Estimating damage in a rod from changes in node positions

Abstract

This paper is an analytical/experimental investigation of the effect of damage on the nodes of free vibration modes of a thin rod in longitudinal vibration. The damage, a notch, is simulated by a simple spring. It is shown that nodes move toward the notch. The direction and amount by which they move may be used to estimate the position and severity of the damage. Analytical results agree well with experimental tests.