Saqlain Abbas^1,2,*, Zulkarnain Abbas³, Xiaotong Tu⁴, Yanping Zhu²

Journal on Artificial Intelligence, Vol.5, pp. 43-56, 2023, DOI:10.32604/jai.2023.040948

Abstract Structural health monitoring (SHM) is considered an effective approach to analyze the efficient working of several mechanical components. For this purpose, ultrasonic guided waves can cover long-distance and assess large infrastructures in just a single test using a small number of transducers. However, the working of the SHM mechanism can be affected by some sources of variations (i.e., environmental). To improve the final results of ultrasonic guided wave inspections, it is necessary to highlight and attenuate these environmental variations. The loading parameters, temperature and humidity have been recognized as the core environmental sources of variations that affect the SHM sensing… More >

Mingyu Lu^1,*, Kaige Zhu¹, Qiang Wang²

Structural Durability & Health Monitoring, Vol.15, No.3, pp. 207-225, 2021, DOI:10.32604/sdhm.2021.017720

Abstract The increasing use of ultrasonic guided waves (GWs) has been shown to have great potential for the detection of fatigue cracks and non-fatigue type damages in metallic structures. This paper reports on a study demonstrating an energy-based damage imaging approach in which signal characteristics identified through relative time differences by fatigue crack (RTD/f) through different sensor paths are used to estimate the location of fatigue crack in steel plates based on GWs generated by an active piezoceramic transducer (PZT) network. The propagation of GWs in the original 10 mm-thick plate was complicated due to its thick geometry, wave dispersion, boundary… More >

Dongyue Gao¹, Yunlong Ma², Zhanjun Wu^3,*, Yuebin Zheng³, Hongbo Lu¹

Structural Durability & Health Monitoring, Vol.15, No.1, pp. 23-37, 2021, DOI:10.32604/sdhm.2021.013737

Abstract Guided waves based damage detection methods using base signals offer the advantages of simplicity of signal generation and reception, sensitivity to damage, and large area coverage; however, applications of the technology are limited by the sensitivity to environmental temperature variations. In this paper, a Spearman Damage Index-based damage diagnosis method for structural health condition monitoring under varying temperatures is presented. First, a PZT sensor-based Guided wave propagation model is proposed and employed to analyze the temperature effect. The result of the analysis shows the wave speed of the Guided wave signal has higher temperature sensitivity than the signal fluctuation features.… More >

Younho Cho, Weibin Li, Bin Yang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.2, pp. 49-50, 2011, DOI:10.3970/icces.2011.017.049

Abstract This paper aims at an experimental method for detecting thermal-damages in a tube-like structure using acoustic nonlinear parameter of ultrasonic guided waves. The material nonlinearity of aluminum pipe specimens, which have been subjected to different heat-loading cycles, is measured to characterize the micro-damages. Flexible Polyvinylidene Fluoride (PVDF) comb transducers are used to generate and receive the fundamental and second harmonic waves. The amplitude of the second harmonic wave is extracted from the Fast Fourier Transform (FFT) spectrum of a received signal. The measured relative nonlinear parameter increases monotonically as a function of the propagation distance, and the relative nonlinear parameter… More >

LIN Xiao-Ping, LEI Zhen-Kun, LIU Zeng-Hua, WU Zhan-Jun

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.1, pp. 29-30, 2011, DOI:10.3970/icces.2011.017.029

Abstract Recently, a technology named ultrasonic guided wave has a rapid development and wide application. It is more and more popular for the advantage compared with traditional detection. An enormous amount of work has contributed to our current understanding of wave propagation. The case of a hollow cylinder loaded by the outside liquid has been considered by Rose et al. Kwun investigated the propagation of guided waves in water filled pipes. C. Aristegui discussed propagation of guided waves in fluid-filled pipe surrounded by different fluids. Lafleur and Shields have studied the propagation of low frequency modes in a liquid-filled tube.

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Jiaqi Zhang¹, Kehai Liu^2,*, Chang Gao¹, Zhanjun Wu¹, Yuebin Zheng¹, Dongyue Gao³

Structural Durability & Health Monitoring, Vol.13, No.1, pp. 41-59, 2019, DOI:10.32604/sdhm.2019.05142

Abstract Probability-based diagnostic imaging (PDI) is one of the most well-known damage identification methods using guided waves. It is usually applied to diagnose damage in plates. The previous studies were dependent on the certain damage index (DI) which is always calculated from the guided wave signals. In conventional methods, DI is simply defined by comparing the real-time data with the baseline data as reference. However, the baseline signal is easily affected by varying environmental conditions of structures. In this paper, a reference-free diagnostic imaging method is developed to avoid the influence of environmental factors, such as temperature and load conditions. The… More >

Xiaoming Zhang¹, Jiangong Yu^1,2, Min Zhang¹, Dengpan Zhang¹

CMC-Computers, Materials & Continua, Vol.48, No.3, pp. 163-179, 2015, DOI:10.3970/cmc.2015.048.163

Abstract The characteristics of the guided waves propagation in functionally graded rods with rectangular cross-section (finite width and height) under initial stress are investigated in this paper based on Biot’s theory of incremental deformation. An extended orthogonal polynomial approach is present to solve the coupled wave equations with variable coefficients. By comparisons with the available results of a rectangular aluminum rod, the validity of the present approach is illustrated. The dispersion curves and displacement profiles of various rectangular functionally graded rods are calculated to reveal the wave characteristics, and the effects of different width to height ratios and initial stress and… More >