Abstract
In this paper, the finite element method is used to study the dynamic behavior of the damaged rotating composite blade. Three dimensional, finite element programs were developed using a nine node laminated shell as a discretization element for the blade structure (the same element type is used for damaged and non-damaged structure). In this analysis the initial stress effect (geometric stiffness) and other rotational effects except the carioles acceleration effect are included. The investigation covers the effect speed of rotation, aspect ratio, skew angle, pre-twist angle, radius to length, layer lamination and fiber orientation of composite blade. After modeling a non-damaged rotating composite blade, the work procedure was to apply different damage cases in reference to the non-damaged structure in order to compute the shift in the fundamental natural frequency and stresses. Damage occurs in several layers of the composite sheet in different locations throughout its volume, and through several layers of the sheet. The numerical results show a good agreement compared with the available investigations using other methods.
References
[2] N. G. Stephen and P. J. Wang, “Stretching and bending of rotating beam”, J. of Applied Mechanics, Transactions of the ASME, Vol. 53, PP. 869-872, December 1986.
[3] Leissa AW, Ewing MS. "Comparison of beam and shell theories for the vibrations of thin turbomachinery blades", J. Eng Power 1983; 105: 383–92.
[4] Dokainish MA, Rawtani S. "Vibration analysis of rotating cantilevered plates", Int. J. Numer. Meth. Eng. 1971;3: 233–48.
[5] Ramamurti V, Kielb R. "Natural frequencies of twisted rotating plates", J. Sound Vib 1984 ;97(3):429–49.
[6] Leissa AW, Lee JK, Huang AJ. "Vibrations of cantilevered cylindrical shallow shells having rectangular planform" J. Sound Vib 1981;78(3):311–28.
[7] Leissa AW, Lee JK, Wang AJ. "Rotating blade vibration analysis using shells", J. Eng Power 1982;104: 296–302.
[8] Leissa AW, Lee JK, Huang AJ. "Vibrations of cantilevered doublycurved shallow shells", Int. J. Solids Struct 1983; 19 (5): 411–24.
[9] Leissa AW, Lee JK, Huang AJ. "Vibrations of twisted rotating blades", ASME J. Vib Acoust Stress Reliability Des 1984; 106(2):251–7.
[10] Henry TY, Masud A, Kapania RK. "A survey of recent shell finite elements", Int. J. Numer Meth Eng 2000;47:101–27.
[11] Sohrabuddin Ahmad, Irons BruceM, Zienkiewicz OC. "Analysis of thick and thin shell structures by curved finite elements" Int. J. Numer Meth Eng 1970;2:419–51.
[12] Ramm E. "A plate/shell element for large deflections and rotations" In: Bathe KJ, editor. Formulations and computational algorithms in finite element analysis. Cambridge, MA: MIT press; 1977.
[13] Bathe KB, Bolourchi S. "A geometric and material nonlinear plate and shell element", Comput Struct 1980;11: 23–48.
[14] Huang HC, Hinton E. "A new nine node degenerated shell element with enhanced membrane and shear interpolation", Int. J. Numer Meth Eng 1986; 22:73–92.
[15] Lee SJ, Han SE. "Free vibration analysis of plates and shells with a nine-node assumed natural degenerated shell element", J. Sound Vib 2001; 241(4):605–33.
[16] Bhumbla R, Kosmatka JB, Reddy JN. "Free vibration behavior of spinning shear-deformable plates composed of composite materials", AIAA J. 1990; 28(11):1962–70.
[17] Lam KY, Qian W. "Vibration of thick rotating laminated composite cylindrical shells", J. Sound Vib 1999;225(3):483–501.
[18] Prema Kumar WP, "Palaninathan R. Finite element analysis of laminated shells with exact through-thickness integration", Comput Struct 1997;63(1):173–84.
[19] Young-Jung Kee & Ji-Hwan Kim, "Vibration characteristics of initially twisted rotating shell type composite blades", J. Composite Structures, (2004), 64, pp 151–1.
[20] Abdullah O. Ibraheem, Ehsan M. Z and Wassan Safaa, “A finite Element Analysis of Damaged Composite Sheet”, Engineering & Development (College of Engineering/ Al-Mustansiriya University), Vol. 12, No. 4, December (2008).
Copyright: Open Access authors retain the copyrights of their papers, and all open access articles are distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided that the original work is properly cited. The use of general descriptive names, trade names, trademarks, and so forth in this publication, even if not specifically identified, does not imply that these names are not protected by the relevant laws and regulations. While the advice and information in this journal are believed to be true and accurate on the date of its going to press, neither the authors, the editors, nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.