Complexities and Solution Strategies in Structural Health Assessment

The complexities and solution strategies in the health assessment of civil infrastructures are briefly
discussed. To meet the current needs of locating defect spots and their severity accurately and
efficiently, infrastructures are represented by finite elements. To increase the implementation
potential, the stiffness parameters of all the elements are tracked using only few noise-contaminated
dynamic responses measured at small part of the infrastructures. To extract the required information,
Kalman filter concept is integrated with other advanced numerical schemes. An unscented Kalman
filter (UKF) concept is developed for highly nonlinear dynamic systems. The basic UKF concept is
improved in several ways. Instead of using one long duration time history uased in one global
iteration, very short duration time histories and multiple global iterations with weight factors are used
to locate the defect spot accurately and efficiently. The capabilities of the procedure are demonstrated
with the help of two informative examples. The proposed procedure is much superior to the extended
Kalman filter-based procedures developed by the team earlier