Modeling of piezo-induced ultrasonic wave propagation in composite structures using layered solid spectral element

Wave propagation in composite structures with shunted piezoelectric patches is investigated in this study. The wave finite element approach is first developed as a prediction tool for wave propagation characteristics such as dispersion curves in composite structures, and subsequently extended to consider shunted piezoelectric elements through the diffusion matrix model. A three-layered composite beam equipped with a pair of resistor–inductor shunted piezoelectric patches is modeled and analyzed carefully with these numerical techniques. Reflection and transmission coefficients of propagating waves in this smart composite structure are calculated, and the performance of shunted piezoelectric patches on the control of wave propagation is investigated numerically with the diffusion matrix model. Another finite element formulation, named modified wave finite element method, which is dedicated to the analysis of wave propagation in multilayered composite structures, is proposed and developed for considering piezoelectric elements in the structures. It is a dynamic substructuring technique that allows the dynamics of a typical layer cross section to be projected on a reduced local wave mode basis with appropriate dimensions. Results issued from this method are compared to those issued from the classical wave finite element and diffusion matrix model formulations to demonstrate the pertinence of the modelings.

This paper shows the applicability of data-driven model identification to describe guided wave propagation in composite structures. The model identified can be useful to predict waveform or further conditions considering the dynamics of wave propagation in composites media, mainly when the geometry or boundary conditions are complex and make it very difficult to propose an analytical model. Thus, the main purpose of this paper is to use a simple autoregressive with exogenous terms model to fit the experimental data assuming different frequencies of excitation and the effect of temperature changes. An example using a composite plate is performed in this paper to show the steps and applicability. After these analyses, the results obtained demonstrate the practical benefits of the black-box model for modeling of guided wave propagation in complex composite structures for aeronautical applications.

Traditional models of ultrasonic wave propagation are primarily useful for NDE of homogeneous and isotropic materials. In the presence of spatial variations of elastic properties in materials, ultrasonic wave propagation simulation as well as NDE becomes challenging. In view of these challenges, the computational modeling approaches are suitable to incorporate the spatial elastic property variations and elastic anisotropy into simulations of ultrasonic wave propagation. This paper investigates the application of finite element based simulation of ultrasonic wave propagation in materials with varying grain sizes and associated ultrasonic wave velocities. As an example, the method is used to simulate ultrasonic wave propagation through Aluminum‐Lithium high strength structure. Acoustic microscopically measured local elastic properties across the weld are incorporated into the simulation. Results of simulation of Rayleigh Surface Wave (RSW) and bulk acoustic wave propagation in the FSW structure are presented.

Efficient layerwise multiphysics spectral element model for delaminated composite strips with PWAS transducers

The use of fiber reinforced plastics (FRPs) as structural components has significantly increased in recent years. FRPs are made of stacks of plies, each of which is reinforced by fibers. When modeling ultrasonic wave propagation in FRPs, it is important to introduce three-dimensional mesoscopic and microscopic structures to account for the anisotropy and heterogeneity caused by fiber orientation and the lay-up of laminates. In this study, a finite element method using an image-based modeling is applied to simulation of ultrasonic wave propagation in a carbon FRP (CFRP). Here, the elastic stiffness of a single ply is determined using a homogenization method, where a CFRP microstructure is incorporated on the basis of a two-scale asymptotic expansion. The wave propagation in a CFRP specimen composed of unidirectionally aligned fibers is calculated, and the simulation results are compared to visualization results obtained for ultrasonic wave propagation using a laser scanning device.

The use of ultrasonic wave technology was anticipated as an important technology in monitoring the health of composite materials and/or structures. However, the propagation of ultrasonic wave becomes very complicated in polymer-based composite materials due to reflection, transmission, dispersion and other behaviors, which may occur at the interface of the matrix and reinforcements. Therefore, in this study, the elastic wave motion equation is evaluated using finite element analysis; then the propagation of ultrasonic waves in several model composite materials was simulated. The influences of the fiber/matrix interface, fiber size and other fiber properties on wave propagation were clarified. Moreover, the complicated propagation resulting from reflection, transmission and refraction on the fiber/matrix interface was visualized, and the influences of the arrangement of the fibers, the debonding position at the interface, and the volume fraction of fiber are discussed.

A constitutive model for the analysis of second harmonic Lamb waves in unidirectional composites

This paper presents a local interaction simulation approach (LISA) numerical method to analyze the guided wave propagation in composite structures. The method is based on recursive iterative equations, derived from the elastodynamic equilibrium equations. Derivation of the iterative equations is presented for a generalized orthotropic medium in a non-principal axis frame with non-uniform spatial discretizations. The new iterative equations have the capability to model generic laminated composite plates. The results show the validation of the numerical simulations through comparisons with experimental studies of laminated composite plates.

Modeling concept and numerical simulation of ultrasonic wave propagation in a moving fluid-structure domain based on a monolithic approach

Simulations of ultrasonic wave propagation in concrete based on a two-dimensional numerical model validated analytically and experimentally

Three dimensional image-based simulation of ultrasonic wave propagation in polycrystalline metal using phase-field modeling

A 2D spring model for the simulation of ultrasonic wave propagation in nonlinear hysteretic media

Numerical analysis of wave propagation in composite structures needs large-scale computation which is not feasible in practice. This paper investigates the possibility of applying a wave finite element method (WFEM) to composite structure. The key feature of the WFEM is its capability of accurately analyzing the discontinuities in stress wavefront along with the discontinuities in velocities and strains. In addition, the numerical analysis of the WFEM is unconditionally stable and reduces numerical computation. This paper studies a periodically layered composite rod to analyze the dispersion and propagation of stress waves using the WFEM. The numerical results are compared with other numerical/analytical solutions, paying attention to the accuracy of computing the strong discontinuities in the stress wavefront as well as the dispersion of pulses in a heterogeneous elastic rod. It is shown that the WFEM can be used as an affordable tool for numerically solving wave propagation in composite structures.

Structural waves with well-defined time functions involving relatively large wavelengths with respect to the thickness are generated at some adequately chosen part of composite structures such as filament-wound tubes or fiber-reinforced cross-ply laminates. Theoretical predictions based on asymptotic analysis of the basic three-dimensional equations of elastodynamics are compared with experimental results and allow a thorough understanding of the main physical mechanisms of structural wave propagation in composite structures.

<p><span>Concrete is a strongly heterogeneous and densely packed composite material. Due to the high density of scattering constituents and inclusions, ultrasonic wave propagation in this material consists of a complex mixture of multiple scattering, mode conversion and diffusive energy transport. For a better understanding of the effect of aggregates, porosity and of crack distribution on elastic wave propagation in concrete and to optimize inverse techniques it is useful to simulate the wave propagation and scattering process explicitly in the time domain. For this purpose, we use the rotated staggered grid (RSG) finite-difference technique for solving the wave equations for elastic, anisotropic and/or viscoelastic media. This study is part of the CoDA project (DFG project 398216472, FOR 2825), which aims to develop a novel method based on ultrasonic coda wave interferometry (CWI) for the assessment of safety and durability of reinforced concrete structures. For this purpose, the coda technique is a suitable method to detect small changes in concrete members. In order to distinguish changes in the coda signal in terms of their origin (i.e. mechanical load, temperature, moisture), wave propagation simulations are performed to support the experimental investigations within the project. The idea is to create realistic digital twins for the experiments on two different scales: The specimen scale and the structural scale. In this study, high-performance simulations of ultrasonic wave propagation within concrete structures on the specimen scale were performed and evaluated using coda wave interferometry (CWI).</span></p>