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09 December 2018, Volume 37 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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Temperature Distribution of Box Girder with Corrugated Steel Webs XU Xiangfeng1, 2, ZHANG Feng3, LIU Jiaqi3 2018, 37(12): 1-10.  DOI: 10.3969/j.issn.1674-0696.2018.12.01 Abstract ( )   PDF (701KB) ( )   The temperature gradient of the box girder with corrugated steel webs is an important problem in the design of box girder bridges with corrugated steel webs. The temperature field test of box girder bridge with corrugated steel webs was carried out for 9 months; and a 2D finite element model of the temperature field of corrugated steel webs was established. Typical weather conditions were selected to carry out the numerical simulation. The validity of the finite element model of temperature field is verified by comparing the results of numerical simulation and real bridge temperature test. The temperature difference between day and night in the area where the corrugated steel webs box girder bridge was located was analyzed by mathematical statistics, and the representative values of atmospheric temperature difference between day and night in the area where the corrugated steel webs box girder bridge was located were obtained. The temperature distribution of box girder with corrugated steel webs was analyzed based on the representative value of atmospheric temperature difference between day and night. Research results show that: the temperature difference between day and night in the area where the corrugated steel webs box girder bridge is located obeys W (10.453, 2.577) distribution. For the roof, the temperature gradient of numerical simulation is similar to that of steel-concrete composite bridge in General Code for Design of Highway Bridges and Culverts . The difference is that the maximum temperature difference obtained by theoretical analysis is 20.8℃, while that of the standard is defined as 25 ℃. References | Related Articles | Metrics

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Mechanical Properties Degradation of Corroded Main Cable Wires of Suspension Bridge HAN Yixuan1, 2, XIN Fukai3, ZHANG Guorong1, 2, ZHU Xiaowen1, 2 2018, 37(12): 11-17.  DOI: 10.3969/j.issn.1674-0696.2018.12.02 Abstract ( )   PDF (815KB) ( )   To study the mechanical degradation state of the corroded main cable wires of suspension bridge, the high-tensile wires from main cables with 18-year service life were employed and the complete main cable that intercepted from the suspension bridge was inspected. The corrosion degree evaluation index of loss rate of the minimum sectional area was proposed. The degradation rule of mechanical properties of the corroded main cable wires was studied and the degradation model of corroded steel wires was established, according to the tensile test and fracture surface analysis of corroded steel wire in service. The experiment results show that the corrosion has little effect on the elastic modulus of the steel wires. However, the increase of corrosion degree will lead to a significant decrease in elongation and ultimate strain of steel wire; meanwhile, it will also reduce the ultimate strength and yield strength. Based on the test results, the constitutive relation model for the corroded steel wires with the loss rate of the minimum cross-sectional area less than 10% was established, which provided the basis for evaluating the mechanical properties and residual strength of main cable steel wires. References | Related Articles | Metrics

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Influence of Shock Absorption Measures and Traveling Wave Effect on Seismic Response of Kilometer Grade Cable-Stayed Bridge TANG Shuanglin 2018, 37(12): 18-23.  DOI: 10.3969/j.issn.1674-0696.2018.12.03 Abstract ( )   PDF (572KB) ( )   Based on the design scheme of a cable stayed bridge with a main span of 1500 m, a finite element analysis model was established; and the reasonable design parameters of the longitudinal damping device of the bridge were developed through the parameter sensitivity analysis. For the structural design scheme of tower and girder longitudinal bridges with three different restraint modes, the influence of traveling wave effect on the seismic response of the structure was analyzed by large-mass method (LMM). The results show that the internal force response of the main tower structure may be increased by about 20%, after considering the traveling wave effect on the structural design scheme of tower and girder longitudinal bridges with three different restraint modes. Therefore, in the seismic design of kilometer grade cable-stayed bridge, whether longitudinal damping measures are adopted or not, if the traveling wave effect is not considered, it may lead to unsafe design results. References | Related Articles | Metrics

Highway & Railway Engineering

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Voids Distribution Characteristics of Asphalt Mixture Based on Multifractal Theory ZHOU Xinglin, LI Qingfeng, XIAO Shenqing 2018, 37(12): 29-35.  DOI: 10.3969/j.issn.1674-0696.2018.12.05 Abstract ( )   PDF (931KB) ( )   In order to describe the voids distribution characteristics of the asphalt mixture accurately, medical CT was used to scan four types of asphalt mixtures (e.g., AC-13, AC-16, ATB and AM) to obtain the internal section image. Then, digital image technology was used to extract the voids characteristics of CT scanning images of asphalt mixture specimens. Finally, the multifractal spectral characteristic parameters of voids distribution were calculated out with the help of MATLAB software. The relationship between the splitting strength of the mixture and the characteristic parameters of the multifractal spectrum was analyzed. The results demonstrate that: the void distribution has multifractal characteristics and the multifractal spectral parameters can reflect the voids distribution from different angles. The peak value of multifractal spectrum fmax has a good logarithmic regression relationship with the surface voidage, and the fractal dimension D0 of the void increases with the increase of fmax, which means the porosity is larger. The spectrum width Δα reflects the whole range of the regional void distribution, while the height difference between both ends of the fractal spectrum Δf reflects the degree of void relative aggregation and dispersion. The splitting strength is significantly correlated with the porosity and the uniformity of distribution. The multifractal characteristics of voids distribution of asphalt mixture can provide a new method and idea for analyzing its pavement performance. References | Related Articles | Metrics

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Influence of Gradation Parameters on Fatigue Performance of Asphalt Stabilized Macadam ZHU Hongzhou1, GE Qi2, HE Zhaoyi1, LI Haoshuang3 2018, 37(12): 36-40.  DOI: 10.3969/j.issn.1674-0696.2018.12.06 Abstract ( )   PDF (389KB) ( )   The fatigue performance of asphalt stabilized macadam directly affects the service life of flexible pavement. Based on the fatigue test data of 9 grades of asphalt stabilized macadam about ATB-25 and ATB-30, the influence of different aggregate gradation parameters on the fatigue performance of asphalt stabilized macadam was analyzed by grey relational analysis, in order to get the impact analysis of the different aggregate gradation parameters on the fatigue properties of asphalt stabilized macadam. Through the statistical method of regression analysis, the regression curves between the key factors obtained by grey correlation analysis method and the representative values of fatigue performance of asphalt stabilized macadam were established. The results show that the mixture passing rate of 2.36 mm sieve and 4.75 mm sieve, the aggregate mass fraction of 0.30~1.18 mm and the 0~0.30 mm sieve interval are the four key factors that affect the fatigue performance of asphalt stabilized macadam in the optimum asphalt aggregate ratio conditions. And the asphalt stabilized macadam mixture has the best fatigue performance under these conditions: the mixture passing rate of 2.36 mm sieve is 27%, the mixture passing rate of 4.75mm sieve is 34%, the aggregate mass fraction of 0~0.30 mm sieve interval is 11%, the aggregate mass fraction of 0.30~1.18 mm sieve interval is 9%. References | Related Articles | Metrics

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Water Stability Compound Improvement Technology of Gravel Asphalt Mixture GUO Yinchuan1, 2, WEI Ziyu1, SHEN Aiqin1, ZHAO Tianyuan1 2018, 37(12): 41-48.  DOI: 10.3969/j.issn.1674-0696.2018.12.07 Abstract ( )   PDF (718KB) ( )   With the development of highway construction and ecological awareness of environmental protection, high quality gravel is increasingly scarce. Although gravel is rich in resources, its application in asphalt surface is restricted by its acidity. In order to improve the adhesion of crushed gravel and asphalt as well as improve the water stability of the gravel asphalt mixture, the inorganic materials such as cement or lime and anti-stripping agent were used as composite modifiers. Therefore, the gravel asphalt mixture was modified in different ways, such as single mixing or compound mixing, in order to enhance the bond between gravel and asphalt. 14 kinds of single mixing and compound incorporation schemes were designed; the influence law of types and contents of modified materials on the water stability of gravel asphalt mixture was studied by residual stability and freeze-thaw test. Based on the pullout test, the effect of admixture on the adhesion between asphalt and gravel interface was studied. The results show that single or compound admixture can improve the water stability of the mixture, but the effect of compound admixture is more remarkable. The improving effect of adding 0.4% amount of AMRⅠ-type anti-stripping agent is better than that of adding cement and lime. The effect of mixing 0.4% AMRⅠ-type anti-stripping agent and 1% cement is best, whose freeze-thaw strength ratio (TSR) and residual stability are increased by 28.8% and 22.6% respectively. With the same dosage, the pullout force is the largest, and the adhesion between asphalt and gravel is the best. The research results are of great theoretical and practical value for the popularization and application of gravel asphalt mixture. References | Related Articles | Metrics

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Crack Reflection of Semi-rigid Base Asphalt Pavement Based on Analytical Method GAO Yuanyuan1, 2, WANG Weiyu2, ZHAO Qingxin1 2018, 37(12): 49-54.  DOI: 10.3969/j.issn.1674-0696.2018.12.08 Abstract ( )   PDF (432KB) ( )   Aiming at the cracking of semi-rigid base of asphalt pavement and the gradual reflection of cracks, the mechanical response research on the cracked pavement was carried out on the basis of analytical method. Firstly, based on the theory of fracture mechanics, a theoretical analysis model of the cracked asphalt pavement was established. Then, the system of partial differential equations was solved by Fourier integral transform, and dislocation density function was introduced to characterize fracture mechanics. The residue theorem was used to calculate complex integrals and singular integral equations were obtained. Lobatto- Chebyshev quadrature formula was applied to solve singular integral equations. Finally, the analytical expressions and numerical solutions of displacement, stress and stress intensity factors at any point of the road were obtained. Based on the engineering example, the main factors affecting the crack reflection of the base course were analyzed. The calculation results show that: under the action of vehicle load, shear failure is the main form of crack propagation, and the elasticity of semi-rigid base is the main factor affecting crack reflection. The research results can provide theoretical reference for the design and construction of semi- rigid base asphalt pavement. References | Related Articles | Metrics

Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment

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Radial Basis Functions Methods for Strongly Nonlinear Beam ZU Fuxing1, 2, XU Jiqing1, 2, LI Yanting1, 2 2018, 37(12): 55-60.  DOI: 10.3969/j.issn.1674-0696.2018.12.09 Abstract ( )   PDF (440KB) ( )   The idea of Radial Basis Functions (RBFs) approximation and the method of weighted residual collocation were combined to solve strongly nonlinear beams. And for different boundary conditions problems, the corresponding RBFs interpolation functions were proposed to decrease the numerical oscillation. By using proper compactness positive definite RBFs, a better solution could be obtained. The actual examples demonstrate that the proposed method has high calculation accuracy that the modified wavelet-Galerkin method and the numerical integration algorithm of the symplectic-conservative and energy-preserving method can achieve. Therefore, the proposed method provides a new way to solve the strongly nonlinear beam because of the simpler calculation process of collocation method than integration method. References | Related Articles | Metrics

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Experimental Study on Navigation Technology Model of Shuikou Dam Downstream Hub of Minjiang River, Fujian YAO Shi, HU Xiaowen 2018, 37(12): 61-68.  DOI: 10.3969/j.issn.1674-0696.2018.12.10 Abstract ( )   PDF (674KB) ( )   The regulation project of the water level of Shuikou Dam of Minjiang River, in Fujian was built to solve the problems of river bed cutting down, water level lowering and inadequate navigation depth in the lower reaches of Shuikou Hydropower Station. The main buildings of the hub were backwater weir and retaining dam, ship lock, and the left bank slope protection, etc. In the engineering design, aiming at raising the downstream water level, improving navigation conditions and other issues, a multi-program model test was carried out. The experiment results show that the adjustment sections of upstream and downstream approaches can effectively improve the navigation flow condition and meet the operation requirements by adding the solid guide wall and waterproof board; the navigation flow condition of the anchor section of upstream approach can also be improved by appropriately extending the navigation wall combined with comprehensive measures, such as void isolating wall. This article is a brief introduction to the research on the navigation conditions of the hub. References | Related Articles | Metrics

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Evaluation of Ecological Purification Effect on Water Quality of River Source Area in Lixia River HANG Qingfeng1, XIA Ting2, WU Qinkai2, HE Tao2 2018, 37(12): 69-76.  DOI: 10.3969/j.issn.1674-0696.2018.12.11 Abstract ( )   PDF (615KB) ( )   In order to ensure long-term and stable operation of the Yanlong Lake project and regional water supply safety, the change trends of 4 key water quality factors such as DO, NH3-N, CODMn and TP were analyzed, according to the monitoring data of water quality in 5 drinking water source areas (Longgang, Yancheng New, Dazong Lake, Dagang, Gu Dianbao ) from 2009 to 2016, in the Lixiahe River network region in northern Jiangsu province. Meanwhile, combined with the corresponding water quality factors and Chl-a index changes in different purification function areas of the Yanlong Lake Project, the water quality purification effect and existing problems of the ecological engineering in the source area were evaluated. The results indicate that the water quality in 5 water source areas is greatly diverse in different water periods. In high and flat water periods, the standard-exceeding rates of water quality are obviously higher than that in dry periods, especially for the factors of DO and CODMn in high periods, with the higher standard- exceeding rates. The Yanlong Lake Project generally has a better purification effect on the water quality of the source area of Mangshe River, but the purification effect of different water quality factors is different in different water periods and different functional areas. On the whole, the project has the best effect to enhance DO, but the reduction rate of CODMn is low, meanwhile, the concentration of Chl-a is high in spring and summer. References | Related Articles | Metrics

Traffic & Transportation Engineering

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Traffic State Identification for Freeway Network Based on MF DDING Heng1, ZHU Liangyuan1,2, JIANG Chengbin1, ZHENG Xiaoyan1 2018, 37(12): 77-83.  DOI: 10.3969/j.issn.1674-0696.2018.12.12 Abstract ( )   PDF (767KB) ( )   In order to identify the traffic state freeway network real-timely and accurately, a method of traffic state identification for freeway network was proposed, combined with the characteristics of Macroscopic Fundamental Diagram (MFD) of freeway network. According to the detection data of floating car, the MFD of the freeway network was obtained and the freeway network was primary divided into 5 categories. Furthermore, according to the real-time data of road network, the state parameters of road network were further corrected by clustering algorithm. Based on the above and according to the relationship of flow and velocity, the freeway traffic state identification model was established, which comprehensively considered the influence of the main flow of freeway traffic, different combination forms of on-ramp and off-ramp and the condition of the road network adjacent to the ground. Finally, the proposed model was compared with the results obtained by road traffic operation index and vehicle travel time method, through the actual road network traffic data. The results show that the proposed traffic state identification model for freeway network is more real-time and accurate. References | Related Articles | Metrics

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Road Network Connectivity Model Based on the Dominant Direction of the Building Collapsing DUAN Manzhen, MI Xueyu, DONG Bo, YA Hongying 2018, 37(12): 84-91.  DOI: 10.3969/j.issn.1674-0696.2018.12.13 Abstract ( )   PDF (742KB) ( )   Based on the macro law of buildings damage under the earthquake, the road network connectivity was researched, which was influenced by the dominant collapsing direction of the damaged buildings. Firstly, the connectivity reliability of evacuation network (CREN) was defined; based on the connectivity analysis of the simple network and that of its equivalent network, a complex connectivity model of the equivalent network was established. And then the collapsing buildings dominant direction in historical earthquakes was analyzed; the related seismological research achievements and traffic theory were combined to study the influence of macroscopic law of earthquake damage on CREN after earthquake. Therefore, a road network connectivity estimation model based on the dominant direction of collapsing buildings under earthquake damage was established, and the systematic evaluation steps of the connectivity of the damaged road network were given. Finally, the application process of the proposed model was illustrated by an example, which provided a reference for the planning of buildings and road networks along the earthquake-prone areas. References | Related Articles | Metrics

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Degradation Index of Regional Network Service Based on Urban Traffic Congestion HU Liwei1, MENG Ling1, QI Shouming2, ZHANG Yaping2, LUO Zhenwu1 2018, 37(12): 92-97.  DOI: 10.3969/j.issn.1674-0696.2018.12.14 Abstract ( )   PDF (503KB) ( )   Referring to the radiation ability of congestion center, the traffic congestion state was classified and the concept of degradation index of regional road network service was proposed. Based on the improved AHM model, five indexes, including saturation of road capacity, time-delay coefficient of traffic congestion, level of free flow, traffic volume and space occupancy, were selected to evaluate the regional road network service and build the degradation index model of regional road network service. Through different regional road network service degradation index, which was corresponding to different congestion degradation level, the proposed method was applied to Kunming trunk road network. The results verify that the quantitative results are consistent with the actual congestion situation, which proves the proposed method has good applicability. Through the research results, the proposed method is expected to provide a new method for evaluating the degree of urban road traffic congestion from the macro level, and to provide a certain reference value for improving the traffic environment and the level of traffic management. References | Related Articles | Metrics

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Evaluation of Public Bicycle Service Quality Based on SERVPERF Model MA Shuhong1, MA Jinlei1, WANG Yuanqing1, HAN Sunsheng2 2018, 37(12): 98-104.  DOI: 10.3969/j.issn.1674-0696.2018.12.15 Abstract ( )   PDF (482KB) ( )   Based on the importance degree of users attention to public bicycle system, a corresponding service evaluation system was established by combining the characteristics of public bicycle and the related factors that affected users choice. Through the form of questionnaire, the SERVPERF model was combined with IPA method to evaluate the service quality of Xian public bicycle. The results show that the reliability and validity of the questionnaire are reliable; the passengers are basically satisfied with the service of public bicycle system in Xian. At the same time, the grey relational degree analysis is used to evaluate and rank the service quality of partition objectively, which provides suggestions for improving the service quality of public bicycle system. References | Related Articles | Metrics

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Influence Factors Analysis on Drivers Driving Behavior on Road Section at Urban-Rural Fringe Based on TPB Theory ZHANG Huiling1, WANG Yi1, 2, YANG Jinyan1 2018, 37(12): 105-110.  DOI: 10.3969/j.issn.1674-0696.2018.12.16 Abstract ( )   PDF (441KB) ( )   In order to provide theoretical support for the establishment and improvement of traffic safety facilities in the urban- rural fringe of China, the driving tendency of drivers was analyzed. A questionnaire was designed based on the Theory of Planned Behavior (TPB). Through the pre-survey data, the use of reliability and validity analysis verified that the questionnaire could be used to analyze the psychological causes of drivers unsafe driving behavior at the urban-rural fringe. The questionnaire survey was launched in Heilongjiang, Hunan, Shandong, Sichuan, Guizhou and other provinces and 155 effective samples were obtained. A hierarchical regression model was used to verify the TPB model. The results show that TPB can be used to explain the causes of drivers  unsafe driving behavior at urban-rural fringe; among them, attitude and perceptual behavior control factors have a key impact on actual driving behavior. References | Related Articles | Metrics

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Drivers Gaze Behavior for Right Turning Vehicle Based on Eye Movement Experiment LI Zhihong1, ZHAO Li2, XU Wangtu3 2018, 37(12): 111-117.  DOI: 10.3969/j.issn.1674-0696.2018.12.17 Abstract ( )   PDF (1585KB) ( )   The characteristics of mixing traffic of vehicle, bicycle and pedestrian make intersections an accident-prone area. The study of drivers gaze behavior is an important way to guide drivers to turn right safely and reduce conflicts. Based on the psychological test of driving tendency, the questionnaire data of 109 drivers were collected and drivers were classified into radical type and cautious type. Six different types of drivers were selected to carry out eye movement experiment in real car, and the gaze behavior of drivers with different inclinations during right turn was studied. The research results show that: cautious drivers are composed mainly of women and people with higher driving experience, and radical drivers are composed mainly of people with lower driving experience and the ones who are about 30 years old. The drivers viewpoint path is linear in the right turn of the motor vehicle. Cautious drivers have higher fixation density and intensity than radical drivers when turning right. Radical drivers neglect the right side of the road when turning right, which results in more blind spots and dangerous spots in the conflict with pedestrians. The study provides a theoretical basis for solving the core issues of the conflict between right-turning vehicles and pedestrians, which trains the drivers visual search and risk awareness, improves drivers driving technology and reduces traffic accidents of right-turning vehicles and crossing pedestrians. References | Related Articles | Metrics

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Investigation and Analysis on Formation Mechanism of the Tidal Phenomenon of the Spring Festival Return by Motorcycle CHEN Fujian, XU Peipei, FENG Feiyu 2018, 37(12): 118-125.  DOI: 10.3969/j.issn.1674-0696.2018.12.18 Abstract ( )   PDF (517KB) ( )   Aiming at the phenomenon of returning home by motorcycle during the Spring Festival, the formation mechanism of this phenomenon was investigated and analyzed by using large sample sampling and cluster analysis methods under the direction of statistical sampling theory, which was based on traffic economics and transportation systems analysis method. The results show that the expensive bus ticket, lack of rail capacity and convenience of riding motor are major reasons of this phenomenon. The research results provide a scientific basis for guiding the peasant workers to rationally choose the way of returning home and for the administrative departments to formulate countermeasures. References | Related Articles | Metrics

Vehicle &Electromechanical Engineering

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Influence of Centroid Change on Roll Stability of Tank Truck under Turning Condition LI Gangyan1, LIANG Haotong1, FAN Li1, 2, LONG Xiang1 2018, 37(12): 126-132.  DOI: 10.3969/j.issn.1674-0696.2018.12.19 Abstract ( )   PDF (650KB) ( )   Under turning condition, the liquid sloshing of tank truck will affect its driving stability. According to the liquid distribution in the liquid tank when sloping, the computational model of liquid centroid position was inferred. According to the vehicle dynamics model, three degrees of freedom model under the influence of centroid variation was optimized and the computational model of lateral load transfer rate (LTR) of tank truck was inferred. The proposed model was simulated by MATLAB/Simulink software and compared with results of Hardware in the Loop platform. In addition, the changes of centroid and LRT under different velocity and front wheel steering angle were simulated. The results show that the proposed model can reflect the motion state of tank truck well; the change of centroid and lateral load transfer rate is similar to the variation trend of angle of heel, which can provide model reference for subsequent control. Meanwhile, according to the simulation results, the critical curve of speed and front wheel steering angle is obtained. Under this curve, the vehicle is safe. References | Related Articles | Metrics

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Experimental Research on Internal Piezoelectric Cantilever Energy Harvesting From FIV ZHANG Min, ZHANG Hongxin, LIU Yongzhen, LEI Lin 2018, 37(12): 133-137.  DOI: 10.3969/j.issn.1674-0696.2018.12.20 Abstract ( )   PDF (1027KB) ( )   In order to study the performance of the internal piezoelectric cantilever device, the free vibration attenuation experiment of the piezoelectric cantilever was carried out to determine the main parameters such as natural frequency, effective stiffness and electromechanical coefficients. The variation law of the natural frequency, damping, output voltage and power changing with the load resistance was obtained, and the optimum resistance of the piezoelectric cantilever beam to output the maximum power was determined. Then the FIV energy harvesting experiment was carried out in the wind tunnel. The results show that the vibration frequency of the external cylinder almost keeps stable within the experimental wind speed, whereas the amplitude increases as the wind speed increases; with the excitation of the external cylinder, the internal piezoelectric cantilever beam is forced to vibrate, and its output voltage and power increase as the wind speed increases. With the increase of wind speed, the vibration frequency of the cylinder changes little and the amplitude increases. References | Related Articles | Metrics

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Structural Dynamic Optimization of Double Front Axle Steering Mechanism of Heavy Truck WU Jungang1, DING Fei1, YANG Qinglong2 2018, 37(12): 138-142.  DOI: 10.3969/j.issn.1674-0696.2018.12.21 Abstract ( )   PDF (856KB) ( )   A 8×4 heavy truck double front axle steering mechanism has engineering problems such as large deformation and even plastic deformation of some parts. The deformation of parts and stress results of the steering system under full load and in-situ steering conditions were obtained by simulation method, and the structure optimization of parts was carried out. In order to obtain the optimal structural scheme of some members, the traditional static optimization method and the structural dynamic optimization method— Equivalent Static Load (ESL) method were adopted respectively. The results show that the proposed optimization scheme can obviously improve the deformation of steering mechanism and reduce the tire angle error caused by deformation. Moreover, the dynamic structure optimization is superior to static optimization. References | Related Articles | Metrics