Influence of modified maximum force criterion-based forming limit curves and process parameters on forming height in deep drawing of LK75-0.5 brass sheets

Accurate prediction of forming limits and appropriate process-parameter selection are essential for reliable and efficient deep drawing. This study develops a direction-dependent forming-limit prediction approach for 1-mm-thick LK75-0.5 brass sheets by combining the Modified Maximum Force Criterion (MMFC) with Voce hardening laws calibrated from uniaxial tensile tests along the rolling direction (RD, 0°), diagonal direction (DD, 45°), and transverse direction (TD, 90°). The resulting forming limit curves (FLCs) are incorporated into a finite element model and validated against experimentally measured maximum forming heights during cylindrical cup deep drawing. Among the investigated hardening descriptions, the Voce-RD FLC provides the closest prediction, with a deviation of only 2.1%. The effects of blank holder force, punch corner radius, and drawing ratio are then investigated using a Taguchi design. ANOVA identifies punch corner radius as the most influential parameter (52.22%), followed by drawing ratio (29.22%) and blank holder force (16.72%). A nonlinear regression model is further developed for rapid forming-height prediction. The proposed MMFC–FLC–FE–Taguchi/ANOVA framework provides a practical basis for failure-risk assessment, parameter selection, and process optimization of anisotropic brass sheets.