Papers by Keyword: Heavy Rail

Abstract: In this paper, the ABAQUS is adopted to carry on numerical simulation on straightening process of R65 heavy rail. The straightening process has been simulated here using the FE package of ABAQUS. All the input data were extracted from experimental tests according to tail manufacturing. Moreover, initial camber of the rail was measured after hot rolling and cooling process.

Abstract: Abstract：Based on the real geometry and boundary conditions of the wheels and rails, the models of 60kg/m U75V heavy rail and the wear regions of LM are built using ANSYS/LS-DYNA software. The internal stress value and variation of the heavy rails that were repeatedly crushed by the rolling wheels are analyzed using the ANSYS/LS-DYNA3D software. The relationship of the internal stress and variation of heavy rails with the repeated rolling of the wheels are obtained. It provides an important theoretical proof and reference significance to prevent the different failure behaviors of the rails.

Abstract: Rail end quenching temperature field calculation is quenched in the process of simulation of organization transformation and distribution of the foundation, the calculation for quality directly affects the organization field. As much as possible in order to make the temperature field of simulation accord with the facts, this chapter will give full consideration to the influence of the phase change latent heat on temperature field of heavy rail, under different heating time by comparing the different heavy rail track the hardening layer depth, it is concluded that heavy rail of the induction heating 40 s conform to the requirements of the project, made a theoretical support to practical production.

Abstract: The hot preflex cooling and compound straightening are the last two consecutive deformation processes and determine the straightness, residual stress and cross-sectional size for fabricating hundred-meter heavy rail products. The compound straightening process needs to be adjusted by the preflex cooling status. For studying the straightness, residual stress and cross-sectional size of heavy rail products, the preflex cooling model (including the residual stress) of heavy rail after cooling should be taken as straightening model for studying the compound straightening. In this paper, the results by ANSYS implicit analysis (geometry model and stress state of the cold heavy rail) is fully imported to the compound straightening by ANSYS/LS-DYNA explicit analysis through an implicit-explicit conversion method, which resolved the connection problem of coupling and analysis models for solving complex models in multi-physical fields. It is very significant for solving the similar problems in engineering.

Abstract: Uneven distribution of temperature is one of the important factors which influences heavy rail bending changes during the cooling process. Through the research of temperature field can reasonable analysis the heavy rail bending change rule, so it is necessary to study the temperature change rule during heavy rail cooling process. This paper adopts finite element analysis software ANSYS to set up three-dimensional models of U75V heavy rail and the cooling bed, and numerical simulate the cooling process. In which, it is studied the temperature changing rules and its distribution rules, emphatically analyzed temperature changing rule during the phase transition phase, and got the temperature changing rules and distribution rules in final cooling time. Especially, it is considered that the heavy rail placed on its side, the latent heat of phase transition and thermal radiation. This research can provide the theory basis and the advisory opinion on the formulation of cooling technological parameters and preflex regulations of the rail.

Abstract: The cooling process of heavy rail is the important step to the output, that the preflexed rail is cooled on the stepping-type cold bed which has been carried by the chain transmission device. We employed the finite element method to analyze the bending deformation of the U75V rail through natural cooling process, the effected factors including the rail side-laying on the cold bed, the latent heat of phase change, and the thermal radiation are considered in the analysis. In the paper, we discussed the establishment of the heavy rail cooling model, the cooling parameters and the boundary condition, and emphatically analyzed the rail bending deformation changes and its principles through the cooling process. The study of the hundred-meter high speed heavy rail can provide the theoretical foundation and reference value to the formulation of cooling technical parameters and preflex technical schedule.

Abstract: Using the finite element software ANSYS/LS-DYNA for the universal rolling machine to simulate,research unit of the universal rolling deformation etc, and the use of universal mill for heavy rail rolling to simulate of lead samples, study of both. By comparing experimental results, the results show rolling simulation of laboratory lead samples and finite element simulations of computer are basically the same, use the universal pass, the difference of pressure coefficient for the rail head and rail base and rail back that work on the workpiece at the universal pass is small, deformation of workpiece is uniformity, it ensure the dimensional accuracy of the finished rail on the rail section.

Abstract: The finite element 3D model of heavy rail roller complex straightening is established by the finite element method in this paper.The straightening process is optimized by orthogonal experimentation and regression analysis. The formative mechanics and the regulation of the residual stress in the process of straightening are researched. The results of the simulation show that: whatever is on the basement of the residual stress or flatness, the new schedule is better than the real field one, residual stress is controlled within 250Mpa.

Abstract: Through the metallurgical testing on a lot of samples from different parts of the heated slab and the finished product in heavy rail manufacturing process, analysis on the surface decarburization characteristics of U71Mn and U75V is carried out. Through analyzing the main affecting factors on the decarburization depth of heavy rail in the heating and rolling process, some effective means to reduce the product surface decarburization are put forward. The results show: (1) The surface decarburization depth distribution of heavy rail slab heated in the regenerative furnace is seriously imbalanced, and the fluctuation ranges between 30% -40%.(2) Under the same production conditions, decarburization of U75V is serious, and the average depth of U75V is more than 11% higher than the U71Mn. (3) The rolling process in the production of heavy rail has a great influence on the distribution of the surface decarburization depth. (4) Because the deformation rate of rectangle slab in the rolling process everywhere is different, in order to reduce the decarburization depth of finished product, it is useful to select the narrow surface of slab to generate the head of heavy rail, as well as to change the structure of the slab cross-section from right-angle to arc.

Abstract: Temperature of the head, the waist, the bottom and angle of the bottom of same heavy rail lying on the cooling bed is tested continuously, time interval is 5min, which can provide the basis for prebending process. Additionally, the U75V 60Kg/m heavy rail straightening processes using the horizontal and edge roll compound straightening machine is discussed in this paper, and contrasts the cross-section dimension and straightness of heavy rail before and after being straightened, which is important to make certain of optimum straightening parameters.