Research On Failure Mechanism And Damage Recognition Algorithm Of Turnout Slide Plate In Alpine Region

The structure of turnout is complex,which is one of the main weak points of railway line.In the process of maintenance and repair of turnout in Lan-Qing railway,it is found that the problem of slide plate damage occurs in some sections.As a key component that affects the opening and closing of the switch rail,the slide plate bears complex mechanical coupling effects when the train passes through the turnout,and is one of the key parts that affect the safety and stability of the turnout.At present,the mechanical mechanism of the slide plate is not clear in the research on the damage of the slide plate,and there are no targeted measures for the frequent failure of the slide plate.It is particularly important to study the mechanical mechanism of the slide plate in train operation,analyze the key factors affecting the damage of the slide plate,and provide targeted suggestions for line maintenance and repair.To this end,this paper mainly carries out the following research work:(1)Statistics and analysis of turnout slide plate damage in alpine regionStatistics were conducted on the damage situation of slide plate and their corresponding meteorological data in three work areas,and it was found that the number of slide plate damage significantly increased in alpine region,with a certain degree of climate correlation.Through the macroscopic fracture inspection of the slide plate,it is found that there are some holes in the weld seam of the slide plate,and the welding quality is poor.The metallographic analysis results show that the microstructure of the slide plate material is good,but the grains are relatively coarse.Preliminary statistical analysis found that the damage to the slide plate mainly occurred at sleepers 14,15,and 16.(2)Construct a three-dimensional finite element model of the track structure in the main damage area of the slide plate,and study the mechanical mechanism and crack propagation law of the slide plateBased on ANSYS,finite element models of the slide plates and related track structures at sleepers 14,15,and 16 were established.The overall model consists of wheel sets,rails,slide plates,rubber pads,sleepers,and other parts.Hyper Mesh is used to pre-process the model and refine the mesh area where the slide plate and rail may contact.Applying extreme load conditions,analyze the stress state of the slide plate when passing through the turnout in both vertical and lateral directions.The results show that there is stress concentration at the root of the tongue depressor,and the failure of the rail support will lead to stress yield of the slide plate,causing permanent damage.Semi-elliptical cracks of different angles and lengths are added to the weld position to calculate the value of the stress intensity factor,analyze the effect of cracks on the slide plate de-welding,and find the main weak points of the slide plate injury and damage.The analysis results show that the weld has a tendency to crack when the crack length reaches 1.2 mm.(3)Fatigue life analysis of slide plate based on n CodeThe fatigue life of the slide plate is calculated by using n Code Design Life,creating a random alternating load spectrum from white noise,and analyze the adverse effects on the slide plate caused by straight and lateral passing through the turnout.Seek the lowest position of fatigue life under the most unfavorable working conditions,and analyze the impact of weld cracks on the fatigue life of the slide plate.(4)Research on the damage recognition algorithm of slide plate based on edge detectionCollect images on-site,use image template matching algorithm to identify the image of the slide plate,and determine the research area range through pixel extraction.Calculate and draw image histograms and perform equalization processing.Transform the time-domain to frequency-domain using two-dimensional discrete Fourier transform,eliminate image noise through linear filtering,and compare different image segmentation algorithms.The results show that the Mean-Shift method can achieve good results.The Sobel operator,Scharr operator,Laplacian operator,and Canny operator were used for image edge detection,and the results showed that the Canny operator had the best edge detection effect.By using binary threshold processing,good damage contours of the slide plate were obtained.Morphological operations were performed on the image after binary threshold processing,and damage line segments were extracted after Hough transform.The damage judgment of the slide plate was achieved by calculating the length of the line segments.