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Optimization of the Evaluation Indexes for the Low-Temperature Performance of Asphalt Mixture Based on Relaxation Characteristics of Thermal Cracking Mechanism

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SSRN 2022年

作者： Sun, Zhiqi Qi, Haonan Yi, Jie Li, Shaohua Tan, Yiqiu Ren, Jianying Xu, Yongli State Key Laboratory of Mechanical behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China Key Laboratory of Mechanical Behavior Evolution and Control of Traffic Engineering Structures Shijiazhuang Tiedao University Hebei Shijiazhuang050043 China School of Transportation Science and Engineering Harbin Institute of Technology Harbin150090 China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology China School of Civil Engineering Northeast Forest University Harbin150090 China

Thermal cracking behavior of asphalt pavement includes thermal contraction, low temperature relaxation and low temperature damage. A great quantity of theoretical and experimental studies on the characterization of low-temperature performance had mostly focused on characterizing low-temperature performance with low-temperature relaxation or low-temperature failure performance, resulting in incomplete evaluation of low-temperature performance of asphalt mixtures. Considering the relaxation performance is one of the key factors in the thermal cracking mechanism of the asphalt mixture, the evaluation indexes were established and optimized according to the relationship between the viscoelastic characteristics and the relaxation performance. Combined with the relationship among the low-temperature performance obtained by Thermal Stress Restrained Specimens Test (TSRST) and the evaluation indexes, then the evaluation indexes for the low-temperature performance of asphalt mixture were preferably selected. Firstly, according to the conversion of viscoelastic information in the time domain and frequency domain, the relationship between viscoelastic characteristics and relaxation characteristics was analyzed. Secondly, depending on the characteristics of relaxation characteristics in time, the relaxation rate and the cumulative stress per unit strain rate were proposed as evaluation indexes to characterize the long-term and short-term relaxation characteristics of asphalt mixtures, respectively. Finally, the relationship between asphalt binders and asphalt mixtures with different evaluation indexes and low temperature performance was analyzed. The results showed that relaxation rate, stored shear modulus and cumulative stress per unit strain rate (below -20 °C) apply to the evaluation of low-temperature performance among gradation types, and the average slope of complex modulus and the average slope of relaxation rate-temperature curve with temperature apply to the evaluation

关键词： Asphalt mixtures

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Fault Diagnosis Method for Multiple Sources based on IESFSC-SSRgram

Fault Diagnosis Method for Multiple Sources based on IESFSC-...

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International Conference on Sensing, Diagnostics, Prognostics, and control (SDPC)

作者： Wu Zhihao Gong Shixian Huang Chenguang Jin Hang Liu Zechao National Engineering Laboratory CRRC Qingdao Sifang Locomotive and Rolling Stock Co. Ltd Qingdao China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structure and School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang China Weichai Power Co. Ltd. Data Management Engineering Center Weifang China Institute of Magnetic Levitation and Electromagnetic Propulsion China Aerospace Science and Industry Corporation Limited Beijing China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China

ISBN: (数字)9798350388855

ISBN: (纸本)9798350388862

The division and determination of frequency bands are always core problems in fault diagnosis methods for rotating machinery. Currently, the frequency band division strategy of most fault diagnosis methods is the 1/3-binary tree or realized by wavelet packet transform (such as fast kurtosis diagram and Autogram). This method is relatively fixed, making it difficult to accurately cover the resonance frequency band and achieve multi-source fault identification. To address the above problems, an adaptive frequency band division strategy based on Fast Spectral Correlation (FSC) and Scale-Space Representation (SSR) is proposed. The enhanced enveloping spectrum (EES) of each frequency band after division is obtained, and the improved Fault Quantification Index (IFQI) is used to measure the richness of target information in each enveloped spectrum (ES), generating a two-dimensional diagram. The envelope spectrum with the largest IFQI value is selected as the improved envelope spectrum (IES) obtained by the FSC and SSR division strategy (IESFSC-SSRgram), enabling the fault diagnosis of the axle box bearing. The effectiveness and superiority of the proposed method in identifying multi-source concurrent faults in the wheelset bearing system are verified by comparing it with the traditional method.

关键词： Fault diagnosis Correlation Resonant frequency Frequency conversion Wavelet packets Power capacitors Frequency measurement Sensors Indexes Frequency control

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Compressive Sensing Reconstruction for Rolling Bearing Vibration Signal Based on Improved Iterative Soft Thresholding Algorithm

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SSRN 2022年

作者： Wang, Haiming Yang, Shaopu Liu, Yongqiang Li, Qiang School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing010044 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China

A new method of acquisition and reconstruction based on compressive sensing theory is introduced in this paper. An improved ISTA (IISTA) is proposed. Firstly, an acceleration operator considering step size is proposed to estimate the gradient, which can accelerate convergence speed. Then for breaking the limitation of fixed internal gradient step size, a bidirectional search principle is introduced to backtrack its iteration step size. Finally, the constraints of the quadratic approximation model on the reconstruction objective function is proposed to adaptively determine optimal iteration step size. The effectiveness of the method is verified by the reconstruction of bearing vibration signals in different health states. The results show that the proposed method can achieve convergence faster, improve the sparsity of the regular term, and has a better reconstruction performance than the conventional ISTA under different sampling rates. © 2022, The Authors. All rights reserved.

关键词： Compressed sensing

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Factors Influencing Driver's Expected Psychological Vulnerability When Sharing the Road with Driverless Vehicles

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SSRN 2022年

作者： Wang, Yunze Zhao, Xuhan Zhang, Chunbo State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China Key Laboratory of Traffic Safety and Control of Hebei Province Shijiazhuang050043 China School of Traffic and Transportation Shijiazhuang Tiedao University Shijiazhuang050043 China

Few studies have examined the psychological experience of drivers of manned vehicles sharing the road with driverless vehicles. To judge whether drivers think they are in a vulnerable state and find out what makes drivers feel they will be in a state we called "expected psychological vulnerability", this paper conducted a questionnaire to collect information about the attitude, perceived usefulness, trust, perceived risk, and demographic information of drivers in a hypothetical situation involving driving on the same road as driverless vehicles. Our goal was to identify areas where the drivers felt that they would be in a "vulnerable psychological state", i.e., that they would be more vulnerable to making poor psychological judgments. The survey results indicated that 43.7 % of the respondents believed that they would be in a vulnerable state in mixed traffic competition, 30.2 % of the respondents did not know whether they would be in a vulnerable state. Further, women, people with a higher education, people with a more aggressive driving personality, older people, and those with more driving experience were more inclined to think that they would not be in a vulnerable state. Attitude, trust, and perceived usefulness all had positive impacts on judgments regarding psychological vulnerability, and perceived risk had a negative impact. Therefore, the early promotion of driverless technology should give priority to people with a higher education, more driving experience, older age, and more aggressive driving personality, and focus on attitudes towards this technology, including perceived usefulness, trust, and perceived risk. © 2022, The Authors. All rights reserved.

关键词： Vehicles

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Optimization and evaluation of a solar energy, heat pump and desiccant wheel hybrid system in a nearly zero energy building

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建筑模拟（英文版） 2020年第6期13卷 1291-1303页

作者： Shaochen Tian Xing Su Xiaolu Shao Lei Wang School of Mechanical Engineering Tongji University Shanghai 200092 China Key Laboratory of Performance Evolution and Control for Engineering Structures of Ministry of Education Tongji University Shanghai 200092 China

Traditional conventional air conditioners (CACs) are not applicable to nearly zero energy buildings (NZEBs), especially for residential buildings in regions with a humid climate in China. On the one hand, indoor thermal environment can be significantly affected in buildings by adopting insulations with higher thermal resistance and air tightness. On the other hand, CACs may not be able to meet the energy requirement of NZEBs when dehumidification is in high demand. Therefore, in this paper, a novel hybrid system, which featured solar panel, a multi-evaporator and multi-condenser heat pump, and a desiccant wheel, i.e., the SHDW system was proposed. The evaporator is for pre-cooling, and the desiccant wheel (DW) for handling the whole moisture load. The regeneration air of DW is heated by heat recovery condenser and the solar panel. By varying the evaporation temperature of HP, the energy performance was evaluated, and compared with that of a typical CAC, for controlling indoor temperature and humidity of a residential NZEB, using TRNSYS. The simulations were conducted for Shanghai (in a humid climate) in summer (July and August) and the transition seasons (June and September). The results showed that, first, the optimized evaporation temperature of the system is determined to be 12 °C and 9 °C, respectively, on a typical day both in summer and the transition seasons. Second, the daily coefficient of performances are 3.4 and 2.4 in summer and in transition seasons, ***, compared to either the temperature or humidity control mode of the CAC, the proposed SHDW system showed better promise for achieving indoor thermal comfort for residential NZEBs, especially in transition seasons. In a typical weekend, the daily energy consumption of the proposed SHDW system is 9.0％ and 12.3％ lower than that of the CAC with humidity control mode, respectively, in summer and the transition seasons.

关键词： desiccant wheel solar energy heat pump nearly zero energy building humid environment

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Modeling and Simulation for Microscopic traffic Flow Based on Comprehensive Information of The Preceding And the Following Vehicles

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SSRN 2022年

作者： Wang, Yunze Wang, Yawen Zhang, Chunbo State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang05043 China Key Laboratory of Traffic Safety and Control of Hebei Province Shijiazhuang050043 China School of Traffic and Transportation Shijiazhuang Tiedao University Shijiazhuang050043 China

A new car-following model is proposed in this study, and it considers the comprehensive information of the preceding and the following vehicles (i.e., the CIPF model) including the headway, speed difference, and acceleration. This model can be considered as a further extension of the existing forward-backward velocity difference (FBVD) model. Based on the linear stability analysis of the CIPF model, the judgment basis of the traffic flow stability is obtained. Compared with the optimal velocity (OV) model, the full velocity difference (FVD) model, and the FBVD model, the CIPF model has the largest stable region and the smallest unstable region. Using the reductive perturbation method, the nonlinear analysis of the CIPF model is performed, and the modified Korteweg-de Vries (mKdv) equation, which is used to describe the traffic flow characteristics of the system near the critical point, is obtained. Finally, the numerical simulation results show that the CIPF model can respond to the state of traffic flow better and faster than the FBVD model in vehicle start and stop simulation, and can better alleviate traffic congestion and improve the traffic flow stability in the simulation of circular road. The kink-antikink wave described by mKdV equation is simulated in the unstable region after the pe © 2022, The Authors. All rights reserved.

关键词： Nonlinear analysis

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Modeling and Simulation for Microscopic traffic Flow Based on Comprehensive Information of The Preceding And the Following Vehicles

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SSRN 2022年

关键词： Nonlinear analysis

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Heat Transfer-Based Frost Heave Deformation and Structure Optimization of High-Speed Railway Foundation Bed in Frozen Areas

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SSRN 2024年

作者： Qing, Caolin Jie, Shaolong Yue, Zurun Mao, Shuai Zhai, Zhongang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China College of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China Shijiazhuang University Shijiazhuang050035 China College of Transportation Shijiazhuang Tiedao University Shijiazhuang050043 China

The deformation of the subgrade surface caused by frost heave and thawing settlement is the main cause of railway subgrade deformation in the frozen area, and controlling the deformation of the subgrade surface by reducing the freezing depth is the key to ensure the stability of train operation. Based on the measured temperature field and deformation field of the subgrade of the HQTJ-5 bid section of the Haqi passenger special project, and taking the freezing depth and frost heave deformation in the center of the subgrade on the minimum temperature date as the control standards, the simulation models of the subgrade temperature field and the deformation field were established, and the thermal insulation effects of 13 different types of subgrade surface structures were explored. The results show that under the premise of not considering the hot blanket effect of asphalt mixture layer, both asphalt mixture and cement-stabilized gravel have thermal insulation effect, and laying on the surface layer of subgrade bed can reduce the freezing depth. Appropriately increasing the 2.36-4.75mm particles in the asphalt mixture can reduce the thermal conductivity, the rubber powder cement stabilized gravel can further improve the thermal insulation capacity, and when the surface structure of the foundation bed adopts "10cm thick AC-16 C asphalt mixture reinforced layer + 30% rubber powder cement stabilized gravel", the thermal insulation effect is the best, and the freezing depth can be controlled within 0.97m, and the frost heave deformation can be controlled within 3.23mm. The structure is of great significance to the design of thermal insulation and waterproof roadbed in the frozen area. © 2024, The Authors. All rights reserved.

关键词： Structural optimization

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Research on brake failure control of heavy commercial vehicles based on turning conditions 4

Research on brake failure control of heavy commercial vehicl...

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4th CAA International Conference on Vehicular control and Intelligence, CVCI 2020

作者： Lu, Yongjie Wang, Fahui Zhang, Guangfeng State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China

ISBN: (纸本)9781728184968

With the rapid rise of the transportation industry, commercial vehicles as an important means of transportation, its safety and stability are paid more and more attention. In order to improve the safety performance of heavy commercial vehicles when braking failure occurs under turning conditions. Based on the vehicle dynamics characteristics, this paper designed the stability control strategy in the case of brake failure in the above conditions, designed a fuzzy PID controller based on yurch angular velocity control, carried out the Trucksim-Simulink joint simulation and hardware in the loop experiment to jointly verify the control effect of the brake. The results show that the influence of vehicle brake failure on vehicle driving stability is reduced, the performance of vehicle brake under long and downhill conditions and turning conditions is improved, and the safety stability of vehicle brake failure in hardware loop is improved, which meets the requirements of national standards for vehicle braking. © 2020 IEEE.

关键词： Commercial vehicles

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Research on Intelligent Trajectory Finding and Escape Dilemma Tracking Strategy of Tire Blowout Vehicle

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SSRN 2023年

作者： Han, Zexuan Lu, Yongjie Li, Haoyu Zhang, Junning School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhaung Tiedao University Shijiazhuang China Department of Engineering Mechanics Shijiazhuang Tiedao University Shijiazhuang China School of Mechanicsand Engineering Science Shanghai University Shanghai China

To improve the safety and stability after a vehicle tire blowout in complex road environment, an intelligent trajectory finding and escape dilemma tracking strategy integrating decision-making, planning and control is proposed. The nonlinear static Dugoff tire formula is improved based on the dynamic change of tire blowout mechanical parameters. Combined with multi-body vehicle dynamics model and steering control driver model, a joint simulation platform for tire blowout vehicle is established. Considering the real-time state of the vehicle and the complexity of the road environment, the original driving trajectory is kept. And based on the Bessel curve method and the fifth-order polynomial method, the vehicle obstacle avoidance and lane change path are planned. The model predictive control algorithm is designed to achieve escape dilemma tracking control of the vehicle after tire blowout. The CarSim/Simulink joint simulation test is used to verify the control effect of the intelligent trajectory finding and escape dilemma tracking strategy in different scenarios. The results show that this strategy can reasonably and effectively plan the trajectory of keeping, obstacle avoidance and lane change, and bring vehicle out of danger in time while maintaining safety and stability. © 2023, The Authors. All rights reserved.

关键词： Trajectories

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