Circular saws are a common tool for cutting a variety of materials like stone, wood or alloys. Cutting results are significantly influenced by vibrations occurring during processing. Negative consequences are for example increased cutting width and noise emissions. Vibration results from impulses generated at the entrance of the tool teeth into the work piece, from axial run of the cutting tool as well as vibrations transmitted from the machines drive. Therefore, the implementation of effective and cost efficient damping measures is of significant interest. Passive damping approaches are favored because of their low costs.
One approach to dampen vibrations in circular tools and tool flanges passively is the use of shape memory alloys (SMA) as damping elements. SMA and especially NiTi are able to convert large amounts of mechanical stress into heat energy by a stress induced austenite-martensite phase transformation providing the potential to dampen vibrations with more compact damping elements in contrast to other common damping materials like steel or copper used in circular saws. SMA are suitable for damping low frequencies at high amplitudes, e.g. during earthquakes and the damping of single or repetitive shocks, such as those occurring in positioning. The attenuation of higher-frequency vibrations caused by machining with fast rotating cutting tools has so far been considered inadequate but has not been sufficiently investigated in relevant frequency ranges for industrial circular saws.
This paper compares the damping properties of NiTi to those of copper and steel for industrial circular saws. Therefore, the first chapter introduces different sources and types of vibrations in industrial cutting processes while the second chapter describes exemplarily the vibrations occurring in an industrial circular saw. Based on this, the third chapter illustrates common approaches to modify the static and dynamic behavior of circular saws. The fourth chapter gives a brief description of internal damping mechanism, especially the damping mechanism of SMA. The experimental methodology and evaluation of NiTi, steel and copper is in the focus of the fifth chapter. The paper concludes with a summary of findings and an outlook on following work packages.