Structural Health Monitoring Using Smart Sensors - ideals ...

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Normalized accumulated stress
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3 4 5 6 7 8 9 1011 7 8 9 10 111213 1415 1112 1314 151617 1819
Element ID
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3 4 5 6 7 8 9 1011 7 8 9 101112131415 111213141516171819
Element ID
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Figure 8.16. Damage detection (damaged element: Element 11): (a) mass perturbation
DLV; and (b) SDLV.
Normalized accumulated stress
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Normalized accumulated stress
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3 4 5 6 7 8 9 1011 7 8 9 10 111213 1415 1112 1314 151617 1819
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3 4 5 6 7 8 9 1011 7 8 9 101112131415 111213141516171819
Figure 8.17. Damage detection (damaged element: Element 12): (a) mass perturbation
DLV; and (b) SDLV.
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Element ID
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weight may explain the observed false-negatives. Nonlinearity of the structure and
observation noise are also considered possible causes of the false-negatives.
One of the two DLV methods is not always better than the other in terms of damage
detection capability. For example, damage detection on a vertical element, Element 11, in
Figure 8.16 indicates the SDLV method performs better than the mass perturbation DLV
method. On the other hand, damage on another vertical element, Element 19, in Figure
8.18 can be detected more reliably by the mass perturbation DLV method.
When the number of false-positives and false-negatives is counted, the SDLV method
seems to experience fewer false damage detections. The number of false-positives and
false-negatives is summarized in Tables 8.4. to 8.7. For example, elements 7, 8, 9, and 10
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