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A Hybrid Method for Analyzing the Dynamic Responses of Cavities or Shells Buried in an Elastic Half-Plane

Published online by Cambridge University Press:  05 May 2011

Chau-Shioung Yeh*
Affiliation:
Department of Civil Engineering, Institute of Applied Mechanics, National Taiwan University, Tainan, Taiwan 10617, R.O.C.
Tsung-Jen Teng*
Affiliation:
National Center for Research on Earthquake Engineering, Tainan, Taiwan 106, R.O.C.
Wen-Shinn Shyu*
Affiliation:
Department of Civil Engineering, National Taiwan University, Tainan, Taiwan 10617, R.O.C.
I-Chang Tsai*
Affiliation:
Chung-Shan Institute of Science & Technology, Tao-Yuan, Taiwan 320, R.O.C.
*
* Professor
** Research Fellow
*** Graduate student
**** Senior Specialist
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Abstract

In this paper, based on a variational formalism which originally proposed by Mei [1] for infinite elastic medium and extended by Yeh, et al. [2,3] for elastic half-plane, a hybrid method which combines the finite element and series expansion method is implemented to solve the diffraction of plane waves by a cavity buried in an elastic half-plane. The finite domain which encloses all inhomogeneities including the cavity can be easily formulated by finite element methods. The unknown boundary data obtained by subtracting the known free fields from the total fields which include the boundary nodal displacements and tractions at the interface between the finite domain and the surrounding elastic half-plane are not independent of each other and can be correlated through a series representation. Due to the continuity condition at the interface, the same series representation is still valid for the exterior elastic half-plane to represents the scattered wave. The unknown coefficients of this series are treated as generalized coordinates and can be easily formulated by the same variational principle. The expansion function of the series is composed of basis function. Each basis function is constructed from the basis function for an infinite plane by superimposing an additional homogeneous reflective term to satisfy both traction free conditions at ground surface and radiation conditions at infinity. The numerical results are made against those obtained by boundary element methods, and good agreements are found.

Type
Articles
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2002

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References

[1]Mei, C. C., “Boundary Layer and Finite Element Techniques Applied to Wave Problem,” Acoustic, Electromagnetic and Elastic Wave Scattering—Focus on the T-Matrix Approach, edited by Varadan, V. V. and Vardan, V. K., Pergamon, New York (1980).Google Scholar
[2]Yeh, C. S., Teng, T. J., Shyu, W. S. and Liao, W. I., “A Hybrid Method to Solve the Half-Plane Radiation Problem–Numerical Verification,” 2000 ASME Pressure Vessels and Piping Conference., PVP-402-2, Seismic Engineering 2000 Volume 2, ASME 2000, pp. 145149 (2000).Google Scholar
[3]Yeh, C. S., Teng, T. J., Shyu, W. S. and Liao, W. I., “A Hybrid Method for Wave Diffraction by a Semi-Cylindrical Alluvial Valley,” The First International Conference on Structural Stability and Dynamics, Dec. 7∼9, Taipei, Taiwan, pp. 189198 (2000).Google Scholar
[4]Lee, V. W. and Trifunac, M. D., “Response of Tunnels to Incident SH-Waves,” J. of Eng. Mech., ASCE, 105, pp. 643659 (1979).Google Scholar
[5]Balendra, T. D. P., Thambiratnam, C. G.Koh, and Lee, S. L., “Dynamic Response of Twin Circular Tunnels Due to Incident SH-Waves,“Earthquake Engng. Struct. Dyn., 12, pp. 181201 (1984).CrossRefGoogle Scholar
[6]El-Akily, N. and Datta, S. K., “Response of Circular Cylindrical Shell to Disturbances in Half-Space,” Earthquake Engng. Struct. Dyn., 8, pp. 469477 (1980).CrossRefGoogle Scholar
[7]Datta, S. K., Shah, A. H. and Wong, K. C., “Dynamic Stresses and Displacements in Buried Pipe,” J. of Eng. Mech., ASCE, 110, pp. 14511466 (1984).Google Scholar
[8]Wong, K. C., Shah, A. H. and Datta, S. K., “Dynamic Stresses and Displacements in Buried Tunnel,” J. of Eng. Mech., ASCE, 111, pp. 218234 (1984).Google Scholar
[9]Luco, J. E. and de Barros, F. C. P., “Seismic Response of Cylindrical Shell Embedded in a Layered Viscoelastic Half-Space, I. Formulation,” Earthquake Engng. Struct. Dyn., 23, pp. 553560 (1994).Google Scholar
[10]Yeh, C. S., Teng, T. J. and Tsai, I. C., “Dynamic Response of a Cavity in an Elastic Half Plane Subjected to P-wave,” Proc. of the 5th KU-KAIST-NTU, Tri-Lateral Seminar/Workshop on Civil Engineering, Taipei, Taiwan, ROC, pp. 1924 (1995).Google Scholar
[11]Yeh, C. S., Teng, T. J., Liao, W. I. and Tsai, I. C., “A Series Solution for Dynamic Response of a Cylindrical Shell in an Elastic Half-Space,” 3th National Conference on Structure Engineering, Kenting, Taiwan, ROC, pp. 15531562 (1996).Google Scholar
[12]Chen, H. S. and Mei, C. C., “Oscillations and Wave Forces in a Manmade Harbor in the Open Sea,” Proc, 10th Symp. Naval Hydrody, Cambridge, Mass. pp. 573596 (1974).Google Scholar
[13]Pao, Y. H., “The Transtion Matrix for the Scattering of Acoustic Waves and for Elastic Waves,” Proceedings of the IUTAM Symposium on Modern Problems in Elastic Wave Propagation, edited by Miklowitz, J. and Achenback, J., Wiley-Interscience, New York (1978).Google Scholar
[14]Yeh, C. S., Teng, T. J. and Liao, W. I., “On Evaluation of Lamb's Integrals for Waves in a Two-Dimensional Elastic Half-Space,” The Chinese Journal of Mechanics, 16(2), pp. 109124, and Erratum, The Chinese Journal of Mechanics, 16(3), p. 177 (2000).Google Scholar
[15]Aranha, J. A., Mei, C. C. and Yue, D. K. P., “Some Properties of a Hybrid Element Method for Water Waves,” Int. Journal of Numerical Methods in Engineering, 14, pp. 16271641 (1979).CrossRefGoogle Scholar
[16]Watson, G. N., A Treatise on the Theory of Bessel Function, 2nd ed., Cambridge University Press (1966).Google Scholar
[17]Luco, J. E. and de Barros, F. C. P., “Seismic Response of Cylindrical Shell Embedded in a Layered Viscoelastic Half-Space, II. Validation and Numerical Results,” Earthquake Engng. Struct. Dyn., 23, pp. 561580 (1994).CrossRefGoogle Scholar