FORMABILITY PREDICTION OF MONOLITHIC AND TAILOR WELDED SHEET METALS DURING SINGLE POINT INCREMENTAL FORMING PROCESS

Abstract

The main objective of this study is replication and validation of finite element (FE) model to predict the formability in terms of forming depth, effective plastic strain, major strain, minor strain and thickness strain distribution during single point incremental forming (SPIF) process of laser tailor welded steel sheet (St12 and St14) with different thickness of 1mm, 1.5mm welding combination to make truncated pyramid of constant wall angle. In order to do this, the maximum forming depth has been associated with five significant process parameters: tool diameter, feed rate, spindle speed, part shape, and step depth. According to the studies, the ideal parameters were determined to be a 10 mm tool diameter, a constant feed rate of 1200 mm/min, and a spindle speed of 300 rpm. The part geometry was found to be 210 mm by 210 mm, with a vertical step of 0.5 mm, a wall angle range of 60° to 71°, and the most suitable angle was determined to be 67°. Additionally, it was found that the maximum wall angle is significantly influenced by the tool's diameter, followed by feed rate, shape, and step depth. Additionally, using LS-DYNA FE models and tests, the wall thickness distribution of produced parts under various process circumstances has been investigated. A strong correlation was discovered between LS Dyna and Abaqus FE simulation. This FE simulated model using LS DYN is able to find out the formability of sheet metals.