New Stability Equation for Columns in Braced Frames
Publication: Journal of Structural Engineering
Volume 118, Issue 7
Abstract
A new approximate method that overcomes some limitations of the current design procedures for determining effective‐length factors for columns in braced frames is presented. Generalized stability functions are developed, including a linear model for joint flexibility and the column‐strength curve of the Structural Stability Research Council (SSRC) to take into account the inelastic behavior of members subjected to axial compression. Thereafter, a mathematical formulation based on the interaction between the column being analyzed and the adjacent members is presented by considering differentiated stiffness parameters as well as the boundary conditions at the far ends of all the attached elements. A computer program was implemented and an extensive numerical analysis about the influence of the involved variables was performed. It is proved that the use of some current design methods, such as the alignment‐chart procedure and related modifications, may provide unconservative results.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Ackroid, M. H., and Gerstle, K. H. (1983). “Elastic stability of flexibly connected frames.” J. Struct. Engrg., ASCE, 109(1), 241–245.
2.
Bleich, F. (1952). Buckling strength of metal structures. McGraw‐Hill Book Co., Inc., New York, N.Y.
3.
Borland C++ 2.0 programmer's guide. (1991). Borland International, Inc., Scotts Valley, Calif.
4.
Bridge, R. Q., and Fraser, D. (1987). “Improved G‐factor method for evaluating effective lengths of columns.” J. Struct. Engrg., ASCE, 113(6), 1341–1356.
5.
Chapra, S., and Canale, R. (1985). Numerical methods for engineers. McGraw‐Hill Book Co., Inc., New York, N.Y.
6.
Chen, W.‐F., and Kishi, N. (1989). “Semirigid steel beam‐to‐column connections: Data base and modeling.” J. Struct. Engrg., ASCE, 115(1), 105–119.
7.
Disque, R. O. (1973). “Inelastic K‐factor for column design.” Engrg. J., (2), 33–35.
8.
Duan, L., and Chen, W.‐F. (1988). “Effective length factor for columns in braced frames.” J. Struct. Engrg., ASCE, 114(10), 2357–2370.
9.
Duan, L., and Chen, W.‐F. (1989). “Effective length factor for columns in unbraced frames.” J. Struct. Engrg., ASCE, 115(1), 149–165.
10.
Fraser, D. J. (1983). “Evaluation of effective length factors in braced frames.” Canadian J. Civ. Engrg., 10, 18–26.
11.
Handbook of structural stability. Column Research Committee of Japan, (1971). Corona Publishing, Tokyo, Japan.
12.
Goncalves, R. (1990). “Nuevas ecuaciones de estabilidad para la evaluatión de factores de longitud efectiva de elementos estructurales sometidos a compressión axial” (in Spanish). Internal Report, Universidad Simón Bolívar, Caracas, Venezuela.
13.
Hu, K.‐K., and Lai, D. C. (1986). “Effective length factor for restrained beam‐column.” J. Struct. Engrg., ASCE, 112(2), 241–256.
14.
Johnston, B. G. (1976). Structural Stability Research Council guide to stability design criteria for metal structures, 3rd Ed., John Wiley and Sons, New York, N.Y.
15.
Kavanagh, T. C. (1962). “Effective length of framed columns.” Trans., ASCE, 127, 81–101.
16.
Newmark, N. M. (1949). “A simple approximate formula for effective end‐fixity of columns.” J. Aero. Sci., 16(2), 116.
17.
Osgood, W. R. (1934). “Contribution to the design of compression members in aircraft.” J. Res., 13, 157–160.
18.
Shanley, F. R. (1947). “Inelastic column theory.” J. Aero. Sci., 14(5), 261–268.
19.
Smith, C. V. (1976). “On inelastic column buckling.” Engrg. J., (3), 86–88.
20.
Specification for the design, fabrication and erection of structural steel for buildings. (1978). American Institute of Steel Construction (AISC), New York, N.Y.
21.
Ueda, Y., Rashed, S. M. H., and Nakacho, K. (1990). “An improved joint model and equations for flexibility of tubular joints.” J. Offshore Mech. and Arctic Engrg., 112, (May), 157–168.
22.
Yura, J. A. (1971). “The effective length of columns in unbraced frames.” AISC Engrg. J., 8(2), 37–42.
Information & Authors
Information
Published In
Copyright
Copyright © 1992 ASCE.
History
Published online: Jul 1, 1992
Published in print: Jul 1992
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.