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

Abstract

Structural health monitoring of existing infrastructure is currently an active field of research, where elaborate experimental programs and advanced analytical methods are used in identifying the current state of health of critical structures. Change of static deflection as the indicator of damage is the simplest tool in a structural health monitoring scenario of bridges that is least exploited in damage identification strategies. In this paper, some simple and elegant equations based on loss of symmetry due to damage are derived and presented for identification of damage in a bridge girder modeled as a simply supported beam using changes in static deflections and dynamic parameters. A single contiguous and distributed damage, typical of reinforced or prestressed concrete structures, is assumed for the structure. The methodology is extended for a base-line-free as well as base-line-inclusive measurement. Measurement strategy involves application of loads only at two symmetric points one at a time and deflection measurements at those symmetric points as well as at the midspan of the beam. A laboratory-based experiment is used to validate the approach.

Estimation of damage severity using sparse static measurement

“…In existing papers dealing with damage localization and estimation of damage severity using only static displacements the deviation of simulated and calculated values of damage are up to 18% (Yang, Sun 2011), 20% (Maity, Saha 2004), 30% (Terlaje, Truman 2007), 40% (Bakhtiari-Nejad et al 2005), 60% (Chen et al 2005). The method proposed by RaghuPrasad et al (2013) gives the smallest deviation of simulated and calculated damages of 8%, but the method is limited to detection and severity estimation of single damage. In all these damage severity estimation methods the length of damage was equal to the length taken into damage estimation analysis (whole segment length); no one deals with detection and severity estimation of damages shorter than the segment.…”

“…Although the theoretical formulation is based on assumption of materially linear structure, the method can be successfully used for detection of changes in structural stiffness as result of changes in E-modules and/or moment if inertia I as it is done in some previous researches (RaghuPrasad et al 2013;Capozucca 2008;Ndambi et al 2000Ndambi et al , 2002.…”

Closed-form solution based genetic algorithm software: Application to multiple cracks detection on beam structures by static tests

“…Dynamic identification of damage has been widely explored in the literature because of the easiness in the measurement of the natural frequencies [1][2][3][4][5][6][7][8][9] and, to a smaller extent, of the modes [10][11][12]. On the other hand, a limited effort was dedicated to the static identification of damage [13][14][15][16], for different structural typologies, mainly by employing displacement measurements, that are more sensitive to instrumental errors.…”

A procedure for the identification of multiple cracks on beams and frames by static measurements

“…In the pioneering study by Sanayei and Onipede, [18] an analytical method that makes use of static data test is employed to assess the damage in frames. More recently, regarding the static identification of damage parameters in structures, further studies were devoted to propose an alternative strategy for frames, [19] to assess instrumental errors with reference to beam-like structures, [20] to the identification of damage in arches, [21] to the identification of diffuse damage in beam-like structures [22] and to the identification of multiple concentrated cracks in beams by making use of evolutionary algorithms for the optimization procedure. [23] In this paper, by utilizing the solution provided by the mentioned distributional approach, a further contribution towards the identification of multiple cracks in straight beams by static response measurements, leading to explicit expressions for damage positions and severities, is provided.…”