Assessment of influence of some process parameters on sheet metal blanking

Abstract The blanking of thin sheet (0.1–1 mm) of mild steel has been analysed using an elastic–plastic finite element method based on the incremental theory of plasticity. The blank diameters are considered in the range 1–4 mm. The study has helped to evaluate the influence of tool clearance, friction, sheet thickness, punch/die size and blanking layout on the sheet deformation. The punch load variation with tool travel and stress distribution in the sheet have been obtained. The results indicate that a reduction in the tool clearance increases the blanking load. The blanking load increases with an increase in the coefficient of friction. These observations are very similar to the case of blanking of component of large size. Further, these effects are very similar in the case of both single and double blanking. An interblanking site distance of about twice the sheet thickness is good to reduce the thinning of sheet at the intermediate regions between the two blanking sites. For a particular sheet thickness, the blanking load requirement reduces as the blank diameter increases.