Finite Element Vibration Analysis of Laminated Composite Folded Structures With a Channel Section using a High-order Shear deformation Plate Theory

고차전단변형 판이론을 이용한 채널단면을 갖는 복합적층 절판 구조물의 유한요소 진동 해석

  • 유용민 (서울시립대학교 토목공학과) ;
  • 장석윤 (서울시립대학교 토목공학) ;
  • 이상열 (MIT토목환경공학과)
  • Published : 2004.03.01

Abstract

This study deals with free vibrations of laminated composite structures with a channel section using finite element method. In this paper, the mixed finite element method using Lagrangian and Hermite interpolation functions is adopted and a high-order plate theory is used to analyze laminated composite non-prismatic folded plates with a channel section more accurately for free vibration. The theory accounts for parabolic distribution of the transverse shear stress and requires no shear correction factors supposed in the first-order plate theory. An 32×32 matrix is assembled to transform the system element matrices from the local to global coordinates using a coordinate transformation matrix, in which an eighth drilling degree of freedom (DOF) per node is appended to the existing 7-DOF system. The results in this study are compared with those of available literatures for the conventional and first-order plate theory. Sample studies are carried out for various layup configurations and length-thickness ratio, and geometric shapes of plates. The significance of the high-order plate theory in analyzing complex composite structures with a channel section is enunciated in this paper.

본 연구에서는 유한요소법을 이용한 채널단면을 갖는 복합재료 적층 구조물의 자유진동을 다룬다. 복합적층 절판구조물에 고차항 판이론을 적용하기 위하여 개발된 유한요소 프로그램은 Lagrangian 및 Hermite 보간함수를 병용하여 면내회전각 자유도를 포함한 절점 당 8개의 자유도를 갖는다. 전단보정계수의 가정을 필요로 하지 않고 전단변형의 3차항 비선형 특성이 고려된 본 논문의 절판 요소는 국부좌표계와 전체좌표계에 대한 좌표변환행렬에 의하여 요소 당 32×32의 국부요소행렬로 구성된다. 본 해석 프로그램의 결과는 기존의 고전적 이론 및 일차항 이론에 의한 문헌 결과와 비교ㆍ분석하였으며, 화이버 보강각도, 길이-두께비, 기하학적 형상 변화 등의 다양한 매개변수 연구를 수행하였다. 본 연구에서는 특히 경계조건 및 길이-두께비 변화에 따라 예측하기 힘든 복잡한 거동을 보이는 복합적층 채널단면 구조물의 자유진동에 대하여 정밀한 고차항 이론 적용에 의한 엄밀 해석의 필요성을 제기하였다.

Keywords

References

  1. J. E. Goldberg and H. L. Leve, 'Theory of prismatic folded plate structures', Int. Association for Bridge and Structural Engineering J., Vol. 17, 1957
  2. T. Irie, G. Yamada and Y. Kobayashi, 'Free vibration of a cantilever folded plate', J. of the Acoustical Society of America, Vol. 76, No. 6 1984, pp.1743-1748 https://doi.org/10.1121/1.391622
  3. B. W. Golley and W. A. Grice, 'Prismatic folded plate analysis using finite strip element', Computer Methods in Applied Mechanics and Engineering, Vol. 76, 1989, pp.101-118 https://doi.org/10.1016/0045-7825(89)90090-X
  4. A. N. Danial, J. E. Doyle and S. A. Rizzi, 'Dynamic analysis of folded platestructures', J. of Vibration and Acoustics, Vol. 118, 1996, pp.591-598 https://doi.org/10.1115/1.2888339
  5. W. H. Liu and C. C. Huang, 'Vibrationanalysis of folded plates', J. of Sound and Vibration, Vol. 157, No. 1, 1992, pp.123-137 https://doi.org/10.1016/0022-460X(92)90570-N
  6. Nihal Eratli and A. Yalcin Akoz(2002), 'Mixed finite element formulation for foldedplates', Structural Engineering and Mechanics, Vol. 13, No. 2, 2002, pp.155-170 https://doi.org/10.12989/sem.2002.13.2.155
  7. K. J. Bathe, Finite Element Procedures in Engineering Analysis, Englewood Cliff
  8. O. C. Zienkiewicz and R. L. Taylor, The Finite Element Method, Vol. 2, 4th edition, McGraw- Hill, 1991
  9. A Guha Niyogi, M. K. Laha and P. K. Sinha, 'Finite element vibration analysis of laminated composite folded plate structures' Shock and Vibration, Vol. 6, No. 5/6, 1997, pp.273-284
  10. K. H. Lo, R. M. Christensen and E. M. Wu, 'A higher-order theory of plate deformation, Part 1:homogeneous plates', Journal of Applied Mechanics, 1984, Vol. 44, pp. 663-668 https://doi.org/10.1115/1.3424154
  11. K. H. Lo, R. M. Christensen and E. M. Wu, 'A higher-order theory of plate deformation, Part 2:laminated plates', Journal of Applied Mechanics, Vol. 44, 1977, pp.669-676 https://doi.org/10.1115/1.3424155
  12. J. N. Reddy, 'A refined nonlinear theory of plates with transverse shear deformation', Int. J. of Solids and Structures, Vol. 20, No. 9/10, 1984, pp.881-896 https://doi.org/10.1016/0020-7683(84)90056-8
  13. J. N. Reddy, 'A simple higher-order theory for laminated composite plates', Journal of Applied Mechanics, Vol. 51, 1984, pp.745-752 https://doi.org/10.1115/1.3167719
  14. J. N. Reddy, 'A general non-linear third-order theory of plates with moderate thickness', Int. J. of Non-Linear Mechanics, Vol. 25, No. 6, 1990, pp.677-686 https://doi.org/10.1016/0020-7462(90)90006-U
  15. T. Kant, J. H. Varaiya and C. P. Arora(1990), 'Finite element transient analysis of composite and sandwich plates based on are fined theory and implicit time integration schemes', Computers and Structures, Vol. 36, No. 3, 1990, pp.401-420 https://doi.org/10.1016/0045-7949(90)90279-B
  16. C. Meimaris and J. D. Day, 'Dynamic response of laminated anisotropic plates', Computers and Structures, Vol. 55, No. 2, 1995, pp.269-278 https://doi.org/10.1016/0045-7949(94)00452-9
  17. D. K. Maiti and P. K. Sinha, 'Impact response of doubly curved laminated composite shells using higher-order shear deformation theories', Int. J. of Reinforced Plastics and Composites, Vol. 15, No. 6, 1996, pp.575-601
  18. J. N. Reddy, Mechanics of Laminated Composite Plate, CRC Press. 1997
  19. 한성천, 윤석호, 장석윤, '비등방성 복합적층판 및 쉘의 고차전단변형을 고려한 비감쇄 동적응답', 한국강구조학회, Vol. 9, No. 3, 1997, pp.333-340
  20. 유용민, 이상열, 장석윤, '고차 전단변형 이론을 이용한 임의의 각도를 갖는 비등방성 절판 구조물의 안정성', 대한토목학회, Vol. 23, No. 3-A, 2003, pp 527-535
  21. 이상열, 백한솔, 장석윤, '비등방성 복합적층판의 고유진동 및 모드특성에 대한 수치비교연구', 대한토목학회, Vol. 20, No. 3-A, 2000, pp.357-366