Entity

Time filter

Source Type


Zhang W.,Changan University | Duan X.,Yunnan Traffic Consulting Co. | Wei L.,Changan University
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011 - Proceedings | Year: 2011

Aimed at the particularity of the vehicles ride pulse input running test, based on the rigid ring tire model and effect road profile, the 4 DOF dynamics model of vehicles is set up. Using Visual C++ 6.0 as development platform, the digital simulation program was developed by Runge-Kutta method. Comparison between simulation result and test result indicates that there is a well consistency between simulation results and test results. Compared with the point contact tire model, the average error of body acceleration drops 26.88%. the average error of axle's acceleration drops 11.75%. © 2011 IEEE. Source


Chen W.,Kunming University of Science and Technology | Chen W.,Yunnan Traffic Consulting Co. | Xu Z.-M.,Kunming University of Science and Technology | Liu W.-L.,Kunming University of Science and Technology | Liu W.-L.,Kunming Prospecting Design Institute of China Nonferrous Metals Industry
Yantu Lixue/Rock and Soil Mechanics | Year: 2015

Differential weathering can cause unstable rock mass in rock slope with alternating strata. The alternating strata can be sandstone and mudstone and belong to the soft and hard rocks. The rock collapse damage is a common form of geological disasters. This paper uses unstable rock mass at Puerdu as case study. The calculation formula for the compressive stress of unstable hard rock block on the soft mudstone base is derived for the slope rock mass with cavity in the soft mudstone due to differential weathering. The stress increases as the cavity depth increase. According to the slope topography, geomorphology and characteristics of geological structure of unstable rock blocks at Puerdu, two kinds of four unstable rock mechanical models due to differential weathering are established. The first type is the type of mudstone base fracturing damage and rotational damage unstable rock block whose main control fissure connectivity rate is equal to 1. The second type is the type of falling and toppling of unstable rock block whose main control fissure connectivity rate is less than 1. The rock strength theory is used to derive the quadratic parabolic Mohr strength envelope equation for sandstone at the study area. The limit equilibrium theory and Mohr strength theory is used to deduce the collapsing damage and judgment expression of four kinds of unstable rock blocks under the gravity, earthquake force and fissure water pressure. The critical collapse boundary equation is derived for the unstable rock mass at the study area. The relationships among rock cavity depth, thickness, height and the main control fissure depth are also derived. Those results provide an intuitive and reliable basis for the prediction and judgment of stability and collapse of the unstable rock mass. ©, 2015, Academia Sinica. All right reserved. Source


Zhang W.,Changan University | Zhang Y.-M.,Changan University | Wei L.,Changan University | Duan X.,Yunnan Traffic Consulting Co. | Chen J.-H.,Yunnan Traffic Consulting Co.
Jiaotong Yunshu Gongcheng Xuebao/Journal of Traffic and Transportation Engineering | Year: 2012

The relationship between axle load and the service life of highway was analyzed. Based on the frequency domain model and time domain model of pavement roughness, vehicle dynamics model with four degrees of freedom was set up. Numerical simulation calculation was carried out by using Mathcad software, and the maximum dynamic loads of front and rear wheels under different conditions were obtained. The relationships among wheel dynamic load and vehicle velocity, wheel load and overloading, wheel load impact factor and overloading were analyzed respectively, the actual service lifes of highway under different conditions were forecasted. Analysis result shows that there are linear increasing relationships between wheel dynamic load and vehicle velocity, wheel load impact factor and vehicle velocity. When vehicle velocity increases from 10 km·h-1 to 100 km·h-1, wheel dynamic load increases by 2.5-3.1 times, and wheel load impact factor increases by 17%-20%. Overloading decreases wheel load impact factor, but increases the real maximum wheel load greatly. Under the condition of overloading 100%, the actual service life of highway will decrease by 96% while the bottom layer tensile stress of asphalt layer is taken as design index, and the actual service life of highway will decrease by 99% while the bottom layer tensile stress of semi-rigid material layer is taken as design index. Source

Discover hidden collaborations