Thermomechanical simulations of blanking process operated over a wide range of punch velocities

numerical model based on the finite element method has been developed
to simulate the blanking process. Thanks to this model we analyse the influence of
punch velocities during blanking on the quality of the sheared edge and the
characteristic parameters governing the process (maximum punch force and
displacement, temperature increase). In this model, inertia, viscous and thermal effects
are properly considered by means of a unified thermomechanical framework. A full
remeshing approach is adopted to overcome the high distortion of elements due to
large deformations, prior to fracture. The material strain-rate sensitivity is introduced
by means of an extension of elasto-viscoplastic constitutive equations for the large
strain regime. The inertial effects are considered thanks to an implicit time integration
scheme. Crack propagation during the process is tracked using the element deletion
method driven by an uncoupled damage criterion. Finally, the coupled
thermomechanical problem is solved by an isothermal staggered scheme.
Experimental and numerical results are compared for the entire range of punch
velocities under consideration. Good agreement between both results has been found.