Investigating the Incremental Forming Capabilities of A11050 H14 Copper EDD Steel and CP Ti Grade 2 Using Ductile Damage Criterion

Abstract

Incremental sheet forming (ISF) is evolving as a capable technology in the sphere of sheet metal forming. ISF relies on minimum part-specific tooling for forming the metal sheets into the desired geometry. The present work is devoted to investigate the incremental forming capabilities of aluminium alloy Al1050 H14, C10100 oxygen-free electronic copper, extra deep drawn (EDD) steel, and commercially pure titanium (CP Ti) grade 2 using ductile damage criterion. The whole research work is divided along two verticals, namely: newline1. Establishing the ISF process with Lemaitre damage model to form the components of 2.0 mm thick aluminium alloy Al1050 H14 and copper sheets. newline2. Investigating the incremental forming capabilities of EDD steel and CP Ti grade 2 sheets of newline newline1.0 mm thickness. newline newlineThe work begins with the preparation of the Lemaitre damage model as a user subroutine (VUMAT) and linking it with Abaqus/Explicit for the simulation of the ISF process on Al1050 H14 and copper sheets of 2.0 mm thickness. In the present work five hardening laws, namely Hollomon, Voce, Swift, Mixed Swift-Voce, and Kim-Tuan law were considered. However, in the algorithm of the Lemaitre model, four hardening laws (Hollomon law was excluded) were incorporated to define the hardening behaviour of the material during finite element (FE) simulation of the ISF process. To identify the elastoplastic and damage parameters, tensile testing has been conducted on three kinds of specimens, i.e., pure tension (PT), pure shear (PS), and combined tension-shear (CTS). The hardening parameters for the considered hardening laws were identified for all these specimens using the curve fitting technique for both materials. To identify the damage parameters (damage exponent and damage denominator) of the Lemaitre damage model, the digital image correlation (DIC) technique has been used during the tensile testing of the pure tension specimens.