Research Of The Pressure Distribution Regularities From Granular Cargo To C80B Open Wagon

Railway transportation plays a very important role in our national economy,70%of thecargo is granular cargo in railway transportation. The current standards of applied force fromthe granular cargo to the open wagon are not perfect and especially do not agree with therealistic experiments. As we enter the time of high speed and heavy loaded of the open wagon,this kind of contradiction becomes more obvious. So, it is a very urgent task to study theproblem deeply and update the standards of the applied force from the granular cargo to theopen wagon.The study is focused on the C80B open wagon. We take the wheat, coal and sand torepresent the granular cargo and investigate the laws of its applied force to the end walls andside walls of the open wagon. The work in detail is as followings:(1) Considering the arch of granular cargo, the traditional mathematical model of staticside pressure of granular cargo based on the cycloid fracture surface is improved. Theexperimental results validate the correctness of the formula of this paper. The effects of thechanges of friction angle between the granular media and the open wagon and internal frictionangle of granular cargo on the distribution regularities of side pressure of the granular cargoare investigated in detail.(2) The granular cargo is proposed to obey the yield criterion of Drucker-Prager based onthe finite element method(FEM) and the continuum theory, and the3D finite element modelof the open wagon was set up according to the ‘surface to surface’ method. The finite elementanalysis of static side pressure from the granular cargo to the end and side walls is carried out.We also analyse some parameters such as the internal friction angle of the granular cargo, thefriction angle between the granular cargo and the open wagon, and the Poisson ratio.(3) The3D reduced element model is set up based on the discrete element method(DEM)and the non-continuum theory, the particles are generated using the stratification method. thismodel is adopted to analyse the static side pressure from granular cargo to the open wagon.The effect of the change of friction angle between the granular media and the open wagon,internal friction angle of granular cargo on the end and side walls of the open wagon areinvestigated in detail. (4) On the basis of research of static side pressure from the granular cargo to the openwagon, The discrete element method was used to simulate the dynamic side pressure from thegranular cargo to the end and side walls of the open wagon under the action of the impact load.We also analyse some parameters such as the acceleration, the action time, the internalfriction angle of granular cargo, and the friction angle between the granular cargo and openwagon.