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18 December 2017, Volume 36 Issue 12 Previous Issue    Next Issue
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Bridge & Tunnel Engineering
Highway & Railway Engineering
Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment
Traffic & Transportation Engineering
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Bridge & Tunnel Engineering

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Mechanical Behavior Analysis on Y-Type Tension Joint of Rectangular Concrete-Filled Steel Tube Truss XIANG Zhongbao1，WANG Wei1，CHENG Gao2，NIE Jiliang1，CHANG Qizhong1 2017, 36(12): 1-5.  DOI: 10.3969/j.issn.1674-0696.2017.12.01 Abstract ( )   PDF (4435KB) ( )   Taking a rectangular concrete-filled steel tubular truss bridge as an example，the K-type connections were divided into Y- type tension joints and Y-type compression joints. The nonlinear finite element analysis model was established from the most basic Y- type tensile joints. The influence of the parameters such as the concrete filled in the chord and the PBL stiffener on the deformation ，failure mode and stress distribution of the joints were analyzed. The results show that filling concrete in steel tube can increase anti-deformation ability and reduce stress level of the joints，but the phenomenon of debonding between the steel pipe and concrete is easy to occur; setting PBL stiffener can effectively increase the bonding force of the interface between steel and concrete，prevent interface debonding，greatly improve the node deformation resistance，obviously decrease the node stress level and effectively improve the ultimate bearing capacity of the node and the node stiffness. References | Related Articles | Metrics

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Effect of the Restrainer Pier Expansion Joint Spacing on the Longitudinal Seismic Performance of Long Bridges WANG Xu1，2，HUANG Chao1，LI Huaqiang1，LI Shiya1，LIU Huailin2，LIU Haiming2 2017, 36(12): 6-12.  DOI: 10.3969/j.issn.1674-0696.2017.12.02 Abstract ( )   PDF (969KB) ( )   Practice and experience in engineering shows that restrainer piers can greatly reduce the occurrence of collapse of long bridge，while the size of expansion joints at the restrainer piers top can affect the longitudinal seismic performance of long bridge tremendously. Consequently，the effect of expansion joint spacing on the dynamic response of long bridge under the action of the longitudinal seismic was analyzed by means of finite element analysis. Researches show that with the increase of the spacing，the main beam does not appear collision and the impact force does not show a downward trend. The maximum bending moment of the ordinary pier bottom does not show a particularly obvious law; however，the maximum pier bottom bending moment of the restrainer pier is mainly affected by the impact force，and the change of the maximum pier bottom bending moment is similar to the maximum impact force at the pier top. As a matter of fact，the maximum relative displacement between girder and pier，the maximum impact force as well as the maximum pier bottom bending moment of the ordinary pier do not make difference with the increase of the expansion joint spacing. References | Related Articles | Metrics

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An Improved Filtering Algorithm for Bridge Crack Image WANG Ying 2017, 36(12): 13-17.  DOI: 10.3969/j.issn.1674-0696.2017.12.03 Abstract ( )   PDF (2259KB) ( )   For the complicated noise information around the bridge crack，the traditional filtering method can get the denoising effect in some aspects when dealing with such noises，but they often have their own big defects. Therefore，based on the traditional morphological filter，an algorithm based on multi-angle multi-structure element morphological filter was proposed. By combining mathematical morphology，a variety of structural elements were combined to avoid the single effect of single structural element on image processing，which could not only analyze the whole region of the image，but also retain the detail information of the image. The comparison analysis on the experimental data shows that the proposed filtering algorithm has achieved remarkable results. References | Related Articles | Metrics

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Detection System of Tunnel Portal Steel Ring Based on C# and SQL Server ZHANG Yang1，ZHANG Zhigang1，QIAN Dong1，TIAN Linya2，BI Jixin2 2017, 36(12): 18-21.  DOI: 10.3969/j.issn.1674-0696.2017.12.04 Abstract ( )   PDF (692KB) ( )   The research on the algorithm that directly obtains the center coordinates and the radius based on space vector fitting 3D circle was carried out，and the proposed algorithm was applied to the detection and analysis of tunnel portal steel ring’s spatial formation. C# programming language and SQL Server database were used to develop the data processing and analysis system for detection of tunnel portal steel ring. The proposed system could fit portal steel ring’s spatial formation，calculate the center coordinates and radius of tunnel portal steel ring and accomplish the quality evaluation of the spatial formation of portal steel ring. Through an example of engineering application，the correctness of the proposed detection method and analysis system was verified. Research results can provide the reference to the detection work of spatial formation for other similar buildings. References | Related Articles | Metrics

Highway & Railway Engineering

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Feasibility Analysis of Cylindrical Specimen for National Standard Rutting Dynamic Stability Test LI Weiyong1，ZHANG Lei1，YANG Jianhua2，ZHANG Zhengqi2 2017, 36(12): 22-29.  DOI: 10.3969/j.issn.1674-0696.2017.12.05 Abstract ( )   PDF (1762KB) ( )   In order to analyze the feasibility of cylindrical specimens used to evaluate the anti-rutting performance of asphalt mixture，a comparative and contrastive method of indoor experiment was adopted. Firstly，the internationally recognized Hamburg rutting test，APA rutting test and small-scaled acceleration loading test were selected; the cylindrical specimens of 6 different types of asphalt mixtures were experimented respectively; and the correlation between the results obtained from the above three methods and the national standard rutting test results of cylindrical specimen proposed in the text was analyzed. Secondly，the variation of void fraction and dynamic stability of specimen formation of plate specimen and cylindrical specimen used in national standard rutting tester was compared，and the reliability of cylindrical specimen rutting test was discussed. The results show that there is a close correlation among the dynamic stability indexes of the cylindrical specimen national standard rutting test，the rutting depth of Hamburg，the dynamic stability of APA rutting test and the creep rate of small-scaled acceleration loading test. Also ，the reliability of the cylindrical specimen for national standard rutting test is higher than that of the slab specimen，which represents that it is feasible for cylindrical specimen applied in national standard rutting tester to evaluate the anti-rutting performance of asphalt mixture. References | Related Articles | Metrics

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Experimental Study on Micro-cracks Technology of Cement Stabilized Macadam Based on Crack Width Statistics WEI Lianyu，LI Na，ZHANG Jing 2017, 36(12): 30-35.  DOI: 10.3969/j.issn.1674-0696.2017.12.06 Abstract ( )   PDF (3499KB) ( )   For the settlement of shrinkage cracks of semi-rigid base，the micro-crack technology of cement-stabilized macadam base in our country has been at the early stage of research and development. Through the study on the relationship between vibration time of the compaction tester and reducing percentage of unconfined compressive strength，the relationship between the degree of micro-crack and vibration time was determined; the micro-crack width value on the specimen surface after micro-crack was observed and read by the crack width detector; the processing and statistical analysis on the filed measurement data of micro-crack width was carried out with the help of SPSS. The results show that：through descriptive statistical analysis，the range of micro-crack width value at various degrees of micro-crack is determined，which provides the theoretical reference for the quantitative relationship for the micro-crack technology of cement-stabilized macadam base. At the same time，by using univariate analysis of variance (UNIANOVA) to research the impact significance which the micro-crack degree and the type of material structure have on the micro-crack width value，it is concluded that the micro-crack degree has a significant effect on micro-crack width value while the type of material structure has no significant effect on that. References | Related Articles | Metrics

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Mechanical Properties and Microcosmic Mechanism of Cement Mortar Modified by Graphene Oxide YUAN Xiaoya1，YANG Yaling1，ZHOU Chao1，ZENG Junjie1，XIAO Guilan1，LIU Shaoli2 2017, 36(12): 36-42.  DOI: 10.3969/j.issn.1674-0696.2017.12.07 Abstract ( )   PDF (2571KB) ( )   Graphene oxide (GO) were prepared by Hummers method and ultrasonic dispersion method; the structure was characterized by TEM，FT-IR and X-ray photoelectron spectroscopy. The influence rules of single GO，both GO and PC addition on the flexural strength and compressive strength of cement mortar were studied. The results indicate that with the presence of polycarboxylate superplasticizer (PC)，GO has good dispersion ability in cement-water system; after adding GO and PC，the flexural compressive strength of cement mortar for 3 and 28 days is improved by 20% higher than that of single doped GO or single doped PC specimen，and the strength at early stage is improved significantly. The scanning electron microscope (SEM) and the pore size analysis of cement paste show that GO can participate in the hydration process of cement and regulate the growth of cement hydration crystal; GO modified cement mortar C-S-H crystal can have dense，neat and regular growth on the GO layer，so the internal structure of the specimen is more dense，which makes GO modified cement mortar exhibit excellent mechanical properties. References | Related Articles | Metrics

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Influence of Complete Local Void in Middle and Lower Surface Layers on the Stress of Three-Layer Asphalt Pavement Surface SONG Chaolin1，NING Jincheng2 2017, 36(12): 43-46.  DOI: 10.3969/j.issn.1674-0696.2017.12.08 Abstract ( )   PDF (350KB) ( )   Typical structure of asphalt pavement with 3 layer structure was adopted. Aimed at the situation of complete local void of middle and lower surface layer，the comparison model between full bond and complete local void was established by the finite element method，considering the load acting on two different load positions，that is，the middle and the edge of the void. The deflection， shear stress and bending tensile stress of each layer of asphalt pavement with different contact conditions under vertical load were calculated and studied，and the influence of different load positions on the mechanical response of each layer was compared. The study shows that the influence of complete local void on the surface layer can’t be neglected. References | Related Articles | Metrics

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Field Experimental Study on Seasonal Variation Rule of Water Content of Highway Subgrade in Guangzhou Area XU Guoyuan1，YANG Jian1，LIN Lixin2，HUANG Hao2 2017, 36(12): 47-52.  DOI: 10.3969/j.issn.1674-0696.2017.12.09 Abstract ( )   PDF (1094KB) ( )   In order to study the seasonal variation rule of water content of highway subgrade in Guangzhou area and put forward a reasonable model of the water content variation of the subgrade，the fill subgrade of North Second Ring Expressway of Guangzhou was selected，and the volume moisture content of subgrade in different depth was measured in filed for 1 year by embedding water sensor. The results show that the rainfall in Guangzhou area mainly concentrates in April to October; and the peak values of the volumetric moisture content of subgrade occur in May to August，which all exceed 0.33 m3 /m3 and fluctuate with rainfall. All the maximum values of variation coefficients of volumetric moisture content of subgrade with different depth appear in the rainy season of May to July， and mainly concentrate in the roadbed. The volumetric moisture content of subgrade exhibits a periodic variation rule with time. The regression analysis shows that the variation rule of the monthly average water content has a good sine function relationship with the month，and the relationship between the variation range and the depth of the subgrade can be characterized by exponential function. References | Related Articles | Metrics

Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment

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1D Shallow Water Wave and 3D VOF Coupling Simulation of Transient Open-Channel Flow ZHANG Xiaoxi1，ZHANG Chunze2，CHEN Qiuhua3 2017, 36(12): 53-57.  DOI: 10.3969/j.issn.1674-0696.2017.12.10 Abstract ( )   PDF (571KB) ( )   A numerical method for simulating the transient open-channel flow by coupling 1D shallow water wave and 3D VOF models was proposed. Firstly，by establishing the mathematical relationship between the variables of the two calculation models，the proposed method realized that 3D region provided flow for 1D region and 1D region provided the pressure and volume fraction distribution of water for 3D region. Then，two typical transient conditions of rectangular cross-section channel during load rejection and increase were simulated by coupling method. Comparing the above results with the calculation results obtained by 1D shallow water wave model， it shows that the proposed method is qualitatively correct，and the accuracy is high in quantitative. Finally，the transient open- channel flow in a pressure fore bay of a hydropower station with inlet pipes was simulated by the proposed method，and the critical parameters，such as the maximal overflow discharge，the maximal and minimal water levels were obtained. The coupling method combines the efficiency of 1D model in the calculation of a fine long canal and the accuracy of 3D model in the simulation of local open- channel blast flow，which can provide a better choice for analyzing complex open-channel flow problems in engineering. References | Related Articles | Metrics

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Geological Characteristics and Foundation Pretreatment Method in Tongzhou Bay New District Engineering LIU Jian1，LIU Peigui1，WU Yuelong2，TANG Tongzhi3，CAI Rui1，SUN Sucai1 2017, 36(12): 58-66.  DOI: 10.3969/j.issn.1674-0696.2017.12.11 Abstract ( )   PDF (1471KB) ( )   The geological background of Tongzhou bay new district was expounded，and many regional geological survey materials of some developing areas including science and technology city A03，A04，B01，B03 block and Chunhui Lu were organized，summarized and analyzed. At the same time，relying on typical engineering cases，several foundation pretreatment techniques suitable for the new district were analyzed and compared. Research results show that：the geological soil layer in the new district is a double layer loose geological type alternating with rhythmic sand layer and clay layer，which has both regional environment geological characteristics and local particularity. The high water level and continuous rainfall is another feature of the new district，which brings great difficulty to the foundation construction and the dewatering. The new dewatering dynamic compaction method and drainage consolidation method are more appropriate for the foundation pretreatment of large area in new district. Reasonable choice of composite foundation method can combine the foundation pretreatment and treatment，which greatly shortens the project duration and saves the cost. References | Related Articles | Metrics

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Experimental Study on Basic Physical Property of Dunkirk Marine Soils XING Wei1，WANG Dongxing2 2017, 36(12): 67-72.  DOI: 10.3969/j.issn.1674-0696.2017.12.12 Abstract ( )   PDF (680KB) ( )   Laboratory tests have been carried out to determine the physical property of marine sediment from Dunkirk harbor，and the mineral composition and effect of temperature effect on the physical property was studied. The laboratory results show that：the main minerals of the test marine sediment samples are calcite，quartz and halite，and the main chemical elements are silicon，oxygen and calcium; for the sediments with high water content，the duration required for the complete drying of sediment samples is 48 hours and 7 hours respectively for oven drying method at 40 ℃ and 105 ℃; under the two conditions at 450 ℃ and 550 ℃，the content of organic matter obtained by the method of mass ignition loss is usually greater than that tested by the oxidation method; the ignition loss of samples increases with the increase of the temperature，and the absolute density of the samples increases with the increase of ignition temperature. The results obtained by the thermo gravimetric-differential thermal analysis reveal that the mass loss of sludge samples and the variation rule of the physical-chemical reaction changing with temperature，and explain the main causes of mass loss of samples induced by ignition loss method and thermo gravimetric-differential method at different temperatures. References | Related Articles | Metrics

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Ecological Security Assessment of Chongqing Section of Three Gorges Reservoir Area Based on Fuzzy Matter-Element Model GUAN Dongjie，ZENG Yixiao 2017, 36(12): 73-81.  DOI: 10.3969/j.issn.1674-0696.2017.12.13 Abstract ( )   PDF (874KB) ( )   Taking the Three Gorges Reservoir area (Chongqing section) as the research scope，the evaluation index system of ecological security was established. Based on fuzzy matter-element principle and conceptual framework，21 indicators were selected from the aspects of social，economic，natural geographical features and etc.，and the fuzzy matter-element evaluation matrix of 22 counties in the study area was determined. The ecological safety evaluation of the above counties in the research scope was carried out，and according to the research results the ecological security was divided into 5 grades，including “very insecure，insecure，relatively secure，secure and very secure”; meanwhile，it was compared with the evaluation method and conclusion of AHP-PSR method. Research results show that：in the evaluation process of fuzzy matter-element model，the optimal subordinate degree and joint domain of each index are set，and its conclusion is more scientific，compared with AHP-PSR evaluation results. In the northeast Three Gorges Reservoir area，the ecological security situation is good; in the relatively developed area of west Three Gorges Reservoir area，the ecological environment protection should be strengthened，and the city environmental diseases should be alleviated. References | Related Articles | Metrics

Traffic & Transportation Engineering

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Influence of Speed Limits on Operation Efficiency of Two-Lane Highway on the Qinghai-Tibet Plateau HE Yulong，ZHANG Lufei 2017, 36(12): 82-90.  DOI: 10.3969/j.issn.1674-0696.2017.12.14 Abstract ( )   PDF (631KB) ( )   Through the investigation of vehicle speed，vehicle composition，road alignment，altitude oxygen content and current speed limit combination mode of two-lane highway in Qinghai Tibet plateau，the car speed limit velocity mean model and speed mean-operation speed model of two-lane highway in plateau area were established respectively by the method of multiple linear regression and SPSS statistical software，considering the control delay caused by the speed limit as an index to evaluate the operation efficiency of the plateau highway. Finally，the interaction model between speed limit and operation efficiency-delay was obtained. The results show that ：the speed limit value of the car and cart，the longitudinal slope of the road，the length of the road section and the design speed of the road have an influence on the running efficiency of the vehicle running on the road system. The difference is that the factors such as different road grade and the proportion of cars on the road will have a certain impact on the efficiency of the car，but a little impact on the cart. In addition，with the increase of altitude，the operation efficiency of large and small cars is gradually decreased，and the delay caused by the cart is higher than that of the car. References | Related Articles | Metrics

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Analysis and Evaluation Method for Traffic State of Urban Regional Road Network HUANG Yanguo1，SONG Ermeng1，ZHONG Jianxin2 2017, 36(12): 91-96.  DOI: 10.3969/j.issn.1674-0696.2017.12.15 Abstract ( )   PDF (513KB) ( )   In order to improve the accuracy of the traffic state discrimination of the regional road network，the difference of the impact of different sections and intersections on the whole traffic running condition of road network should be considered. The traffic state models of sections and intersections were established through building a road network structural model. According to the topology relationship between the sections of the road network，a traffic state matrix was established，which can be used to represent the temporal and spatial information of road network. Considering the importance of road network elements in the road level and their influence，the weight coefficient models of the road section and intersection were established. On this basis，a comprehensive discrimination model was established to reflect the traffic status index of the regional road network，and the traffic state levels of the road network were determined. Through the simulation of regional road network，the traffic state of road network was analyzed with the average travel speed as evaluation index. The results show that the proposed method is practical and effective for the discrimination of regional traffic congestion state. References | Related Articles | Metrics

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On-Line Measurement of Vehicle Driving Deviation ZHOU Xinglin，WU Yang，LV Wensha，YIN Haohui 2017, 36(12): 97-101.  DOI: 10.3969/j.issn.1674-0696.2017.12.16 Abstract ( )   PDF (1134KB) ( )   In order to solve the all-weather and high precision measurement problem of vehicle driving deviation，a vehicle driving deviation test method based on satellite real-time differential positioning technology was developed. The mobile station receiver was set in the measured vehicle to receive the real-time vehicle trajectory coordinates. The vehicle driving deviation trajectory model was established and the parameters of vehicle driving deviation were calculated. Meanwhile，wavelet transform was used to filter the satellite signal，which weakened the interference of multipath effect and improved the detection precision of the system. Through the comparative test with the same vehicle measured by two mobile station receivers at the same time，it is proved that the proposed method can detect the vehicle driving deviation quickly and effectively，and the test precision is high. Moreover，it can realize all-weather measurement. References | Related Articles | Metrics

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A Multi-objective Public Transit Network Planning Model HU Jihua1，2，GAO Lixiao1，2，LIANG Jiaxian1，2，CAI Ming1，2 2017, 36(12): 102-109.  DOI: 10.3969/j.issn.1674-0696.2017.12.17 Abstract ( )   PDF (1400KB) ( )   Transit network planning is one of the important parts of urban traffic planning. A multi-objective programming model for public transit network was proposed to address the transit network planning problem. The objective function of the proposed model was to minimize the total travel time and the total numbers of transfers as well as to maximize the demand density of the network. Taboo search and simulated annealing algorithms were used to solve the proposed model. The proposed model and algorithms were tested by using the Sioux-falls network. The results show that compared with previous studies，the results of the proposed model have higher nonstop ratio，less transfer times，better service level and attractiveness of public transport. Compared with the taboo search algorithm，the simulated annealing results have higher nonstop ratio，larger demand density and higher efficiency. Therefore，the proposed model can be effectively applied to the planning of public transport network. References | Related Articles | Metrics

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Transportation Route Selection in Stochastic Time-Dependent Network LIU Shuai1，TANG Boming1，LIU Song2 2017, 36(12): 110-114.  DOI: 10.3969/j.issn.1674-0696.2017.12.18 Abstract ( )   PDF (457KB) ( )   The travel time at each section of road transportation network was affected by traffic management，traffic congestion， weather changes and other uncertainties，so it showed stochastic time-dependent characteristics. The three-time valuation method in road network evaluation technique was introduced，and a path optimization model in stochastic time-dependent road network to minimize the travel time was established. A time-dependent function of the road sections when the vehicle travelled inter-temporally was proposed. Moreover，an algorithm of dynamically programming and labeling was designed to solve the function. Through a comparative analysis of the optimization results of the application examples，the effectiveness of the proposed model and algorithm was verified. References | Related Articles | Metrics

Vehicle &Electromechanical Engineering

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Experiment Study and Finite Element Analysis of Cantilever Beam Piezoelectric Energy Harvesting Device ZHANG Min，ZHANG Hongxin，LEI Lin，LIU Yongzhen，ZHANG Lin 2017, 36(12): 115-120.  DOI: 10.3969/j.issn.1674-0696.2017.12.19 Abstract ( )   PDF (1218KB) ( )   The excited experiments for unimorph and bimorph piezoelectric cantilever beams were carried out. The first order natural frequencies of four piezoelectric cantilevers were determined，and the voltage and power response curves of each structure under different frequencies were obtained with the increase of load resistance. The experiments indicate that these piezoelectric cantilever beams can export the maximum voltage and power when the excited frequency is matched with the natural frequency of piezoelectric cantilever beams. Then the structure models of the piezoelectric cantilever beams were simulated by COMSOL software. The results of the output voltage and power of FEM are consistent with the experiments. A multi-cantilever piezoelectric energy harvester was proposed to deal with the vibrational energy dissipation in marine diesel engine. Frequency domain analysis of the harvester was carried out by COMSOL. The results show that this harvester can achieve a good and stable output power from marine diesel engine in multiple main vibration frequency. References | Related Articles | Metrics

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Design and Simulation Verification of Vehicle Simulation Impact Test Device DU Xuejing，WANG Dongsheng，PEI Yulong， WANG Zhanyu 2017, 36(12): 121-126.  DOI: 10.3969/j.issn.1674-0696.2017.12.20 Abstract ( )   PDF (866KB) ( )   In order to study the distribution characteristics of group fallout loaded by vehicle in the traffic accident，a vehicle simulation impact test device was designed on the basis of the domestic and international automobile impact test benches. According to the requirements of collision speed in the simulation collision test device，the selection of three-phase induction motor and the strength of the traction rope were calculated，and the simulation of the whole system was carried out by using ANSYS/LS-DYNA software. The results show that the proposed test device can accelerate the test vehicle to a required crash speed within a certain distance and can simulate the frontal impact of vehicle at low speed，which meets the requirements of relevant national laws and regulations. Moreover，the proposed test device has enough strength and can be used repeatedly. References | Related Articles | Metrics