Dynamics of a circular membrane with an eccentric circular areal constraint: Analysis and accurate simulations

AlSahlani, Assaad; Mukherjee, Ranjan

doi:10.1016/j.simpat.2012.10.008

Cited by 12 publications

(5 citation statements)

References 32 publications

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“…According to Huygens' principle, two opposite wavefronts of the SW are superposed, resulting in a smaller in-phase region than the TW, inhibiting the diffraction effect that causes the focal beam distortion, and forming a smaller focal area. Furthermore, previous studies show that asymmetric distribution of load and wrinkles on the Kapton membrane causes changes in its resonant frequencies and shape of vibration modes, but the position of the maximum displacement at the (0,n) mode is confined to a small region [42,43]. The suppressed focus shift of a spherical cavity transducer is due to the established resonant field inside the cavity rather than the reflection from the opposite concave surface (confirmed by using both acoustic ray and wave models, but the data are not included).…”

Section: Discussionmentioning

confidence: 99%

Highly accurate and reliable ultrasonic focusing capability in heterogeneous media using a spherical cavity transducer

et al. 2023

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Introduction: Focused ultrasound ablation surgery (FUAS) has been emerging to treat a wide range of conditions non-invasively and effectively with promising therapeutic outcomes. The focusing capability of an ultrasound transducer (i.e., focus shift, beam distortion, and acoustic pressure at the focus) determines the ablation effects. However, the focus shift and focal beam distortion after ultrasound propagating through multi-layered heterogeneous viscoelastic biological tissues become significant and are found to deteriorate the performance of FUAS in clinics.Methods: To achieve an accurate and reliable focal field among patients with large variations in the anatomical structures and properties, a spherical cavity transducer with open ends and sub-wavelength focal size (Li et al., APL, 2013,102:204102) was applied here. Both experimental measurements and numerical simulations were performed to characterize the acoustic fields of the spherical cavity transducer in water, the multi-layered concentric cylindrical phantom, and the heterogeneous tissue model (an adult male pelvis enclosed by porcine skin, fat, and muscle) and then compared with those of a conventional concave transducer at the same electrical power output.Results: It is found that standing-wave focusing using the spherical cavity transducer results in much less focus shift (0.25λ vs. 1.67λ) along the transducer axis and focal beam distortion (−6 dB beam area of 0.71 mm2vs. 4.72 mm2 in water and 2.55 mm2vs. 17.30 mm2 in tissue) in the focal plane but higher pressure focusing gain (40.05 dB vs. 33.61 dB in tissue).Discussion: Such a highly accurate and reliable focal field is due to the excitation at an appropriate eigen-frequency of the spherical cavity with the varied media inside rather than the reverberation from the concave surface. Together with its sub-wavelength focal size, the spherical cavity transducer is technically advantageous in comparison to the concave one. The improved focusing capability would benefit ultrasound exposure for not only safer and more effective FUAS in clinics, but also broad acoustic applications.

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Section: Discussionmentioning

confidence: 99%

Highly accurate and reliable ultrasonic focusing capability in heterogeneous media using a spherical cavity transducer

et al. 2023

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“…Assaad Alsahlani and Ranjan Mukherji compared the vibration symmetric and unsymmetric modes with their literature survey. They also developed tools to study membrane vibrations [4]. Mobukatsu Okuizumi in his research analyzed the modes of rotating membrane.…”

Section: Introductionmentioning

confidence: 99%

Modal and harmonic acoustical analysis of a circular rubber membrane and classification of resonant frequencies using deep learning

Dixit,

Wani

2023

J. Phys.: Conf. Ser.

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Mode shapes of a component or a structure can be determined by conducting Modal analysis. Chladni figures can also be used to determine the mode shapes of a plate. In this research comparison of these mode shapes using Chladni figures and ANSYS simulation has been carried out. Analysis systems used for ANSYS simulation are Harmonic Acoustic Analysis and modal analysis. With the help of wave equation, a mathematical formulation has been achieved. The experimental and simulation results are compared, and an error of not more than 9% for modal and 10% for harmonic acoustics is found. Classification of these Chladni figures which are obtained experimentally, using Deep Learning algorithms like Inception ResNetV2, VGG16 and Xception and have achieved 100 percent accuracy at different converging times.

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“…Among the different types of membranes, circular membranes are the most commonly used due to their large number of applications, namely musical instruments, condenser microphones, hearing aids, etc. [ 1 , 2 ].…”

Section: Introductionmentioning

confidence: 99%

“…Due to complex boundary conditions, shapes and applications, the vibration of membranes remains an active subject of research [ 1 ]. The accuracy of membrane strain and the behavior of the membrane under the sound pressure drive the response and sensitivity of the acoustic sensor.…”

Section: Introductionmentioning

confidence: 99%

Inkjet-Printed Membrane for a Capacitive Acoustic Sensor: Development and Characterization Using Laser Vibrometer

Haque

Ogam

Benaben

et al. 2017

Sensors

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This paper describes the fabrication process and the method to determine the membrane tension and defects of an inkjet-printed circular diaphragm. The membrane tension is an important parameter to design and fabricate an acoustic sensor and resonator with the highest sensitivity and selectivity over a determined range of frequency. During this work, the diaphragms are fabricated by inkjet printing of conductive silver ink on pre-strained Mylar thin films, and the membrane tension is determined using the resonant frequency obtained from its measured surface velocity response to an acoustic excitation. The membrane is excited by an acoustic pressure generated by a loudspeaker, and its displacement (response) is acquired using a laser Doppler vibrometer (LDV). The response of the fabricated membrane demonstrates good correlation with the numerical result. However, the inkjet-printed membrane exhibits undesired peaks, which appeared to be due to defects at their boundaries as observed from the scanning mode of LDV.

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Dynamics of a circular membrane with an eccentric circular areal constraint: Analysis and accurate simulations

Cited by 12 publications

References 32 publications

Highly accurate and reliable ultrasonic focusing capability in heterogeneous media using a spherical cavity transducer

Highly accurate and reliable ultrasonic focusing capability in heterogeneous media using a spherical cavity transducer

Modal and harmonic acoustical analysis of a circular rubber membrane and classification of resonant frequencies using deep learning

Inkjet-Printed Membrane for a Capacitive Acoustic Sensor: Development and Characterization Using Laser Vibrometer

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