scholarly journals An inverse method for design and characterisation of acoustic materials

2019 ◽  
Vol 304 ◽  
pp. 02002
Author(s):  
Huina Mao ◽  
Romain Rumpler ◽  
Peter Göransson
Keyword(s):  
Elastic Material ◽  
Material Properties ◽  
Inverse Method ◽  
Measurement Data ◽  
Experimental Tests ◽  
Material Model ◽  
Full Field ◽  
Inverse Estimation ◽  
Anisotropic Elastic ◽  
Anisotropic Elastic Material

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.

Linear Anisotropic Elastic Materials

1996 ◽  
Author(s):  
T. T. C. Ting
Keyword(s):  
Elastic Constants ◽  
Elastic Material ◽  
Positive Definite ◽  
Material Symmetry ◽  
Two Dimensional ◽  
Elastic Materials ◽  
Rectangular Coordinate System ◽  
Full Symmetry ◽  
Anisotropic Elastic ◽  
Anisotropic Elastic Material

The relations between stresses and strains in an anisotropic elastic material are presented in this chapter. A linear anisotropic elastic material can have as many as 21 elastic constants. This number is reduced when the material possesses a certain material symmetry. The number of elastic constants is also reduced, in most cases, when a two-dimensional deformation is considered. An important condition on elastic constants is that the strain energy must be positive. This condition implies that the 6×6 matrices of elastic constants presented herein must be positive definite. Referring to a fixed rectangular coordinate system x1, x2, x3, let σij and εks be the stress and strain, respectively, in an anisotropic elastic material. The stress-strain law can be written as . . . σij = Cijksεks . . . . . .(2.1-1). . . in which Cijks are the elastic stiffnesses which are components of a fourth rank tensor. They satisfy the full symmetry conditions . . . Cijks = Cjiks, Cijks = Cijsk, Cijks = Cksij. . . . . . .(2.1-2). . .

Asymptotic Field Near the Tip of a Debonded Anticrack in an Anisotropic Elastic Material

2020 ◽  
Vol 73 (1) ◽  
pp. 76-83
Author(s):  
Xu Wang ◽  
Peter Schiavone
Keyword(s):  
Stress Intensity ◽  
Elastic Material ◽  
Stress Intensity Factors ◽  
Orthotropic Materials ◽  
Intensity Factors ◽  
Power Type ◽  
Material Force ◽  
Real Power ◽  
Anisotropic Elastic ◽  
Anisotropic Elastic Material

Summary We use the sextic Stroh formalism to study the asymptotic elastic field near the tip of a debonded anticrack in a generally anisotropic elastic material under generalised plane strain deformations. The stresses near the tip of the debonded anticrack exhibit the oscillatory singularities $r^{-3/4\pm i\varepsilon }$ and $r^{-1/4\pm i\varepsilon }$ (where $\varepsilon $ is the oscillatory index) as well as the real power-type singularities $r^{-3/4}$ and $r^{-1/4}$. Two complex-valued stress intensity factors and two real-valued stress intensity factors are introduced to respectively scale the two oscillatory and two real power-type singularities. The corresponding three-dimensional analytic vector function is derived explicitly, and the material force on the debonded anticrack is obtained. Our solution is illustrated using an example involving orthotropic materials.

scholarly journals Normal shock reflection-transmission in rubber-like elastic material

1989 ◽  
Vol 31 (1) ◽  
pp. 29-47
Author(s):  
S. Kosinski ◽  
B. Duszczyk
Keyword(s):  
Shock Wave ◽  
Elastic Material ◽  
Material Properties ◽  
Inverse Method ◽  
Simple Wave ◽  
Plane Interface ◽  
Shock Reflection ◽  
Normal Shock ◽  
Reflected Wave ◽  
Unbounded Medium

AbstractA finite transverse shock wave propagates through an unbounded medium consisting of two joined incompressible elastic half-spaces of different material properties, in the direction normal to the plane interface. A semi-inverse method is used to examine the reflection-transmission of this wave at the interface. It is found that, depending on the material properties, the reflected wave is either a simple wave or a shock; the transmitted wave is always a shock.

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