Design of complex NiTi dampers trough subtractive and additive production processes: three case studies

This work presents a comparison between two dampers based on conventional NiTi pseudoelastic elements, wires and tapes, and a NiTi pseudoelastic component realized through additive manufacturing. The first case study is a linear damper consisting in parallel groups of pseudoelastic NiTi wires with different length. This device achieves high level of dissipated energy during one working cycle and permits the control and the modulation of the elastic domain. The second case study is a torsional damper composed by a set of pseudoelastic NiTi tapes assembled radially with respect to the direction of rotation. With this configuration, the flag-shaped pseudoelastic behavior is completely hindered. The output torque has a peak-like trend; each peak is related to the bending of a single tape and at the maximum deflection, the corresponding registered torque is null. The third case study is an "A-shaped" auxetic complex structure to use as damper, produced with additive manufacturing technology (Selective Laser Melting). Results show that additive manufacturing permits the fabrication of devices with complex geometries and superior specific damping properties.