SIMULATION OF PSEUDOELASTIC NITI SHAPE MEMORY ALLOYS UNDER COMPRESSIVE LOADING TO ASSESS THE POTENTIAL USE IN VIBRATION DAMPING IN THE TOOL INTERFACE

Passive vibration isolation is a key element to achieve precise results in milling processes and to increase tool durability. Damping of vibrations near to the cutting edge is considered highly effective as well as hard to implement because of the limited damping properties of conventional materials in the available space. Particularly long projecting tools tend to be unstable with high vibration amplitudes due to their low material damping and high compliance.

Since previous approaches to solving stability problems are often complex and cost-intensive, the development of simpler vibration-reducing solutions is required. The use of damping elements made of NiTi shape memory alloys represents an innovative approach.

Shape memory alloys based on NiTi are known as suitable damping materials for various applications, e. g. for damping large circular saws or buildings. Their use bases on the ability to convert large amounts of mechanical energy into thermal energy through the pseudoelastic effect, whereby the pronounced conversion hysteresis of the material provides information about the usable damping potential.

Since an iterative approach is required to find out which geometry of the damping element or which preload during operation is ideal for the respective application, the development can be cost- and time-intensive.

The paper describes the simulation model with the selection of the required input parameters and the results of the simulations to determine the hysteresis properties under different loading conditions. The simulations are to be used to predict and optimize the different installation situations without having to rebuild and test further specimens.