameters was established through the multi-body system dynamics software SIMPACK.The wheel-rail dynamics behaviour and the force law between sub-frame and adapter were discussed.The FEM simulation and fatigue test for sub-frame connection reliability were carried out.Analysis result indicates that, compared to ZK7 type bogie, when the new radial bogie passes through a 0.01 rad sinking track joint, the wheel-rail low frequency force approximately reduces by 10.78%;when it runs on AAR5 irregular track, the wheel-rail vertical and lateral forces respectively reduce by about 2.98%-4.03%, 2.96%-9.77%, and the vehicle wheel-rail wear friction power reduces by about 5.03%-29.46%.The stress of adapter connection rivet inside is obviously bigger than the one outside, where the maximum shear stress is about 58.13 MPa.The maximum stress near rivet orifice is about 180.76MPa.Both of them are less than the material allowable values 128 MPa and 345MPa respectively.The connection fatigue strength and running reliability are sufficient.More>

2013, 13(5): 39-46.

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Wheel-rail contact features of self-steering radial bogie locomotive

BI Xin, MA Wei-hua, WANG Shao-lin, LUO Shi-hui

Abstract: The working principle of radial steering structure for three axle locomotive was studied.Wheel-rail contact features of locomotives with radial bogie and conventional bogie during passing transition curve were analyzed in detail by using the numerical simulation method.It is concluded that radial structure can balance the steering torques between wheelsets and improve locomotive primary suspension force to promote the bogie frame moving along the radial direction.The guide wheelset of conventional bogie is more susceptible to flange contact, which leads to a greater angle of attack.The guide wheelset in the radial bogie can maintain a smaller angle of attack on a large radius curve.When the flange contact occurs on the guide wheelset, the steering ability of radial bogie is weakened.The creep force distributions are almost same for the two types of bogies, i.e.the lateral creep force is greater than the longitudinal creep force for the guide wheelset, but the longitudinal creep force is greater than the lateral creep force for the third wheelset.The change of lateral creep force shows strongly nonlinear characteristic that smaller angle can cause larger lateral creep force.More>

2013, 13(5): 47-53.

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Optimization design of acoustic radiation for S-form web plate wheel

LIU Lin-ya, ZHANG Bin, SHAO Wen-jie, LU: Rui

Abstract: In order to reduce the vibration noise produced by the wheels of running train, wheel structure dynamics optimization principle was applied to wheel structure section optimization design. By means of finite element numerical simulation method and boundary element acoustic simulation method, railway train low-noise wheel acoustic radiation optimizationmodel, which took wheel structure acoustic radiation power as objective function, was built. Using structure vibration acoustic radiation optimization theory and multi-parameter highly efficient optimization GA(genetic algorithm)method, the solution of model was programed successfully. Compared to standard wheel, optimized wheel plate vibration reduction is more obvious, for which the maximum vibration acceleration amplitude reduces from 209.2 m·s^-2 to 194.6 m·s^-2. According to wheel acoustic radiation power, optimized wheel acoustic radiation power decreases within most frequency ranges. The most obvious reductions are 2.31 dB and 2.42 dB at 1 200 Hz and 3 200 Hz, respectively. Analysis result indicates that it is available to optimize wheel by GA, and it provides a way for the vibration and noise reduction of vehicle.More>

2013, 13(5): 54-60.

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Static stiffness calculation model of water-lubricated rubber stern tube bearing

ZHANG Sheng-dong, LIU Zheng-lin

Abstract: In order to shorten the distence between the experience value and actual value of water-lubricated rubber stern tube bearing, a static stiffness calculation model was proposed by phenomenological theory. The calculation model was linearized to obtain the parameters by linear regression method and finite element method. Significance test for the influence factors of bearing static stiffness was carried out by difference method. Test method offered the stiffness correction coefficient, which verified the correctness and validity of the model. Analysis result shows that the most significant influence on static stiffness of stern tube bearing is length-diameter ratio, the second ones are modulus and pressure ratio, and the last one is rubber thickness. Compared the static stiffness model with the methods of estimation or experience in references, the minimum and maximum relative errors are 0.41% and 34.77% respectively, indicating a closer value to the real. With the increase of pressure ratio, the static stiffness increases nonlinearly, the maximum change value is 1.83×10⁸ N·m^-1.More>

2013, 13(5): 61-66.

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3D measure method of space-time unbalance for arrival and departure wagon flows at railway technical station

XUE Feng, CHEN Chong-shuang, YANG Yun-gui

Abstract: In order to measure the space-time unbalance of arrial and depature wagon flows at railway technical station, the characteristics of arrival and departure wagon flows times, the arrival and departure amounts of trains and the connecting directions of technical station were ananlyzed, and the calculation method of arrival and depature wagon flow unbalance was provided.Through analyzing the influence of space-time unbalance for arrival and departure wagon flows on technical station, the wagon flow structures of different connecting directions, transformation range and arrival time interval were considered, and relevant parameters such as line direction and train amount were designed.By using maximum variance ratio method, the time unbalance degree of arrival and departure wagon flows and the amount unbalance degree of arrival and departure wagon flows from different connecting directions were calculated, the unbalance degree of arrival and departure wagon flow amouts at different periods was calculated by using Gini coefficient.The 3D unbalance characteristic of arrival and departure wagon flows was divided from space, time and amount, the relations among train amount, time change and space transformation were described, the 3D measure method of space-time unbalance for arrival and departure wagon flows at railway technical station was set up, and an example of Guiyang Nan Railway Station was given to prove the measure method.Research result shows that when the amount of arrival trains is 67, calculation time is 12 hand receiving train level is 4, the unbalance degree of arrival and departure wagon flow amounts from different connecting directions is 0.21, the unbalance degree of arrival and departure wagon flow times is 0.03, and the unbalance degree of arrival and departure wagon flow amounts at different periods is 0.13.The wagon flows are comparatively balanced, which accord with the actual situation of Guiyang Nan Railway Station.More>

2013, 13(5): 67-75.

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Transportation status of Chinese expressway network in 2012

LI Bin, XIAO Run-mou, CHEN Yin-san

Abstract: Based on the database of expressway network toll system and the typical sampling investigation data at toll station, the transportation status of Chinese expressway network in 2012 was analyzed.Analysis result shows that compared with the transportation status in 2011, passenger transportation density in expressway network in 2012 reduced by 5.09%.49.99% of passenger turnover volume was produced by mini-type buses (the seat amount of every bus is less than 8), and the volume rose by 2.88%.The average speed ofⅠ-type bus reduced by 3.68%, the average speed ofⅡ-type bus reduced by 3.18%, the average speed ofⅢ-type bus reduced by 4.12%, and the average speed ofⅣ-type bus rose by 0.25%.Freight transportation density reduced by 9.59%, and 80.46% of freight turnover volume was produced by tractor-trailer combination.The percentage of empty to loaded truck kilometers was 21.22% and reduced by 1.02%.According to the standard of GB 1589—2004, the percentage of trucks with the overweight more than 30% was 3.16%.In 2012, the mini-type bus passenger transportation of Chinese expressway network kept continuous high-speed growth, the increasing speed of commercial bus (seats amount of every bus is more than 19) passenger and freight transportation reduced.More>

2013, 13(5): 76-82.

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Choice behaviour model and influencing factor analysis of travel destination for rural resident

YANG Qi, YANG Yun-feng, YUAN Hua-zhi, FENG Zhong-xiang, CI Yu-sheng

Abstract: In order to analyze the influencing factors and influencing process of travel destination choice for rural residents, travel characteristic data of 3 329 rural residents were obtained through self-designed questionnaire.According to the distribution of conventional travel destinations of rural residents, the destinations were divided into neighboring villages, towns, counties and cities.Using disaggregate theory, personal, family and travel attributes such as rural residents genders, ages, education levels, annual household incomes, travel purposes and travel distances were considered as influencing factors, and four destinations were selected as four alternative parts, the travel destination choice behavior measurement model was established.The sensibility of each factor was analyzed combined with elastic theory.Analyhsis result shows that the corresponding elasticity values of travel distance and travel destination of rural resident are greater than 1, indicating that the above-mentioned factors on the travel destination choice are of flexibility and significant effect.The age, transfer and time are of flexibility for some destination choice, the corresponding elasticity values of genders, education levels, annual household incomes and total travel time are less than 1, indicating that the above-mentioned factors on the travel destination choice are of no inflexibility.More>

2013, 13(5): 83-90.

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Determination method of speed-limit sign position in expressway work zone

YU Ren-jie, MA Rong-guo, HAN Hai, YAN Ying, WANG Jun-ling

Abstract: Based on the visibility and short-term memory of driver, the adaptability of driver and the controllability of vehicle under the influence of speed-limit sign were analyzed, and the front distance, post distance and repetitive distance of speed-limit sign in expressway constrution area were calculated. Based on the calculation model of length partition in expresswaywork zone, the influences such as vehicle queue length, the short-term memory of driver and repetitive distance were considered, the determintation method of speed-limit sign position in expressway work zone was proposed, and the example verification was carried out by using VISSIM simulation software. Simulation result shows that when the lowest speed-limit value is 40 km·h^-1, the cart mix rate is 40% and traffic volume is 1 400 pcu·h^-1, the minimum conflict rates of the first, second and third grade speed-limit signs are 0.06, 0.10 and 0.21 times·m^-1, the maximum conflict rates are 0.56, 0.14 and 0.23 times·m^-1. When traffic volume is 1 960 pcu·h^-1, the minimum conflict rates of the three speed-limit signs are 0.84, 0.28 and 0.36 times·m^-1, the maximum conflict rates of the three speed-limit signs are 0.87, 0.31 and 0.40 times·m^-1. When traffic volume is 2 240 pcu·h^-1, the minimum conflict rates of the three speed-limit signs are 0.72, 0.31 and 0.39 times·m^-1, the maximum conflict rates of the three speed-limit signs are 0.74, 0.34 and 0.48 times·m^-1.More>

2013, 13(5): 91-98.

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Business mode of service-oriented manufacturing enterprise based on value-added service

FANG Hong-wei, MA Jian

Abstract: Aiming at the transformation problem of manufacturing industry from production manufacturing to service-oriented manufacturing under the background of service economy, the relation between value-added service and service-oriented manufacturing industry was researched.The types of value-added services for service-oriented automobile manufacturing industry were analyzed, the development models of value-added services and business mode based on valueadded service for automobile manufacturing industry were proposed, and the business mode of service-oriented manufacturing for Shaanxi Automobile Group Co., Ltd.was researched from three aspects such as transaction mode, trade mode and pricing mode.Research result indicates that through intergrating social resources or developing value-added services, traditional automobile manufacturing enterprise can build platform business mode and form the total solution based on the combination of production and value-added service, can create new competitive advantage, and can accelerate the transformation process from traditional automobile manufacturing enterprise to service-oriented manufacturing enterprise.More>

2013, 13(5): 99-104.

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Control technology review of traffic congestion in urban road network under networked dynamic scheduling and control

HUANG Da-rong, SONG Jun, LI Shu-qing, XIANG Hong-yan

Abstract: With the application of urban traffic security supervision under networked dynamic-link transportation equipment, the present domestic and overseas researches of traffic congestion control technology for urban road network were summarized based on the road network traffic safety performances including reliability evaluation indexes and evaluation methods. The problems and further development of recent researches were pointed.Analysis result shows that because of transmitting delay, data packet loss, and data exception of traffic information in networked dynamic scheduling and control, the traditional traffic congestion control technologies and methods of road network have the lack of global coordination ability, multi-dimension dynamic mode, and coordination ability between traveler and traffic performance. The arrangement of networked dynamic-link resource can be used for the implementation of linkage control at traffic congestion status, but the traditional factors for unimpeded transportation and the factors relating to information resources, such as information transmitting mechanism and channel capacity etc., have to be comprehensively considered.The key sub-control models for the traffic congestion control of road network are proposed.These sub-models are further integrated to establish a systematic-model based on the framework of traffic congestion control technology.It is pointed out that the core content of the model-based frame is the construction of traffic sate database.The future development trend and research focus of traffic congestion control technology are distributed intelligent control, adaptive intelligent control, and integrated intelligent control.More>

2013, 13(5): 105-114.

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ANP estimation algorithm of onboard navigation system based on numerical integration

LAI Ji-zhou, WANG Wei, LIU Jian-ye, LIU Min, MA Yan-ling

Abstract: In order to accurately estimate the actual navigation performance (ANP) of plane and ensure the safety of flight, the two-dimensional normal distribution characteristic of position error for onboard integrated navigation system was studied based on the operation mode of performance based navigation (PBN).An error model of plane's estimated position in the estimation of ANP was established.The numerical integration of the probability of error circle was derived.An ANP real-time estimation algorithm of onboard integrated navigation system was proposed based on the numerical integration of navigation error.Then a simulation of the estimation algorithm was carried out based on a typical integrated navigation mode of an airliner.Simulation result indicates that the ANP value can effectively make the accuracy of error estimation reach 95%.The algorithm can estimate the real-time error characteristics of integrated navigation system authentically, has high ANP assessment precision for actual navigation performance, and is a kind of effective method.More>

2013, 13(5): 115-120.

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Wear characteristics of contact area among transmission conductor strands of electrified railway

ZHAO Mei-yun, LIU Zheng-lin, ZHAO Xin-ze, GAO Wei, WANG Qi-feng

Abstract: Taking LGJ150/25 aluminum cable steel reinforced (ACSR) wire as tested wire, aeolian vibrations under dry and acidic conditions were simulated on a self-made test rig.The surface morphology of wear scar of tested wire and its elements were observed by using scanning electron microscope (SEM) and energy dispersive spectrometry (EDS).A finite model of inside and outside wire contact areas was built under the same conditions.The analysis results of the finite model and the surface morphology of wear scar were compared.Comparison result indicates that both the wear scar shapes and the stress distributions of contact area among inner aluminum strands are oval-shaped under two conditions.Oval-shaped major axis and strand axis have a certain angle.The contact stress in the central contact area is significantly higher than other areas.The plastic deformation and a large number of wear debris occur on the surface of wear area because of high stress.The compression of mutated stress from the center area, especial transition area, causes the elastic deformation at the edge of wear area and the phenomena of plastic flow and stacking of surface tissue.The transition area between the center and the edge parts has stress concentration, where fatigue cracks are resulted from the mutation of normal stress and shear stress.More>

2013, 13(5): 121-126.

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2013 Vol. 13, No. 5

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