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Study of skid steering method for distributed-drive articulated heavy vehicle based on the co-simulation model

University of Science and Technology Beijing-Yahui Liu
Tsinghua University-Tao Xu, Xuewu Ji, Cong Fei, Yanhua Shen
  • Technical Paper
  • 2020-01-0761
To be published on 2020-04-14 by SAE International in United States
Distributed-driver articulated steering vehicles (DASVs), the particular engineering equipment, have good maneuverability and tractability in poor road and narrow space conditions. They are always used in the mining, construction, forest, and agricultural industry. Its structure comprise front and rear frame connected by an articulation joint and two hydraulic struts. In the steering process, these two struts are driven by pump of hydraulic system, and the vehicle will turn following the control of steering wheel with the coupling effects of articulation joint and struts. But due to the high load of the DASVs, the influence of pressure of outlet chamber, and the compressible of the oil, it is easy to cause the high pressure level, the low energy efficiency, and poor stability in hydraulic steering process. This is not conducive to improving the security, economy, and stability of DASVs. Therefore, in order to solve these problems, this paper will make the DASVs as the objective vehicle, and take full advantage of its independent driving method to study the novel skid steering mode. Combining with the discussions…
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Simulation Analysis of a Dual-Purpose Intelligent Mobile Platform for Highway and Railway

University of Science and Technology Beijing-Nan Sun, Wenming Zhang, Jue Yang
Published 2019-06-05 by SAE International in United States
Railways play a huge role in China's transportation industry. In order to ensure intelligence, advanced technology and high efficiency in functions such as railway inspection, rescue and transportation, a dual-purpose intelligent mobile platform for both roads and railways was developed. Due to the height limitation of this platform, resilient wheels and rubber dampers with short stroke are used as the suspension system for the rail chassis. Based on this special suspension form, the dynamic model of the whole platform is derived, and the simulation model of the whole platform is established in the simulation software. The effects of resilient wheels’ axial stiffness, radial stiffness and vertical stiffness, lateral stiffness of rubber dampers on the vertical and lateral stability of the platform were studied. It is found that the increase of the radial stiffness of the resilient wheels will deteriorate the vertical stability and lateral stability of the platform. The increase in the axial stiffness of the resilient wheels will deteriorate the vertical stability of the platform and the lateral stability will be improved. The increase…
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Equivalent Stiffness and Equivalent Position for Torque Strut Mount in Powertrain Mounting System

SAE International Journal of Engines

University of Science and Technology Beijing-Rang-Lin Fan, Chu-Yuan Zhang, Zhen-Nan Fei
DongFeng Motor Corporation Technical Center-Shao-Ju Qu, Jiong-Yang Shao, Peng-Jun Song
  • Journal Article
  • 03-11-03-0021
Published 2018-06-18 by SAE International in United States
The torque strut is a key mount in three-point pendulum mounting system of powertrain. Its equivalent stiffness in two orthogonal directions is close to zero meanwhile the equivalent stiffness in another direction always remains the same as the original stiffness, which facilitates mounting system design and matching and has been widely used. In this article, it is aimed to answer the issues for the equivalence of torque strut mount theoretically, such as the equivalent linear stiffness, equivalent torsional stiffness and equivalent position. The torque strut mount has been simplified to an equivalent ordinary mount, the equivalent linear stiffness and equivalent torsional stiffness are derived, and has been verified by ADAMS, then the equivalent position is discussed. The effect of the mass of torque strut on powertrain modals is investigated. An equivalent model of powertrain mounting system with equivalent stiffness at equivalent position for torque strut is established, the results of the nature characteristics show that the equivalent torque strut model is usable in engineering.
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Effects of Entrapped Gas within the Fluid on the Stiffness and Damping Characteristics of a Hydro-Pneumatic Suspension Strut

SAE International Journal of Commercial Vehicles

University of Science and Technology Beijing-Jue Yang
Concordia University Montreal-Yuming Yin, Subhash Rakheja
  • Journal Article
  • 2017-01-0411
Published 2017-03-28 by SAE International in United States
This study is aimed at characterizing the nonlinear stiffness and damping properties of a simple and low cost design of a hydro-pneumatic suspension (HPS) that permits entrapment of gas into the hydraulic fluid. The mixing of gas into the oil yields highly complex variations in the bulk modulus, density and viscosity of the hydraulic fluid, and the effective gas pressure, which are generally neglected. The pseudo-static and dynamic properties of the HPS strut were investigated experimentally and analytically. Laboratory tests were conducted to measure responses in terms of total force and fluid pressures within each chamber under harmonic excitations and nearly steady temperature. The measured data revealed gradual entrapment of gas in the hydraulic fluid until the mean pressure saturated at about 84% of the initial pressure, suggesting considerably reduced effective bulk modulus and density of the hydraulic fluid. An analytical model of the HPS strut was formulated considering polytropic change in the gas state and increased fluid compressibility due to entrapped air. Both the measured data and the model results showed progressively hardening stiffness…
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Wear Modeling and Prediction of Off-road Dump Truck Body based on Stochastic Differential Equation

University of Science and Technology Beijing-Fulin Wei, Yanhua Shen, Tao Xu
Published 2016-04-05 by SAE International in United States
Off-road dump truck body is exposed to abrasive wear during handling of granular materials. The wear rate of body of dump truck has direct influence on maintenance and replacement during its service process. In this paper the discrete element method (DEM) is used to simulate the granular materials of dump truck. The wear of body floor during one dumping process can be achieved by cosimulation of FEM-DEM. The wear depth variation of body has the stochastic characteristic which can be modeled by Geometric Brownian Motion (GBM). The two parameters in the stochastic differential equation, drift coefficient and diffusion coefficient, can be estimated by the wear depth measuring data. It is possible to quantitatively predict the wear evolution of every grid point of the body floor by solving this stochastic differential equation. The simulation result of the wear model is helpful to optimize design of off-road dump truck body.
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In-Situ Steering Dynamics Analysis of Skid Steering for Articulated Motor-Driven Vehicle

SAE International Journal of Passenger Cars - Mechanical Systems

University of Science and Technology Beijing-Tao Xu, Yanhua Shen, Wenming Zhang
  • Journal Article
  • 2016-01-1646
Published 2016-04-05 by SAE International in United States
The traditional hydraulic steering mode in articulated motor-driven vehicle makes the vehicle structure complex. Further more, the forces between the front and rear part of the articulated vehicle could damage the articulated joint body in the process of vehicle steering. However, skid steering mode could make the vehicle steer with the different speed of each wheel, which is flexible without hydraulic steering system. The purpose of this paper is to introduce the principle of skid steering mode in articulated motor-driven vehicle. In this paper, the theory of traditional wheeled vehicle’s skid-steering mode and hydraulic steering mode of articulated vehicle are used to establish the in-situ skid-steering kinematic and dynamic model. Based on the model, the vehicle trajectory and the dynamic relationships among the body structure of the vehicle, longitudinal forces, lateral forces of each wheel are described. With these analyses, the kinematic and dynamic simulations are implemented according to the parameters of an underground mine articulated vehicle, which could provide references for the designing and studying of articulated motor-driven vehicle with skid steering mode.
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Evaluation Method for Driver Risk Perception Models in Car-Following Situations

University of Science and Technology Beijing-Xiao Du
Beihang Univ.-Qingfeng Lin
  • Technical Paper
  • 2011-08-0194
Published 2011-10-12 by Society of Automotive Engineers of Japan in Japan
This study proposed an evaluation method for the performance assessment of risk perception model (RPM) in car-following situation based on signal detection theory. The driving experiments were carried out by 20 candidates using driving simulator at Tsinghua University. Data of driving operations and vehicle states in "Safe" (Leading vehicle braking onset) and "Dangerous" (Subject vehicle braking onset) situations were acquired. Five typical RPMs including TTC, THW, RP, KdB(KdB_c) and PRE were evaluated. The evaluation results suggested that the performance of PRE model was the best among the RPMs.
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Simulation Based Design for Heavy Truck Brake

University of Science and Technology Beijing-Wenming Zhang
Zhejiang University of Technology-Xiaobin Ning, Bin Meng, Jisheng shen
Published 2009-04-20 by SAE International in United States
Begin Brakes in cars and trucks are safety parts. Requirements not only in performance but also in comfort, serviceability and working lifetime are high and rising. Simulation based design (SBD) technology refers to the application of simulation technology in design of products, which means not physical prototype but Virtual Prototype (VP) was made to study the static and dynamic performance of the products. With SBD technology, lower cost, higher quality and shorter design cycle can be expected. An example of SBD of Heavy Truck’s Brake is demonstrated. In order to accurately calculate the braking efficiency factor of drum brake shoe of heavy truck, the finite element analysis software ANSYS and the multi-body system simulation software MSC.ADAMS were used to establish the drum brake virtual prototyping model. The model was built by developing joint program module between the rigid shoe and the flexible lining and nonlinear contact force program module between the lining and the rigid drum. Using this model, the simulation was executed for the drum brake of 32t heavy duty truck. The results show…
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The Fixed Points on the Nonlinear Dynamic Properties and the Parameters Identification Method for Hydraulic Engine Mount

SAE International Journal of Engines

University of Science and Technology Beijing-Rang-Lin Fan
Tsinghua University-Zhen-Hua Lu
  • Journal Article
  • 2008-01-2763
Published 2008-04-01 by SAE International in United States
Based on the third generation of hydraulic engine mounts (HEMs), which has three types of hydraulic mechanisms such as inertia track, decoupler and disturbing plate, the influences of the three different hydraulic mechanisms on the dynamic properties were studied experimentally. The working principles of the three hydraulic mechanisms and the relationship between the dynamic properties of the three generations of HEMs were revealed clearly, these experimental results will be helpful for HEM design selection. It was discovered experimentally that the frequency-dependent dynamic properties of HEM with inertia track or orifice have fixed points under different excitation displacement amplitudes. Based on the facts that the analytical results matched well with the experimental ones, a new parameter-identification-method for HEM is presented, which is clear in theory and is time- and cost-saving, the identified results were reliable.
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Versatility of Newly Developed Si3N4-Based Ceramic Inserts in Machining Various Materials for the Automobile Industry

University of Science and Technology Beijing-C. Ge, Y. Xia, L. Chen, T. Zhang
  • Technical Paper
  • 1993-25-0586
Published 1993-09-13 by ISATA - Dusseldorf Trade Fair in United Kingdom
Design features and good combination of RT and HT properties dictate the superior performance of newly developed ST-Si3N4 ceramic inserts and its versatility in machining gray cast irons, various kinds of alloyed cast irons and a series of quenched steels ranging from low-C-alloyed structural steels to high-alloyed steels. Further developments on applications of St-Si3N4 inserts in automobile industry are expected in the near future.