Applications of nonlinear system identification to structural health monitoring.

Conference · Thu Jan 01 04:00:00 EST 2004

OSTI ID:977626

Farrar, C R ^[1]; Sohn, H ^[2]; Robertson, A N ^[3]

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1. Charles R.
2. Hoon
3. Amy N.

The process of implementing a damage detection strategy for aerospace, civil and mechanical engineering infrastructure is referred to as structural health monitoring (SHM). In many cases damage causes a structure that initially behaves in a predominantly linear manner to exhibit nonlinear response when subject to its operating environment. The formation of cracks that subsequently open and close under operating loads is an example of such damage. The damage detection process can be significantly enhanced if one takes advantage of these nonlinear effects when extracting damage-sensitive features from measured data. This paper will provide an overview of nonlinear system identification techniques that are used for the feature extraction process. Specifically, three general approaches that apply nonlinear system identification techniques to the damage detection process are discussed. The first two approaches attempt to quantify the deviation of the system from its initial linear characteristics that is a direct result of damage. The third approach is to extract features from the data that are directly related to the specific nonlinearity associated with the damaged condition. To conclude this discussion, a summary of outstanding issues associated with the application of nonlinear system identification techniques to the SHM problem is presented.

• Research Organization: Los Alamos National Laboratory
• Sponsoring Organization: DOE
• OSTI ID: 977626
• Report Number(s): LA-UR-04-2947
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
DAMAGE
DATA ANALYSIS
DETECTION
MECHANICAL STRUCTURES
MONITORING
NONLINEAR PROBLEMS