| Wheel tread stripping leads to the serious reduction of the service life of the wheel,which not only increases the operating cost of the railway,but also directly endangers the driving safety.After a eertain type of freight locomotive runs a very short mileage on the upper line of a certain section,most of the wheel treads have serious stripping damage,mainly are in the form of a large area of pit spalling.As a result,a considerable number of locomotives are forced to carry out wheel repair in advance,which results in great economic losses and serious safety risks to the operation department.In this paper,the actual problems originating from the railway field are studied and discussed.The main research contents and achievements are as follows:(1)This paper discusses the problem of wheel damage in the course of development of rail transit,and makes a detailed suumary of the present research situation at home and abroad in this field.After comprehensive analysis,the research ideas and technical route of this paper are obtained.(2)The structure characteristics of locomotive and track,the operation characteristics,wheel tread stripping state and test results in a eertain section are introduced in detail.the relationship between sanding quantity and tread stripping is studied in depth.It is found that the serious stripping of the wheel tread of the locomotive is closely related to the type of sanding quantity and the amount of sand dropped per unit time.(3)The wheel-rail contact simulation test bench was built,the wheel-rail contact performance was analyzed by cutting the wheel on the spot,and a series of wheel sand rail multi-body contact tests were carried out,and the Sanding quantity was reappeared on the test bench.The forming mechanism of wheel tread stripping is determined,that is,bad shape of the river sand used in the object section after compaction,which is the main cause of the sanding quantity of the wheel,and too large amount of sanding quantity will lead to large area stripping.(4)The finite element contact theory is used to establish the calculation model,and the elastic-plastic contact problems of wheel-rail and wheel-sand-rail are analyzed.From the angle of mechanics,the forming mechanism of wheel tread stripping and the influence laws of various related factors are discussed and obtained as follows:the river sand used in the object section is badly shaped after being compacted,which will lead to sanding quantity on the wheel surface;With the increase of the amount of sand,the distribution area of sanding quantity increases accordingly.The numerical results are in good agreement with the field measurements and experimental results,which verify the correctness of the results.(5)By synthetically analyzing the research results of field irrvestigation,test and numerical calculation,the formation mechanism of the wheel tread stripping of the object locomotive and the law of multi-factor influence are obtained,and the mitigation measures are put forward and the improvement of the operation department is directed.After tracing and testing,it is found that the wheel stripping problem is obviously improved after the object locomotive adopts the mitigation measures proposed in tihis paper,which further illustrates the correctness of the research method and the engineering practicability of this paper. |
