Dynamic P-Delta Effects for Flexible Inelastic Steel Structures
Publication: Journal of Structural Engineering
Volume 126, Issue 1
Abstract
Inelastic seismic response of steel moment resisting frame structures, which are usually quite flexible and subject to large displacements under severe ground motions, may be severely influenced by the structure P-delta effect. For structures in which this effect induces a negative postyield story stiffness, as seen from a pushover (story shear-story displacement) curve, the response becomes very sensitive under ground motions that are sufficiently strong to drive the structure into this negative postyield stiffness range. The response under such conditions may be highly nonsymmetric with progressive displacements to one side, which increases the collapse potential of the structure in a sidesway mode. This paper focuses on two case studies that (1) illustrate P-delta sensitive behavior; (2) demonstrate the sensitivity of predicted behavior to ground-motion characteristics and analytical modeling; and (3) contribute to the development of engineering guidelines for protection against excessive P-delta effects. A relatively simple procedure is proposed for identifying P-delta sensitive cases, and recommendations are made for improving the P-delta response of flexible steel frame structures.
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References
1.
Bernal, D. (1998). “Instability of buildins during seismic response.” Engrg. Struct., 20(4–6), 496–502.
2.
Challa, V. R. M., and Hall, J. F. (1994). “Earthquake collapse analysis of steel frames.” Earthquake Engrg. and Struct. Dyn., 23(11), 1199–1218.
3.
Gupta, A., and Krawinkler, H. (1999). “Seismic demands for performance evaluation of steel moment resisting frame structures.” John A. Blume Earthquake Engrg. Ctr. Rep. No. 132, Dept. of Civ. Engrg., Stanford University, Stanford, Calif.
4.
Krawinkler, H., and Seneviratna, P. (1998). “Pros and cons of a pushover analysis for seismic performance evaluation.” J. Engrg. Struct., 20(4–6), 452–464.
5.
MacRae, G. A. (1994). “P-Δ effects on single-degree-of-freedom structures in earthquakes.” Earthquake Spectra, 10(3).
6.
“NEHRP recommended provisions for seismic regulations for new buildings.” (1995). 1994 Ed., FEMA 222A, Federal Emergency Management Agency, Building Seismic Safety Council, Washington, D.C.
7.
“NEHRP guidelines for the seismic rehabilitation of buildings.” (1997). FEMA 273, Federal Emergency Management Agency, Building Seismic Safety Council, Washington, D.C.
8.
Roeder, C. W., Schneider, S. P., and Carpenter, J. E. (1993). “Seismic behavior of moment-resisting steel frames: Analytical studies.”J. Struct. Engrg., ASCE, 119(6), 1866–1884.
9.
Schneider, S. P., Roeder, C. W., and Carpenter, J. E. (1993). “Seismic behavior of moment-resisting steel frames: Experimental study.”J. Struct. Engrg., ASCE, 119(6), 1885–1902.
10.
Somerville, P., et al. (1997). “Development of ground motion time histories for phase 2 of the FEMA/SAC steel project.” Rep. No. SAC/BD-97/04, SAC Joint Venture, Sacramento, Calif.
11.
Uniform building code. (1994). Vol. 2, International Conference of Building Officials, Whittier, Calif.
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Received: Apr 5, 1999
Published online: Jan 1, 2000
Published in print: Jan 2000
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