Manufacture of an automobile lower arm by hydroforming

An automobile lower arm has been fabricated in a prototype form by hydrofor ming with the aids of numerical analysis and experiments. For the numerical process design, a program called HydroFORM-3D developed here on the basis of a rigid-plastic model, has been applied to the lower arm hydroforming. T he friction calculation between die and workpiece has been dealt with caref ully by introducing a new scheme in three-dimensional surface integration. To accomplish successful hydroforming process design, thorough investigatio n on the proper combination of process parameters such as internal hydrauli c pressure, axial feeding and tool geometry has been performed. Results obt ained from numerical simulation for a lower arm in the hydroforming process are compared with a series of experiments. The comparison shows that the n umerical analysis successfully provides the manufacturing information on th e lower arm hydroforming, and it predicts the geometrical deformation and t he thinning. (C) 2001 Elsevier Science Ltd. All rights reserved.