Vibro-acoustic modulation and data fusion for localizing alkali–silica reaction–induced damage in concrete

Abstract

This article investigates the application of vibro-acoustic modulation testing for diagnosing damage in concrete structures. The vibro-acoustic modulation technique employs two excitation frequencies on a structure. The interaction of these excitations in the measured response indicates damage through the presence of sidebands in the frequency spectra. Past studies using this technique have mostly focused on metals and composites (thin plates or laminates). Our research focuses on concrete, which is a highly heterogeneous material susceptible to a variety of chemical, physical, and mechanical damage processes. In particular, this article investigates diagnosing cracking in concrete from an expansive gel produced by an alkali–silica reaction in the presence of moisture. Past studies have been limited to damage detection using vibro-acoustic modulation testing, whereas this article extends the technique to damage localization. A cement slab with pockets of reactive aggregate is used to investigate the diagnosis technique. The effects of different testing parameters, such as locations, magnitudes, and frequencies of the two excitations, are analyzed and incorporated in the damage localization methodology. A Bayesian probabilistic methodology is developed to fuse the information from multiple test configurations in order to construct damage probability maps for the test specimen. The results of vibro-acoustic modulation–based damage localization are validated by petrographic study of cores taken from the slab.

Diagnosis of internal cracks in concrete using vibro-acoustic modulation and machine learning

“…VAM is a damage diagnosis methodology that utilizes damage (delamination or crack)-induced nonlinear dynamic signatures to perform damage detection as well as localization. [6][7][8][9][10] In a VAM test, the component of interest is excited using a bi-harmonic excitation. The higher excitation frequency is called the probing frequency, whereas the lower frequency is termed as the pumping frequency.…”

“…8 This technique was demonstrated for concrete slabs, numerically at first, 9 and then experimentally to localize (in 2D) ASR-induced damage in thick concrete specimens. 10 Note that the VAM-based diagnosis method cannot distinguish between the types of nonlinearities (geometric, material, or hybrid) that produce sidebands; however, it can help localize the site of dynamic nonlinearity creation (crack or delamination). The previously reported approach for VAM-based damage localization 10 suffers from the following limitations: (a) the methodology relies on relative values of damage indices measured at different sensor locations, and hence requires the analyst's judgment to define the damage index threshold for damage classification and localization; (b) in Bayesian diagnosis, computation of the likelihood of damage at a sensor location given the damage index value and the threshold is expensive 10 (proposed an approximate, averaged likelihood-based method); and (c) the methodology localizes damage along two (surface) dimensions of the component but does not provide the location along the third (depth) dimension.…”

Influence of Sensor Position and Low-Frequency Modal Shape on the Sensitivity of Vibro-Acoustic Modulation for Impact Damage Detection in Composite Materials

“…Among the non-linear techniques, the vibro-acoustic modulation (VAM) has gained increased attention in the last few decades because of its sensitivity to different types of damage in various classes of materials [7,[12][13][14][15][16][17][18][19]. The VAM technique is based on the simultaneous introduction in a component so that it can be monitored at a low-frequency wave (pump excitation) and a high-frequency wave (probe excitation).…”

“…The dependence of the VAM performance on the frequencies of the pump and probe excitation has been reported in the literature not only for impact damage in composite laminates, but also for other classes of materials, such as metals and concrete, and for a variety of sources of nonlinearity, including fatigue cracks in metal components [13,[25][26][27]; bolt looseness in mechanical joints [28]; artificial scatterers or kissing bonds [29,30]; and diffuse micro-and macro-cracking [17].…”

Breathing crack damage diagnostic strategy using improved MFCC features

“…single tone harmonic vibration). Karve and Mahadevan (2020) and Karve et al (2020) extended the VAM/sideband based damage mapping algorithm for damage localisation due to loss of stiffness and as well as localisation of alkali-silica reaction-induced damage in concrete structures. However, majority of the works utilising bitone harmonic vibration response or VAM, employ only the first sideband on either side of probing frequency or first intermodulation peaks for breathing crack identification (Kim et al, 2011; Klepka et al, 2012).…”