Experimental methodology for the dynamic analysis of slender structures based on digital image processing techniques

There are several problems in engineering where the structural response may be affected by conventional devices for displacement measurements. This work presents an alternative methodology for the experimental dynamic analysis of structures, which cannot be monitored by conventional sensors. This methodology is based on digital image acquisition and processing techniques. The importance of this methodology is that it enables one to perform non-contact displacement measurements, without introducing undesirable changes in the structure's behavior, as for example, in models with an extremely reduced scale. The proposed methodology uses sticking markers of a negligible mass in relation to the structure, facilitating the implementation of the instrumentation of the experimental test. To evaluate the efficiency, precision and accuracy of this methodology, two different experimental tests are carried out and the obtained results are favorably compared with the theoretical results and with the ones provided by conventional sensors. This has shown to be a highly cost-effective and easy to implement experimental procedure for the analysis of very flexible structures, and yet maintains the advantage of dynamic measurements with high resolution. (C) 2010 Elsevier Ltd. All rights reserved.