Improved shear correction factors for deflection of simply supported very thick rectangular auxetic plates

T. C. Lim1
1School of Science and Technology, SIM University, Singapore, Singapore

Tóm tắt

The first-order shear deformation theory (FSDT) for plates requires a shear correction factor due to the assumption of constant shear strain and shear stress across the thickness; hence, the shear correction factor strongly influences the accuracy of the deflection solution; the third-order shear deformation theory (TSDT) does not require a correction factor because it facilitates the change in shear strain across the plate thickness. This paper obtains an improved shear correction factor for simply supported very thick rectangular plates by matching the deflection of the Mindlin plate (FSDT) with that of the Reddy plate (TSDT). As a consequence, the use of the exact shear correction factor for the Mindlin plate gives solutions that are exactly the same as for the Reddy plate. The customary adoption of 5/6 shear correction factor is a lower bound, and the exact shear correction factor is higher for the following: (a) very thick plates, (b) narrow or long plates, (c) high Poisson’s ratio plate material, and (d) highly patterned loads, while the commonly used shear correction factor of 5/6 is still valid for the following: (i) marginally thick plates, (ii) square plates, (iii) negative Poisson’s ratio materials, and (d) uniformly distributed loadings.

Tài liệu tham khảo

Boldrin, L., Hummel, S., Scarpa, F., Di Maio, D., Lira, C., Ruzzene, M., Remillat, C. D. L., Lim, T. C., Rajasekaran, R., & Patsias, S. (2016). Dynamic behaviour of auxetic gradient composite hexagonal honeycombs. Composites Structures, 149, 114–124. Chan, K. T., Lai, K. F., Stephen, N. G., & Young, K. (2011). A new method to determine the shear coefficient of Timoshenko beam theory. Journal of Sound and Vibration, 330(14), 3488–3497. Dong, S. B., Alpdogan, C., & Taciroglu, E. (2010). Much ado about shear correction factors in Timoshenko beam theory. International Journal of Mechanical Sciences, 47(13), 1651–1655. Han, S. M., Benaroya, H., & Wei, T. (1999). Dynamics of transversely vibrating beams using four engineering theories. Journal of Sound and Vibration, 225(5), 935–988. Hlavacek, I., & Chleboun, J. (2000). Reliable analysis of transverse vibrations of Timoshenko-Mindlin beams with respect to uncertain shear correction factor. Computer Methods in Applied Mechanics and Engineering, 190(8-10), 903–918. Hull, A. J. (2005). An exact analytical expression of the shear coefficient in the Mindlin plate equation. Journal of the Acoustical Society of America, 117(4), 2601–2601. Hull, A. J. (2006). Mindlin shear coefficient determination using model comparison. Journal of Sound and Vibration, 294(1&2), 125–130. Hutchinson, J. R. (1980). Vibrations of solid cylinders. ASME Journal of Applied Mechanics, 47(4), 901–907. Hutchinson, J. R. (2001). Shear coefficients for Timoshenko beam theory. ASME Journal of Applied Mechanics, 68(1), 87–92. Lee, K. H., Lim, G. T., & Wang, C. M. (2002). Thick Levy plates re-visited. International Journal of Solids and Structures, 39(1), 127–144. Lim, T. C. (2010). In-plane stiffness of semiauxetic laminates. ASCE Journal of Engineering Mechanics, 136(9), 1176–1180. Lim, T. C. (2015a). Shear deformation in beams with negative Poisson’s ratio. IMechE Journal of Materials Design and Applications, 229(6), 447–454. Lim, T. C. (2015b). Auxetic Materials and Structures. Singapore: Springer. Lim, T. C. (2016a). Refined shear correction factor for very thick simply supported and uniformly loaded isosceles right triangular auxetic plates. Smart Materials and Structures, 25(5), 054001. Lim, T. C. (2016b). Higher order shear deformation of very thick simply-supported equilateral triangular plates under uniform load. Mechanics Based Design of Structures and Machines, 44(4), 514–522. Lim, T. C. (2016c). Combined effect of load waviness and auxeticity on the shear deformation in a class of rectangular plates. IOP Conference Series: Materials Science and Engineering, 157, 012011. Lim, T. C. (2016d). Large deflection of circular auxetic membranes under uniform load. ASME Journal of Engineering Materials and Technology, 138(4), 041011. Pai, P. F., Anderson, T. J., & Wheater, E. A. (2000). Large-deformation tests and total-Lagrangian finite-element analyses of flexible beams. International Journal of Solids and Structures, 37(21), 2951–2980. Pai, P. F., & Schultz, M. J. (1999). Shear correction factors and an energy-consistent beam theory. International Journal of Solids and Structures, 36(10), 1523–1540. Popescu, B., & Hodges, D. H. (2000). On asymptotically correct Timoshenko-like anisotropic beam theory. International Journal of Solids and Structures, 37(3), 535–558. Puchegger, S., Bauer, S., Loidl, D., Kromp, K., & Peterlik, H. (2003). Experimental validation of the shear correction factor. Journal of Sound and Vibration, 261(1), 177–184. Rössle, A. (1999). On the derivation of an asymptotically correct shear correction factor for the Reissner-Mindlin plate mode. Comptes Rendus de l'Académie des Sciences - Series I – Mathematics, 328(3), 269–274. C. R. Steele, C. D. Balch (2009) Introduction to the Theory of Plates. Stamford University. http://web.stanford.edu/~chasst/Course%20Notes/Introduction%20to%20the%20Theory%20of%20Plates.pdf. Accessed 24 October 2016. Stephen, N. G. (1997). Mindlin plate theory: best shear coefficient and higher spectra validity. Journal of Sound and Vibration, 202(4), 539–553. Ting, T. C. T. (2005). Poisson's ratio for anisotropic elastic materials can have no bounds. Quarterly Journal of Mechanics and Applied Mathematics, 58(1), 73–82. Wang, C. M., Reddy, J. N., & Lee, K. H. (2000). Shear Deformable Beams and Plates. Oxford: Elsevier. Yu, W., & Hodges, D. H. (2004). Elasticity solutions versus asymptotic sectional analysis of homogeneous, isotropic, prismatic beams. ASME Journal of Applied Mechanics, 71(1), 15–23.