Analytical and Numerical Study on Mechanical Behavior of Unit Cell of Pyramidal Truss Core Structures

피라미드 트러스 코어 단위셀의 기계적 특성에 관한 해석적 및 수치적 연구

  • Kim, Sang-Woo (Materials Deformation Group, Korea Institute of Materials Science) ;
  • Lee, Young-Seon (Materials Deformation Group, Korea Institute of Materials Science) ;
  • Kang, Beom-Soo (Department of Aerospace Engineering, Pusan National University)
  • 김상우 (재료연구소 변형제어연구그룹) ;
  • 이영선 (재료연구소 변형제어연구그룹) ;
  • 강범수 (부산대학교 항공우주공학과)
  • Received : 2010.10.18
  • Accepted : 2011.02.10
  • Published : 2011.05.01

Abstract

Metallic sandwich panels based on a truss core structure have been developed for a wide range of potential applications with their lightweight and multi-functionality. Structural performance of sandwich panels can be predicted from the studies on mechanical behavior of a unit cell of truss core structures. Analytical investigations on the unit cell provide approximated guidelines for the design of overall core structures for a specific application in short time. In this study, the effects of geometrical parameters on mechanical behavior of a pyramidal shape of unit cell were investigated with analytical models. The unit cell with truss member angle of 45 degree was considered as reference model and other models were designed to have the same weight and projected area but different truss member angle. All truss members were assumed to be connected with pin joint in analytical models. Under the assumptions, the equivalent strength and stiffness of the unit cell under compressive and shear loads were predicted and compared. And finally, the optimum core member angle to have maximum mechanical property could be calculated and verified with FE analysis results.

Keywords

Acknowledgement

Supported by : 한국기계연구원 부설 재료연구소

References

  1. Gibson, L. J. and Ashby, M. F., "Cellular solids: structure and properties, 2nd Ed.," Cambridge University Press, 1997.
  2. Evans, A. G., Hutchinson, J. W. and Ashby, M. F., "Multifunctionality of cellular metal systems," Progress in Materials Science, Vol. 43, No. 3, pp. 171-221, 1999.
  3. Evans, A. G., Hutchinson, J. W., Fleck, N. A., Ashby, M. F. and Wadley, H. N. G., "The topological design of multifunctional cellular metals," Progress in Materials Science, Vol. 46, No. 3-4, pp. 309-327, 2001.
  4. Lee, Y. H., Lee, B. K., Jeon, I. S. and Kang, K. J., "Wire-woven bulk Kagome truss cores," Acta Materialia, Vol. 55, No. 18, pp. 6084-6094, 2007. https://doi.org/10.1016/j.actamat.2007.07.023
  5. Jung, C. G., Seung, D. Y., Yang, D. Y., Na, S. J. and Ahn, D. G., "Development of a continuous fabrication system for a metallic sandwich plate with a threedimensional truss core," Int. J. Adv. Manuf. Technol., Vol. 45, No. 3-4, pp. 352-361, 2009. https://doi.org/10.1007/s00170-009-1964-4
  6. Despande, V. S. and Fleck, N. A., "Collapse of truss core sandwich beams in 3-point bending," Int. J. of Solids and Structures, Vol. 38, No. 36-37, pp. 6275-6305, 2001. https://doi.org/10.1016/S0020-7683(01)00103-2
  7. Despande, V. S., Fleck, N. A. and Ashby, M. F., "Effective properties of the octet-truss lattice material," J. of Mechanics and Physics of Solids, Vol. 49, No. 8, pp. 1747-1769, 2001. https://doi.org/10.1016/S0022-5096(01)00010-2
  8. Wadley, H. N. G., Fleck, N. A. and Evans, A. G., "Fabrication and structural performance of periodic cellular metal sandwich structures," Composites Science and Technology, Vol. 63, No. 16, pp. 2331-2343, 2003 https://doi.org/10.1016/S0266-3538(03)00266-5
  9. Sypeck, D. J. and Wadley, H. N. G., "Cellular metal truss core sandwich structures," Advanced Engineering Materials, Vol. 4, No. 10, pp. 759-764, 2002. https://doi.org/10.1002/1527-2648(20021014)4:10<759::AID-ADEM759>3.0.CO;2-A
  10. Wadley, H. N. G., "Cellular metal manufacturing," Advanced Engineering Materials, Vol. 4, No. 10, pp. 726-733, 2002. https://doi.org/10.1002/1527-2648(20021014)4:10<726::AID-ADEM726>3.0.CO;2-Y
  11. Xue, Z. and Huthcinson, J. W., "Constitutive model for quasi-static deformation of metallic sandwich cores," Int. J. for Numerical Methods in Engineering, Vol. 61, No. 13, pp. 2205-2238, 2004. https://doi.org/10.1002/nme.1142
  12. Hyun, S., Karlsson, A. M., Torquato, S. and Evans, A. G., "Simulated properties of Kagome and tetragonal truss core panels," Int. J. of Solids and Structures, Vol. 40, No. 25, pp. 6989-6998, 2003. https://doi.org/10.1016/S0020-7683(03)00350-0
  13. Kim, S. W., Jung, H. C., Lee, Y. S. and Kang, B. S., "Analytical approach to compression and shear characteristics of the unit cell of PCM core with pyramidal configuration," Transactions of Materials Processing, Vol. 19, No. 7, pp. 411-415, 2010. https://doi.org/10.5228/KSTP.2010.19.7.411