Pengcheng Xia¹, Zhihong Pan^1,*, Ruoyu Chen¹, Linyuan Wang²

Structural Durability & Health Monitoring, Vol.20, No.5, 2026, DOI:10.32604/sdhm.2026.080742 - 24 August 2026

Abstract The grouting sleeves in prefabricated structures critically depend on the strength development of the grout; however, existing non-destructive testing methods struggle to capture its time-dependent evolution. This study proposes a hybrid prediction framework that combines the Synthetic Aperture Focusing Technique (SAFT) with a hyperparameter-optimized XGBoost model. Ultrasonic signals were collected at five curing stages (0, 1, 3, 7, and 28 days), from which SAFT-derived features and the area ratios of six color regions were extracted as input variables, with the curing age serving as the model output. Following a correlation analysis with compressive strength, three… More >

Mengxue Li^1,2, Xinyi Chen^1,*, Yuxi Xie²

Structural Durability & Health Monitoring, Vol.20, No.5, 2026, DOI:10.32604/sdhm.2026.079754 - 24 August 2026

Abstract Concrete stress is a critical indicator for evaluating the performance of concrete structures. To achieve non-contact testing of concrete stress, this study analyzed the propagation of laser-generated Rayleigh waves (R-wave) in concrete. A correlation model was established between the concrete stress and the R-wave velocity. To validate the theoretical analysis, ultrasonic experiments were conducted. The experimental results demonstrated that the stress history of concrete determines whether a stable linear relationship exists between the stress and the R-wave velocity. Additionally, the acoustoelastic coefficient of concrete was found to vary with its age. Based on these findings, More >

Kai Luo^1,2,*, Yuzhi Chen³

Structural Durability & Health Monitoring, Vol.20, No.5, 2026, DOI:10.32604/sdhm.2026.079382 - 24 August 2026

Abstract Material property variability in carbon fiber-reinforced polymer composites is a major source of uncertainty in quantitative Lamb wave-based delamination imaging. Even minor deviations in elastic properties can alter dispersion characteristics and wave propagation behavior, thereby reducing the reliability of imaging-based assessments. To systematically investigate this effect, the present study examines the influence of subtle material variations on Lamb wave responses through combined numerical modeling and finite element simulations. Time-of-flight features at the excitation frequency are extracted using a continuous wavelet transform with Morlet wavelets, enabling robust identification of mode-dependent arrival information. Within a finite element… More >

Weiguo Chen¹, Xiaobin Hong^1,*, Kai Chen¹, Yunyun Deng¹, Bin Zhang^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.147, No.3, 2026, DOI:10.32604/cmes.2026.082376 - 30 June 2026

Abstract Structural health monitoring (SHM) of ship piping systems is a core component of predictive maintenance strategies for complex marine engineering systems. During the detection of ship T-shaped pipes using ultrasonic guided waves, signal overlap arises from the diffusion of guided wave branches. To address this issue, an intelligent wave-guidance mechanism based on acoustic metamaterials is proposed for dynamic propagation control of ultrasonic guided waves. First, a metamaterial unit composed of a stainless steel substrate and a copper column is designed. The control of bandgap characteristics by lattice constant, column diameter, and column height is systematically… More > Graphic Abstract

Guopeng Fan^1,*, Xuefeng Chen¹, Hao Liu¹, Jiaqing Zheng²

Structural Durability & Health Monitoring, Vol.20, No.4, 2026, DOI:10.32604/sdhm.2026.079234 - 30 June 2026

Abstract Low-frequency ultrasonic array is commonly used to detect interlayer voids located in high-speed railway ballastless track, which is a typical multilayer concrete bonded structure. The difficulty of detection lies in the fact that the total focusing method (TFM) based on a single fixed sound velocity model cannot adapt to the acoustic propagation characteristics of multilayer structures, which is prone to generating artifacts. In addition, the long duration of low-frequency ultrasonic pulses is prone to causing significant deviations in defect localization. To address these issues, a theoretical model of the layered bonded structure is proposed. The… More >

Naoual Houaidji¹, Kenza Kamli^2,*, Zakaria Hadef², Houssem Eddine Chouial³, Marwa Bendaia¹

Chalcogenide Letters, Vol.23, No.3, 2026, DOI:10.32604/cl.2026.076383 - 03 April 2026

Abstract We present a systematic investigation of FeS₂ thin films deposited by ultrasonic spray pyrolysis (USP) at different deposition times (15–40 min), with the aim of understanding their structural, optical, and electrical evolution and their suitability for heterojunction device applications. Particular attention is given to the integration of the optimized FeS₂ layer with a Co-doped SnS₂ bottom layer to form a p–n heterojunction. Structural analysis by X-ray diffraction reveals a transition from an amorphous/oxidized phase at short deposition times toward well-crystallized pyrite after 25 min, while the 40-min film exhibits the most intense reflections and the largest crystallite… More >

Egidijus Žukauskas^1,*, Damira Smagulova¹, Elena Jasiūnienė^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.146, No.3, 2026, DOI:10.32604/cmes.2026.077492 - 30 March 2026

Abstract Adhesively bonded joints are widely used in modern lightweight structures due to their high strength-to-weight ratio and design flexibility. However, the reliable non-destructive evaluation of bond integrity remains a significant challenge. This study presents a numerical investigation of adhesively bonded joints with different adhesive properties using ultrasonic guided waves. The main focus of the investigation is to evaluate the feasibility of using guided waves to assess bond integrity, particularly for detecting challenging weak bonds. For this purpose, a theoretical analysis of dispersion curves was conducted, revealing that the S0 Lamb wave mode is significantly sensitive… More >

Longqi Liao¹, Jing Li², Yuhua Li³, Yuemin Wang³, Jinhua Li^1,*, Liyuan Cao^4,*, Chunxiang Li^4,*

Structural Durability & Health Monitoring, Vol.20, No.1, 2026, DOI:10.32604/sdhm.2025.072237 - 08 January 2026

Abstract Quantitative detection of sleeve grouting compactness is a technical challenge in civil engineering testing. This study explores a novel quantitative detection method based on ultrasonic time-frequency dual-domain analysis. It establishes a mapping relationship between sleeve grouting compactness and characteristic parameters. First, this study made samples with gradient defects for two types of grouting sleeves, G18 and G20. These included four cases: 2D, 4D, 6D defects (where D is the diameter of the grouting sleeve), and no-defect. Then, an ultrasonic input/output data acquisition system was established. Three-dimensional sound field distribution data were obtained through an orthogonal… More >

Weichen Wang¹, Shaofeng Wang¹, Wenjing Liu^1,*, Luncai Zhou², Erqing Zhang¹, Ting Gao³, Grigory Petrishin⁴

Structural Durability & Health Monitoring, Vol.20, No.1, 2026, DOI:10.32604/sdhm.2025.071278 - 08 January 2026

Abstract In dry-coupled ultrasonic thickness measurement, thick rubber layers introduce high-amplitude parasitic echoes that obscure defect signals and degrade thickness accuracy. Existing methods struggle to resolve overlap-ping echoes under variable coupling conditions and non-stationary noise. This study proposes a novel dual-criterion framework integrating energy contribution and statistical impulsivity metrics to isolate specimen re-flections from coupling-layer interference. By decomposing A-scan signals into Intrinsic Mode Functions (IMFs), the framework employs energy contribution thresholds (>85%) and kurtosis indices (>3) to autonomously select IMFs containing valid specimen echoes. Hybrid time-frequency thresholding further suppresses interference through amplitude filtering and spectral focusing. More >

Jianhua Du¹, Shaofeng Wang¹, Ting Gao², Huiwen Sun², Wenjing Liu^1,*

Structural Durability & Health Monitoring, Vol.20, No.1, 2026, DOI:10.32604/sdhm.2025.071189 - 08 January 2026

Abstract In ultrasonic non-destructive testing of high-temperature industrial equipment, sound velocity drift induced by non-uniform temperature fields can severely compromise defect localization accuracy. Conventional approaches that rely on room-temperature sound velocities introduce systematic errors, potentially leading to misjudgment of safety-critical components. Two primary challenges hinder current methods: first, it is difficult to monitor real-time changes in sound velocity distribution within a thermal gradient; second, traditional uniform-temperature correction models fail to capture the nonlinear dependence of material properties on temperature and their effect on ultrasonic velocity fields. Here, we propose a defect localization correction method based on… More >