Design and optimisation of punching/blanking systems aided by experimental modelling

In order to be able to increase cost effectiveness and product quality, for example through the application of in-process control principles, a detailed understanding of the punching/blanking process is required. This can be acquired through analytical, numerical, and experimental modelling of the process. In this paper, a comprehensive experimental modelling programme is presented. The results, set here against theoretical knowledge of the process, can be utilised to gain insight into the punching/blanking process and its sensitivity to machine tool parameters, and can also be used to verify theoretical modelling efforts. The influence of variations in the clearance between the punch and the die, the thickness of the sheet, the radius on the tool, and the use of lubrication are reported. Existing views on the role of hydrostatic stresses in the clearance zone in suppressing rnicro-cracks are compared against these experimental findings. The programme was carried out using annealed steel and cold rolled sheet steel