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An algorithm for analyzing double-crystal rocking curves from the near-surface layers of monocrystals has been proposed, and corresponding software has been developed. It is taken into account that to obtain correct results, both coherent and diffuse components of X-ray scattering need to be considered. The possibility of simultaneous analysis of rocking curves from several reflections is provided. To approximate experimental rocking curves with theoretical ones, an approach that simultaneously uses three different approximation methods has been utilized. The effectiveness of the proposed approach is confirmed by verifying the uniqueness of the obtained results.

An algorithm for analyzing double-crystal rocking curves from the near-surface layers of monocrystals has been proposed, and corresponding software has been developed. It is taken into account that to obtain correct results, both coherent and diffuse components of X-ray scattering need to be considered. The possibility of simultaneous analysis of rocking curves from several reflections is provided. To approximate experimental rocking curves with theoretical ones, an approach that simultaneously uses three different approximation methods has been utilized. The effectiveness of the proposed approach is confirmed by verifying the uniqueness of the obtained results. [ABSTRACT FROM AUTHOR]

• DFOSS for detailed tie strain profiling. • Optimized B-spline function improves strain profile fitting. • Accurate predictive under-tie force continuous distribution. Previous studies have attempted to determine the under-tie support condition using strain gauges and stress cells. However, there have been limited successes due to either poor sensor accuracy or insufficient measuring points. The objective of this paper is to examine a new method using distributed fiber-optic strain sensors (DFOSSs) for predicting the tie force distribution and assessing the under-tie support condition through tie strain profile. A high-definition DFOSS was instrumented along a scale wood tie to collect strain profiles. This method includes two steps: (1) fitting the strain profiles by a customized high-order B-spline function; and (2) deriving the B-spline functions of tie bending moment, shear force, and force distribution based on Euler–Bernoulli beam theory. Test results obtained on ties with various predetermined support settings demonstrate the algorithm's ability to accurately predict support conditions. Moreover, the paper discusses the effectiveness of using shear force profiles for calculating applied loads. [ABSTRACT FROM AUTHOR]

• Employed a Brillouin Scattering based optical fiber sensor for structural health monitoring of a Bridge. • Developed a method for distributed detection of damage along the lengths of multi-span continuous Bridges. • Developed a damage index for detection of microcracks along the length of the Bridge. A method for distributed detection of damage along the lengths of multi-span continuous Bridges is introduced. It is based on monitoring the distributed strains along the length of the bridge by using Brillouin scattering based optical fiber sensors. Identification of damage beyond the signal to noise limits of the instrument is achieved by normalization of the measured distributed strains during multiple positions of a truck with respect to the theoretical influence line of the bridge. Formulation of the method leads to the introduction of a damage index for identification of microcrack locations along the spans of the Bridge. Effectiveness of the proposed method was evaluated by load testing of a five span continuous precast post-tensioned concrete box girder bridge. Locations of detected microcracks by the distributed sensor system were further verified by visual inspections. [ABSTRACT FROM AUTHOR]

This paper presents observation and results of an experimental study undertaken to investigate the time dependant behaviour of bond between external Carbon Fibre Reinforced Polymer (CFRP) reinforcement and concrete subjected to temperature cycles, wet-dry cycles and outdoor environment separately. Single shear tests (pull-out test) were conducted to investigate bond strengths (pull-out strengths) of control (unexposed) and exposed specimens. Based on the results, the most significant degradation of bond strength was observed in specimens exposed to outdoor environment, whereas no significant deterioration due to temperature cycles was found probably due to the nature of applied cyclic temperature where the temperature was below the glass transition temperature of epoxy resin and the difference between the upper and lower boundary of the temperature envelope was small. [ABSTRACT FROM AUTHOR]

An efficient block matching and spectral shift estimation algorithm for freehand quasi-static ultrasound elastography is described in this paper. The proposed method provides a balance between computational speed and robustness against displacement estimation error and bias; a fundamental aspect of elastography. The new algorithm was tested on an extensive set of simulated 1-D RF ultrasound signals, replicating various strain profiles. Additionally, real 2-D scans were conducted on an ultrasound phantom with prescribed elastic properties; the algorithm output was further validated with a comparison to a finite element model (FEM) of the phantom. Clinical data from a breast cancer study and histology slides were used to demonstrate the in vivo use of the new elastography technique. The algorithm showed a significant computational savings (at least 60 times faster) over existing spectral shift analysis methods. Accurate strain images were produced in as little as 2 s with the scope for further speed enhancements through parallel processing; making real-time implementation a future possibility. Moreover, it demonstrated a robustness toward displacement estimation error when compared with conventional gradient-based techniques, and was able to perform at high strain values (>5%) while showing relative insensitivity to various parameters settings, such as sample rate and block window size; a desirable performance for a practical clinical tool. [ABSTRACT FROM AUTHOR]

Twisting the angle between van der Waals stacked 2D layers has recently sparked great interest as a new strategy to tune the physical properties of the materials. The twist angle and associated strain profiles govern the electrical and optical properties of the twisted 2D materials, but their detailed atomic structures remain elusive. Herein, using combined atomic-resolution electron microscopy and density functional theory (DFT) calculations, we identified five unique types of moiré features in commensurately twisted 7 a × 7 a transition metal dichalcogenide (TMD) bilayers. These stacking variants are distinguishable only when the moiré wavelength is short. Periodic lattice strain is observed in various commensurately twisted TMD bilayers. Assisted by Zernike polynomial as a hierarchical active-learning framework, a hexagon-shaped strain soliton network has been atomically unveiled in nearly commensurate twisted TMD bilayers. Unlike stacking-polytype-dependent properties in untwisted structures, the stacking variants have the same electronic structures that suggest twisted bilayer systems are invariant against interlayer gliding.