Welding Numerical Simulation For The Side Sill Of The Bogie Framework Of Railway Vehicles

This paper strives for the real welding material parameters used in analyses viaAnsys and studying on the resolving strategies of welding problems, for the sake ofenhancing the simulation level for the side sill of bogie framework.The2^ndchaper conducts the discussion from the two hierarchies of the theory forwelding numerical simulation and software implementation, which contains foursection, namely, the mathematical model for heat source, the method for nonlinearproblems, the internal material hardening model of Ansys and the selection of coupledway and corresponding elements in analyses.The better choice is the bilinear modelafter comprehensively compare the difficulty in the acquisition of detail material dataand practical computation. Besides, the usage of No.70and No.45solid elements forsequent couple analyses is to gain adequate storage of safety and fine flexibility forelements application.The3^rdchapter decomposes movement of heat source into three sub goals:theortical model transformation, the movement and achievement of reasonabletemperature field distribution. Via continuous test, we obtain the equivalent data tableform of parameterized heat sorce, develop the curved welding path technique,provided the principle and method for determination of the thermal efficiencyconstant, preliminary realize the movement of heat source, and allow the finaltemperature field tends to be reasonable via repeated adjustment of parameter η,thus guarantee the applied effect of the heat source.The4^thchapter obtain thermal boundary parameters by a simple superpositionway based on classical heat transference rules, namely Newton and Boltzman. Basedon SpringerMaterials and Sysweld database, through studying physical significanceand benchmarking of hardening modulus, making a distinction of relation for trueand engineering stress vs. strain, determination of volume content for each phase inphases analyses and taking the linear mixture principle, we finally gain the material’svarious macroscopic thermal and the mechanical properties data.The5^thchaper continues the basic tamped of the curved welding path from the 3^rdchapter and the real weld material data from the4^thchapter and study theresolution strategies of temperature and displacement field using Yupiter’sproportional model to solve the awkward situation such as high computational cost,distortion of elements, solution divergence, abatement of convergence threshold,reduction of the loss of accuracy, inconsistency of results for displacement solutionsvs. test results. In the temperature solution, we abandon the uniform time step duringthe cooling phase, keep the load step number constant, make the time step geometric,thus can solve the contradiction between the loss of evolution of the mechanicalbehavior under high temperature and highly consumed time. For the displacement,the angular deformation mode and angular deformation are taken as measurementindex, successively verify the feasibility of nodes from contact surface withmatching treatment and cut-off technique at high temperature, we can obtain thesame angular deformation mode as test via the two strategies. Especially by thecut-off technique, the elevated temperature region can carry out the concept of“consistent strain” and “consistent temperature”. Thus it contributes to avoid severedistortion of elements, simplify tangential Jacobian matrix, enhance the stability andthe convergence and save the time cost. Finally, the welding resolution strategies areapplied to the side sill of bogie framework, and then simply discuss the results offields such as temperature, displacement and stress.