Practical measurement of circular saw vibration mode shapes

Abstract

Natural frequency measurement provides a convenient quantitative method for monitoring the tensioning state of a circular saw. However, it can often be difficult to interpret the measurements because the corresponding vibration mode shapes are not explicitly known, especially when adjacent natural frequencies are close together. A mode shape identification method is presented. It involves using two vibration sensors, one fixed and one orbiting the sawblade circumference. The performance of a simple prototype measurement device using this technique is described. The device could successfully identify the nodal diameter and nodal circle numbers of the major sawblade vibration modes.

Keywords:

• Circular saw
• mode shape
• nodal diameter
• critical speed
• saw tensioning