Gaozheng Zhao¹, Changchao Liu¹, Lingyu Sun¹, Ning Yang², Lei Zhang¹, Mingshun Jiang¹, Lei Jia¹, Qingmei Sui^1,*

Structural Durability & Health Monitoring, Vol.16, No.1, pp. 81-96, 2022, DOI:10.32604/sdhm.2022.016905

Abstract Fatigue crack prediction is a critical aspect of prognostics and health management research. The particle filter algorithm based on Lamb wave is a potential tool to solve the nonlinear and non-Gaussian problems on fatigue growth, and it is widely used to predict the state of fatigue crack. This paper proposes a method of lamb wave-based early fatigue microcrack prediction with the aid of particle filters. With this method, which the changes in signal characteristics under different fatigue crack lengths are analyzed, and the state- and observation-equations of crack extension are established. Furthermore, an experiment is conducted to verify the feasibility… More >

Dongyue Gao¹, Yishou Wang¹, Zhanjun Wu¹, Rahim Gorgin¹

Structural Durability & Health Monitoring, Vol.9, No.3, pp. 233-252, 2013, DOI:10.32604/sdhm.2013.009.233

Abstract In this study, a Lamb wave-based damage extension diagnosis method to monitor the damage on typical structures of composite aircraft is proposed. First, an overview of the damage extension diagnosis method is given. In the method, probability-based damage diagnostic imaging was combined with empirical threshold value to distinguish damage location and estimate damage size in damage extension process. To validate the effectiveness of method, extension diagnosis of simulate delamination damage in typical structure on aircraft were processed. To illustrate the capability of the damage extension diagnostic method, a delamination growth monitoring experiment was performed in a typical reinforce component (Tjoint… More >

Tsung-Tsong Wu¹, Tzung-Chen Wu¹, Jin-Chen Hsu¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.1, pp. 9-10, 2009, DOI:10.3970/icces.2009.010.009

Abstract Recently, propagation of bulk and surface acoustic waves in periodic structures called phononic crystals (PCs) has attracted a lot of interests. The existence of band gaps, the frequency ranges in which acoustic wave propagation is forbidden, in such periodic structures has demonstrated many potential applications to acoustic-wave devices, such as filters, resonators, efficient acoustic waveguides, etc.
In this paper, Lamb wave propagation in a thin plate with a periodic stubbed surface is investigated numerically and experimentally. A detailed evolution of how the band structure form the complete band gaps as the increase of the stub height is studied numerically using… More >

C. Soutis¹, K. Diamanti¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.2, pp. 49-54, 2007, DOI:10.3970/icces.2007.001.049

Abstract A cost and time effective inspection strategy for in-service health monitoring of composites is demonstrated using the fundamental anti-symmetric A0 Lamb mode at frequencies of 15-20 kHz. In principle, this method involves analysis of the transmitted and/or reflected wave after interacting with the test-piece boundaries or discontinuities (defects). In the present work, the applicability of the technique to composite sandwich structures is explored. More >

Jiayong Tian^1,2, Ulrich Gabbert², Harald Berger², Xianyue Su¹

CMC-Computers, Materials & Continua, Vol.1, No.4, pp. 327-336, 2004, DOI:10.3970/cmc.2004.001.327

Abstract In this paper, we investigate Lamb wave interaction with delamination in an infinite carbon fiber reinforced plastics (CFRP) laminate by a hybrid method. The infinite CFRP laminate is divided into an exterior zone and an interior zone. In the exterior zone, the wave fields are expressed by wave mode expansion. In the interior zone, the wave fields are modeled by the finite element method (FEM). Considering the continuity condition at the boundary between the exterior and interior zones, the global wave fields can be calculated. Lastly, numerical examples show how a delamination in the laminate influences the mode conversion of… More >

M. Morii¹, N. Hu^1,2, H. Fukunaga³, J.H. Li¹, Y.L. Liu¹, S. Atobe³, Alamusi³, J.H. Qiu⁴

CMC-Computers, Materials & Continua, Vol.26, No.1, pp. 37-66, 2011, DOI:10.3970/cmc.2011.026.037

Abstract Lamb wave tomography (LWT) is a potential and efficient technique for non-destructive tomographic reconstruction of damage images in structural components or materials. A new two-stage inverse algorithm with a small amount of scanning data for quickly reconstructing damage images in aluminum and CFRP laminated plates was proposed in this paper. Due to its high sensitivity to damages, the amplitude decrease of transmitted Lamb waves after travelling through the inspected region was employed as a key signal parameter related to the attenuation of Lamb waves in propagation routes. A through-thickness circular hole and a through-thickness elliptical hole in two aluminum plates,… More >

Y. L. Liu¹, N. Hu², H. Xu³, H. Ning¹, L. K. Wu¹

CMC-Computers, Materials & Continua, Vol.40, No.1, pp. 1-20, 2014, DOI:10.3970/cmc.2014.040.001

Abstract A real-time monitoring technique for local plasticity using Lamb waves was developed. Tensile test of a thin aluminum plate with a circular hole where high stress concentration was induced was conducted to verify this technique. During the tensile test, a series of wave signals passing through the local plastic region were collected using a directional actuator/sensor set to monitor plasticity evolution. A pulse compression technique was used to process the wave signals. With the increase of tensile stress in the specimen, the amplitude changes of S₀ and A₀ modes were obtained and the difference of Lamb wave signals was further… More >