A non-linear vibration spectroscopy model for structures with closed cracks

Ogam, Géry; Groby, Jean‐Philippe; Ogam, Erick

doi:10.1016/j.ijnonlinmec.2013.11.003

Cited by 10 publications

(2 citation statements)

References 39 publications

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“…Generally, the nonlinearity of ultrasonic wave propagation in an elastic solid with microcrack comes from three main sources: the elastic nonlinearity of material [ 9 ], the geometric nonlinearity [ 10 ], and the contact acoustic nonlinearity (CAN) (or the boundary nonlinearity of contact) [ 11 ]. In the field of NDE, there are mainly five techniques for nonlinear ultrasonic detection: vibration acoustic modulation [ 12 ], nonlinear wave modulation spectroscopy technique [ 13 , 14 ], nonlinear resonance technique [ 15 ], second-harmonic generation [ 16 ] and wave-mixing technique [ 17 , 18 ]. The second-harmonic generation based technique has already been studied numerically, analytically, and experimentally to detect the fatigue damage [ 19 , 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

Characterization of Microcrack Orientation Using the Directivity of Secondary Sound Source Induced by an Incident Ultrasonic Transverse Wave

Wang

Zhao

et al. 2020

Materials

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In this paper, characterization of the orientation of a microcrack is quantitatively investigated using the directivity of second harmonic radiated by the secondary sound source (SSS) induced by the nonlinear interaction between an incident ultrasonic transverse wave (UTW) and a microcrack. To this end, a two-dimensional finite element (FE) model is established based on the bilinear stress–strain constitutive relation. Under the modulation of contact acoustic nonlinearity (CAN) to the incident UTW impinging on the microcrack examined, the microcrack itself is treated as a SSS radiating the second harmonic. Thus, the directivity of the second harmonic radiated by the SSS is inherently related to the microcrack itself, including its orientation. Furthermore, the effects of the stiffness difference between the compressive and tensile phases in the bilinear stress–strain model, and the UTW driving frequency, as well as the radius of the sensing circle on the SSS directivity are discussed. The FE results show that the directivity pattern of the second harmonic radiated by the SSS is closely associated with the microcrack orientation, through which the microcrack orientation can be characterized without requiring a baseline signal. It is also found that the SSS directivity varies sensitively with the driving frequency of the incident UTW, while it is insensitive to the stiffness difference between the compressive and tensile phases in the bilinear stress–strain model and the radius of the sensing circle. The results obtained here demonstrate that the orientation of a microcrack can be characterized using the directivity of the SSS induced by the interaction between the incident UTW and the microcrack.

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Section: Introductionmentioning

confidence: 99%

Characterization of Microcrack Orientation Using the Directivity of Secondary Sound Source Induced by an Incident Ultrasonic Transverse Wave

Wang

Zhao

et al. 2020

Materials

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“…Therefore, for real nonlinear system, the structure vibration/chatter should be modeled. 3 And in machining process, two extreme cases always happen in the schedule of milling parameters, the first is that the choice of process parameters is over-conservative and the other is to determine those process parameters only depending on the experience of workers. For these reasons, the issues of cutting stability, including the generation mechanism of the chatter and high-accuracy prediction of the stability lobes, are attracting increasingly attentions in order to obtain a good combination of process parameters.…”

Section: Introductionmentioning

confidence: 99%

Determination of the stability lobes with multi-delays considering cutter’s helix angle effect for machining process

Guo

Sun

Jiang

et al. 2016

Proceedings of the Institution of Mechanical Engineers, Part B:

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As a common phenomenon, chatter is one of the most important factors that inhibit the improvement of productivity and deteriorate the machined surface quality in milling process. In this article, the mathematical model of the dynamic machining process is first constructed with multi-delays, in which the effect of the cutter’s helix angle on the chatter is considered. And a new integral interpolation method is proposed to predict the stability lobes. Based on this method, the mathematical model which is divided into two parts is calculated respectively with an interpolation method and an integration method. Using the Floquet theory, the stability limits of the dynamic milling system for an arbitrary point can thus be precisely predicted. Subsequently, the convergence rate of this integral interpolation method is analyzed. In order to verify the mathematical model, the stability lobes with uniform and variable cutter pitch angle are computed and the results show a good agreement with published experimental data; also one experiment is conducted to validate the proposed model and the method. Simultaneously, the simulation of a stability lobe with non-zero helix angle is also performed and the results validate the fact that the proposed method is capable of predicting stability limits with high accuracy. Finally, the influences of the cutter and process parameters such as helix angle, pitch angle, down-milling or up-milling and radial cutting depth on the milling chatter are analyzed.

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