Finite Element Simulation of Deep Drawing Processes for Shell Bar RR Impact RH/LH

Abstract

Finite Element Method (FEM) is one of the most useful techniques to analyze problems in metal forming process because of this technique can reduce cost and time in die design and trial step [1]. This research is aimed to predict the optimal parameters in order to eliminate cracks and wrinkles on automotive deep drawing product “Shell Bar RR Impact RH/LH”. The material was made from high strength steel JSC440W sheet with thickness 1.8 mm. The parameters that had been investigated were blank holder force (BHF) and drawbead restraining force (DBRF). In order to simplify the process, punch and die in the simulation were assumed to be a rigid body, which neglected the small effect of elastic deformation. The material properties assumed to be anisotropic, behaved according to the constitutive equation of power law and deformed elastic-viscoplastic, which followed Barlat 3 components yield function. Most of the defects such as cracks and wrinkles were found during the processes on the parts. In the past, the practical productions were performed by trial and error, which involved high production cost, long lead time and wasted materials. From the results, when decreased blank holder force to 30 tons, cracks on the part were removed but wrinkles had a tendency to increase in part area because of this part is the asymmetrical shape. Finally, applying about drawbead restraining force at 154.49 and 99.75 N/mm could improve product quality. In conclusion, by using the simulation technique, the production quality and performance had been improved.

Un aperçu sur l’emboutissage profond

“…La force exercée par le jonc de retenue a une influence significative sur la qualité de la pièce, de sorte que la diminution de son effort élimine les fissures et améliore les plis (voir Figure 8) (Sunanta & Suranuntchai, 2018)), la figure 7 ci-dessous présente la position des trois joncs de retenue : La force du jonc de retenue a également un effet positif sur le retour élastique en emboutissage, cependant, elle provoque une augmentation des forces de formage et des contraintes dans la pièce. La figure 9 montre que l'utilisation d'un jonc de retenue de 5 mm de hauteur entraîne des angles de retour élastique inférieurs par rapport à celui de 2,2 mm de hauteur, telle que α2.2= (90.1 ±1.5) ° et α5= (70.6 ±1.4) °, néanmoins la force de frappe augmente telle que F5max = (29.4 ±0.1) KN (Rigas et al, 2021).…”