Effects of pressure fluctuations and vibration phenomenon on striation formation in AWJ cutting

After a first period in which the Waterjet/Abrasive Waterjet research was focused on the optimisation of the process parameters, the attention is now focused on aspects that were usually neglected. However, they are very important in order to understand the physics of the cutting process and to improve the cutting quality. Particularly, the striation formation is a subject of research, In fact, the surface generated by AWJ cutting is characterized by a streaked morphology in the bottom zone of the cutting surface. The traditional interpretation of the mechanism of striation formation, in AWJ cutting, asserts that their formation depends mainly on the material removal mechanism, on the jet instability and on vibration phenomenon during the cutting process. In this work, the effects of the pressure fluctuations and of the cutting head vibrations on the striation formation have been investigated. In order to do this, the pressure signals of two different high pressure generation systems, having different technological characteristics, and the corresponding cutting head vibration signals have been measured and analysed in time and frequency domain. In order to investigate the correlation between the surface structure with the pressure fluctuations and the cutting head vibrations, the surface produced by AWJ has been acquired and analysed. © BHR Group 2004 Water Jetting.