Influence of process parameters on thickness distribution and damage mechanisms in single point incremental forming

This study presents a comprehensive investigation into the single-point incremental forming (SPIF) of Al 1050 A-H16 alloy, focusing on the critical issue of material thinning and failure. While SPIF offers significant advantages for small-batch production and prototyping, its industrial application is often limited by unpredictable thinning and fracture. To address this, a combined approach of experimental validation and finite element analysis (FEA) was employed to systematically analyse the influence of seven key process parameters including wall angle, tool diameter, and toolpath strategy on the final thickness distribution. The primary contribution of this work is a three-fold analysis: (1) a quantitative ranking of process parameters affecting material thinning, (2) an in-depth examination of the complex stress state using stress triaxiality and the Lode angle parameter, and (3) a clear elucidation of the ductile damage mechanism leading to material failure. The results conclusively demonstrate that the wall angle is the most dominant factor governing thickness reduction and plastic strain. Furthermore, the analysis of the stress state provides crucial insights into the mechanics of void growth and coalescence, which are directly linked to the onset of fracture. This research provides a robust, quantitative foundation for optimizing SPIF processes to control material thinning, mitigate failure risks, and enhance the formability of complex geometries, thereby bridging a critical gap between theoretical understanding and practical industrial application. • The wall angle significantly influences thickness reduction in single point incremental forming (SPIF). • A thinning ratio exceeding occurs when geometries are designed with a wall angle of . • The complex stress state in SPIF is revealed through stress triaxiality and Lode angle parameter analysis. • The damage mechanism in SPIF is elucidated by examining the stress state’s effect on void growth and coalescence. • Solid elements are required to fully capture the stress state in the thickness direction and the damage mechanism.