Simulação numérica do processo de hidroformagem de componentes tubulares em múltiplas etapas

摘要

Tubular hydroforming process is characterized by the plastic forming ofmetallic tubular components through the conjugation of compressive axialfeeding and internal pressure. A proper definition of these parameters,known as loading path, allows the plastic forming of more complex parts,with variable thicknesses distributions. Additionally, the final part has excellentsurface finishing and mechanical properties that may be adjustedtowards the specified application. In terms of industrial products, tubularhydroforming plays a crucial role in automobile and aerospace industries, asan attractive process for production of lightweight structures, where structuralstiffness is not compromised when compared to conventional formingprocesses. For that purpose, the use of numerical simulation based on finiteelement analyses, with the comprehension and prediction of the instabilitiesassociated to the process (necking and wrinkling), is of maximum relevance.In this work, two benchmarks are taken into account: (i) a bulge tube withaxisymmetric geometry, and (ii) a T-shaped tube. By defining the models ina numerical analysis environment by finite elements, using Abaqus software,loading paths with multiple stages, as well sensitivity analyses towards thetype and mesh refinements applied, are conducted in order to evaluate theeffects of the instabilities previously mentioned. In both benchmarks, it'salso evaluated the influence of a longitudinal weld line by defining the weldbead and heat affected zone (HAZ) by means of their mechanical properties.The presence of this type of weld line is neglected in most of the researchworks in literature as a measure of simplification, which may lead to misleadingresults regarding the case when compared to those experimentallyobtained.