International Journal of Advanced Culture Technology

The International Promotion Agency of Culture Technology (국제문화기술진흥원)
권호 표지
DOI QR코드

DOI QR Code

Acoustic Estimation of Phase Velocity of Closed-Cell Kelvin Structure based on Spectral Phase Analysis

  • Kim, Nohyu (Dept. of Mechatronics Engineering, Korea Univ. of Technology and Education)
  • Received : 2022.07.31
  • Accepted : 2022.09.05
  • Published : 2022.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, the effect of porosity on the acoustic phase velocity of the 3D printed Kelvin closed-cell structure was investigated using the spectral phase analysis. Since Kelvin cells bring about the large amount of scattering, acoustic pulses in ultrasonic measurements undergoes a distortion of waveforms due to the dispersion effect. In order to take account on the dispersion, mathematical expressions for calculating the phase velocity of longitudinal waves propagating normal to the plane of the Kelvin structure are suggested by introducing a complex wave number based on Fourier transform. 3D Kelvin structure composed of identical unit-cells, a polyhedron of 14 faces with 6 quadrilateral and 8 hexagonal faces, was developed and fabricated by 3D CAD and 3D printer to represent the micro-structure of porous materials such as aluminum foam and cancellous bone. Total nine samples of 3D Kelvin structure with different porosity were made by changing the thickness of polyhedron. Ultrasonic pulse of 1MHz center frequency was applied to the Kelvin structures for the measurement of the phase velocity of ultrasound using the TOF(time-of-flight) and the phase spectral method. From the experimental results, it was found that the acoustic phase velocity decreased linearly with the porosity.

Keywords

Acknowledgement

This work was supported by the Technology Development Program (S3060576, Tech-Bridge) of the Ministry of SMEs and Startups(MSS, Korea) in 2021 and also by Education and Research Promotion Program of KOREATECH in 2022.

References

  1. Kumar, P., Investigation of Kelvin-like solid foams for potential engineering applications: An attractive set of geometrical and thermo-hydraulic properties, Ph. D thesis, Department of Mechanical Engineering, Aix-Marseille University, France, 2014, DOI:https://doi.org/10.48550/arXiv.1501.05333
  2. Gabbrielli, R., Foam geometry and structural design of porous material, Ph. D thesis, Department of Mechanical Engineering, University of Bath, England, 2009.
  3. Sullivan, R. M., Ghosn, L. J., Lerch, B. A., "Application of an Elongated Kelvin Model to Space Shuttle Foams", Journal of Spacecraft and Rockets, Vol. 46, No. 2, pp. 411-418, 2009, DOI: https://doi.org/10.2514/1.37555
  4. Ryan, G., Pandit, A. and Apatsidis, D. P., "Fabrication methods of porous metals for use in orthopaedic applications", Biomaterials, Vol. 27, No. 13, pp. 2651-2670, 2006, DOI: https://doi.org/10.1016/j.biomaterials.2005.12.002
  5. Sullivan, R. M., Ghosn, L. J., Lerch, B. A., "A general tetrakaidecahedron model for open-celled foams", International Journal of Solids and Structures, Vol. 45, pp.1754-1765, 2011, DOI: https://doi.org/10.1016/j.ijsolstr.2007.10.028
  6. Tekoglu, C., Gibson, L.J. , Pardoen, T., Onck, P.R. ,"Size effects in foams: Experiments and modeling", Progress in Materials Science, Vol. 56, pp. 109-138, 2011, DOI: https://doi.org/10.1016/j.pmatsci.2010.06.001
  7. Kim, N., Choi, M. J., "Acoustoelastic Characteristics of Kelvin-structured Model of Porous Materials", Journal of the Korean Society for Nondestructive Testing, Vol. 41, No. 6, pp. 366-373, 2021, DOI:http://dx.doi.org/10.7779/JKSNT.2021.41.6.366
  8. Kim, N., Hong, M.," Measurement of Axial Stress using Mode-Converted Ultrasound", NDT& E International, Vol. 42, Issue 3, pp. 163-169, 2009, DOI: https://doi.org/10.1016/j.ndteint.2008.09.005
  9. Nam, T., Lee, T., Kim., C., Jhang K., Kim., N., "Harmonic generation of an obliquely incident ultrasonic wave in solid-solid contact interfaces", Ultrasonics, vol.52, issue.6, pp.778-783, 2012, DOI: https://doi.org/10.1016/j.ultras.2012.02.008
  10. Jeong H. and Hsu, D. K., "Experimental analysis of porosity-induced ultrasonic attenuation and velocity change in carbon composites", Ultrasonics, vol.33, issue.3, pp.195-203, 1994, DOI: https://doi.org/10.1016/0041-624X(95)00023-V