Damage identification of beam-like structures with contiguous and distributed damage

摘要

Structural health monitoring of existing infrastructure is currently an active field of research, where elaborate experimentalnprograms and advanced analytical methods are used in identifying the current state of health of criticalnstructures. Change of static deflection as the indicator of damage is the simplest tool in a structural health monitoringnscenario of bridges that is least exploited in damage identification strategies. In this paper, some simple and elegantnequations based on loss of symmetry due to damage are derived and presented for identification of damage in a bridgengirder modeled as a simply supported beam using changes in static deflections and dynamic parameters. A singlencontiguous and distributed damage, typical of reinforced or prestressed concrete structures, is assumed for thenstructure. The methodology is extended for a base-line-free as well as base-line-inclusive measurement.Measurementnstrategy involves application of loads only at two symmetric points one at a time and deflection measurements at thosensymmetric points as well as at the midspan of the beam. A laboratory-based experiment is used to validate thenapproach. Copyright © 2012 John Wiley & Sons, Ltd.