In-plane measurements using a novel streamed digital image correlation for shake table test of steel structures controlled with MR dampers

The major problems related to structural control and monitoring systems are the challenges involved with the installation of traditional transducers, the number of transducers required to obtain the desired structural responses, and the computation effort and time required to analyze, process, and post-process the recorded signals. Non-contact measurements employing digital image correlation (DIC) techniques have become popular in control engineering in recent years. However, it can only be used on certain types of members with a narrow frequency range, minor deflections, and a slower image frame rate. This study aims at determining a in-plane measurement of a five-story steel frame controlled with magnetorheological dampers (MR) on a shaking table using the streamed DIC technique employing a template matching algorithm. The MR dampers (Passive-ON and Passive-OFF) are involved in varying the characteristic of the structural response and therefore assess the accuracy and flexibility of the proposed DIC technique. A high level of precision was achieved for all response quantities for each image. The measurements of acceleration, displacement, velocity, inter-story drift of the floors, and column base strains of the structure subjected to high-intensity bi-directional ground motions are obtained and compared with results obtained from traditional transducers. The shaking table results specified the efficiency and precision of the proposed DIC system in monitoring the structural responses compared to the noisy transducer responses, which emphasized the potential of using this technique for monitoring, control, and reconnaissance of a wide range of structures during and after extreme events.