Hierarchical, multitasks optical system for health monitoring of civil engineering structures

Abstract

In this paper a distributed intelligent system for civil engineering structures on-line measurement, remote monitoring, and data archiving is presented. The system consists of a set of full-field optical displacement sensors connected to a controlling server. The server conducts measurements according to a list of scheduled tasks and stores the primary data or initial results in a remote centralized database. The description of an exemplary set of full-field sensors including IP and thermovision camera, 2D and 3D digital image correlation systems, and grating interferometry based extensometers is provided. Three different measurement tasks performed by means of this systems are presented in details.

Digital image correlation method: a versatile tool for engineering and art structures investigations

“…The methods include coherent (holographic and speckle interferometry, grating interferometry) [2,3] and noncoherent image-based methods (moiré fringe methods, structured light methods, digital image correlation) [4,5]. Sometimes, due to different global and local measurement requirements investigation of a structure is performed by a hierarchical system of full-field methods [6,7]. Analyzing a variety of demands coming from different end users it seems that in many cases 3D digital image correlation method is the very flexible and useful measurement tool [5,8].…”

Combining Digital Image Correlation and Thermal Measurements

“…Features such as simple hardware, full-field, noncontact measurements, scalable field of view make possible application in laboratory as well as insitu measurements. Often, in order to address a variety of measurement requirements even within one complex object, these methods are applied in hierarchical measurement system using combination of optical methods [3]. Some objects, however, experience thermal load and simultaneous information about distributions of displacements, strains and temperature is required.…”

Application of Image Based Methods for Monitoring and Measurements of Structures in Power Stations

“…The methods include coherent (holographic and speckle interferometry, grating interferometry) [3,4] and noncoherent image-based methods (moire fringe methods, structured light methods, digital image correlation) [5,6]. However in the case of big engineering structures and the tests performed outside laboratory, in difficult outdoor conditions noncoherent image based methods are most often applied [7,8,9]. It is mainly due to relatively easy measurement procedures, less expensive hardware configurations and big measurement range of investigated quantities.…”