A pseudo-modal structural damage index based on orthogonal empirical mode decomposition

Abstract

A structural damage identification technique hinged on the combination of orthogonal empirical mode decomposition and modal analysis is proposed. The output-only technique is based on the comparison between pre- and post-damage free structural vibrations signals. The latter are either kinematic (displacements, velocities or accelerations) or deformation measures (strains or curvatures). The response data are decomposed by means of the orthogonal empirical mode decomposition to derive a finite set of orthogonal intrinsic mode functions; the latter are used as a multi-frequency and data-driven basis to build pseudo-modal shapes. A new damage index, the so-called pseudo-mode index, is introduced to compare the response obtained for the two states of the structural system and detect potential damages. The performance of the devised index in detecting a localised damage is shown through numerical and experimental tests on two structural models, namely a 4-degrees-of-freedom system and a two-hinged parabolic arch.

Damage identification of structures based on sensitivity equations using PCA and PSD data

“…These include structural responses such as natural frequency, 3,4 mode shape, 5,6 frequency response function (FRF), 7,8 modal flexibility, 9 mode shape curvature, 10,11 modal strain, modal strain energy, 12,13 static responses, 14 and other dynamic responses. 15…”

“…Abdel-Basset 14 used changes in the measured static response to locate structural damage in an overhanging beam and a two-span continuous beam. Lofrano et al 15 proposed an approach that combined orthogonal empirical mode decomposition and modal analysis to experimentally identify damage to steel structures.…”

Structural Health Monitoring of 2D Plane Structures

“…In the maintenance and rehabilitation process of the structures, in addition to the in situ measurements and visual inspections, precise damage detection might be performed using numerical and analytical analysis [4,5]. Examples of non-modelbased damage identification approaches can be found in [6,7].…”

Optimal Sensors Placement in Dynamic Damage Detection of Beams Using a Statistical Approach

“…As reported by many authors, when structural responses of dynamic systems are exploited to trace the signature of the damage, one deals with an inverse problem, where damage influence is recognized starting from its effect. On the one hand, techniques not model based, see for instance [8,9], are able to directly detect the alterations due to any variation, but their mechanical interpretation is often cumbersome. On the other hand, model-based approaches, such as the techniques based on one-dimensional elements [10,11], usually need to rely on accurate structural modeling and to select proper response signals.…”