scholarly journals A formula for the admittance of laterally excited bulk wave resonators (XBARs)

2021 ◽  
Author(s):  
Victor Plessky ◽  
Seniz Küçük ◽  
Soumya Yandrapalli ◽  
Luis Guillermo Villanueva
Keyword(s):  
Bulk Wave

Visualization techniques for bulk wave resonators

2002 ◽  
Author(s):  
D. Silver ◽  
J.T. Stewart ◽  
Y.-K. Yong
Keyword(s):  
Bulk Wave ◽  
Visualization Techniques

scholarly journals A novel semi-implicit scheme for elastodynamics and wave propagation in nearly and truly incompressible solids

2021 ◽  
Author(s):  
Chennakesava Kadapa
Keyword(s):  
Wave Propagation ◽  
Wave Speed ◽  
Critical Time ◽  
Incompressible Material ◽  
Implicit Scheme ◽  
Bulk Wave ◽  
Lumped Mass ◽  
Time Step ◽  
Material Models ◽  
Shear Wave Speed

AbstractThis paper presents a novel semi-implicit scheme for elastodynamics and wave propagation problems in nearly and truly incompressible material models. The proposed methodology is based on the efficient computation of the Schur complement for the mixed displacement-pressure formulation using a lumped mass matrix for the displacement field. By treating the deviatoric stress explicitly and the pressure field implicitly, the critical time step is made to be limited by shear wave speed rather than the bulk wave speed. The convergence of the proposed scheme is demonstrated by computing error norms for the recently proposed LBB-stable BT2/BT1 element. Using the numerical examples modelled with nearly and truly incompressible Neo-Hookean and Ogden material models, it is demonstrated that the proposed semi-implicit scheme yields significant computational benefits over the fully explicit and the fully implicit schemes for finite strain elastodynamics simulations involving incompressible materials. Finally, the applicability of the proposed scheme for wave propagation problems in nearly and truly incompressible material models is illustrated.

Erratum: Broadband bulk-wave cancellation in acoustic-surface-wave devices

1973 ◽  
Vol 9 (3) ◽  
pp. 72
Author(s):  
R. Larosa ◽  
C.F. Vasile
Keyword(s):  
Surface Wave ◽  
Bulk Wave ◽  
Acoustic Surface Wave

Mathematical methods for the characterization of ultrasound in anisotropic materials

2000 ◽  
Vol 78 (9) ◽  
pp. 803-821 ◽  
Author(s):  
B O'Neill ◽  
R Gr. Maev
Keyword(s):  
Wave Propagation ◽  
Acoustic Waves ◽  
Asymptotic Theory ◽  
Anisotropic Materials ◽  
Bulk Wave ◽  
Mathematical Methods ◽  
Theoretical Methods ◽  
The Past ◽  
Fundamental Equations

Although the fundamental equations for the propagation of elastic and acoustic waves in anisotropic materials have not changed in more than a 100 years, the last few decades have seen a surge in interest in the topic. Much of this interest stems from the growing need for characterization of an increasing number of exotic materials. The intent of this paper is to review, for the benefit of beginning researchers in acoustics and ultrasonics, the fundamental phenomena related to elastic wave propagation in anisotropic media. We also present the most common and interesting theoretical methods developed over the past 20 years to model bulk wave propagation in such media. The methods discussed include plane wave superpositions, ray asymptotic theory, paraxial beams, and Green's functions. More peripheral issues, including anisotropic effects combined with various other exotic effects, are dealt with in the bibliography. PACS No.: 43.90

Interface acoustic waves in piezoelectric bi-crystalline structures of specific types

2005 ◽  
Vol 461 (2056) ◽  
pp. 895-911 ◽  
Author(s):  
A. N Darinskii ◽  
M Weihnacht
Keyword(s):  
Acoustic Waves ◽  
The Other ◽  
Imaginary Component ◽  
Sufficient Condition ◽  
Bulk Wave ◽  
Piezoelectric Crystal ◽  
Piezoelectric Media ◽  
Crystalline Structures ◽  
Material Constants ◽  
Bulk Waves

The paper discusses the properties of the acoustic waves guided by an interface inside piezoelectric media. The interfaces of two types have been considered: (i) an infinitesimally thin metallic layer inserted into homogeneous piezoelectric crystal of arbitrary symmetry; (ii) rigidly bonded crystals whose piezoelectric coefficients differ by sign while the other material constants are identical. Several general theorems have been proved regarding the existence of interface acoustic waves (IAWs) propagating more slowly than bulk waves. In particular, a sufficient condition for the existence of such ‘slow’ IAWs has been derived. The propagation of leaky IAWs has been studied. Special attention has been paid to the analysis of the situation when the imaginary component of the leaky IAW velocity vanishes, resulting in the appearance of non-attenuating IAWs travelling faster than the slow transverse bulk wave. The computations performed for LiNbO 3 and LiTaO 3 illustrate general conclusions.

Laterally-excited bulk-wave resonators (XBARs) with embedded electrodes in 149.5° Z-cut LiNbO3

2021 ◽  
Author(s):  
Xiyu Gu ◽  
Jieyu Liu ◽  
Yao Cai ◽  
Yan Liu ◽  
Chao Gao ◽  
...  
Keyword(s):  
Bulk Wave

Nonlinear Inversion of Ultrasonic Guided Waves for in Vivo Evaluation of Cortical Bone Properties

2021 ◽  
Author(s):  
Xiaojun Song ◽  
Tiandi Fan ◽  
Jundong Zeng ◽  
QinZhen Shi ◽  
Qiong Huang ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Cortical Bone ◽  
Cortical Thickness ◽  
Guided Waves ◽  
Transverse Velocity ◽  
Ultrasonic Guided Waves ◽  
Bulk Wave ◽  
True Value ◽  
The Impact

Abstract Ultrasonic guided waves (UGW), which propagate throughout the whole thickness of cortical bone, are attractive in the early diagnosis of osteoporosis. However, it is challenging due to the impact of soft tissue and the inherent difficulties related to the multiparametric inversion of cortical bone quality factors, such as cortical thickness and bulk wave velocities. Therefore, an UGW based multiple-parameter inversion algorithm is developed to predict strength-related factors in this research. In simulation, a free plate (cortical bone) and a bilayer plate (soft tissue and cortical bone) are used to validate the proposed method. The inverted cortical thickness (CTh), longitudinal velocity (V L ) and transverse velocity (V T ) are in accordance with the true value. Then four bovine cortical bone plates are used in the in vitro experiments. Compared with the reference values, the relative errors for cortical thicknesses are 3.96%, 0.83%, 2.87% and 4.25% respectively. In the in vivo measurements, ultrasonic guided waves are collected from ten volunteers’ tibia. The theoretical dispersion curves depicted by the estimated parameters (V T , V L , CTh) match well with the extracted experimental ones. In comparison to the dual-energy x-ray absorptiometry (DXA), the results show that the estimated transverse velocity and cortical thickness are highly sensitive to the osteoporosis. Therefore, these two parameters (CTh and V T ) of long bones have potential to diagnose bone status in clinical applications.

scholarly journals Fast and Accurate Finite Transducer Analysis Method for Wireless Passive Impedance-Loaded SAW Sensors

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3988
Author(s):  
Wei Luo ◽  
Yang Yuan ◽  
Yi Wang ◽  
Qiuyun Fu ◽  
Hui Xia ◽  
...  
Keyword(s):  
Computation Time ◽  
Processing Unit ◽  
Bulk Wave ◽  
Analysis Method ◽  
Accurate Analysis ◽  
Central Processing ◽  
Finite Transducer ◽  
Long Time ◽  
High Degree ◽  
Element Method

An accurate and fast simulation tool plays an important role in the design of wireless passive impedance-loaded surface acoustic wave (SAW) sensors which have received much attention recently. This paper presents a finite transducer analysis method for wireless passive impedance-loaded SAW sensors. The finite transducer analysis method uses a numerically combined finite element method-boundary element method (FEM/BEM) model to analyze non-periodic transducers. In non-periodic transducers, FEM/BEM was the most accurate analysis method until now, however this method consumes central processing unit (CPU) time. This paper presents a faster algorithm to calculate the bulk wave part of the equation coefficient which usually requires a long time. A complete non-periodic FEM/BEM model of the impedance sensors was constructed. Modifications were made to the final equations in the FEM/BEM model to adjust for the impedance variation of the sensors. Compared with the conventional method, the proposed method reduces the computation time efficiently while maintaining the same high degree of accuracy. Simulations and their comparisons with experimental results for test devices are shown to prove the effectiveness of the analysis method.

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