An algorithm for on-line detection of damage to structures caused by g
round shaking is presented. Real-time sampled response data are proces
sed by templates in the form of ID (for structural identification) neu
ral networks, which differentiate damage according to similarity of th
e response to those encapsulated in the templates. Numerical examples
based on a simple 2-story steel-frame building are used to illustrate
the proceedings and to underscore the limitations of the method. The c
hallenges of on-line damage detection are discussed in detail to promo
te better understanding of how the proposed algorithm has evolved and,
in particular, why neural networks are used. Widespread application o
f the algorithm, and damage detection in general, depends on the estab
lishment of an adequate ID networks database, a Far more daunting task
in practice than in the theoretical setting of the paper.