| Belt conveyor is widely used in food,tobacco,mineral and other industries because of its advantages of long distance,large volume,flexible line layout and stable work.So as to solve the issue of line change in the course of belt conveyor operation,there are many ways to realize turning,including the use of some special conveyor,such as round pipe conveyor,U-belt conveyor and so on.U-belt conveyor has been widely used in recent years for its large conveying dip angle,low investment expense and ability to attain horizontal turning with little radius.For U-belt conveyor,not only the structure of idlers in turning section should be studied,but also the design level of conveyor belt in turning section should be improved.In the paper,the stress of the conveyor belt in the turning section is analyzed particularly,and the smallest turning radius is derived by using FEM,DEM,DEM-FEM coupling method,combined with mathematical calculation,mechanics and other related theories.The main factors affecting the conveyor belt stress in the turning section are analyzed,and the stress distribution rule of the conveyor belt section under different conditions.Firstly,when calculating the turning radius,the spatial mechanical model of the conveyor belt is built,and the smallest turning radius is got according to the restricted conditions in the stable operation of the turning.The affect of important parameters on turning radius is analyzed,including the inner curve elevation angle,the roller inclining angle,the angle of turn and the Max tension.Secondly,the forming force of U-type belt is calculated indirectly by finite element method.The three-dimensional model of conveyor belt-idler in turning section was established,and the influence of idler spacing,pulling force and turning radius on conveyor belt stress was analyzed.The effect degree of each factor on conveyor belt stress was explored by orthogonal test method.The stress distribution law of the same section of the conveyor belt with different rollers spacing were analyzed.Finally,the DEM is used to analyze the pressure of the material on the conveyor belt in the turning section,and pressure changes on the inside,outside and bottom of the conveyor belt at different positions in the turning section,and the influence of different belt speeds on the pressure of the conveyor belt is explored.The coupling method of DEM-FEM is used to analyze the stress and strain of conveyor belt in turning section.According to the relevant parameter standards in the design manual,the material transportation in the turning section under different loads was simulated by EDEM software.Then,the coupling relationship between discrete element and finite element was established to import the load information of the material on the conveyor belt in the turning section into Workbench.The stress distribution law of different sections at the bottom of the conveyor belt is compared under different load conditions,and the stress concentration part of the conveyor belt is defined.Through the stiffness analysis of the conveyor belt in the turning section,the strain and deformation of the conveyor belt under different conditions are got.It provides reference for the design and improvement of U-belt conveyor’s turning section. |
