@Article{sl.2009.002.063,
AUTHOR = {S.R. Soni, E.D. Swenson, R.T. Underwood},
TITLE = {Crack Detection in High Strain Aerospace Applications<sup>1</sup>},
JOURNAL = {Structural Longevity},
VOLUME = {2},
YEAR = {2009},
NUMBER = {2},
PAGES = {63--79},
URL = {http://www.techscience.com/sl/v2n2/42670},
ISSN = {1944-6128},
ABSTRACT = {Detecting through-thickness fatigue cracks in a geometrically constrained structure is a challenging structural health monitoring (SHM) problem due
to potentially degraded sensor performance. Fatigue cracks are typically found
in aircraft structures during visual inspections and non-destructive testing (NDT);
however, there exists a real need to detect damage between NDT intervals. Over
the last decade, a significant amount of research effort has been focused on developing “hot spot” approaches to monitor areas of structures known to have damage
using Lamb waves generated from surface-mounted lead zirconate titanate (PZT)
transducers. This research is focused on evaluating an SHM approach for detecting
fatigue cracks in a “hot spot” that takes into account tight geometric constraints
and changes in sensor performance due to high strain levels and high-cycle fatigue,
so as to maintain a high probability of damage detection. In order to account for
changes in PZT performance due to high-cycle fatigue and static loads, relative
changes in signals from a reference pair of PZTs mounted in close proximity are
removed from measured test signals. These relative changes indicate that fatigue
cracks can in many cases be sensed under various loads even after considerable
sensor degradation.},
DOI = {10.3970/sl.2009.002.063}
}