Determination of the dampening characteristics of a tubular beam filled with vibration dampening materials

摘要

The effects of vibrations during micro and mesoscale machining operations require a rigid machine tool frame that can dissipate heat and vibrating waves in a symmetrical fashion. A tetrahedral machine tool frame is a stable structure and it is considered that the geometry could minimise vibrations by changing the characteristics of the machine tool frame. To explore the hypothesis, an experimental modal analysis established the vibration characteristics of the columns that support the framework. Modal analysis consisted of measuring the frequency response functions from impact tests to determine the natural frequencies, damping and mode shapes of hollow structural steel columns filled with vibration dampening media. The purpose of this paper is to investigate the increase in structural dampening characteristic with the addition of a granular medium such as sand, or a viscous fluid such as oil. The outcome of this research shows that substantial dampening benefits the machining operation by reducing, or eliminating, the effects of vibration on the machined workpiece.