A novel vibration based damage detection and structural health monitoring system

近年来，利用动力响应识别结构损伤及其定位已成为结构工程中的一个重要研究热点。现有的基于振动的损伤评估方法大多依赖于模态特性，对结构损伤，特别是局部或区域集中的损伤类型不敏感，因此不被认为是合适的损伤指标。申请人已经开发了一个鲁棒损伤检测系统，其中使用了鲁棒信号处理技术（即经验模态分解）和一种新的基于能量的公式来确定结构中的损伤。到目前为止，该方法对通过压电传感器获得的结构振动信号进行处理。该方法的核心是基于其新颖的“损伤指数”公式。到目前为止，我们的研究结果表明，开发的配方和系统用于监测缺陷管道和粘接管道接头的稳健性和准确性。动机：开发一种技术，使人们能够评估局部损伤的完整性，例如粘合接头的脱落或机械紧固接头的松动/缺陷紧固件，使用廉价的设备和简单的方法是非常可取的。在这种情况下，检测对现有程序构成严重挑战。例如，应用传统的基于振动的损伤检测方法来检测任何剥离几乎是不可能的。然而，我们的方法可以对这种情况提供非常准确的评估。然而，它需要进一步的改进以使其更加健壮和用户友好，并且其对各种现实生活情况的适用性需要进一步的研究。为此，提出了用激光辅助振动监测来代替压电传感器来建立完整的损伤检测程序。我们坚信，建立所提出的激光辅助程序的适用性及其对各种实际情况的适用性，将使该系统在当今市场上具有自成体系、适销对路和很强的竞争力。

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.