Joining of sheets by sheet-bulk forming: a numerical and experimental study

The authors present a new mechanical joining process that allow to connect two sheets perpendicular to one another, a variant of the traditional ‘mortise-and-tenon’ joint. This investigation is focused on joining similar and dissimilar sheets based on sheet-bulk forming and it is supported by experimental data and numerical simulation with an in-house finite element program, I-form. Results show that is possible to join materials by sheet-bulk forming and is also presented the joinability window as a function of the main operating parameters. The divided flux technique could be a valid option to eliminate the observed small clearance related to the elastic recovery of polymers. Furthermore, this technique could also be applied whether a lower initial punch force is required or even a different head morphology is desired. Destructive tensile tests were performed to determine the maximum force that the joints are capable to withstand without failure and to identify the failure mechanism. Ivo M.F. Bragança1,2*, Maria A.R. Loja1,2, Carlos M.A. Silva2, Luís M. Alves2, Paulo A.F. Martins2