Method and system for deciding damage degree category

A system for deciding a damage degree category comprising:

• at least one sensor selected from an accelerometer, a velocimeter, and a displacement meter, the sensors being installed on all layers or a plurality of predetermined layers of a building;
• a recording device for storing measured data of each of said one or more layers;
• and
• a microprocessor for processing the measured data, the microprocessor determining a performance curve of each of said one or more layers of the building from the measured data of each layer each of said one or more layers stored in the recording device,
• the microprocessor performing:
• determining from each of the said performance curves a polygonal line including a first break point, a second break point, and a maximum response point, wherein the first break point and the second break point are searched in this order as maximum points within a predetermined range of discrepancy between the performance curve and the polygonal line,
• calculating a maximum interlayer deformation angle of each of said one or more layers from a maximum interlayer displacement of each of said one or more layers and a corresponding interlayer height,
• calculating a safety limit deformation angle of each of said one or more layers,
• calculating a safety margin of each of said one or more layers from the maximum interlayer deformation angle and the safety limit deformation angle of each of said one or more layers, comparing the safety margins, and selecting one polygonal line having a smallest safety margin of the safety margins;
• calculating a safety limit point from the selected polygonal line;
• defining damage degree categories (□) to (□) using the first break point and the second break point and the safety limit point, wherein the damage degree category (I) is defined with the first break point, the damage degree category (II) is defined with the second break point, the damage degree categories (III) to (VI) are defined with the second break point and the safety limit point;
• and
• deciding one damage degree category, to which a maximum response point corresponds, out of the damage degree categories.