Research On Rail Profile Grinding Mode Based On Interpolation Principle

With the rapid development of high-speed railways,the operating mileage of China high-speed railway has increased rapidly,the density of high-speed rail networks has continued to increase,and the transportation capacity has been continuously strengthened.As an important part of railway engineering maintenance and repair,rail grinding is becoming more frequent,and the quality requirement of its operation is also getting higher.Objectively,it is required that the construction and evaluation methods of grinding operations should be more standardized and scientific in order to meet the needs of the rapidly developing high-speed rail lines.The thesis uses relevant software to accurately extract the key parameters of the rail profile geometry after drawing,and establishes a mathematical model.The symbolic operation is used to obtain the analytical expression of the rail profile geometry segmentation function;using the interpolation principle,the rail profile data obtained by the measurement is combined with the foregoing analytical formula.The obtained target profile data have the same dimension and step size,and the residual value is obtained.The rail profile and residual value are visualized to determine the rail grinding range and amount;the 2-norm method is used to obtain the 2-norm value of the target profile and the measured profile is obtained,which reflects the closeness between the measured profile of the rail and the target profile within the specified range,which is used to evaluate the effect of rail grinding and further optimize the rail grinding mode.The main conclusions of the thesis research are as follows:(1)Auto CAD was used to accurately draw the 60 kg/m and 60 N rail profiles used for high-speed rail,and the "_dataextraction" command was employed to obtain the geometric parameters of the rail profile and segment function parsing expressions.(2)Comparative analysis of various interpolation methods such as nearest point interpolation,linear interpolation,Hermite interpolation,cubic spline interpolation and B-spline interpolation was done,thus the B-spline interpolation method that is most suitable for the rail profile shape is selected.(3)After interpolating the target profile data and the measured profile data,the dimension and step size of the two data are the same,the residual value is obtained,and the target profile and the measured profile are obtained by the software drawing function as well as its residual value visualization.From the visual graph,when the profile of the two rail heads is within the contact range of the wheel and rail,the measured profile is higher than the target profile area,which is the area that needs to be polished by the rail.The higher the residual curve is,the higher the amount of rail grinding is needed.(4)Putting forward the concept of 2-norm method to evaluate the effect of rail grinding.After interpolation processing is performed on the target profile data array and the measured profile data array,the deviation between them within the wheel-rail range is obtained.The 2-norm value is used to reflect the grinding effect of the rail.When the array dimension and step size are fixed,the smaller the 2-norm value is,the closer the measured profile is to the target profile in the wheel-rail area,and the better the polishing effect will be.