Research On Rail Repair Technology Based On High-pressure Abrasive Water Jet

The status and role of railways in our country’s economic and social development is very important.As the core components of railways,steel rails will produce a series of diseases under the action of complex alternating loads and wheel-rail friction during service,which seriously threatens the safety of train operation.Regular repair is the key to railway operation and maintenance.However,due to the serious work hardening of the rail material and the difficulty of heat dissipation,the traditional rail repair technology generally has problems such as easy tool wear,serious environmental pollution,and low efficiency.Therefore,it is of great engineering significance to realize green,high-precision,and efficient online repair of rails.Based on this,this paper takes the high-pressure abrasive water jet machining process of rails as the research object,analyzes the processing mechanism of abrasive water jets on rail materials,explores the influence of process parameters on the cutting effect,and systematically studies the rail repair technology based on high-pressure abrasive water jets.The main research content as follows:(1)To solve the problem of the unclear processing mechanism of high-pressure abrasive water jet on rail materials,considering the characteristics of high-speed,high-pressure and high-strain in the processing process,on the basis of theoretical analysis,using LS-DYNA as a platform,a new method based on SPH-FEM was proposed.The abrasive water jet cutting rail material simulation method solves the calculation termination problem caused by large deformation of traditional single FEM mesh simulation;analyzes the influence of main process parameters on the maximum cutting depth,so as to clarify the impact of high-pressure abrasive water jet on rails The processing mechanism of the material lays the foundation for the subsequent high-pressure abrasive water jet repairing process experiments on rails.(2)To cope with the problems of low processing efficiency and unstable cutting quality caused by the high-pressure abrasive water jet process parameters selected only by experience,the Taguchi experimental method was used to prove the optimal combination of process parameters for high-pressure abrasive water jet repairing of rails.The top surface repair experiment verifies the effectiveness of the combination of optimized process parameters;in view of the complex nonlinear problem of the interaction between the process parameters of the high-pressure abrasive water jet,the influence of the main process parameters on the machining results is analyzed,and its influence on the machining results is revealed.degree,and construct empirical formulas for abrasive water jet process parameters.(3)To handle the problem that the complex profile of the rail and the difficulty of repairing the profiling envelope of a single jet beam,a multi-jet beam curve arrangement method was constructed,a segmental fitting method of multi-jet beams based on the least squares method was proposed,and a curve fitting function was established.On this basis,the spatial layout of multi-jet nozzles is constructed to solve the problem of low accuracy of fitting the target profile with traditional 3D modeling methods,and to achieve accurate positioning of multi-jet nozzles for rail profile repair.In this paper,the processing mechanism of high-pressure abrasive water jet machining of rail materials is explored,and the influence of process parameters on the machining effect in the high-pressure abrasive water jet machining process is analyzed.The comprehensive evaluation results show that the researched rail repair process based on high-pressure abrasive water jet can effectively repair the surface diseases of the rail,and the surface quality of the repaired rail meets the requirements of rail repair.