A study on the application ofCCD to the evaluation of dynamic structural properties

Abstract

TheCCD measuring technique is effectively applicable to structures which are not physically accessible or contain the radioactive waste material or other harmful materials to man. Unlike other measuring systems with numerous sensors attached to the structure, it simplifies the complicated problems in transferring the signal and thereby makes it possible to work more effectively. Such a non-contact type ofCCD measuring technique is suggested to measure some structural characteristics of civil infrastructures. Calibration of this system is performed based on the DLT theory. And based on the calibration, three-dimensional coordinates for changing displacement of a structure are measured. This measuring system also compares the result of trigonometrical leveling in terms of its exactitude. After the calibration, a spectrum analysis of a spring mass model has been performed in the one degree of freedom. Based on the results from the experiment, another experiment was made to the structure. Finally the same experiment was performed to the cantilever and thereby changing positions were obtained from four channels all simultaneously. Such experiments enabled us to get to the following conclusions. TheCCD measurement turns out to be very useful in large structures. A spectrum analysis of the structures was made after inducing the acceleration from the continuously changing displacement, and the structural characteristics were found on the basis of the analysis, which finally proved the practical usefulness of theCCD measuring system.