Vibroacoustic behavior of a plate surrounded by a cavity containing an inclined part–through surface crack with arbitrary position

Abstract

Acoustical investigation of a thin plate having a part–through surface crack surrounded by an air enclosure is studied in this paper. The enclosure comprises five rigid walls and a flexible plate based on the Kirchhoff plate theory. It is also assumed that the crack is located at an arbitrary position and orientation with a specific length. Accordingly, partial differential equation related to the coupled cracked plate–cavity system is presented. In order for the partial differential equation (PDE) to be solved, firstly, the sound pressure inside the cavity is estimated by a suitable number of the plate modes. Then, the coupled PDE decomposes to some ordinary differential equations in the time-domain by employing the Galerkin method for three different boundary conditions. In addition, the linear natural frequencies are obtained in vacuo and coupled conditions for an uncracked plate and then, a similar procedure is performed for a cracked plate. Furthermore, comparing the results with available data in the literature shows the reliability and accuracy of the present work. Finally, the influences of the crack angle, crack length, crack position, and cavity depth on the natural frequencies are investigated.

Acoustic insulation characteristics improvement of a thick CNT-reinforced doubly-curved shell by using GPLRC and MEE composite layers

“…Sharma et al [68,69] employed numerical approaches to present the acoustic propagation analysis of sandwich and composite panels under a thermal environment. The linear and nonlinear vibroacoustic characteristics of coupled plate-enclosure systems with partthrough surface crack were investigated by Motaharifar et al [70,71]. The authors [72] presented the three-dimensional relationships of acoustic-structure interaction problem for a thick doubly-curved shell by taking advantages of the state space method.…”

Improving soundproof characteristics of an FG-CNT–reinforced composite structure by adding a coating magneto-electro-elastic layer

“…Their next research was carried out concerning the numerical acoustic analysis of laminated sandwich curved shells with the aid of coupled finite and boundary elements. Motaharifar et al (2019Motaharifar et al ( , 2021 presented the linear and nonlinear response concerning the vibroacoustic behavior of a plate-cavity system containing a part-through surface crack. The authors (Zarastvand et al, 2021a(Zarastvand et al, , 2021b(Zarastvand et al, , 2021c reviewed all the research which has been carried out so far on acoustic transmission through plate and shell structures.…”

Application of scaled boundary finite element method for vibration-based structural health monitoring of breathing cracks

“…Classical nonlinearities, which include microstructural distortion, stress concentration, thermoelastic dependence, and large strains, emerge as the formation of higher harmonic generation (HHG) (Trojniar et al, 2014) or frequency shift (FS) (Jalali and Bonab, 2013;Matlack et al, 2015) in the frequency response function, whereas the nonclassical nonlinear behaviors mainly arise from the kissing contact (due to cracked edges or loose joints) (Guyer and Johnson, 1999) or the hysteresis damping factors in the structure (Guyer and Johnson, 2009). In the technical literature, various phenomena, such as contact acoustic nonlinearity (Solodov et al, 2002;Turnbull et al, 1995), the Luxemburg-Gorky effect (Zaitsev et al, 2002), the memory effect (Solodov and Korshak, 2001), and the VAM (Donskoy and Sutin, 1998;Motaharifar et al, 2019), are attributed to nonclassical nonlinear behavior of structures. The nonclassical nonlinearities in the frequency response spectrum of the structure are represented by the formation of higher and lower harmonics, frequency mixing, linear (first degree) resonant frequency transfer (Meo et al, 2008), and frequency modulation (Jhang, 2009).…”