Research On Stretch Bending Process Of Aluminum Alloy Profiles For Rail Vehicles’ Structural Components

The railway is an important part of the transportation system. High-speed railway, as abranch of the railway system, is developing rapidly in recent years. While the train’s speedincreases, the problems of comfort, safety, reliability, economy and applicability become moreprominent, and lightweight of automobile, which is closely related, is particularly important.Considering aesthetics and dynamics requires more in the shape and quality of railwayvehicles’ structural components. That is why stretch bending forming process for structuralcomponents needs to be improved. Finite element numerical simulation is low maintenanceand does better in saving time and manpower than the traditional way which is based onworkers’ experience. Displacement control mode has better performance in forming precisionthan force control. Thus doing the research on the stretch bending of aluminum profile for railvehicles’ structural components and taking one step further doing the research on threedirection stretch bending with displacement control mode will make a difference to industrialproduction. In this paper, three-dimensional geometric models of structural components andforming die are made, and then the simulation is done with a finite element software.Firstly,6065aluminium alloy profile tensile test is made to get the parameters ofmechanical properties. The clamp loading trajectory calculation formula is based on tangentcontact condition theory, which can be used to calculate the loading trajectory for structuralcomponent forming. The basic steps to establish the model is discussed and a numericalmodel is set up to do the forming and springback simulation.The specific research contents are as follows:1.6065minium alloy material tensile test is made to get the mechanical parameters ofthe yield strength, tensile strength, elastic modulus, Poisson’s ratio. 2. The clamp loading trajectory calculation formula is based on tangent contactcondition theory, which can be used to calculate the loading trajectory for structuralcomponent forming. A software is used to get the value of parameters.3. The basic steps to establish the model is discussed, including the selection ofalgorithms and units, the contact conditions, meshing. The clamp loading trajectory is appliedas the displacement boundary conditions of numerical simulation. Optimization is madeaccording to the minimum springback value, which allows us to determine the bestparameters and get the ideal forming results.After doing the simulations with different total deformation, prestretching deformationand poststretching deformation, the conclusions are as follows: the total deformation greatlyinfluences the forming quality and springback value.The total deformation greater, the valueof springback bigger. The stress shows a downward trend. The prestretching andpoststretching deformation is good for forming but makes little difference to springback value.Increasing strain is conducive to the stability of the springback after unloading.