Shear Correction Factors for Thin-Walled Composite Boxbeam Considering Nonclassical Behaviors

Abstract

In this study, shear correction factor for thin-walled composite boxbeam is investigated with considering the anisotropic coupling effects in its laminated walls parallel to the external shear load. We first consider a generally orthotropic laminated beam whose cross section is rectangular. The beam does in-plane shear deformation by the applied shear force, so that there arises the effect of extension-shear coupling which does not arise in the conventionally studied out-of-plane shear deformation. The shear correction factor is defined by the energy considerations with taking into account the coupling effect. Then the procedures are extended to the case of laminated thin-walled boxbeam, where the coupling plays a significant role due to the geometric characteristics of boxbeam. The shear correction factors for the representative boxbeams which are the core structural components of modern composite helicopter rotor blade are presented with the change of their laminate sequences.

Get full access to this article

View all access options for this article.

References

1. Smith, E. C. and I. Chopra . 1991. "Formulation and Evaluation of an Analytical Model for Composite Box-Beams," J. the American Helicopter Society, 36:23-35.

2. Rehfield, L. W. , A. R. Atilgan and D. H. Hodges . 1990. "Non-Classical Behavior of Thin-Walled Composite Beams with Closed Cross Section," J. the American Helicopter Society, 35:42-50.

3. Bicos, A. S. and G. S. Springer . 1986. "Design of a Composite Boxbeam'" J. Composite Materials, 20:86-109.

4. Hodges, D. H. 1990. "Review of Composite Rotor Blade Modeling," AIAA Journal, 28:561-565.

5. Jung, S. N. and S. J. Kim . 1994. "Aeroelastic Response of Composite Rotor Blades Considering Transverse Shear and Structural Damping," AIAA Journal, 32:820-827.

6. Chow, T. S. 1971. "On the Propagation of Flexural Waves in an Orthotropic Laminated Plate and Its Response to an Impulsive Load," J. Composite Materials, 5:306-319.

7. Vlachoutsis, S. 1992. "Shear Correction Factors for Plates and Shells," Int. J. Numer. Meth. Eng., 33:1537-1552.

8. Cowper, G. R. 1966. "The Shear Coefficient in Timoshenko's Beam Theory," J. Applied Mechanics, 33:335-340.

9. Bert, C. W. 1973. "Simplified Analysis of Static Shear Factors for Beams of Nonhomogeneous Cross Section," J. Composite Materials, 7:525-529.

10.

10. Whitney, J. M. 1973. "Shear Correction Factors for Orthotropic Laminates under Static Load," J. Applied Mechanics, 40:302-305.

11.

11. Barbero, E. J. , R. L. Anido and J. F. Davalos . 1993. "On the Mechanics of Thin-Walled Laminated Composite Beams," J. Composite Materials, 27:807-829.

12.

12. Shames, I. H. and C. L. Dym . 1985. Energy and Finite Element Methods in Structural Mechanics. Hemisphere Publishing Co.

13.

13. Jones, R. M. 1975. Mechanics of Composite Materials. New York, NY: Hemisphere Publishing Co.

14.

14. Timoshenko, S. P. and J. N. Goodier . 1970. Theory of Elasticity. New York: McGraw-Hill Book Co.

15.

15. Gjelsvik, A. 1981. The Theory of Thin Walled Bars. New York: John Wiley & Sons, Inc.

16.

16. Singh, G. and V. Rao . 1991. "Analysis of the Nonlinear Vibrations of Unsymmetrically Laminated Composite Beams," AIAA J., 29:1727-1735.

17.

17. Megson, T. H. 1972. Aircraft Structures for Engineering Students. Bristol, England: Edward Arnold Ltd.