Summary This paper presents a hybrid non‐destructive testing (NDT) approach based on (non‐contact) infrared thermography (IRT), (passive) acoustic emission (AE), and (active) ultrasonic (UT) techniques for effective damage assessment of partially grouted concrete masonry walls (PGMW). This hybrid monitoring approach could be implemented for the health monitoring of concrete masonry structures. The implementation of this system assists the cross validation of in‐situ recorded information for structural damage assessment. NDT was performed on PGMW subjected to cyclic horizontal loading. The obtained IRT, AE, and UT results successfully monitored the progressive damage process throughout the loading history. Copyright © 2014 John Wiley & Sons, Ltd.

This article demonstrates the potential of the digital image correlation (DIC) method to provide accurate full-field deformation measurements and successfully monitor the development of damage during seismic excitation of a partially grouted reinforced masonry building. The building was subjected to a sequence of earthquake ground motion records using the Large High Performance Outdoor Shake Table at the University of California, San Diego. The DIC setup was capable of measuring surface deformations of the single-story building with high frame rate cameras located at a distance greater than 50 ft away. The accuracy of the measurements was assessed with data obtained using mounted displacement transducers. The full-field deformation data collected by the DIC system was capable to detect strain localization patterns associated with the onset of wall cracking before it could be shown by the displacement sensor data or by post mortem visual inspection. The research findings reported herein demonstrate, for the first time to the authors' best knowledge, the potential of in situ monitoring of actual structures for damage induced by non-stationary loading profiles using optical metrology.

The maximum strength of polycrystalline metals/alloys has been suggested to occur at nanoscale grain sizes where the governing deformation mechanism transitions from dislocation plasticity to grain boundary mediated deformation. Despite tremendous progress recently uncovering links between transitions in nanoscale mechanisms and peak strength, the scientific literature is mostly devoid of any quantitative support, owing to the difficulty in measuring the resolved contribution of individual mechanisms to microstructural strain accommodation. In this study, the contribution of individual nanoscale mechanisms to the overall deformation of nanocrystalline Ni is calculated from atomistic simulations leveraging continuum-based kinematic metrics to compute mechanistic contributions to microstructural strain. By employing such a quantitative approach to analyze deformation behavior, it is shown that the realization of maximum strength in nanocrystalline metals corresponds to a grain size regime where the operative nanoscale mechanisms transition, and are thus equally competing to accommodate strain. However, the transition occurs between intergranular and intragranular mediated mechanisms, as it is found that dislocation plasticity alone is not the governing mechanism at all grain sizes above the peak strength regime.

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This paper presents a methodology to make coefficient of thermal expansion measurements through the combined use of two non-contact and full field optical metrology methods including digital image correlation and infrared thermography. In this context, active Infrared Thermography techniques combined with contact and non-contact deformation measurement methods have already been reported to measure materials' thermal expansion. In addition, such techniques have been reported to be capable to detect surface and subsurface defects from changes in homogenous heat diffusion due to damage. Based on this knowledge, it is hypothesized in this article that the material response induced by thermal loading and quantified by coefficient of thermal expansion measurements could be further used as an indicator of damage. To validate the hypothesis three measurements were performed. The first established the effectiveness of using deformation and thermal full field data for coefficient of thermal expansion measurements. The second intended to demonstrate the advantage of using such full field data in order to provide site-specific measurements of thermal expansion. Finally damage was a priori induced to a metallic specimen, and the measured variations of local CTE confirmed the potential of using the described approach as a means of damage quantification in materials and structures.