Investigation of backing plate effects on the formability and fracture behaviour of AA1100 sheet in electromagnetic forming: Analytical, experimental and numerical analysis

Abstract

This study investigates the formability of AA1100, 0.8 mm sheet thickness in electromagnetic forming (EMF), using two different backing plates, namely, G10 Fiber and mild steel. These backing plates were chosen due to their distinct material properties and potential to influence the formability and fracture behaviour of the workpiece. The increasing discharge voltage level with increasing dome height and location of failure is examined. An analytical study of a magnetic field in a rectangular spiral coil (RSC) at a point above the center axis and spatial magnetic field strength is conducted. Additionally, numerical analyses are performed using the LS-DYNA EM module, and the data is validated experimentally and analytically. Fracture analysis of the formed workpiece with G10 Fiber and MS backing plates is also carried out. Furthermore, variation of thickness distribution, true major-minor strain, and Vickers microhardness testing is conducted in the formed workpiece to assess the residual stresses developed on the workpiece surface post-EMF. This research provides insights into the effects of backing plates on the performance and outcomes of electro-forming processes. © IMechE 2025.