Elke Deckers

Elke Deckers
KU Leuven | ku leuven · Department of Mechanical Engineering

PhD

About

138
Publications
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1,326
Citations

Publications

Publications (138)
Article
Full-text available
A novel resonant metamaterial solution is designed and applied to a vehicle in order to reduce the structure-borne noise in the interior compartment due to the first acoustic tyre resonances around 230 Hz. This noise control solution consists of metal 3D printed resonant elements applied to the rear wheel arches of a vehicle and is designed as a po...
Article
The frequency response of vibro-acoustic systems can be improved by using various forms of damping materials. Their material properties are typically varying with the excitation frequency and are introduced by one or multiple complex-valued functions. Numerical models of such systems are typically large and require efficient solving strategies. In...
Article
The recently introduced framework enabling Model Order Reduction (MOR) for systems arising within the acoustic Boundary Element Method (BEM) [1] allows for fast frequency sweeps to obtain the detailed response of an acoustic system. Nevertheless, in many cases it is desirable to include additional parameters in the MOR scheme to facilitate iteratio...
Article
In recent years, a wide variety of inhomogeneous periodic structures including locally resonant metamaterials and phononic crystals have come to the fore in the search for innovative noise and vibration solutions which are lightweight and compact. With the often intricate design of these periodic cells, noise and vibration attenuation is achieved i...
Preprint
Full-text available
The analysis of sound and vibrations is often performed in the frequency domain, implying the assumption of steady-state behaviour and time-harmonic excitation. External excitations, however, may be transient rather than time-harmonic, requiring time-domain analysis. Some material properties, e.g.\ often used to represent for damping treatments, ar...
Preprint
Full-text available
A novel resonant metamaterial solution is designed and applied to a vehicle in order to reduce the structure-borne noise in the interior compartment due to the first acoustic tyre resonances around 230Hz. This noise control solution consists of metal 3D printed resonant elements applied to the rear wheel arches of a vehicle and is designed as a pot...
Article
Full-text available
Sparsity-based methods have recently come to the foreground of damage detection applications posing a robust and efficient alternative for traditional approaches. At the same time, low-frequency inspection is known to enable global monitoring with waves propagating over large distances. In this paper, a single sensor complex Group Lasso methodology...
Article
The cylindrical cup geometry, an archetype model, used to analyze the dimensional stability of the deep drawing process, is employed to study the vibro-acoustic performance subsequent to the forming simulations. Cylindrical cups are manufactured with a depth of 24 mm, thicknesses (0.97 mm & 1.21 mm) and using two different blank holder force (BHF)...
Article
New applications, such as material characterization, auralization and virtual sensing, have renewed the need and interest in efficient transient time-domain simulations of dynamical systems. However, the typical required numerical simulations for these applications are cumbersome to compute due to the high computational burden involved in the calcu...
Article
Metamaterials have recently emerged in the search for lightweight noise and vibration solutions. One of their appealing properties for noise control engineering is the ability to create stop bands, which are frequency ranges without free wave propagation. These stop bands arise from the sub-wavelength addition of identically tuned resonators in or...
Conference Paper
Full-text available
Individual Head Related Transfer Functions (HRTFs), necessary for the realistic audio rendering of a virtual scene, can be efficiently computed using numerical methods on three-dimensional scans of the ears and head of a subject. However, accurate geometries are required to obtain perceptually valid HRTFs. The most precise scanning techniques gener...
Conference Paper
Full-text available
To comply with stringent environmental and noise standards in the automotive sector, a resonant metamaterial solution is applied to a vehicle to reduce the interior structure- borne noise due to the acoustic tyre resonances around 220 Hz. This novel solution consists of metal 3D printed resonant elements applied on the rear wheel arches of a vehicl...
Article
Transient responses impose additional restrictions concerning model order reduction of acoustic finite element systems. Time-stable model order reduction methods achieve model compaction while guaranteeing frequency domain models transform in a physically meaningful way. Efficiency and stability are of course of little consequence if the model is r...
Conference Paper
In the search for lightweight solutions with favourable noise and vibration attenuation, locally resonant vibro-acoustic metamaterials have emerged as a promising candidate due to their stop band behaviour. When used in a sound transmission context, vibro-acoustic metamaterial panels allow to greatly improve the acoustic insulation in a targeted fr...
Article
Full-text available
This paper deals with the extraction of wave features in elastic media. An inverse approach is proposed for the identification of wave dispersion characteristics (e.g. k-space) in one- and two-dimensional structures (1D, 2D). The proposed method is similar to the ESPRIT algorithm and the Prony series method and can be considered as an extension of...
Conference Paper
Metamaterials have recently emerged and shown great potential for noise and vibration reduction in specific frequency ranges, called stop bands. To predict stop bands, their often periodic nature is exploited and dispersion curves are calculated based on a single representative unit cell, typically modelled using the finite element method. Since th...
Conference Paper
In this paper we study the application of high-speed cameras for the measurement of the acoustic radiation of (baffled) plates and plate-like structures, independent of their mechanical boundary conditions. High-speed cameras offer contact-less, transient and spatially dense displacement measurements. We use the measured displacement as boundary co...
Conference Paper
View Video Presentation: https://doi.org/10.2514/6.2021-2274.vid In the search for novel Noise, Vibrations and Harshness (NVH) solutions, vibro-acoustic locally resonant metamaterials (LRMs) have recently emerged, combining a good NVH behavior and a lightweight design in desired frequency regions, referred to as stop bands i.e.\ frequency zones of...
Conference Paper
Metamaterials, i.e. artificial structures with unconventional properties, have shown to be highly potential lightweight and compact solutions for the attenuation of noise and vibrations in targeted frequency ranges, called stop bands. In order to analyze the performance of these metamaterials, their stop band behavior is typically predicted by mean...
Article
Resonant metamaterials have recently emerged as lightweight and performant noise and vibration solutions for the hard-to-address low-frequency ranges. These engineered materials are made by an assembly of resonant elements onto a host structure. Their interaction leads to tuneable frequency ranges, known as stop bands, in which they can outperform...
Article
This paper investigates the mechanisms that can be used to enhance the absorption performance of poro-elastic materials in the viscous regime. It is shown that by adding small inclusions in a poro-elastic foam layer, a mass-spring effect can be introduced. If the poro-elastic material has relatively high viscous losses in the frequency range of int...
Article
Full-text available
Recently, the potential of metamaterials and phononic crystals to cope with conflicting requirements of obtaining lightweight structures with desirable noise and vibration properties has been demonstrated. These, often periodic, structures are commonly studied based on their representative unit cell of which the vibro-acoustic performance is examin...
Article
This paper presents a way to obtain angle-dependent reflection, transmission and absorption coefficients of a sample based on the modal decomposition method in a rectangular waveguide. Microphone locations are optimized to ensure that the modal decomposition can be applied. The method is subsequently validated both numerically and experimentally.
Article
The inclusion of vibroacoustic treatments at early stage of product development through the use of poro-elastic media with periodic inclusions, which exhibit proper dynamic filtering effects, is a powerful strategy for the achievement of lightweight sound packages and represents a convenient solution for manufacturing aspects. This can have differe...
Article
This work presents the design, optimization and combination of fully parameterized Archimedean spiral cavities (ASCs) as acoustic resonators, in order to achieve perfect absorption at frequencies below 1000 Hz while using a completely modular design. The assembly of two ASCs in the same system is also presented. An optimization is performed and res...
Chapter
Due to environmental and economic requirements, lightweight design is increasingly used in automotive applications. However, the use of lightweight design typically comes at the cost of impaired NVH performance. Classic solutions to improve the NVH performance usually rely on adding mass or volume, conflicting with lightweight design. In the search...
Article
Recycling of Krylov subspaces is often used to obtain an augmentation subspace in the context of iterative algorithms for the solution of sequences of linear systems. However, it still remains difficult to quantify the effect of subspaces recycling and thus to determine the dimension of the subspaces to be recycled targeting a specific accuracy. In...
Book
Full-text available
An increasing complexity of models used to predict real-world systems leads to the need for algorithms to replace complex models with far simpler ones, while preserving the accuracy of the predictions. This three-volume handbook covers methods as well as applications. This third volume focuses on applications in engineering, biomedical engineering,...
Conference Paper
The characterization of poroelastic materials typically requires various dedicated tests to estimate all necessary material parameters. Therefore, a characterization is linked with a lot of effort and usually it is not possible to perform in a standard acoustic laboratory. However, for designing vibro-acoustic systems that include poroelastic mater...
Chapter
Full-text available
This chapter presents several case studies to illustrate specific aspects in setting up reduced-order models of acoustic and vibration models in mechanical applications. Modal truncation approaches have been a proven workhorse for over half a century in civil and mechanical engineering, but, for many (recent) applications, these techniques are too...
Conference Paper
Full-text available
Metamaterials have recently emerged and shown potential as lightweight and compact noise and vibration solutions. By adding or embedding resonant structures to or in a flexible host structure on a sub-wavelength scale, stop bands can be created, which enable frequency ranges of strong vibration and noise attenuation. These often periodic structures...
Article
Locally resonant metamaterials have recently emerged and gained attention in the field of noise control engineering. The addition of resonant structures to a flexible partition on a sub-wavelength scale enables a targeted frequency range of strongly reduced vibration and sound transmission. These structures have been widely studied and are typicall...
Conference Paper
Cup-shaped components, besides being basic forming objects, are also important for investigating the complex real-time behaviour of sheet metal components. Initial experimental investigations of cylindrical cups of same geometrical dimensions but produced with different blank holding forces (BHF) revealed significantly altered dynamic behaviour. Th...
Article
Full-text available
The purpose of this work is to check if additive manufacturing technologies are suitable for reproducing porous samples designed for sound absorption. The work is an inter-laboratory test, in which the production of samples and their acoustic measurements are carried out independently by different laboratories, sharing only the same geometry codes...
Article
Full-text available
The present work deals with multi-layer rectangular core topology systems built up by stacking layers made of different rectangular core geometries. Multi-layer systems have been intensively studied in terms of mechanical performances whereas their vibroacoustic behavior, acoustic efficiency and design is however still an open issue. Several design...
Article
Metamaterials have been proven to hold potential to enhance the Noise, Vibration and Harshness (NVH) performance in several applications, as they can create stop bands, which lead to frequency zones of pronounced noise and/or vibration attenuation. This paper investigates the influence of the footprint between resonant inclusions and host structure...
Article
Double panel partitions with a foam core suffer a poor sound transmission loss at their mass-spring-mass resonance frequency. This paper considers the use of vibro-acoustic resonant metamaterials to improve the acoustic insulation performance at the frequency region of this resonance while adding only 8% of mass to the double panel, hence maintaini...
Article
Full-text available
The implementation of increasingly complex periodic structures for vibro-acoustic purposes in civil engineering and transportation industry creates new modeling and computational challenges, mainly due to the multi-scale nature of the structures. Homogenization techniques able to describe the local dynamics effects appearing in periodic structures...
Article
Boundary Element Method frequency sweep analyses in acoustics are usually accompanied by a vast numerical cost of assembling and solving numerous linear systems. In that context, this work proposes a model order reduction technique to mitigate the resulting computational cost of such analyses. First, a series expansion of the Green’s function BEM k...
Article
This paper investigates the influence of the boundary conditions on the stop band effect in finite locally resonant metamaterial beams. In a first step, a Timoshenko beam with tuned vibration absorbers is used to describe a metamaterial beam. The influence of different boundary conditions for beams with different lengths as well as of tuned vibrati...
Article
This paper presents a second order optimization method based on the WFEM framework that enables the optimization of finite 1D periodic structures and 2D infinite ones. While optimization at the unit cell level has been done in previous studies, it did not account for the boundary conditions and excitation on the system, which might have an importan...
Article
This study presents the performance and the potential use of an isogeometric indirect variational boundary element method (IGiBEM) for industrial acoustics applications. The method is validated against semi-analytical frequency response solutions for a basic problem. After being validated, the performance of the IGiBEM is tested and benchmarked aga...
Article
In this work a method for the virtual sensing of the acoustic intensity is derived for exterior vibro-acoustic radiation of a complex deepdrawn structure. The proposed method estimates the acoustic intensity and acoustic pressure resulting from structural excitation in the full acoustic domain, by utilizing a model-based state estimator in the form...
Article
This paper discusses the design and validation of a thermoformed locally resonant metamaterial panel tuned to attenuate the excitation of the first acoustic mode of a cavity. Moreover, it brings resonant metamaterials closer to industrial realisations by exploiting a cheap and widely used production process. The concept is explained, and it is show...
Article
A non-destructive testing strategy is proposed that combines microphone measurements and structural measurements in one array. The aim is to lower the total inspection time by reducing the number of structural sensors. This is possible by making use of the easier and faster installation of microphones as compared to structural sensors. Structural s...
Article
A parametric model order reduction scheme is presented for second order systems that does not require a priori sampling of the parameter space. The proposed scheme transfers the parameter dependence to the throughput matrix of the dynamic system by using an auxiliary input matrix. The resulting model can thus be reduced with non-parametric model re...
Article
Vibro-acoustic locally resonant metamaterials with structural stop band behaviour can lead to a strongly increased sound transmission loss in a targeted frequency range. This work assesses the impact of damping in the constituents of metamaterial plates on their acoustic insulation performance by means of infinite periodic and finite structure mode...
Conference Paper
Over the past decades, automotive companies have sought lightweight and performant noise, vibration and harshness (NVH) solutions to comply with stringent regulations for CO2 emissions and noise pollution. Combining lightweight design with improved NVH solutions is often a challenging task: low mass and high stiffness materials are generally charac...
Conference Paper
Full-text available
At low frequencies the acoustic field in a reverberation room is not diffuse, and it should therefore be modeled by means of a deterministic approach. In this work, a finite element model was developed to include the modal behavior of the room. Dissipation in the empty reverberation room is taken into account by means of a volumetric approach, usin...
Conference Paper
Full-text available
The bending wave stop band behavior of locally resonant metamaterial and phononic crystal plates can strongly improve the vibration performance of flexible plates in targeted frequency ranges. Their acoustic insulation performance, however, is found to strongly depend on the stop band mechanism, also influencing the frequency range of improvement....
Conference Paper
Stringent regulations for CO2 emissions and noise pollution reduction demand lighter and improved Noise, Vibration Harshness (NVH) solutions in automotive industries. Designing light, compact and, at the same time, improved NVH solutions is often a challenge, as low noise and vibration levels often require heavy and bulky additions, especially to b...
Article
This paper investigates a metamaterial solution for efficient vibration attenuation and acoustic radiation reduction of an aluminum pipe. To this end, using unit cell predictions, locally resonant structures are designed to have a pronounced flexural resonance frequency at the vicinity of a dominant vibration mode of the pipe. A direct approach of...
Article
Full-text available
This work discusses many practical and some theoretical aspects concerning modelling and design of plates with micro-slits, involving multi-scale calculations based on microstructure. To this end, useful mathematical reductions are demonstrated, and numerical computations are compared with possible analytical estimations. The numerical and analytic...
Article
Full-text available
To enhance the sound insulation performance of double panel partitions at their mass-air-mass resonance frequency, novel compact and low-mass solutions are sought. This paper investigates the use of the locally resonant vibro-acoustic metamaterial concept as a possible solution. The metamaterial solution is applied to one panel of a double panel pa...
Article
A novel method is presented that detects the proper boundary conditions of a test setup in a short time period by combing numerical models with experimental data. This allows for detection and localization of possible anomalies in the assumed boundary conditions of the system. The method works by combining a low-rank parametric model order reductio...
Chapter
Full-text available
While Krylov based model order reduction for vibro-acoustic systems has been shown to be an effective method when only a single input is considered, the method has been reported to yield big models for systems with many inputs. New developments, such as the tangential iterative Krylov algorithm show that it might be possible to still reduce the sys...
Conference Paper
The vibration and noise amplitude levels at resonance frequency depends on the amount of damping present in the component. In this work, damping enhancement is achieved through a cold working process like shot peening. The residual stress measurements—using X-ray diffraction technique—and vibro-acoustic property measurements of a sheet metal plate...
Conference Paper
Metamaterials have shown great potential as lightweight and performant vibro-acoustic solutions. Made from conventional materials, metamaterials exhibit stop band behavior resulting from the dynamic interaction between a host structure and its resonant additions on a subwavelength scale. In these stop bands, metamaterials outperform common vibro-ac...
Conference Paper
Full-text available
In this work, harmonic and temporal responses of structures composed of 1D periodic waveguides are computed using the wave finite element method framework (WFEM) in conjunction with model order reduction (MOR) methods. First, a model order reduction strategy at the unit cell level is introduced and extended to parametric model order reduction (PMOR...
Conference Paper
Full-text available
In recent years, extensive research has been carried out on dynamic homogenization approaches. Most of them are based on an analytical formulation of the equivalent medium and their validity is limited to low frequencies and availability of a dynamic description of the heterogonous medium. In this paper, a two-step homogenization method is develope...
Conference Paper
Full-text available
In this paper, we focus on multi-layer core topology systems which consists in piling up layers made by different kind of cores and offers innovative solutions to periodic structures design. The main objective of this study is to analyze the phenomena occurring in these multilayer core topologies, and then compare the numerical models with experime...