CHATTER IN MILLING

摘要

Chatter is a vibration phenomenon that has been an issue in material removal processes (MRP) in manufacturing for many years. Since 1995 there have been more than 50 publications on the topic each year with a majority of the work focusing on metal cutting with various control methods of eliminating and/or reducing the effects of chatter. This work focuses on understanding when chatter is imminent due to different speeds and analyzing the surface finish of the parts for comparison between the different speeds. A simple machining operation is performed on a predetermined plastic workpiece and accelerometers are used to monitor the vibration at different locations of the workpiece. The accelerometers are used to measure the frequency response functions (FRFs) of the workpiece in order to determine the natural frequencies of the workpiece as well as measure the frequencies of vibration during the MRP. A finite element analysis (FEA) is used to determine the mode shapes of the natural frequencies and understand any relationship between chatter and the mode shapes. Finally, the surface finish of the machined workpiece is analyzed using a surface finish machine in order to compare the machining of the workpieces as a function of the speeds.