Evaluation of a Contactless Excitation and Response System (CERS) for process planning applications : An experimental study

Sammanfattning:

Chatter vibration is a common problem for the manufacturing industry that limits the productivity, accuracy and surface quality of machined parts. This study is focused on the out of process methods, such as Stability Lobe Diagrams (SLD), that ensure the selection of the optimal cutting parameters in which the machining process is stable. Previous studies have found that the dynamic properties of the spindle change with the rotational speed. This fact can also affect the accuracy of the SLD predictions, since, the traditional structural dynamic tests such as the Experimental Modal Analysis (EMA) are carried out at static state. An alternative method for the calculation of speed - dependant SLD using a Contactless Excitation Response System (CERS) was proposed. The modal characteristics, such as natural frequencies and damping ratio were determined by EMA tests carried out at idle state whereas CERS measurements were performed at increasing rotational speeds up to 14000 rpm. Subsequently, the SLD at static and dynamic state were computed. Finally, it was concluded that there was not a significant variation of the dynamic properties and SLD prediction with spindle speed at the tested speed range (0 rev/min to 14000 rev/min).