Using mode shapes to overcome vibration

Machine tool vibration are caused by time-varying cutting forces and the amplitude of the vibration depends on the size of the cutting force, its frequency, and the machine tool structure. The frequencies at which the machine tool vibrate are called its natural frequencies, and most machine tools have many of them. Each natural frequency has its own mode shape that include the entire structure, and a mode shape is often dominated by the deflection of a particular element of the structure. The mode shapes of machine tools can be calculated using a finite element model or they can be experimentally measured using modal analysis techniques. The reason for the vibration is mostly the flexibility of the connection between the tool and toolholder, and this vibration can be addressed by switching to a stiffer connection style.