The appearance of nonlinear effects in elastic wave propagation is one the most reliable and sensitive indicators onset material damage. However, these are usually very small can be detected only using cumbersome digital signal processing techniques. Here, we propose experimentally validate an alternative approach, filtering focusing properties metamaterials to naturally select higher harmonics generated by increase their signal-to noise ratios, enabling realization time-reversal procedures...

The signature of nonlinearity in the elastic response a specimen to an impingent ultrasonic wave is usually determined through Fourier analysis, which provides low amplitude signals, often below noise level. We suggest here alternative, based on dependence system. Our procedure conceptually simple and easy implement. In addition, it keeps simultaneously into account nonlinear effects phases, amplitudes, frequencies response. sensitivity approach presence proven experimentally.

A spring model for the simulation of propagation ultrasonic pulses in arbitrarily complex heterogeneous media is proposed framework local interaction approach (LISA). The algorithm used allows us to include heuristically additional mechanisms. In particular, problem across imperfect contact interfaces considered. quality tensor, which expected be connected, although not necessarily a trivial way, bond quality, introduced directly into order treat interface flaws, such as delaminations and/or...

Fast and slow dynamics in the elastic response of damaged materials to external excitations show evidence an anomalous (hysteretic) behavior. Experimental observations may be used detect eventually characterize state structural components. At same time, reliable theoretical models might support data interpretation development new experiments. Here, we analyze resonance frequency shift undamaged concrete bars, comparing experimental results predictions obtained from a Preisach-Mayergoyz based model.

Analyzing the nonlinear part of a signal generated by response sample to an elastic excitation is powerful tool gain information on material microstructure, including presence damage. Analysis using band-pass filtering or equivalent methods often difficult due low amplitude harmonics contained in signal. This case for detection early damage granular samples with induced quasistatic loading, as analyzed this paper. An experimental study, based scaling subtraction method, presented here,...

In recent years, acoustic metamaterials have attracted increasing scientific interest for very diverse technological applications ranging from sound abatement to ultrasonic imaging, mainly due their ability act as band-stop filters. At the same time, concept of chaotic cavities has been recently proposed an efficient tool enhance quality nonlinear signal analysis, particularly in ultrasonic/acoustic case. The goal present paper is merge two concepts order propose a metamaterial-based device...

Hysteretic nonlinear elasticity is often observed in consolidated granular media, including concrete, mortar, sandstones, or rocks. Nonlinearity frequently quantified using Nonlinear Resonant Ultrasonic Spectroscopy (NRUS), which provides tools to define parameters for both fast and slow dynamic effects, when analyzing the propagation velocity dependence on strain such materials. The of these temperature was studied with aim NRUS quantify induced thermal damage; thus, experiments were...

Several materials with mesoscopic characteristics (e.g., defects or intergrain regions) have been shown to share several nonclassical nonlinear features, which distinguish them from classical media. Most striking among is the log-time recovery of material properties after they conditioned by action an external perturbation. A simple model based on description features as bond regions between elastic portions presented here. The implementation illustrated application a special bi-state...

Recent studies show that a broad category of materials share “nonclassical” nonlinear elastic behavior much different from “classical” (Landau-type) nonlinearity. Manifestations nonlinearity include stress–strain hysteresis and discrete memory in quasistatic experiments, specific dependencies the harmonic amplitudes with respect to drive amplitude dynamic wave which are remarkably those predicted by classical theory. These have common soft “bond” elements, where originates, contained hard...

Elastic hysteresis in solids is a complex matter which may affect wide range of applications. As observed rocks, it the result interplay between nonlinear and nonequilibrium phenomena, such as conditioning, relaxation, memory. Here we will propose theoretical nondeterministic framework effects are natural consequence model. Experimental results be shown to demonstrate that separation fundamental extract truthful information on nonlinearity.

The ionic distribution induced by an external field is investigated means of the Poisson-Nernst-Planck model, taking into account non-blocking properties limiting electrodes. Three types models proposed for description real electrodes are considered. first two assume current on proportional to variation bulk density ions and surface electric field, respectively. third model assumes that sample limited perfectly blocking with a true resistance in parallel cell. Here we show equivalent, sense...

The mechanical properties of consolidated granular media are strongly affected by large temperature changes which induce the development and localization stresses, leading in turn to damage, e.g., cracking. In this work, we study evolution linear nonlinear elasticity parameters when increasing thermal loading process. We prove existence a link between properties. show that change with increase is larger at lower temperatures than corresponding for parameters, suggesting can be exploited...

Abstract Acoustic filters and metamaterials have become essential components for elastic wave control in applications ranging from ultrasonics to noise abatement. Other devices been designed this field, emulating their electromagnetic counterparts. One such case is an acoustic diode or rectifier, which enables one-way transmission by breaking the equation-related reciprocity. Its achievement, however, has proved be rather problematic, current realizations display a number of shortcomings...

Alkaline solutions, such as sodium, potassium or lithium silicates, appear to be very promising healing agents for the development of encapsulated self-healing concretes. However, evolution their mechanical and acoustic properties in time has not yet been completely clarified, especially regarding behavior related kinetics when they are used form a thin layer contact with hardened cement matrix. This study aims monitor, using linear nonlinear ultrasonic methods, sodium silicate solution...

Time-reversed acoustics (TRA) has been developed in the last few years as a powerful tool for several applications, based on theoretical properties emerging from time reversal invariance of wave equation. TRA is expected to be good basis development imaging techniques field nondestructive evaluation. For this purpose, however, data processing necessary discriminate between images due defects (in general nonlinear scatterers) and linear inclusions, boundaries, etc. We propose here an approach...

Lab experiments have shown that the imaging of nonlinear scatterers using time reversal acoustics can be a very promising tool for early stage damage detection. The potential applications are however limited by need an extremely accurate acquisition system. In order to let features emerge from background noise it is necessary enhance signal-to-noise ratio as much possible. A comprehensive analysis determine components in recorded signal, alternative those usually adopted (e.g. fast Fourier),...

Competition for available nutrients is known to be crucial cancer development. Based on this fact, a model proposed that can describe the manifold of morphologies and growth rates characteristic tumoral growth. The formulation consistent set rules governing microscopic interactions leads system coupled nonlinear iteration equations. These equations contain both deterministic stochastic terms are amenable direct numerical simulation. They allow us test effects such parameters as availability,...

A mathematical model, based on the local interaction simulation approach, is developed in order to allow simulations of spatiotemporal evolution neoplasies. The model consists a set rules, which govern cancerous cells among themselves and competition with other cell populations for acquisition essential nutrients. As result small variations basic parameters, it leads four different outcomes: indefinite growth, metastasis, latency, complete regression. In present contribution detailed...

We analyze in which experimental conditions the concept of electrical impedance is useful for an electrolytic cell. The analysis performed by solving numerically differential equations governing phenomenon redistribution ions presence external electric field and comparing results with ones obtained linear approximation these equations. control parameter our study amplitude applied voltage, assumed a simple harmonic function time. show that bulk distribution close to electrodes differs from...

Evolving cracks in consolidated granular media cause a modification of the microstructure area surrounding damaged zone. As consequence, mechanical properties (flexural strength) and elastic characteristics (linear modulus nonlinear parameters) change as well. The same happens during repair, which could be considered symmetric counterpart damaging. Starting from ultrasonic measurements resonance concrete prisms progression damage we propose description evolution, allows to predict observed...