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15 January 2019, Volume 38 Issue 01 Previous Issue    Next Issue
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Bridge & Tunnel Engineering
Highway & Railway Engineering
Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment
Traffic & Transportation Engineering
Vehicle &Electromechanical Engineering


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Bridge & Tunnel Engineering

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Mechanical Influence of Boundary Point on Compound Arch Bridge ZHOU Qian1, 2, ZHANG Ce3, ZHOU Shuixing1, RAN Wenxing1 2019, 38(01): 1-6.  DOI: 10.3969/j.issn.1674-0696.2019.01.01 Abstract ( )   PDF (519KB) ( )   In order to increase the spanning capacity, shorten the construction period and reduce the cost of the arch bridge, a steel-concrete hybrid arch bridge with concrete structure at the arch foot and steel box structure at the rest was proposed. Based on the 420m span Wanzhou Yangtze River Bridge in Chongqing, the influence of the location of steel-concrete boundary point on the main arch deformation, internal force and the selection of arch axis coefficient was analyzed numerically, by using Ansys parametric analysis method. The research indicates that: the location of the steel-concrete boundary point has a significant effect on the stress and deformation of the arch bridge. When the location of the boundary point exceeds 0.181 times the span of the arch ring, the deformation of the main arch tends to be saddle-shaped. When the boundary point is located in one-fourth of the cross-section of the span, it is necessary to take a larger arch axis coefficient in order to reduce the adverse effect of the dead load pressure line of the arch ring and the deviation of the designed arch axis. The boundary point has significant influence on the bending moment of the arch foot to quarter span and the axial force of the 3/8 span to the arch top section, but relatively small influence on the stress of the arch ring of the whole bridge. The results show that considering the deformation of arch ring, the boundary point of hybrid arch should be located in the span section of 0.125 times arch ring to 0.181 times arch ring. References | Related Articles | Metrics

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Concept Design of Continuous Cable-Arch Bridge with a Span of 1 000 m Scale XIE Xiaoli1, MA Biao2, LI Guoping3, QIN Xia1, SUN Zhangjun4, YU Zecheng1，DAI Naxin5 2019, 38(01): 7-13.  DOI: 10.3969/j.issn.1674-0696.2019.01.02 Abstract ( )   PDF (784KB) ( )   Based on the idea of unloading arch ribs and no anchorage for suspension bridges, a new bridge structure system — cable-arch composite bridge was proposed, which was mainly composed of a main arch, a main cable, two main towers, two side arches and a main girder. By choosing appropriate parameters such as vertical-span ratio, sagittal-span ratio and arch axis to adjust the proportion of arch and cable to share the load of the main span bridge deck, the cable could bear more loads. Furthermore, the arch rib could be unloaded substantially, which not only reduced its stress level, but also improved its stability; thus, the span of the cable-arch bridge could surpass the traditional arch bridge. Taking the 1008m span as an example, a conceptual design of cable-arch bridge was carried out, and the strength, stiffness and stability of the structure were studied by finite element method. The study shows that the cable-arch bridge not only retains the characteristics of high bearing capacity and rigidity of suspension bridge, but also has certain aesthetic value. References | Related Articles | Metrics

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Review of Research on Ture Triaxle Test of Concrete LI Jing, JIAN Huawei, LIU Yingwei 2019, 38(01): 14-22.  DOI: 10.3969/j.issn.1674-0696.2019.01.03 Abstract ( )   PDF (612KB) ( )   The research status of true triaxle test of concrete at home and abroad was systematically introduced, including the kinds of concrete, loading apparatus, anti- friction measures, dimensions of specimens, loading paths and failure modes. Some problems in true triaxle test were analyzed and summarized, for example, there were fewer true triaxle tests under strain path and stress-strain mixed path and the corner effect was obvious.The review provides a theoretical basis for the true triaxle test of concrete under complex stress state. References | Related Articles | Metrics

Highway & Railway Engineering

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Numerical Simulation on Light Environment and Secondary Pollution of Sunshade Awning of Adjacent Tunnel Portals PENG Yuhua, FU Xiangxiang, LU Xin, LI Xuan 2019, 38(01): 23-29.  DOI: 10.3969/j.issn.1674-0696.2019.01.04 Abstract ( )   PDF (861KB) ( )   Lighting of adjacent tunnels in the tunnel group is significantly different from that of the single tunnel. In order to reduce the traffic accidents caused by the difference of the light intensity at adjacent tunnel entrances during the daytime, sunshade awnings measures were adopted at tunnel entrances to reduce light, and to satisfy the drivers visual characteristics. However, the structure was often closed, and the pollutants in the upstream tunnel portal could easily flow to the downstream tunnel entrance to form “secondary pollution”. Based on the adjacent tunnels, a sunshade with hollowed-out on both sides of the bottom and closed on the top was constructed, and the light simulation analysis software Daylight Visualizer was used to analyze the rule of brightness change and the light reduction effect of sunshade of adjacent tunnels. The three-dimensional turbulence model based on the standard k-ε two-equation and the multi-group diffusion transfer were used as the physical calculation models. Ansys Fluent fluid analysis software was used to simulate the diffusion of pollutants at adjacent tunnel entrances with or without sunshade awnings. The results show that the constructed sunshade (transmittance 30%) can greatly reduce the gap of road illumination between tunnels, and it can better improve the diffusion of pollutants at tunnel portals, compared with the rather closed sunshade shed. References | Related Articles | Metrics

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Discussion on Design of 3D Highway Model Based on BIM Technology SUN Jiancheng, JIANG Haopeng, ZHU Shuanghan 2019, 38(01): 30-34.  DOI: 10.3969/j.issn.1674-0696.2019.01.05 Abstract ( )   PDF (1086KB) ( )   BIM technology has developed rapidly in the field of construction engineering in China. However,the development of BIM is still in its infancy in highway engineering.Above all, BIM technology route was improved and optimized for highway engineering design, construction and operation through analyzing the type of BIM data exchange standards. And then, taking an example of a secondary highway project in China, Civil3D and Powercivil software were compared in the pre-design stage of the process and applications.BIM technology routes and design concepts were provided for the development of highway design in China. References | Related Articles | Metrics

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Photocatalytic Performance of Potassium-Doped Graphitic Carbon Nitride GUO Xiaofeng1, 2, 3, MA Yuangong2, WU Qifan2, ZHOU Lvjun2, WANG Liying3 2019, 38(01): 35-42.  DOI: 10.3969/j.issn.1674-0696.2019.01.06 Abstract ( )   PDF (989KB) ( )   The potassium-doped graphitic carbon nitride was prepared by using dicyandiamide, thiourea, melamine, potassium hydroxide and potassium iodide as raw materials under different conditions. The influence of different preparation temperature, potassium source and doping amount on the photocatalytic performance was systematically investigated. The structure and morphology of the samples were characterized by X-ray diffraction (XRD), ultraviolet-visible diffuse reflection absorption spectrum (UV-vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and specific surface area analysis (BET). The results show that the doped samples reduce the bandwidth, increase the absorption of visible light, reduce the recombination rate of photogenerated electron-hole pairs and significantly improve the photocatalytic performance of the samples, compared with the pure graphite carbon nitride (g-C3N4). The results of photocatalytic degradation of samples with different temperatures and different doping ratios were compared. It is found that the samples using thiourea and potassium iodide as raw materials have best photocatalysis effect, which are obtained at 550 ℃, with the calcination time of 4 h and under the preparation condition that the doping ratio of potassium ion to carbon nitride is 0.1. Its photocatalytic degradation rate was 4.29 times higher than that of g-C3N4. References | Related Articles | Metrics

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Material Design and Performance Optimization of Resin Bitumen in Cold Area YI Junyan1, ZHU Yiming1,2, FENG Decheng1, REN Zhao1, QIN Weijun3 2019, 38(01): 43-48.  DOI: 10.3969/j.issn.1674-0696.2019.01.07 Abstract ( )   PDF (478KB) ( )   The pulling test and trabecular bending test were carried out for resin asphalt. Orthogonal design and pulling test methods were used to study the influence of factors such as asphalt content, curing agent content, resin content, curing time and curing temperature on the properties of resin asphalt. The optimum ratio, curing time and curing temperature were determined by low temperature trabecular bending test. Then toughening agent was added to improve the low temperature performance of resin asphalt, so as to realize its performance optimization. The research indicates that: the degree of influence on the resin asphalt pulling strength ranks as the content of curing agent>asphalt content>curing time> curing temperature. Furthermore, when curing time is 4 h, curing temperature is 120 ℃, curing agent content is 20%, asphalt content is 30% , content of toughening agent is 5% and the content of turpentine is 2%, it can guarantee its pulling strength as well as better low temperature performance. References | Related Articles | Metrics

Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment

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Influence of Measurement Point Offset on Slab Corner Deflection of Cement Concrete Pavement LIU Haijun1,2, WANG Zibin1,2, NIU Xiaoxia1,2, LI Hao1,2 2019, 38(01): 49-54.  DOI: 10.3969/j.issn.1674-0696.2019.01.08 Abstract ( )   PDF (459KB) ( )   Aiming at the influence of tire loading, undefined location of Beckman beam head and drop hammer on the test results in slab corner deflection test in current specifications, the influence of tire loading, undefined location of Beckman beam head and drop hammer on the values of slab corner deflection was studied by using Beckman beam deflectometer and falling weight deflectometer (FWD). The results indicate that: in the case of slab void, the deflection values obtained by the above two methods are linearly related to the offset distance; as the offset distance increases, the slab corner deflection is approximately linearly reduced. When the slab corner deflection is tested by the Beckman beam deflectometer, the load deviation within 10 cm and 20 cm can meet the application requirements of 5% and 10% allowable errors in engineering applications respectively. It is suggested that the beam head of Beckman beam should be placed 5 cm away from transverse and longitudinal joints of the slab corner. When the slab corner deflection is tested by FWD, the load deviation within 20 cm and 30 cm can meet the application requirements of 5% and 10% allowable errors in engineering applications respectively. References | Related Articles | Metrics

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Design and Implementation of Safety Assessment System for Landslide Surge in River Type Reservoir LIN Xiaosong1, LUO Junhua1,WANG Pingyi2,WANG Meili1,YU Tao2, GONG Yuanhong1 2019, 38(01): 55-61.  DOI: 10.3969/j.issn.1674-0696.2019.01.09 Abstract ( )   PDF (1507KB) ( )   Landslide and its surge of channel reservoir in mountain area causes great threat and damage to the navigation, tourism, production, life and personnel property in the reservoir area. The Wanzhou section of the Three Gorges Reservoir Area was taken as the research scope. Based on professional software like ArcGIS Engine, Skyline and etc., in view of the overall design of the landslide surge safety assessment system for river reservoirs in mountainous areas, the implementation process, calculation algorithms and specific operations of the core functions such as initial surge height, surge propagation attenuation coefficient, solid flow energy exchange coefficient, wave run-up, roll angle and surge safety assessment were analyzed in detail. The proposed system can not only quickly calculate the surge characteristic values of a particular grid element after the landslide occurs, but also obtain the distribution of surge eigenvalues of all grid elements in the river reach of the study area through the systematic batch calculation and simulation. The research results provide a visualization analysis platform for the spatial early warning of landslide surge disasters and the evaluation and management of waterway safety. References | Related Articles | Metrics

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Construction Schedule of Navigation Hub Based on Chaos Accelerated Fruit Fly Optimization Algorithm GENG Jing, ZHANG Yang, LI Mingwei, XU Qian, ZHANG Lidong 2019, 38(01): 62-68.  DOI: 10.3969/j.issn.1674-0696.2019.01.10 Abstract ( )   PDF (719KB) ( )   Aiming at the optimization of construction schedule of navigation power junction for seasonal frozen rivers, the construction schedule optimization model (CSOM) was firstly established with the optimization goal of the project span, considering the seasonal frozen factors and taking the construction intensity as well as the project resources as constraint conditions. Secondly, in order to obtain the better solution of the CSOM, the chaos accelerated fruit fly optimization algorithm (CAFOA) was established by designing the self-adaptation search and the global chaotic perturbation mechanism, on the basis of fruit fly optimization algorithm. And then the construction schedule optimization method of the CAFOA of the construction of navigation-power junction in the seasonal frozen river was put forward with taking advantage of CAFOA to solve the CSOM. Finally, the numerical experiment was operated based on the statistical data collected in the planned project of Yilan navigation-power junction construction. The results indicate that it is feasible to solve the construction schedule optimization problems of navigation-power junction in the seasonal frozen rivers by applying the proposed CAFOA and satisfactory results are obtained. References | Related Articles | Metrics

Traffic & Transportation Engineering

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Development Characteristics and Comparison of Geological Hazards in the Upper and Middle Reaches of Daning River SUN Yingjie, DENG Bing, LE Qilang 2019, 38(01): 69-75.  DOI: 10.3969/j.issn.1674-0696.2019.01.11 Abstract ( )   PDF (1516KB) ( )   Taking the geological hazards of Wuxi County map in the upper reaches of Daning River and Dachang map in the middle reaches of Daning River as an example, the development characteristics of geological hazards in the upper and middle reaches of Daning River were expounded and the differences between the development of geological hazards in the upper and middle reaches were compared. Meanwhile, their internal causes were also analyzed. The results show that: the geological hazards in Wuxi County are dominated by small-scale collapse, debris flow and landslides, among which the number of landslides is the largest. However, in recent years, the frequency of landslides and debris flows is relatively higher, and the damage caused by them is also more serious. The geological hazards in the map of Dachang are dominated by large and medium-sized landslides, whose harm is the most serious. Due to the differences in stratigraphic lithology, topography, geological structure and river erosion, there are obvious differences in the development characteristics of geological hazards between Wuxi and Dachang. References | Related Articles | Metrics

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Equilibrium Model of Taxi Market Considering Traffic Congestion TIAN Lijun, ZHAN Xiaobin 2019, 38(01): 76-82.  DOI: 10.3969/j.issn.1674-0696.2019.01.12 Abstract ( )   PDF (477KB) ( )   In order to measure the effect of traffic congestion on the equilibrium outcomes in the taxi market, the equilibrium model of taxi market including cruise car and online-booking taxi in traffic congestion environment was constructed, by using the Cobb-Douglas production function as the expression of matching function. The examples show that increasing the average speed of the two types has different effects on customers waiting time, taxis vacant time and the proportion of the E-hailing and roadside hailing customers, but both can improve the social welfare of the taxi system. Furthermore, increasing the average speed of the occupied taxi has a more significant effect on improving the social welfare of taxi system when traffic congestion is serious. References | Related Articles | Metrics

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Driving Cycle Construction of Urban Bus Line Based on Clustering Analysis LI Yaohua, LI Zhongyu, GOU Qizhi, REN Tianyuan, SHAO Pandeng, LIU Peng 2019, 38(01): 83-88.  DOI: 10.3969/j.issn.1674-0696.2019.01.13 Abstract ( )   PDF (713KB) ( )   For the construction of driving cycle of Xian bus line, the line intensity was used to select the sampled bus line and a comprehensive stability index of the samples was proposed to judge whether the sampling data were saturated. Based on the method of clustering analysis,the driving cycle of Xian bus line was constructed.The validity of the construction condition was verified by the average error and V-A probability 2-D distribution matrix similarity.The test data indicate that the average error is only 7.3% between the sampling data and the constructed cycle and the similarity coefficient of the V-A probability distribution matrix of both is 0.9957, which shows that the error caused by the clustering method is small and accords with the actual driving condition. References | Related Articles | Metrics

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Location of Dynamic Emergency Materials in the Case of Road Rehabilitation after Disaster MENG Yanping, SHEN Manman 2019, 38(01): 89-96.  DOI: 10.3969/j.issn.1674-0696.2019.01.14 Abstract ( )   PDF (589KB) ( )   In order to study the location of dynamic emergency materials after earthquake disaster, a multi-objective mixed integer programming model was established by considering the road rehabilitation after disaster and balancing the cost of secondary transportation and the psychological punishment cost of victims waiting for materials, which was aiming at minimizing the transportation cost of emergency materials and the psychological punishment cost of victims waiting for materials. And the location schemes of dynamic emergency materials under different road rehabilitation conditions were also determined. Considering the influence of weight and other parameters in the model, 3 kinds of experiments were designed and the experiment results were discussed.Through an actual case,72 hours after the Yaan Earthquake were divided into six periods and each time period corresponded to different road rehabilitation conditions. Therefore, the emergency material location scheme for each time period was determined.The practicability of the proposed model was verified. References | Related Articles | Metrics

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Park and Ride Efficiency Evaluation of Rail Transit Based on Data Envelopment Analysis PENG Jinshuan,ZHANG Lei, XU Lei, PU Key ou 2019, 38(01): 97-101.  DOI: 10.3969/j.issn.1674-0696.2019.01.15 Abstract ( )   PDF (403KB) ( )   In order to ease the dense traffic flow in the central area of large and medium-sized cities in China, park and ride facilities have been built in recent years. Based on the investigation of park and ride facilities in Chongqing rail transit stations, the influence factors of park and ride efficiency were analyzed. The transfer walking distance, the number of berths, transfer fees, departure interval were selected as input indicators,and the transfer time, transfer passenger flow were selected as the output indicators.Based on data envelopment analysis method, the evaluation model of park and ride efficiency was built. Based on DEA model, the park and ride efficiency of 5 typical rail transit facilities in Chongqing were evaluated. The proposed efficiency evaluation model of park and ride facilities has a certain reference value for the current rail transit planning and construction. References | Related Articles | Metrics

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Waiting Time Characteristics of Rail Transit Station Based on IC Card Data CHEN Yanyan1,CHEN Xingbin1,WU Kehan1, LI Jinshan2, XIONG Jie1 2019, 38(01): 102-107.  DOI: 10.3969/j.issn.1674-0696.2019.01.16 Abstract ( )   PDF (866KB) ( )   In the face of a large number of commuting passengers at rush hour,the urban rail transit passengers are likely to wait for the next vehicle because the subway has been fully loaded with passengers, which results in the waiting time for rail stations. Based on the above, a method of calculating the real waiting time of passengers in rush hour based on IC card data of Metro was proposed.The characteristic of the proposed method was to calculate the waiting time in the passenger station at peak time by the relationship between the passengers travel time at peak time and the passengers travel time at non-peak time, aiming at the specific OD. The true and accurate waiting time could be calculated on the basis of IC carddata.The waiting time of 278 railway stations in Beijing was calculated by using the data of Beijing IC card, and the characteristics of waiting time were also analyzed. References | Related Articles | Metrics

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Relation between Visual Search Strategy and Situation Awareness in Tower Control JIN Huibin1, LV Chuan2, ZHU Guolei3 2019, 38(01): 108-112.  DOI: 10.3969/j.issn.1674-0696.2019.01.17 Abstract ( )   PDF (486KB) ( )   To study the visual search strategy of tower controllers with different level of situation awareness, a tower control simulation eye movement experiment platform was built to conduct experiment. Three-dimensional situational awareness assessment technology (3D-SART) was used to evaluate the level of situational awareness of the tested subject.The fixation entropy rate and the number of fixation points in the interest area were introduced as eye movement indicators to analyze the visual search features of the tested subject.The results show that the number of fixation points of the tested subject with high situational awareness mainly concentrates in the air space monitoring area and the ground monitoring area,and their fixation entropy rate is significantly higher than that of the one with low situational awareness.The former allocates attention resources reasonably, shifts attention flexibly and has a larger scanning range, which has a higher visual search efficiency; the latter is the opposite. References | Related Articles | Metrics

Vehicle &Electromechanical Engineering

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Lane Changing Behavior of Vehicles in Urban Road Work Zone Based on Cellular Automata TIAN Sheng, XU Kai, MA Meina 2019, 38(01): 113-118.  DOI: 10.3969/j.issn.1674-0696.2019.01.18 Abstract ( )   PDF (587KB) ( )   In order to study the vehicle daily lane changing behavior of urban road work zone, a microscopic cellular automaton model was established with the consideration of driving characteristics of the work zone; in order to describe the change of lane changing location of vehicles in daily travel, a macroscopic diurnal change model of lane changing location was established. Combined with the microscopic model and the macroscopic model, the numerical simulation was carried out. The influence of evolution days, daily simulation time, vehicle density and acceptability on the traffic characteristics such as the average vehicle speed and fluctuation of two-lane, the probability of lane change at different locations, the temporal and spatial evolution of vehicle and the phase change of traffic flow were analyzed. The results show that with the increase of vehicle density, the average vehicle speed of two-lane decreases, the oscillation amplitude of the vehicle speed increases, and the change of frequency in vehicle speed accelerates. The location of vehicle changing lane moves forward with the evolutionary days and tends to be stable. When the vehicle density increases, the phenomenon that the traffic flow of the lane changing from the free phase to the blocking phase increases. The probability of lane changing at different location is not sensitive to the change of acceptability between (1, 2). References | Related Articles | Metrics

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Reliability Lifetime Distribution of IGBT Module Based on K-S Test and ALTA WU Huawei1, YE Congjin1,2, NIE Jinquan1 2019, 38(01): 119-124.  DOI: 10.3969/j.issn.1674-0696.2019.01.19 Abstract ( )   PDF (440KB) ( )   In order to obtain the life information of insulated gate bipolar transistor (IGBT) and determine its life distribution, a new method was proposed to study the accelerated life test data of IGBT modules by means of Kolmogorov-Smirnov test and accelerated life testing data analysis software (ALTA). Firstly, the lifetime of IGBT module was assumed to obey lognormal distribution. Secondly, a group of IGBT accelerated life data were tested, compared and analyzed by Weibull and log-normal distribution test by using K-S test. Furthermore, the acceleration lifetime data of another group of IGBT were simulated and analyzed by ALTA.The results show that the IGBT lifetime is followed by log-normal distribution under the Arrhenius acceleration model. This proposed method makes it possible to quickly estimate the lifetime of IGBT module. References | Related Articles | Metrics

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Stirring and Dispersing Mechanism of PVA Fiber Bundle Based on ANSYS CFX CAO Yuanwen1, ZHOU Hua1, XIAO Wei1, YANG Xue1, XIA Zhulin2, ZHENG Nanxiang3 2019, 38(01): 125-130.  DOI: 10.3969/j.issn.1674-0696.2019.01.20 Abstract ( )   PDF (1142KB) ( )   In order to improve the agitation and dispersion quality of PVA fiber bundles in certain stirring equipment, the influence of different stirring blades parameters on the dispersion performance was studied. A numerical simulation model of the stirring and dispersing equipment was established based on ANSYS CFX software. Taking the rotational speed and type of impeller as the research object, the mixing mechanism of PVA fiber bundle was analyzed, according to the nephogram of flow velocity and turbulent kinetic energy. The results show that: with the increase of rotational speed, both the flow velocity and the turbulent kinetic energy increase, and the dispersion effect increases first and then decreases. The rotational speed 650r/min is the best stirring speed of PVA fiber bundle mixing equipment. The flow velocity and turbulent kinetic energy distribution in combined impeller have the best effect on shear and mixing of PVA fiber bundle, and the dispersion effect is the best. References | Related Articles | Metrics

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Simulation Analysis on Dynamic Balancing for Crankshaft of a Three Cylinder Diesel Engine XU Guangjv，GAO Jian，ZHAO Yang 2019, 38(01): 131-136.  DOI: 10.3969/j.issn.1674-0696.2019.01.21 Abstract ( )   PDF (683KB) ( )   A rigid body model and a flexible body model for a crankshaft of a three cylinder diesel engine were established by using Pro/E and Adams. The dynamic loads, spectral curves and integral curves of each spindle neck were obtained by using fast Fourier transformation, and the balance performance of the whole machine was judged by the amplitude of various frequencies. In X direction (longitudinal), it is found that different first-order reciprocating inertia moment transfer ratio has little influence on the vibration amplitude of the crankshaft spindle hinge pairs. In Y direction (transverse), it is found that from the frequency domain signal, different transfer rate of the first order reciprocating inertia moment reaches the maximum at the same frequency, and the root mean square decreases with the decrease of the transfer rate of the reciprocating inertial moment. In Z direction (transverse), the different first-order reciprocating inertia moment transfer rate has little influence on the two-order frequency vibration of the crankshaft main shaft hinge pairs. In different first-order reciprocating inertia moment transfer rate, the variation trends of maximum, mean and root mean square of resultant forces on crankshaft main journals are different. Among them, the root mean square (RMS) can reflect the vibration strength most comprehensively. References | Related Articles | Metrics