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| 說明 | 284 p |
| 附註 | Source: Dissertation Abstracts International, Volume: 64-01, Section: B, page: 0323 |
| Professor in charge: Harry W. Shenton, III |
| Thesis (Ph.D.)--University of Delaware, 2003 |
| The objective of the research is to develop a practical and robust methodology for structural health monitoring that can be used in a long term monitoring system to detect the location and severity of damage in large civil structures. The proposed static-based procedure uses the redistribution of dead load in the structure that takes place when damage occurs to identify the damage. The general methodology for damage identification is based on minimizing the error between the model predicted and measured static structural response due to dead load in the damaged structure. The problem is formulated as an optimization problem and solved by genetic algorithm |
| The proposed methodology is first tested on a fixed-fixed beam. An analytical model was developed and damage identification trials were conducted on the beam that include four damage locations and three damage severities. One hundred trials were conducted for each case. Damage was identified with a high degree of accuracy in a majority of the trials. Results show, however, that damage is difficult to identify when it is close to the inflection point of the undamaged beam. This is because the bending moment due to dead load in that region is very small. Tests were conducted to study the effect of measurement noise on the identification results. Simulations show that the procedure is accurate for noise-to-strain ratios of up to 40%. Tests also show that the method is not prone to predicting false positive results |
| For more general structures a finite element model of the damaged structure is used. The proposed methodology is tested on a simple portal frame. The tested damage scenarios include four damage locations and three damage severities. One hundred trials were conducted for each case. Trails were also conducted with simulated measurement noise. Damage was identified with a high degree of accuracy even in the presence of noise |
| The simulation results for the fixed-fixed beam and the simple frame have demonstrated that the method works very well even in the presence of noise. The proposed method could potentially be applied to damage detection in a long-term health monitoring system of civil structures |
| School code: 0060 |
| 主題 | Engineering, Civil |
| 0543 |
| ISBN/ISSN | 0493984682 |
