Buckling Analysis of Polar Orthotropic Circular and Annular Plates of Uniform and Linearly Varying Thickness with Different Edge Conditions
الموضوعات :
F Farhatnia
1
(Mechanical Engineering Faculty, Islamic Azad University - Branch of Khomeinishahr)
A Golshah
2
(Iran Aircraft Manufacturing (HESA), Moallem Highway, Isfahan)
الکلمات المفتاحية: Buckling, Orthotropic Plates, Circular and annular plates, Different edge conditions,
ملخص المقالة :
This paper investigates symmetrical buckling of orthotropic circular and annular plates of continuous variable thickness. Uniform compression loading is applied at the plate outer boundary. Thickness varies linearly along radial direction. Inner edge is free, while outer edge has different boundary conditions: clamped, simply and elastically restraint against rotation. The optimized Ritz method is applied for buckling analysis. In this method, a polynomial function that is based on static deformation of orthotropic circular plates in bending is used. Also, by employing an exponential parameter in deformation function, eigenvalue is minimized in respect to this parameter. The advantage of this procedure is simplicity, in comparison with other methods, while whole algorithm for solution can be coded for computer programming. The effects of variation of radius, thickness, different boundary conditions, ratio of radial Young modulus to circumferential one, and ratio of outer radius to inner one in annular plates on buckling load factor are investigated. The obtained results show that in plate with identical thickness, increasing of outer radius decreases the buckling load factor. Moreover, increase of thickness of the plates results in increase of buckling load factor.
[1] Woinowski-Krieger S., 1958, Buckling stability of circularplates with circular cylindricalAeolotropy, Ingenieur-Archiv 26: 129-131.
[2] Meink T., Huybrechts S., Ganley J., 1999, The effect of varying thickness on the buckling of orthotropic plate, Journal of Composite Materials 33: 1048-1061.
[3] Laura P.A.A, Gutierrez R.H., Sanzi H.C., Elvira G., 2000, Buckling of circular, solid and annular plates with an intermediate circular support, Ocean Engineering 27: 749-755.
[4] Ciancio P.M., Reyes J.A., 2003, Buckling of circular annular plates of continuously variable thickness used as internal bulkheads in submersibles, Ocean engineering 30: 1323-1333.
[5] Bremec B., Kosel F., 2006, Thickness optimization of circular annular plates at buckling, Thin-Walled Structures 32: 74-81.
[6] Gutierrez R.H., Romanlli E., Laura P.A.A., 1996, Vibration and elastic stability of thin circular plates with variable profile, Journal of Sound and Vibration 195: 391-399.
[7] Liang B., Zhang Sh., Chen D., 2007, Natural frequencies of circular annular plates with variable thickness by a new method, Journal of Pressure Vessels and Piping 84: 293-297.
[8] Timoshenko S.P., Gere J.M., 1961, Theory of Elastic Stability, Second Edition, McGraw-Hill, New York.
[9] Gupta U.S., Lal R., Verma C.P., 1986, Buckling and vibrations of polar orthotropic annular plates of variable thickness, Journal of Sound and Vibration 104: 357-369.
