Application of Southwell Method on the Analysis of Lateral Torsional Buckling Tests on Reinforced Concrete Beams

Yıl 2010, Cilt: 2 Sayı: 1, 58 - 66, 15.01.2010

İlker Kalkan

Öz

In this study, different versions of the Southwell plot method were applied on the lateral deflection, twisting rotation and load data of slender rectangular reinforced concrete beams, experiencing elastic lateral torsional buckling. Among different versions of the Southwell plot, the Modified (Trahair) Plots produced the critical load estimates in closest agreement with the experimental buckling loads of the beams. The initial geometric imperfection estimates closest to the actual values were obtained from the standard Southwell Plots. The analysis also indicated that the slope of the Southwell plot of a reinforced concrete beam does not change up to 80-90% of the critical load. In the vicinity of buckling and in the post-buckling stage of the test, cracking of concrete caused by the lateral bending and torsional moments in the beam results in the gradual decrease of the slope of the plot.

Anahtar Kelimeler

Southwell Plot, Massey Plot, Meck Plot, Modified Trahair Plot, Lateral torsional buckling, Lateral deflection, Twisting rotation, Modifications to the Southwell plot, Slender reinforced concrete beams

Kaynakça

• Attard, M. M. (1983), “Extrapolation Techniques for Buckling Loads”, Journal of Structural Engineering, ASCE, Vol. 109, No. 4, pp. 926-935. Cheng, J. J. R. and Yura, A. Y. (1988), “Lateral Buckling Tests on Coped Steel Beams”, Journal of Structural Engineering, ASCE, Vol. 114, No. 1, pp. 16-30. Dumont, C. and Hill, H. N. (1940), “The Lateral Stability of Equal Flanged Aluminum-Alloy I Beams Subjected to Pure Bending”, N.A.C.A. TN 770. Gregory, M. (1960), “The Application of the Southwell Plot on Strains to Problems of Elastic Instability of Framed Structures, where Buckling of Members in Torsion and Flexure Occurs”, Australian Journal of Applied Science, Vol. 11, pp. 49-64. Kalkan, I. (2009), “Lateral Torsional Buckling of Rectangular Reinforced Concrete Beams”, Ph.D. thesis, Georgia Institute of Technology, Atlanta, Georgia, U.S.A. Mandal, P. and Calladine, C. R. (2002), “Lateral-Torsional Buckling of Beams and the Southwell Plot”, International Journal of Mechanical Sciences, Vol. 44, No. 12, pp. 2557-2571. Massey, C. (1963), “Elastic and Inelastic Lateral Instability of I-Beams”, The Engineer, Vol. 216, No. 5622, pp. 672-674. Meck, H. R. (1977), “Experimental Evaluation of Lateral Buckling Loads”, ASCE Journal of Engineering Mechanics Division, Proceedings, Vol. 103, No. 2, pp. 331-337. Southwell, E.