A semi-analytical framework for predicting far-field responses of complex elastic waves emitters.

Applications of guided waves in various fields of engineering and science rely on elastic wave emitters for wave generation. Accurate prediction and understanding of the far-field responses of these wave emitters are crucial for the reliable and efficient application of guided waves-based technologies. In this paper, we propose a novel semi-analytical framework capable of predicting the far-field response of complex wave emitters of arbitrary shape and internal structure in any type of substrate.

Emerging topics in nanophononics and elastic, acoustic, and mechanical metamaterials: an overview.

This broad review summarizes recent advances and "hot" research topics in nanophononics and elastic, acoustic, and mechanical metamaterials based on results presented by the authors at the EUROMECH 610 Colloquium held on April 25-27, 2022 in Benicássim, Spain. The key goal of the colloquium was to highlight important developments in these areas, particularly new results that emerged during the last two years. This work thus presents a "snapshot" of the state-of-the-art of different nanophononics- and metamaterial-related topics rather than a historical view on these subjects, in contrast to a conventional review article.

Deformation of Bioinspired MXene-Based Polymer Composites with Brick and Mortar Structures: A Computational Analysis.

In this work, the deformation behavior of MXene-based polymer composites with bioinspired brick and mortar structures is analyzed. MXene/Polymer nanocomposites are modeled at microscale for bioinspired configurations of nacre-mimetic brick-and-mortar assembly structure. MXenes (brick) with polymer matrix (mortar) are modeled using classical analytical methods and numerical methods based on finite elements (FE).

Non-symmetric flexural wave scattering and one-way extreme absorption.

The possibility of asymmetric absorption and reflection for flexural waves is demonstrated through analytical and numerical examples. The emphasis is on the one-dimensional (1D) case of flexural motion of a beam for which combinations of point scatterers are considered, which together provide asymmetric scattering. The scatterers are attached damped oscillators characterized by effective impedances, analogous to effective configurations in 1D acoustic waveguides.

Modelling nonlinearity of guided ultrasonic waves in fatigued materials using a nonlinear local interaction simulation approach and a spring model.

Modelling and numerical simulation - based on the framework of the Local Interaction Simulation Approach - was developed to have more insight into nonlinear attributes of guided ultrasonic waves propagating in fatigued metallic materials. Various sources of nonlinearity were considered in this modelling work, with particular emphases on higher-order harmonic generation and accumulation of nonlinearity along wave propagation. The material hyper-elasticity was considered in the model using an energy density approach based on the Landau-Lifshitz formulation; and the "breathing" motion pattern of a fatigue crack in the material was interrogated using a spring model.

Acoustic source localization in an anisotropic plate without knowing its material properties - A new approach.

Acoustic source localization (ASL) in a highly anisotropic plate is a challenging task. The basic assumption in many of the currently available techniques is that the wave propagates along a straight line from the source to the receiving sensor. However, waves in anisotropic solids propagate along curved lines and form non-circular wave fronts.

Amplitude-dependent Lamb wave dispersion in nonlinear plates.

The paper presents a perturbation approach for calculating amplitude-dependent Lamb wave dispersion in nonlinear plates. Nonlinear dispersion relationships are derived in closed form using a hyperelastic stress-strain constitutive relationship, the Green-Lagrange strain measure, and the partial wave technique integrated with a Lindstedt-Poincaré perturbation approach. Solvability conditions are derived using an operator formalism with inner product projections applied against solutions to the adjoint problem.

Time-distance domain transformation for Acoustic Emission source localization in thin metallic plates.

Acoustic Emission used in Non-Destructive Testing is focused on analysis of elastic waves propagating in mechanical structures. Then any information carried by generated acoustic waves, further recorded by a set of transducers, allow to determine integrity of these structures. It is clear that material properties and geometry strongly impacts the result.

Generalized semi-analytical finite difference method for dispersion curves calculation and numerical dispersion analysis for Lamb waves.

The paper presents an efficient and accurate method for dispersion curve calculation and analysis of numerical models for guided waves. The method can be used for any arbitrarily selected anisotropic material. The proposed approach utilizes the wave equation and through-thickness-only discretization of anisotropic, layered plates to obtain the Lamb wave characteristics.