P‐Delta Effect Under Repeated Loading
Publication: Journal of Structural Engineering
Volume 116, Issue 8
Abstract
Recently, a novel P‐Delta method for the design of sway frames was introduced by the writer and demonstrated in conjunction with static proportional loading conditions. The method incorporates the rigid‐plastic collapse load and the elastic buckling load of the structure as the two boundary conditions and does not require iterations or a precise trace of the load history. In this paper it is argued and verified by experiments that the P‐Delta effect for sway frames can also be predicted by the same method if loadings vary independently. Such loadings can lead to a reduced failure load compared with the static load case due to premature incremental collapse if the so‐called shakedown load is exceeded. The presented approach is a simple alternative to much more complex analysis procedures which would have to follow repeatedly the loading and unloading paths until failure is indicated. This has to be done under changing axial forces which requires iterations until the structure stiffness and the axial force level match.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Guralnik, A. S., Singh, S., and Erber, T. (1984). “Elastic collapse, shakedown and hysteresis,” Struct. Engrg., ASCE, 110(9), 2103–2119.
2.
Heyman, J. (1971). Plastic design of frames, 2. Applications, Cambridge University Press, Cambridge, England.
3.
Horne, M. R. (1963). “Elastic‐plastic failure loads of plane frames.” Proc., Royal Society of Engineers, Series A, vol 273, 343.
4.
Horne, M. R., and Chin, M. W. (1966). “Plastic design of portal frames in steel to B.S. 968.” Publ. No. 29, British Constructional Steelwork Association.
5.
Merchant, W. (1954). “Failure load of rigid jointed frameworks as influenced by stability.” Struct. Engr., 12, 185–190.
6.
Müller‐Hoeppe, N., Paulun, J., and Stein, E. (1986). “Einspiellasten ebener Stab‐werke unter Normalkrafteinfluss.” Bauingenieur, 61, 23–26.
7.
Pircher, H. (1988). “RM‐Spaceframe.” Technische Datenverarbeitung, TDV, Graz, Austria.
8.
Scholz, H. (1981). “A new multi‐curve interaction method for the plastic analysis and design of unbraced and partially‐braced frames,” thesis presented to the University of the Witwatersrand, at Johannesburg, South Africa, in partial fulfillment of the requirements for the degree of Doctor of Philosophy.
9.
Scholz, H. (1983). “A new multi‐curve interaction method for the plastic analysis and design of sway frames.” Proc., Third Int. Colloquium on Stability of Metal Structures, May, 431–448.
10.
Scholtz, H. (1984a). “Simplified interaction method for sway frames.” J. Struct. Div., ASCE, 110(5), 992–1007.
11.
Scholz, H. (1984b). “Evolution of an approximate analysis technique for unbraced steel frames.” The civil engineer in South Africa, 26(12), 587–594.
12.
Scholz, H. (1986). “Approximate P‐Delta method for rigid steel sway frames in load and resistance factor design.” Proc., Int. Conference on Steel Structures, Sep.—Part 1, 25–34.
13.
Scholz, H. (1987). “P‐Delta effect in elastic analysis of sway frames.” J. Struct. Engrg., ASCE, 113(3), 534–545.
14.
Scholz, H., and Faller, G. (1986). “A micro‐computer program for the elastic‐plastic analysis and optimum design of plane frames.” Comput. Struct., 24(6), 941–947.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 116 • Issue 8 • August 1990
Pages: 2070 - 2082
Copyright
Copyright © 1990 ASCE.
History
Published online: Aug 1, 1990
Published in print: Aug 1990
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.