An inverse method for design and characterisation of acoustic materials

Huina Mao,Romain Rumpler,Peter Göransson

doi:10.1051/matecconf/201930402002

Huina Mao, Romain Rumpler + Show 1 more

Open Access

https://doi.org/10.1051/matecconf/201930402002

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Abstract

This paper presents applications of an inverse method for the design and characterisation of anisotropic elastic material properties of acoustic porous materials. Full field 3D displacements under static surface loads are used as targets in the inverse estimation to fit a material model of an equivalent solid to the measurement data. Test cases of artificial open-cell foams are used, and the accuracy of the results are verified. The method is shown to be able to successfully characterise both isotropic and anisotropic elastic material properties. The paper demonstrates a way to reduce costs by characterising material properties based on the design model without a need for manufacturing and additional experimental tests.

Highlights

Acoustic materials are popular in the industry for sound absorption, soundproof, sound wave manipulation, etc
The properties of lightweight porous materials are highly dependent on the microstructure and geometry, possibly holding anisotropy in the macroscopic properties of the material in production process or design, as the melamine foam with non-zero shear-compression coupling moduli and negative Poisson's ratio [5]
The results indicate that the modification of specific struts in the open-cell geometry, e.g., changing cross-section areas, could provide a way to tune the moduli of the anisotropic Hooke's matrix

Summary

Introduction

Acoustic materials are popular in the industry for sound absorption, soundproof, sound wave manipulation, etc. Porous materials are one of the most used for sound absorption [1]. The majority of the studies to date have concentrated on conventional porous materials of equivalent isotropic or transverse isotropic [2,3,4]. Some applications require porous acoustic materials exhibiting anisotropic behaviour in certain direction. E.g., anisotropic acoustic metamaterials designed to manipulate sound waves [6]. The progress observed in manufacturing technologies, such as 3-D Printer, micro- and nanomanufacturing techniques, open a door to design artificial materials for specific mechanical applications, and motivate the characterisation of anisotropic materials by giving designed model. The few studies of artificial porous materials have not provided a way to guide the design of acoustic foams based on the application functions. Developing or applying a method that can characterise the material properties during early design phases becomes critical

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