A novel vibration based damage detection and structural health monitoring system

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The use of dynamic response to identify damage and its location in Structural Engineering has become an important research focus in the recent years. Most of the available vibration-based damage assessment methods rely on modal properties and are insensitive to structural damage, especially the locally or regionally concentrated types, and hence, are not regarded as suitable damage indicators.A robust damage detection system has been developed by the applicant, in which a robust signal processing technique (i.e., the empirical mode decomposition) and a novel energy based formulation are used to establish damage in structures. So far, the methodology manipulates the vibration signal of the structure obtained via piezoelectric sensors. The crux of the methodology is based on its novel "Damage index" formulation. The results of our study so far have shown the robustness and accuracy of the developed formulation and system for monitoring of defected pipes and adhesively bonded pipe joints.Motivation: Development of a technique that allows one to assess the integrity of local damage, such as a disbond in bonded joints or a loose/defected fastener in mechanically fastened joints, with inexpensive equipment along with a simple method is quite desirable. In such situations, the detection poses a serious challenge for the available procedures. For instance, it would be virtually impossible to apply the traditional vibration based damage detection methods to detect any disbond. Our methodology however can provide a very accurate assessment of such a situation. However, it requires further refinement to make it more robust and user-friendly, and its applicability to various real-life situations requires further investigation. For that the use of laser assisted vibration monitoring toll, instead of the piezoelectric sensors used to establish the integrity of our damage detection procedure, is proposed. It is strongly believed that the establishment of the applicability of the proposed laser assisted procedure and its applicability to a variety of real situations will make the system self-contained, marketable and very competitive in todays market.