Deformation characteristics and forming force limits of multi-point forming with individually controlled force–displacement.

To solve the problem of springback in traditional multi-point forming (MPF), a new multi-point forming process, namely, multi-point forming with individually controlled force–displacement (MPF-ICFD), is proposed. In this manuscript, traditional MPF and MPF-ICFD are compared. Taking the cylindrical surface as the research object, the change in the springback of a plate is analysed by experiments, and the distribution of the strain and wall thickness of the plate is analysed by numerical simulation. Theoretical analysis is used to calculate the forming window for the MPF-ICFD process, and the results from theoretical analysis are verified by experiments and numerical simulation. The results show that the springback of 1060 aluminium alloy and Q295 for MPF-ICFD can be decreased by 73.8% and 45.5%, respectively, compared with traditional MPF. In traditional MPF, the strain uniformity of the plate is poor, and the maximum thinning rate is 4.5%. For MPF-ICFD, the strain is relatively uniform, and the maximum thinning rate is 0.25%. For an aluminium alloy sheet with a wall thickness of 1.5–3 mm, the upper and lower limits of the forming force for a single head are observed to change linearly from 6.3 to 12.6 kN and from 0.5 to 1 kN, respectively. [ABSTRACT FROM AUTHOR]