Deformation monitoring of wood structures utilizing reflective photosensor

This paper presents a basic scheme for smart deformation monitoring methodology with sensing function and self-reinforcing function. The sensing function utilizes reflective photosensors and the self-reinforcing function employs semiactive wire brace system, which only adds the stiffness to the structure. The reflective photosensor is to quickly detect whether or not the deformation of a structure is beyond the drift limit. In this paper, the reflective photosensor is connected to the microprocessor in order to automatically assess the safety of wood structures. Based upon the assessment results, the microprocessor controls the semiactive wire brace system reinforcing the wood frame to resist severe seismic excitations. The proposed smart deformation monitoring system could automatically provide the real-time information about the structural safety under an earthquake and will provide useful information for implementing more advanced smart simple monitoring system. After the capability of the reflective photosensor is experimentally investigated, the validity of the monitoring system integrating the reflective photosensor is demonstrated by conducting small scale wood-frame model experiments. Finally, the validity of the smart deformation monitoring system with the self-reinforcing capability is demonstrated through shaking table tests.