H. M. Chow

Detection of Multiple Cracks on a Partially Obstructed Plate Structure Following the Probabilistic Approach

This paper addresses the problem of detecting multiple cracks on thin plates utilizing measured dynamic responses from only a few points on the target plate. Most existing model‐based methods in the literature focus on the detection of single‐crack or multi‐crack with given crack number on beams. Only very limited number of researches have been carried out for the detection of multiple cracks for plate‐type structures following the model‐based method. There are two phase contained in the proposed crack detection methodology. The number of cracks is first identified by adopting the Bayesian model class selection method in the first stage. After that, the posterior (updated) probability density function (PDF) of the crack parameters, such as crack locations, lengths and depths are identified in the second phase following the Bayesian statistical identification framework. Very encouraging results are obtained for the case studies showing that the proposed methodology can correctly identify the number of crac...

Enhancing the performance of structural model identification by optimal sensor placement

A methodology is presented in this paper for the identification of an effective way to install a given number of sensors on a structure to extract as much information as possible for structural model identification utilizing measured dynamic data. The information entropy is employed as a measure to quantify the uncertainties of the set of identified model parameters. The problem of optimal sensor placement is then formulated as a discrete optimization problem, in which the information entropy measure is minimized, with the sensor configurations as the minimization variables. The methodology is illustrated numerically and experimentally using shear building models. The performance of the optimal sensor placement technique is verified using the identification results based on the measured acceleration responses of a 4‐storey shear building model under laboratory conditions.