Mechanical Properties Characterization of Sheet Metal Forming materials--Anisotropy of Grade 1 Titanium and Stainless Steel 316
Sheet metal is formed through a process of metal working which produces thin sheets of metal from thicker plates. The sheet metal materials considered in this work are formed through a process of cold rolling. This cold rolling process increases the anisotropic characteristics of the sheet metal product. In this work, the utilization of three uniaxial tensile tests to characterize the sheet metal materials in the rolling, transverse and diagonal directions are discussed. The use of digital image correlation (DIC) to determine the strains experienced by the materials before and after yield by observing the necking regions during the conventional tensile tests is introduced. Due to increased competition in the heat exchanger manufacturing industry, many companies are turning to finite element simulations of the heat exchanger plate forming process in order to reduce product development costs and time to market for new and redesigned products. The accuracy and reliability of the simulation results are largely dependent on how closely the material model used in the simulation matches the behavior of actual material, therefore, it is important to test and understand the behavior of the actual materials used in the fabrication of the products. In this project, an accurate and verified tensile testing simulation is developed. It is suitable to model the forming process of Tranter heat exchanger plates using Tranter provided commercially pure Titanium and stainless steel 316 sheet metals. Tensile tests of two kinds of the sheet metals have been conducted and the full-field deformations are obtained using digital image correlation (DIC) techniques to provide constitutive data for elastic-plastic material models. Anisotropy material models are created for both sheet materials. Simulations of finite element method utilizing the developed material models produced results which closely matched the full-field deformation results obtained using DIC.