Analysis And Experimental Study On Sand-Throwing Of Railway Sand Cleaning Vehicle

This paper focuses on the research on the sand-throwing performance of railway sand cleaning vehicle,including the physical parameter calibration of sand grains,the determination and optimization of sand-throwing performance parameters,the design and construction of the test platform of railway sand cleaning vehicle and the test.Based on the laboratory experiment,the related research is carried out by combining theoretical analysis,numerical simulation analysis and test-platform test.Specifically including the following work:(1)The research progress in the field of sand parameter calibration,discrete element,discrete element and multi-body dynamics,combination of discrete element and finite element,and railway sand cleaning vehicle were summarized at home and abroad,and the research content and technical route of the subject were put forward accordingly.This paper introduces the dynamics of discrete element and multi-body and the principle of joint simulation of discrete element and finite element.(2)In view of the lack of research on the physical characteristics of sand grains in wind sand at home and abroad,the gap between the simulation and test results of railway sand cleaning vehicle is too large.In this paper,the moisture content,packing density,diameter distribution,voyage and static friction coefficient,rolling friction coefficient and recovery coefficient between sand and steel plate and rubber were determined by test method.Static friction coefficient,rolling friction coefficient and recovery coefficient between sand grains were determined by combining discrete element and regression orthogonal test,and the rest angle of sand grains was compared between simulation and actual sand grains by using Matlab image technology to determine the accuracy of parameter calibration.The error between simulation and experiment is 1.39%.The feasibility and validity of the method used in this paper are verified,and reliable sand parameters are provided for the subsequent discrete element simulation test.(3)Plate to throw sand in threw sand may occur in the process of the problem of poor performance,this paper,by using the discrete element combined with orthogonal test and gray analysis method,the impact of screening on throwing sand performance four factors that influence behind the speed of performance,bending angle,bending position and speed of the four factors were analyzed,and the performance parameters of the combination,determined the best throw sand by discrete element simulation test with existing throw sand test-platform is the result of mutual authentication.Finally,according to the actual demand,the optimum parameter combination of four factors that affect the sand-throwing performance is determined to make the sand-throwing performance meet the actual demand.(4)Design and set up the test platform of sand-removing truck,and study the influence of bending angle of sand-throwing plate on root stress and driving shaft torque of the sand-throwing plate.On the premise of ensuring the sand-throwing performance,the root stress and driving shaft torque of the sand-throwing plate with three bending angles were analyzed,and the influence of bending Angle of the sand-throwing plate on root stress and driving shaft torque was obtained.(5)In order to further reduce the heel stress throwing sand,this paper puts forward using discrete element,multi-body dynamics,finite element method,the combination of some sand in the guarantee under the premise of performance,the bending Angle is 170 ° of 3 mm thickness increase root of throwing sand plate stress research and analysis,and through the test platform to test platform cleaning cars.The results show that the stress trend of simulation and test is approximately the same and the stress peak error is 10.97%,which effectively reduces the stress at the root of the sand slab.Thus,the feasibility of combining discrete elements with multi-body dynamics and finite element to analyze practical engineering problems is verified.At the same time,it also proves the correctness of the physical parameter calibration of discrete element sand.