Digital Image Correlation (DIC) provides measurements without disturbing the specimen, which is a major advantage over contact methods. Additionally, DIC techniques provide full-field maps of response quantities like strains and displacements, unlike traditional methods that are limited to a local investigation. In this work, an experimental application of DIC is presented to investigate a problem of relevant interest in the civil engineering field, namely the interface behavior between externally bonded fabric reinforced cementitious mortar (FRCM) sheets and concrete substrate. This represents a widespread strengthening technique of existing reinforced concrete structures, but its effectiveness is strongly related to the bond behavior between composite fabric and underlying concrete. To investigate this phenomenon, a set of notched concrete beams are realized, reinforced with FRCM sheets on the bottom face, subsequently cured in different environmental conditions (humidity and temperature) and finally tested up to failure under three-point bending. Mechanical tests are carried out vis-à-vis DIC measurements using two distinct cameras simultaneously, one focused on the concrete front face and another focused on the FRCM-concrete interface. This experimental setup makes it possible to interpret the mechanical behavior and failure mode of the specimens not only from a traditional macroscopic viewpoint but also under a local perspective concerning the evolution of the strain distribution at the FRCM-concrete interface obtained by DIC in the pre- and postcracking phase.

Prognostic and health management technologies are increasingly important in many fields where reducing maintenance costs is critical. Non-destructive testing techniques and the Internet of Things (IoT) can help create accurate, two-sided digital models of specific monitored objects, enabling predictive analysis and avoiding risky situations. This study focuses on a particular application: monitoring an endodontic file during operation to develop a strategy to prevent breakage. To this end, the authors propose an innovative, non-invasive technique for early fault detection based on digital twins and infrared thermography measurements. They developed a digital twin of a NiTi alloy endodontic file that receives measurement data from the real world and generates the expected thermal map of the object under working conditions. By comparing this virtual image with the real one acquired by an IR camera, the authors were able to identify an anomalous trend and avoid breakage. The technique was calibrated and validated using both a professional IR camera and an innovative low-cost IR scanner previously developed by the authors. By using both devices, they could identify a critical condition at least 11 s before the file broke.

In the interest of our society, for example in Smart City but also in other specific backgrounds, environmental monitoring is an essential activity to measure the quality of different ecosystems. In fact, the need to obtain accurate and extended measurements in space and time has considerably become relevant. In very large environments, such as marine ones, technological solutions are required for the use of smart, automatic, and self-powered devices in order to reduce human maintenance service. This work presents a simple and innovative layout for a small self-powered floating buoy, with the aim of measuring and transmitting the detected data for visualization, storage and/or elaboration. The power supply was obtained using a cantilever harvester, based on piezoelectric patches, converting the motion of ripple waves. Such type of waves is characterized by frequencies between 1.50 Hz and 2.50 Hz with oscillation between 5.0 ° and 7.0 °. Specifically, a dedicated experimental setup was created to simulate the motion of ripple waves and to evaluate the suitability of the proposed design and the performance of the used harvester. Furthermore, a dynamic analytical model for the harvester has been defined and the uncertainty correlated to the harvested power has been evaluated. Finally, the harvested voltage and power have shown how the presented buoy behaves like a frequency transformer. Hence, although the used cantilever harvester does not work in its resonant frequency, the harvested electricity undergoes a significant increase.

Transforaminal lumbar interbody fusion (TLIF) cages are used to reduce compression on the neural tissue of the spine and to restore the intervertebral space. Today, these medical devices can be advantageously obtained by additive manufacturing and consist of one or more lattice structures, which allow for a substantial improvement of the osseointegration process. Due to the small sizes and, above all, to the fine level of detail of the lattice structure, traditional investigation methods applied for evaluating the mechanical behavior of such components are difficult to employ. A promising alternative are non-contact optical measurement techniques. The aim of this work is to evaluate the feasibility of Digital Image Correlation (DIC) to study the mechanical response of small and complex 3D medical protheses, specifically of the TLIF cages structures. A cage was loaded statically, using two dedicated coupling elements, to reproduce the physiological mechanical behavior of the lumbar area of the spine. Both the displacement and the strain fields were measured on three regions of the sample. Load-deflection curves, computed by DIC, have been compared with those obtained by a testing machine and a good agreement was observed. The results highlighted a severe overstress of the lattice structure, which eventually might lead to local failure of the trabeculae, causing injury to the vertebrae, the bones and the connective tissues of the spine.