The strain field method for structural damage identification using Brillouin optical fibersensing

Abstract

The theory of the strain field (SF) method using Brillouin optical fiber sensing(BOFS) is proposed for structural damage identification in this paper. Field testverification of this method was carried out by implementing a destructive loadingtest to an existing prestressed concrete bridge. A series of structural damagescenarios were thus produced for identification. A sub-matrix featuring the damagescenarios was first extracted from the space–time matrix to obtain the strain fielddistribution in space–time coordinates. Furthermore, other feature extractionoperations, including row vector extraction, column vector extraction and boundaryextraction, were performed to characterize the structural damage behavior anddamage evolution patterns. Finally, damage localization and quantification weresuccessfully implemented in both space and time domains in terms of a damageindex vector array. The investigation results demonstrated the SF method usingBOFS is a feasible and efficient approach for structural damage identification.