Abstract
In order to detect damage in structures by using changes of vibration characteristics, it should be made clear whether the changes are caused by damage or within the range of uncertainty. This paper addresses a method to calculate changes of vibration characteristics caused by uncertainty based on Bootstrap analysis, in which vibration characteristics are assumed to be probabilistic variables. Furthermore, a significance testing method using Bootstrap distribution is also proposed. These methods are applied for identification from actual seismic records of a base-isolated bridge and ambient vibration records of a reinforced concrete building. For the former, it is shown statistically and objectively that the change between two earthquakes is significant due to non-linearity of the building. On the other hand, for the latter, it is considered that the changes through one year are caused by uncertainty.
