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Efficacy of Drilling Degrees of Freedom in the Finite Element Modeling of P-and SV-Wave Scattering Problems

Published online by Cambridge University Press:  05 May 2011

Jaehwan Kim ,
Vasundara V. Varadan  and
Vijay K. Varadan
Jaehwan Kim*
Affiliation:
Department of Mechanical Engineering, Inha University 253 Yonghyun-Dong, Nam-Ku, Incheon 402-751, Korea
Vasundara V. Varadan*
Affiliation:
Department of Engineering Science & Mechanics, The Pennsylvania State University, University Park, PA 16802, U.S.A.
Vijay K. Varadan*
Affiliation:
Department of Engineering Science & Mechanics, The Pennsylvania State University, University Park, PA 16802, U.S.A.
*
*Professor
*Professor
*Professor
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Abstract

This paper deals with a hybrid finite element method for wave scattering problems in infinite domains. Scattering of waves involving complex geometries, in conjunction with infinite domains is modeled by introducing a mathematical boundary within which a finite element representation is employed. On the mathematical boundary, the finite element representation is matched with a known analytical solution in the infinite domain in terms of fields and their derivatives. The derivative continuity is implemented by using a slope constraint. Drilling degrees of freedom at each node of the finite element model are introduced to make the numerical model more sensitive to the transverse component of the elastodynamic field. To verify the effects of drilling degrees freedom and slope constraints individually, reflection of normally incident P and SV waves on a traction free half space is considered. For P-wave incidence, the results indicate that the use of a slope constraint is more effective because it suppresses artificial reflection at the mathematical boundary. For the SV-wave case, the use of drilling degrees of freedom is effective in reducing numerical error at the irregular frequencies.

Keywords

Finite element modeling of infinite domainsNonabsorbing boundary conditiondrilling degrees of freedomWave scattering problems
Type
Articles
Information
Journal of Mechanics , Volume 16 , Issue 2 , June 2000 , pp. 103 - 108
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2000

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