System Identification and Damage Assessment of Benchmark Model H

• Main Authors: Cheng-wei Lo, 駱政韋
• Other Authors: Grace S. Wang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/34395947460118907388

碩士 === 朝陽科技大學 === 營建工程系碩士班 === 99 === ABSTRACT Field of system identification has become important discipline due to the increasing need to estimate the behavior of a system with partially known dynamics. Identification is basically a process of developing or improving a mathematical model of a dynamic system through the use of measured experimental data. In addition to updating the structural parameters for better response prediction, system identification techniques made possible to monitor the current state or damage state of the structures. At present, the buildings under damage assessment are actually with minor or serious damages, so the damage indices evaluated accordingly may not be adequate. To solve the problem, the experimental method is used to simulate different states of damage, followed by identifying the parameters of the associated damaged structure. Then, the damage indices describing the damage degree can be computed using the identified parameters, and the threshold value of different damage state can be reached. Therefore, in the paper, the technique of system identification is used to analyze the shaking table test of a series of simulated diagonal bracings in the Benchmark Model H. The structural model (Benchmark Model) is a series of structures simulating different numbers of diagonal bracings on both sides of x direction. The dimention of the structure is 3m in the longitudinal direction and 2m in the transverse direction. Shaking table test is conducted in the sequence from Full Bracing in the x direction to Bare Frame. From Case1 to Case3, it means that the vertical diagonal bracings of the outer side are removed one by one from the first floor to the third floor in the x direction. In this way, the damage of different degree can be modelled by eccentricity of different state. Finally, all diagonal bracings in the x direction are removed, leading to a Bare frame. With the change in the dynamic parameters of elastic system under earthquake, the damage assessment method is used to determine the degree of damage and the location or floor of damage.