Experimental Study on the Mechanical Behavior and the Feasibility of Monitoring of Building Frames with Steel Knee Brace

After a seismic disaster, building damage assessment is conducted by experts to confirm the safety of building. However, field surveys take a long time and have problems with the quality and safety of the survey. In recent years, to solve these problems, structural health monitoring (SHM), which can diagnose buildings from a distance, is in practical use. Previous study proposed a damage evaluation method focusing on the thermal characteristics caused by elastic-plastic deformation of steel members. This study focuses on the heat generation characteristics of steel and suggests the monitoring system for damage detection using steel knee brace. By using the knee brace as sacrificial members, the system can be easily replaced and reused after a disaster. And it allows retrofitting to buildings. In this paper, we aim to establish a damage evaluation system based on the relationship between the kinematic mechanism of steel knee brace and the deformation of the framework, and we have conducted static loading experiments with the knee brace attached to the framework to investigate the feasibility of the damage evaluation method. As a result, it was found that the story drift angle of the framework can be calculated from the deformation of the steel knee brace. It is also shown that the story drift angle of the framework and the damage evaluation of the members are possible from the plastic absorption energy of the knee brace.