| Rail abrasive belt grinding technology is a new rail maintenance method to remove rail surface damage and defects,improve wheel-rail contact relationship and prolong rail service life.The grinding of rail abrasive belt can keep good stability in the process of grinding,but it is easy to lose stability and run off under complex conditions such as instantaneous impact contact,rubber friction and wear between wheels and wheel deflection.The off-track running of abrasive belt seriously affects the grinding efficiency,grinding quality and service life of abrasive belt,and even affects the normal grinding operation of abrasive belt.Therefore,exploring the deviation mechanism of abrasive belt grinding is the basis to ensure the stable grinding of rail abrasive belt grinding machine.However,the existing basic research is very scarce,and the scientific law behind the engineering problem has not been revealed from the theoretical level.This paper will conduct modeling based on multi-body dynamics,and explore abrasive belt deviation and its dynamic characteristics through virtual prototype simulation analysis and relevant experiments.The main research contents are as follows:By analyzing the stress of abrasive belt,the fundamental cause of abrasive belt deviation is explored from the Angle of mechanics.Combined with the lateral dynamics analysis,the lateral dynamics equation of abrasive belt grinding element is established,and the belt speed,tension and belt width are determined to be the factors affecting the deviation of abrasive belt.The rigid-flexible coupling nonlinear multi-body dynamics model of grinding system was established by discretization of abrasive belt with rigid body method.Based on this model,a virtual prototype model of rail abrasive belt grinding is established by using ANSYS and ADAMS.Based on the virtual prototype model,the influence mechanism of driving wheel deflection Angle,belt width,friction coefficient between wheels and belt tension on belt deviation was quantitatively analyzed under non-grinding conditions.The deviation degree of abrasive belt was measured by the lateral displacement of the belt block,the trend of abrasive belt deviation was measured by the lateral velocity and acceleration of the belt block,and the cause of abrasive belt deviation was analyzed by the lateral force of the belt block.Through variance analysis,it is concluded that the most significant factors affecting abrasive belt deviation in non-grinding conditions are the driving wheel deflection Angle,followed by the belt width and tension,and the minimum is the friction coefficient between the wheel and abrasive belt.A virtual prototype model was established under grinding conditions,and the influence mechanism of grinding speed,grinding operation speed and grinding position on abrasive belt deviation was explored through the maximum value and root mean square value of lateral displacement under grinding conditions.The deviation trend of abrasive belt was judged by lateral velocity and lateral acceleration,and the adjustment suggestions of grinding process parameters when abrasive belt deviation occurred were put forward.According to variance analysis,the most significant factor influencing running deviation in grinding conditions is the grinding position of rail abrasive belt,followed by the grinding speed of rail abrasive belt,and the minimum is the grinding speed of abrasive belt.An exploratory experiment was carried out to verify the correctness of the simulation results.It is revealed that the middle convex tensioner can realize automatic alignment to realize automatic deviation correction.At the same time,the range of convex value which can prolong the occurrence time and slow down the degree of deviation is discussed through different experiments.Finally,through the comparative experiment,it is revealed that the middle convex tensioner can better prevent the deviation and slow down the deviation of abrasive belt than the flat tensioner. |
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