A Vibration Technique for Non-Destructively Assessing the Integrity of Structures

TLDR

The study presents a non‑destructive method for assessing structural integrity in systems amenable to one‑dimensional analysis. The technique uses single‑point vibration measurements combined with a theoretical model—typically receptance analysis of axial modes—to locate and quantify defects, and can also be applied to torsional modes. Experiments on prismatic bars, a doubly‑tapered bar, and a camshaft demonstrate that predicted defect locations match the actual damage sites with high accuracy.

Abstract

A method of non-destructively evaluating the integrity of structures is described and applied to structures for which a one dimensional analysis is satisfactory. It is shown how vibration measurements made at a single station in the structure can be used, in conjunction with a suitable theoretical model, to indicate both the location and the magnitude of a defect. Receptance analysis is used in this instance, but the principle is equally applicable to other techniques of mathematical analysis. Experimental results are obtained on a variety of components, including straight prismatic bars, a doubly-tapered bar, and an automobile camshaft, excellent agreement between the predicted and actual damage sites being obtained. The axial mode of vibration is generally used, although somes tests are also carried out successfully in torsion.