Numerical simulation of deformation in multi-point sandwich forming

Multi-Point Sandwich Forming (MPSF) is a new flexible forming technology. In this process, one half of a conventional die set is substituted by a discrete die with wide spaced pins plus deformable die sheet and a polyurethane upper die is used as the other half. FE simulation using this tool design reveals the effect of the shape of the upper die on workpiece deformation and the role played by the deformable interpolator and die sheet. It is shown that the deformed shape is a result not only of the reconfigurable die shape, but of the elastic die shape and elastic interpolator stiffness also. Using an interpolator enables smooth workpiece surfaces to be obtained, even when the die sheet is dimpled by the pins of the reconfigurable die.