Early damage detection is very important for in-time repair and retrofit of civil structures. The past years have seen a growing interest in automatic/programmable damage detection techniques using measurements from structural monitoring because of its potential economic benefit for maintenance practices. Recently, statistical pattern recognition (SPC) has been brought forward as a promising wa...

A wavelet-based approach is proposed for structural damage detection and health monitoring. Characteristics of representative vibration signals under the wavelet transformation are examined. The method­ ology is then applied to simulation data generated from a simple structural model subjected to a harmonic excitation. The model consists of multiple breakable springs, some of which may suffer i...

In initial studies, it has been shown that the combination of Principal Component Analysis (PCA) and the contribution plots of Q and T-statistics can be considered an efficient technique to detect, distinguish and localize damages in structures that are equipped with several piezoelectric transducers (PZT’s). In those previous works, the specimen (aircraft turbine blade) was excited using just ...

In this paper, the structural damage localization on a simple composite plate specimen is identified using probabilistic neural networks. First, the category to be identified is defined according to the structural location, and the number of categories is reduced by grouping neighboring elements to one category. Second, the state data of damaged structure are collected by a data collection syst...

A classification algorithm is developed for evaluating the damage state of buildings subjected to earthquakes. Nonlinear response history analysis is used to generate the time histories of each building subjected to each earthquake. This report summarizes the analysis procedure used to extract data and describes the different classification algorithms that are developed to predict damage state....

One of the important aspects of structural health monitoring is that the technique provides information on the life expectancy of structures, as well as detects and locates structural damage. In general, this requires knowledge of the model of structures in great detail, which is not always possible. In addition, dynamic systems usually present non-linear characteristics, imposing a difficulty ...

Damage in metals is mainly the process of the initiation and growth of voids. A formulation for anisotropic damage is established in the framework of the principle of strain equivalence, principle of increment complementary energy equivalence and principle of elastic energy equivalence. This paper presents the development of an anisotropic damage theory. This work is focused on the development ...

This paper investigates the sound power radiated from a cracked plate. The sound power is obtained by using a lumped parameters model-based acoustics theory and vibration responses obtained by using the finite element method. It is shown that the vibration mode shapes and crack angle are closely related to the sound radiation characteristics, which can be applied to detect damages such as the c...

Novel approaches are presented for structural damagedetection that use virtual passive controllers attached to structures, where passive controllers are energy dissipative devices and, thus, guarantee closed-loop stability. The use of the identiŽ ed parameters of various closed-loop systems can solve the problem that the reliable identiŽ ed parameters, such as natural frequencies, of the open-l...