Springback prediction and control in sheet metal stamping using advanced blank holder load path strategies with ferrofluidic actuators

Abstract

This study investigates an adaptive sheet forming system assisted by magnetorheological (MR) fluid actuators, also known as ferrofluidic actuator, combining experimental testing and numerical simulation to analyze and assess blank holder force (BHF) modulation strategies. Building upon previous developments in ferrofluidic actuation, the present work introduces and compares constant and stepped BHF paths applied to the forming of a hat-shaped component. The stepped strategy was designed to selectively increase the BHF during the initial and final bending stages, where springback originates, while maintaining lower forces during the intermediate phase to reduce energy consumption. Finite element (FE) simulations were employed to replicate the experimental conditions and to analyze the strain and stress evolution during forming and springback. The numerical model, validated against experimental data, provided insights into the local deformation mechanisms and the effectiveness of each BHF strategy. Results show that stepped BHF modulation can achieve a springback reduction comparable to that of high constant-force conditions, but with significantly improved energy efficiency and reduced strain in the vertical walls. The integrated experimental–numerical approach thus demonstrates the potential of MR-actuated systems to enable in-process adaptable control strategies, offering new perspectives for the design of energy-efficient and dimensionally accurate forming operations.