Piezoelectric wafer active sensors can be applied to aging aircraft structures to monitor the onset and progress of structural damage such as fatigue cracks and corrosion. Two main detection strategies are considered: (a) the wave propagation method for far-field damage detection; and (b) the electro-mechanical (E/M) impedance method for near-field damage detection. These methods are developed ...

A novel two-stage algorithm for detection of damages in large-scale structures under static loads is presented. The technique utilizes the vector of response change (VRC) and sensitivities of responses with respect to the elemental damage parameters (RSEs). It is shown that VRC approximately lies in the subspace spanned by RSEs corresponding to the damaged elements. The property is leveraged in...

This paper discusses a new method for damage detection based on the most fundamental concept in continuum mechanics: strain compatibility. Compliance with this principle implies a deformed material is free from discontinuities, which are indicative of many types of structural damage. Therefore the principle of strain compatibility, in its ability to identify discontinuities, is very promising a...

BACKGROUND Psoriatic arthritis may progress to joint damage. Joint damage may be assessed clinically, by identifying deformed, fused, or flail joints, or radiologically, by recording erosions, joint space narrowing, ankylosis, lysis, or surgery. The relation between clinical and radiological damage is unclear. OBJECTIVE To study the ordering of clinical and radiological damage detection, and ...

Piezoelectric wafer active sensors may be applied on aging aircraft structures to monitor the onset and progress of structural damage such as fatigue cracks and corrosion. The state of the art in piezoelectric-wafer active sensors structural health monitoring and damage detection is reviewed. Methods based on (a) elastic wave propagation and (b) the Electro–Mechanical (E/M) impedance technique ...

The objectives of this research are to characterize urban building damage , using a comparative analysis of remote sensing imagery acquired before and after an earthquake event, and to develop preliminary damage detection algorithms for locating collapsed urban structures. R emote sensing technologies are emerging as useful post-earthquake damage evaluation tools. Recent studies in Japan, Europ...

While wireless sensors are increasingly adopted in various applications, the need of developing data reduction methods to alleviate data transmission rate issue between the sensors and the data interpretation unit becomes more urgent. This article presents a new data reduction method for sensors used in structural health monitoring application. Our goal is to achieve an effective data reduction...

In this research, the problem of structural damage detection using noisy frequency response function information is addressed. A methodology for damage detection is proposed that uses an unconstrained optimization problem formulation. To solve the optimization problem genetic algorithms (GA) and a local hillclimbing procedure were used. The inherent unstructured nature of damage detection probl...