Pressure-assisted single-point incremental forming (PA-SPIF) is one of the emerging forming techniques for sheet metals that have been the subject of rigorous research over the past two decades. Understanding of its forming mechanisms and capabilities is growing as a result. Open gaps are still present in material constitutive modelling for accurate numerical predictions and finite-element simulations as the characteristics of localised deformation behaviour in SPIF are different from those of conventional sheet metal forming. The current investigation focused on the comparison of three different material models for the finite-element analysis of PA-SPIF of cold-rolled, dual-phase steel DP600. Experimental trials using different fluid pressures showed good agreement with simulation results with discrepancies in deformed blank thickness and shape geometry predictions of 3–11% and 10–21%, respectively. Within the tested materials and range of parameters, the fracture-forming-limit diagram (FFLD) material model was identified to be of superior accord with experiments.

The single point incremental sheet forming process is a flexible manufacturing process to produce complex three-dimensional products. Unlike traditional forming processes, the single point incremental sheet forming process does not require unique tools or die. This method is constantly being improved to increase the uniform formability of the material. The fluid assisted single point incremental sheet metal forming process with a newly developed system was experimentally investigated in this research. A controlled pressure fluid was applied to the forming surface in the opposite direction during shaping. Shaping processes were carried out using different fluid pressure values. The effect of this pressurised system on the forming quality was investigated by considering material wall thickness changes, heat generation and surface roughness. The results were compared with the results obtained with the traditional single point incremental sheet forming method. It has been determined that our method increases the formability of the finished product and shows a homogeneous thickness distribution.