Online damage diagnosis for civil infrastructure employing a flexibility-based approach

Structural health monitoring (SHM) and damage detection have recently emerged as a new research area in civil engineering. Continuous and long-term monitoring of civil infrastructure is desirable, because it allows the damage in the Structure to be detected at an early stage so that necessary measures can be carried out to prolong and optimize the associated service life and cost. In this paper, an approach which extends a flexibility-based damage detection technique, the damage locating vector (DLV) method, for continuous Online SHM is presented. The essence of the proposed approach is to construct an approximate flexibility matrix for the damaged structure utilizing the modal normalization constants from the undamaged Structure. This extended DLV method can then be applied for Online damage diagnosis. Numerical simulation has been conducted using a 14-bay planar truss structure, with the results showing that the proposed approach works well for both single- and multiple-damage scenarios.