Bulk wave propagation in layered piezomagnetic/piezoelectric plates with initial stresses or interface imperfections

2012 ◽  
Vol 94 (9) ◽  
pp. 2736-2745 ◽  
Author(s):  
Y.Y. Zhou ◽  
C.F. Lü ◽  
W.Q. Chen
Keyword(s):  
Wave Propagation ◽  
Initial Stresses ◽  
Bulk Wave ◽  
Interface Imperfections ◽  
Piezoelectric Plates

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.

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

scholarly journals Wave Dispersion in Multilayered Reinforced Nonlocal Plates under Nonlinearly Varying Initial Stress

Eng ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 31-47
Author(s):  
Mohammad Reza Farajpour ◽  
Ali Reza Shahidi ◽  
Ali Farajpour
Keyword(s):  
Wave Propagation ◽  
Initial Stress ◽  
Volume Fraction ◽  
Wave Dispersion ◽  
Initial Stresses ◽  
Small Scale ◽  
Dependent Model ◽  
Phase And Group Velocities ◽  
The One ◽  
Group Velocities

This paper deals with the effects of initial stress on wave propagations in small-scale plates with shape memory alloy (SMA) nanoscale wires. The initial stress is exerted on the small-scale plate along both in-plane directions. A scale-dependent model of plates is developed for taking into consideration size influences on the wave propagation. In addition, in order to take into account the effects of SMA nanoscale wires, the one-dimensional Brinson’s model is applied. A set of coupled differential equations is obtained for the non-uniformly prestressed small-scale plate with SMA nanoscale wires. An exact solution is obtained for the phase and group velocities of the prestressed small-scale system. The influences of non-uniformly distributed initial stresses as well as scale and SMA effects on the phase and group velocities are explored and discussed. It is found that initial stresses as well as the orientation and volume fraction of SMA nanoscale wires can be used as a controlling factor for the wave propagation characteristics of small-scale plates.

Ultrasonic Wave Considerations for the Development of an NDE Feature Matrix for Anisotropic Media

1989 ◽  
Vol 111 (3) ◽  
pp. 255-262 ◽  
Author(s):  
J. L. Rose ◽  
A. Pilarski ◽  
K. Balasubramaniam ◽  
A. Tverdokhlebov ◽  
J. Ditri
Keyword(s):  
Wave Propagation ◽  
Longitudinal Velocity ◽  
Broad Band ◽  
Anisotropic Media ◽  
Anisotropic Elasticity ◽  
Point Of View ◽  
Experimental Point ◽  
Bulk Wave ◽  
Test Protocol ◽  
Stiffness Coefficients

The problem of ultrasonic surface and bulk wave propagation in an anisotropic media and/or a composite material is addressed so that applications in Nondestructive Evaluation can be considered, emphasis in this paper being placed on bulk wave propagation. Global material property determination is considered in an inverse wave velocity computation of stiffness coefficients based on principles of anisotropic elasticity. A one-sided inspection technique based on practical considerations of a field environment is developed. The concept of a feature matrix, based on the stiffness coefficients, is then introduced as a means of both material characterization and defect analysis in composite materials. A brief discussion on a test protocol and an interpretation of the elements in the feature matrix from an NDE point of view is also presented. The conclusions of a previous theoretical investigation of wave propagation in anisotropic media are considered from an experimental point of view by way of the bulk wave technique. A result of fundamental value is that the actual propagation of quasilongitudinal waves, generated by a standard broad band pulsed transducer, is indeed well matched with the theoretical approximation obtained earlier. This approximation was based on the generalized retarded potential principle with variable energy velocity of the quasilongitudinal mode in an anisotropic medium as the substitute for the constant longitudinal velocity used in the retarded potential scheme for an isotropic medium.

Sign in / Sign up

Export Citation Format

Share Document