Comparison of Constitutive Models for Predicting the Formability of SS 304 by Tubular Hydroforming Process

Pathapalli Venkateshwar Reddy,Perumalla Janaki Ramulu,B Veerabhadra Reddy,U Pranavi

doi:10.4018/ijmmme.293227

Abstract

Finite Element (FE) simulation of sheet/tube forming precision depends mainly on the accuracy of the constitutive modeling. The present paper aim is to compare the constitutive models to fit the stress-strain curves. The accurate deformation behavior of the SS 304 tubes depends on the constitutive modeling of hardening behavior. Deformation data of the tensile specimens cut from tubular sample were collected by conducting Uniaxial tensile tests (UTT) at three different rolling directions. Five constitutive relationships were then recognized by fitting the true stress and strain data with the constitutive models of Hollomon, Power, Krupowsky, Voce and Ghosh, and the fitting accuracy were analyzed and compared. Effects of hardening models on Forming Limit Curves (FLC), pressure loading and bulge height of the hydroformed tube were then studied. The obtained FLC from the simulations were compared with experimental FLC to predict the accuracy of the hardening models.

Highlights

Tube hydroforming (THF) is a high-tech manufacturing method that creates precise shapes with precise dimensions
From fig. 3 (b), it is observed that the loading paths of all the models different for different bulge heights when compared to the experimental data
Experiments and numerical simulations on open bulge tube hydroforming were carried out in this study, with different hardening models taken into account

Summary

Introduction

Tube hydroforming (THF) is a high-tech manufacturing method that creates precise shapes with precise dimensions. Though THF techniques are utilised in various industries such as automotive and aerospace, the development of the process requires expensive tools because the process is based on experimentation. THF is widely employed in various industries to accomplish weight reduction, fewer parts, and lower costs (Ge et al, 2017) due to significant advancements in PC controls and pressure drive frameworks. A brief summary on THF can be observed in literature (Alaswad et al, 2012). The higher formability of materials means to create successful forming behavior. There are many methods in the form of analytical and experimental models developed to generate FLC for different

Objectives

Methods

Results

Conclusion