Design strategy of structural health monitoring system consisting of four sensors for tall buildings

We usually distribute the sensors with equal distance if detailed information on the target building is not available. However, we have not checked if this practice is appropriate or not. In this paper, we present a strategy of designing the placement of sensors for SHM system consisting of limited number of sensors. We learn that the equal distance distribution of sensors is not always the best sensor placement at all and the top sensor can be placed a few floors lower than the roof. As we do not need to install a sensor on the roof top that requires a special care for water proofing, this finding is practically very useful. We evaluate the dependence of the location on the nature of earthquakes such as near-field or far-field. From this study we confirm that the four sensor system is good enough in estimation of story drift angle if accurate mode shape information is available. Finally, the error analysis is conducted for this system. With this careful evaluation, the SHM system with four sensors with appropriate distribution is good enough for most buildings.