Towards Improved Finite Element Modelling of the Interaction of Elastic Waves With Complex Defect Geometries

Rajagopal, Prabhu; Drozdz, M.; Lowe, M. J. S.

doi:10.1063/1.3114296

Cited by 5 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Free meshing algorithms using linear tetrahedral elements (C3D4 in Abaqus) are commonly used for the 3D FE modelling of scattering from obstacles with irregular geometries [24,25]. As is well known, free meshing tends to randomize the distribution and the shape of each element, and thus may introduce unwanted mesh-scattering and dispersion [26]. We therefore combine two different meshing algorithms in three dimensions with a code developed using Matlab (MathWorks, Natick, MA, USA).…”

Section: (B) Simulations Using Three-dimensional Rough Surfacesmentioning

confidence: 99%

“…As is well known, free meshing tends to randomize the distribution and the shape of each element, and thus may introduce unwanted mesh-scattering and dispersion [26]. We therefore combine two different meshing algorithms in three dimensions with a code developed using Matlab (MathWorks, Natick, MA, USA).…”

Section: (B) Simulations Using Three-dimensional Rough Surfacesmentioning

confidence: 99%

See 1 more Smart Citation

The validity of Kirchhoff theory for scattering of elastic waves from rough surfaces

2015

Self Cite

View full text Add to dashboard Cite

The Kirchhoff approximation (KA) for elastic wave scattering from two-dimensional (2D) and three-dimensional (3D) rough surfaces is critically examined using finite-element (FE) simulations capable of extracting highly accurate data while retaining a fine-scale rough surface. The FE approach efficiently couples a time domain FE solver with a boundary integration method to compute the scattered signals from specific realizations of rough surfaces. Multiple random rough surfaces whose profiles have Gaussian statistics are studied by both Kirchhoff and FE models and the results are compared; Monte Carlo simulations are used to assess the comparison statistically. The comparison focuses on the averaged peak amplitude of the scattered signals, as it is an important characteristic measured in experiments. Comparisons, in both two dimensions and three dimensions, determine the accuracy of Kirchhoff theory in terms of an empirically estimated parameter σ 2 /λ 0 ( σ is the RMS value, and λ 0 is the correlation length, of the roughness), being considered accurate when this is less than some upper bound c , ( σ 2 /λ 0 < c ). The incidence and scattering angles also play important roles in the validity of the Kirchhoff theory and it is found that for modest incidence angles of less than 30°, the accuracy of the KA is improved even when σ 2 /λ 0 > c . In addition, the evaluation results are compared using 3D isotropic rough surfaces and 2D surfaces with the same surface parameters.

show abstract

Section: (B) Simulations Using Three-dimensional Rough Surfacesmentioning

confidence: 99%

Section: (B) Simulations Using Three-dimensional Rough Surfacesmentioning

confidence: 99%

The validity of Kirchhoff theory for scattering of elastic waves from rough surfaces

2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…As computational ability has increased over the past few decades, numerical methods for modelling such as the Finite Element (FE) method have become widely used for that purpose. The FE method is particularly well suited for the case with a structure of complex geometrical shape and has also benefited from new developments [1][2][3][4]. However, in spite of the advantages, the data size for the method often leads to a problem, for example, in modelling a whole component, particularly when an irregular defect is of interest, needing a very fine mesh.…”

Section: Introductionmentioning

confidence: 97%

Generic hybrid models for three-dimensional ultrasonic NDE

Skelton¹,

Lowe²,

Rajagopal³

2012

AIP Conference Proceedings

Self Cite

View full text Add to dashboard Cite

“…This can be extracted from the total field at the destination box by two processing methods: we could allow for the dimensions of the box to be large so that the incident and scattered components are separated in time, or we could subtract out the incident component from the total signal (see [13] for a more detailed discussion of these two processing approaches). The separation method usually requires larger dimensions than the subtraction method, which theoretically just requires a very small destination box for the FE calculation of the total field.…”

Section: B Back-scatteringmentioning

confidence: 99%

“…Solutions to some key past impediments to the numerical modelling of wave phenomena, such as representing unbounded domains or complex features and geometries have now become accessible to the wider community via Perfectly Matched Layers and absorbing layers [4], [8]- [11] and have been directly implemented in commercial packages [12], [13]. However, these methods still lead to an enormous computational cost when dealing with large volumes of material and representing complex materials; modelling realistic transduction also remains a challenge.…”

Section: Introductionmentioning

confidence: 99%

A generic hybrid model for bulk elastodynamics, with application to ultrasonic nondestructive evaluation

Rajagopal

Skelton

Lowe

2012

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

Self Cite

View full text Add to dashboard Cite

Practical ultrasonic inspection requires modeling tools that enable rapid and accurate visualisation; due to the increasing sophistication of practical inspection it is becoming increasingly difficult to use a single modelling method to represent an entire inspection process. Hybrid models that utilize different or interacting numerical schemes in different regions, to use their relative advantages to maximal effect, are attractive in this context, but are usually custommade for bespoke applications or sets of modelling methods. The limitation of hybrid schemes to particular modelling techniques is shown here to be related to their fundamental formulation. As a result it becomes clear that a formalism to generalize hybrid schemes can be developed: an example of how such a generic hybrid modelling interface is constructed is illustrated for the abstraction of bulk ultrasonic wave phenomena, common in practical inspection problems. This interface is then adapted to work within a prototype hybrid model consisting of two smaller Finite Element model-domains, and explicitly demonstrated for bulk ultrasonic wave propagation and scattering examples.Sources of error and ways of improving the accuracy of the interface are also discussed.

show abstract

Towards Improved Finite Element Modelling of the Interaction of Elastic Waves With Complex Defect Geometries

Cited by 5 publications

References 0 publications

The validity of Kirchhoff theory for scattering of elastic waves from rough surfaces

The validity of Kirchhoff theory for scattering of elastic waves from rough surfaces

Generic hybrid models for three-dimensional ultrasonic NDE

A generic hybrid model for bulk elastodynamics, with application to ultrasonic nondestructive evaluation

Contact Info

Product

Resources

About