Patent ID: 7930128

Claim:
A method of improving damage detection in a structural health monitoring system, comprising: obtaining a baseline set of signals corresponding to a range of values of an environmental effect variable for a plurality of first selected paths between pairs of a plurality of sensors configured in an array attached to a structure; establishing threshold levels for each of the first selected paths for determining detection of damage in the structure based on differences among the signals in the baseline set of signals for the selected path; acquiring, from the plurality of sensors attached to the structure, a current signal for each of the selected paths; in a digital computer, analyzing the current signals based on the threshold levels to detect damage in the structure, wherein the analyzing further comprises: for each of the selected paths, determining at least one first arrival index value according to a difference between a first arrival portion of the corresponding current signal and one of the corresponding baseline signals; determining second selected paths that have a first arrival index value exceeding the corresponding threshold level; and detecting the damage according to at least one of a number of the second selected paths that are adjacent to each other, and a number of the second selected paths that cross each other.