Numerical – Experimental Correlation of Sheet Hydroformed Component

Abstract

Sheet hydroforming has gained increasing interest in the automotive and aerospace industries because of its many advantages such as higher forming potentiality, good quality of the formed parts which may have complex geometry. The main advantage is that the uniform pressure can be transferred to any part of the formed blank at the same time. This paper reports numerical and experimental correlation for symmetrical hydroformed component. Experimental tests have been carried out through the hydroforming cell tooling, designed by the authors thanks to a research project, characterized by a variable upper blankholder load of eight different hydraulic actuators. The experimental tests have been carried out following a factorial plane of two factors, with two different levels for each factor and three replicates for each test with a total of 12 tests. In particular two process parameters have been considered: blank holder force, die fluid pressure. Each factor has been varied between an High (H) and Low level (L). The order in which have been conducted the tests has been established through the use of the Minitab software, in order to ensure the data normality and the absence of auto-correlation between the tests. An ANOVA analysis has been performed, in addition, with the aim of evaluating the influence of process parameters on the thickness distribution of the component, its formability and feasibility. Finally, finite element analysis (FEA) was used to understand the formability of a material during the hydroforming process. In this paper, the commercial finite element code LS-Dyna was used to run the simulations. A good numerical – experimental correlation has been obtained.