Accelerating numerical modeling of wave propagation through 2-D anisotropic materials using OpenCL

Wave propagation in glass fibre-reinforced polymer (GFRP) bars subjected to progressive damage—Experimental and numerical results

On the modeling of wave propagation on non-uniform currents and depth

Numerical modeling of wave propagation into a harbor using improved characteristic scheme

A critical aspect when modelling wave propagation in the ground with the finite element technique is using non-reflecting boundaries. The choice of element size and domain size to fit non-reflecting boundaries becomes difficult when a forcing function with a large range of frequencies is used. This paper presents the results from a finite element study designed to gain insight into wave propagation in soils due to an applied vertical harmonic load with varying frequency content ranging from 10 Hz to 95 Hz using Abaqus/Explicit. Comparison is made between numerical results and measured field data. It is concluded that Abaqus/Explicit can reliably model the wave propagation problem. Particularly, the phase velocity determined by finite element modelling compared favourably to values obtained theoretically, as well as in the field. In addition, good correlation was found between the dispersion data from the model and field measurements.

Monitoring of structures implies integration of sensors and actuators, smart materials, data transfer as well as computer analyses and simulations with the purpose of damage detection, localization, assessment and prediction of the state of damage at the certain moment and in time. This paper presents the application of the explicit finite element method for modeling of the wave propagation. The examples of concrete plates and thin steel plates in which the propagation of the Lamb waves occur were analyzed. Explicit finite element method was shown to be very efficient even for the waves in ultrasound range. Efficiency, ease of the use and reliability of the wave propagation modeling by the explicit finite element method can contribute to the development of a new and the improvement of the existing methods for the monitoring of structures. The main purpose of this paper is to demonstrate a waveform propagation model using an explicit FEM in ABAQUS software.

Shell type structures are used in a wide variety of industrial components, especially in automotive or aeronautic industries. A full understanding and predictive modeling of elastic waves propagation through those structures can be of great importance at their design stage for several reasons, such as the noise reduction in a vehicle or the control of high energy shock waves triggered by pyrotechnic cut in a space launcher. This paper deals with the theoretical and numerical modeling of elastic wave propagation in shells. The aim is to discuss the relevance of theoretical models and to develop appropriate and efficient numerical tools.

2D anisotropic materials, typically consisting of 1D distorted chains arranged in parallel or anti-parallel patterns, are gaining attention for their potential in anisotropic electronic and optoelectronic devices. 2D anisotropic materials with cross-stacked interconnected 1D chains will show improved anisotropy and stability. Nonetheless, to date, no 2D anisotropic materials featuring cross-stacked motifs have been experimentally realized. This work identifies AgTiPS6 atomic layers, the 2D in-plane anisotropic material with cross-stacked structural motifs, as an n-type semiconductor with a 1.0eV band gap. Significantly, the unique cross-stacked configuration of 2D AgTiPS6 results in a significant in-plane anisotropy, with electrical and optoelectrical anisotropies measuring 5.44 and 2.44, respectively, as well as an axially orientation selectivity. Meanwhile, a broadband response from visible (Vis, 405nm) to middle infrared (MIR, 10.6µm) is achieved in the AgTiPS6-based photodetector, with the photoresponse above the bandgap attributed to photothermoelectric effect. Furthermore, 2D AgTiPS6 has demonstrated environmental stability exceeding 12 months and a laser damage threshold exceeding 10Wcm- 2, attributed to its extra-thick monolayer (1.32nm). This work introduces a novel in-plane anisotropic material, expanding the repertoire of 2D anisotropic materials and offering potential for the development of anisotropic electronic and optoelectronic devices.

“Modeling of seismic wave propagation is a core component in almost every aspect of exploration seismology, ranging from survey design methods to imaging and inversion algorithms. The last time SEG published a reprint volume on numerical modeling was in 1990. Since then, the last two decades has seen a step change in the application and use of Âfull wave equation modeling methods enabled by the tremendous increase in available computational power. Full waveform inversion, reverse time migration and 3D elastic finitedifference synthetic data generation are examples of modeling applications that are currently having a fundamental impact on our business. In Numerical Modeling of Seismic Wave Propagation: Gridded Two-way Wave-equation Methods, readers will find many of the wellknown and referenced papers from the exploration seismic community as well as some of the key papers that have impacted other fields of seismology. Because the modeling literature is vast, we have limited the scope of the reprint volume to papers over the last two decades on modeling methods based on the full wave equation. The reprint volume will be of particular interest to researchers and practitioners interested in modeling methods and their applications. The searchable CD includes the 114-page book of abstracts and the full papers.”

A one-dimensional model of acoustic wave propagation in a multilayered structure of a spot weld is developed. The inhomogeneity of the material properties due to the thermal inhomogeneity is included in the equation of motion. The model enables us to deal with arbitrary spatial distributions of Lamé constants and density. The model allows analysis of travel time, multiple reflections, and interference in a given geometry. Use of this model could provide information to help predict behavior of the waves in the transmission (reflection) mode at different plate thicknesses and welding settings.

Relations of nonlinear processes of seismic wave radiation by a ground-based vibrational source and their ldquoaccumulationrdquo during the propagation of waves in the medium are considered. Results of numerical modeling of the dependence of the parameters of seismic wave field nonlinearity on the characteristics of mediumpsilas inhomogeneity are presented. Fluid-saturated fractured media with different parameters of physical elasticity are considered as examples.

A large body of work has been done in solids, acoustics and electromagnetics on wave propagation in non-homogeneous media. The current work, which is largely exploratory in nature, involves waves in a non-homogeneous elastic rod. Some formulations and methodologies in which analytic solutions are sought are reviewed. Several analytic solutions are found and discussed. For rods with complicated parameter variations, analytic solutions do not exist and the use of MAPLE®’s numerical partial differential equation solver is explored. Discontinuous material changes were modeled using hyperbolic tangent functions. The results are mixed in nature. For scenarios in which the materials and input pulses varied rapidly, good amplitude results were found, but wavelike features were masked by spurious oscillations. For scenarios in which the variations were slow, reliable results were obtained.

ABSTRACTA numerical model for nonlinear wave propagation over a rectangular step is formulated by utilizing the boundary element method. The computation by this model gives a more realistic wave profile than that of linear wave theory. The model is used for study of the formation of higher harmonic components in the process of wave propagation over the step. In comparison with the results of laboratory experiments, the model gives good estimation of the amplitudes of the second and third harmonic components, and gives a over-prediction of the first harmonic component. Reflection and transmission coefficients are calculated by including these harmonic components in the computation of wave height. The model yields the coefficients in good agreement with the experimental results.In addition to the analysis of harmonic components, the energy loss in the process of wave propagation over the step was experimentally investigated. A Fiber Laser Velocimeter is used to measure the water particle velocity at about f...

Numerical modeling of optical wave propagation in atmospheric turbulence is traditionally performed with using the so-called “split”-operator method, when the influence of the propagation medium’s refractive index inhomogeneities is accounted for only within a system of infinitely narrow layers (phase screens) where phase is distorted. Commonly, under certain assumptions, such phase screens are considered as mutually statistically uncorrelated. However, in several important applications including laser target tracking, remote sensing, and atmospheric imaging, accurate optical field propagation modeling assumes upper limitations on interscreen spacing. The latter situation can be observed, for instance, in the presence of large-scale turbulent inhomogeneities or in deep turbulence conditions, where interscreen distances become comparable with turbulence outer scale and, hence, corresponding phase screens cannot be statistically uncorrelated. In this paper, we discuss correlated phase screens. The statistical characteristics of screens are calculated based on a representation of turbulent fluctuations of three-dimensional (3D) refractive index random field as a set of sequentially correlated 3D layers displaced in the wave propagation direction. The statistical characteristics of refractive index fluctuations are described in terms of the von Karman power spectrum density. In the representation of these 3D layers by corresponding phase screens, the geometrical optics approximation is used.

Acoustic and gravity waves propagating in planetary atmospheres have been studied intensively as markers of specific phenomena such as tectonic events or explosions or as contributors to atmosphere dynamics. To get a better understanding of the physics behind these dynamic processes, both acoustic and gravity waves propagation should be modelled in a 3-D attenuating and windy atmosphere extending from the ground to the upper thermosphere. Thus, in order to provide an efficient numerical tool at the regional or global scale, we introduce a finite difference in the time domain (FDTD) approach that relies on the linearized compressible Navier–Stokes equations with a background flow (wind). One significant benefit of such a method is its versatility because it handles both acoustic and gravity waves in the same simulation, which enables one to observe interactions between them. Simulations can be performed for 2-D or 3-D realistic cases such as tsunamis in a full MSISE-00 atmosphere or gravity-wave generation by atmospheric explosions. We validate the computations by comparing them to analytical solutions based on dispersion relations in specific benchmark cases: an atmospheric explosion, and a ground displacement forcing.

2DH numerical model of nonlinear wave propagation based on a hybrid finite-volume and finite-difference scheme