Nondestructive damage detection in Euler-Bernoulli beams using nodal curvatures-Part II: Field measurements

Abstract

The objective of this paper is to evaluate, using field measurements, the performance of the nondestructive evaluation methodology presented in the accompanying paper 'Nondestructive damage detection in Euler-Bernoulli beams using nodal curvatures -Part I: Theory and numerical verification'. Experimental modal data collected from the Interstate 40 bridge are utilized to accomplish the stated objective. Prior to the replacement of the bridge in 1993, researchers from New Mexico State University and Los Alamos National Laboratory introduced incremental levels of damage on the structure and performed experimental modal analyses at each damage stage. The results of the experiments were utilized to evaluate the performance of five previously published nondestructive damage identification methods. Utilizing the measured modal parameters from the Interstate 40 bridge study, structural damage is localized and quantified with the nondestructive evaluation methodology presented in the accompanying paper. The results of this study indicate that the proposed methodology performed equally as well as the damage index method for damage localization and additionally provided realistic estimates of damage severity.

The Simplified Analytical Algorithm to the Time Effect of the Simple-Supported Steel and Concrete Composite Beam

“…Only relying on existing equations ( 3 ) and ( 4 ) cannot meet requirements for the solution so that two equilibrium equations need to be found. According to the assumption that the sectional deformation of the composite beam meets the flat section, two deformation-coordination [ 12 – 14 ] equilibrium equations can be found, in which the strain increment [ 15 – 17 ] and the curvature increment [ 18 , 19 ] for the steel beam and the concrete slab are equal at any fiber: …”

Mode shape-based damage detection in plate structure without baseline data

“…Several advantages and limitations of these methods were also pointed out. Many studies confirm that mode shapes and corresponding mode shape curvatures are highly sensitive to damage and can be used for detection and quantification of the damage. Maia et al in performed extensive numerical simulations on a beam structure to compare damage identification sensitivity within different methods, based on the changes of mode shape, mode shape slope, mode shape curvature and mode shape curvature square, respectively.…”

“…Modal strain energy changes in damage identification were exploited by numerous of researchers. Shih et al in showed that damage can be assessed through changes of resonant frequencies, modal flexibility and modal strain energy. The approach was tested on a full‐scale slab‐on‐girder bridge with different damage scenarios.…”

“…Their studies showed that damage had an influence not only on resonant frequencies but on other frequencies as well and, in some cases, the effect of damage on structure was more pronounced at these other frequencies. In , the authors claimed that the location of damage could be found from the peaks in the changes of modal flexibility and modal strain energy. Ooijevaar et al in used a modal strain energy damage index and later standardization of this index according to statistical hypothesis approach, as well as mode shape curvatures, obtained in vibration measurements, to identify impact damage in two advanced skin stiffener composite structures (in 1D and 2D).…”

Online Monitoring of Flexural Damage Index of a Cable‐Stayed Bridge

“…In addition, the method of using a pseudoinverse can be considered as a solution to the singularity problem. To resolve first and second drawbacks of the MSC method, the flexural damage index equation (FDIE) method [10][11][12][13][14] and the nodal curvature method [15,16] are proposed. ese approaches assume the so-called small damage assumption that the stresses in the deformed configuration are constant during a change of strain due to a small damage event:…”