The Earthquake Engineering Online Archive

Effect of inelastic behavior on the analysis and design of earthquake resistant structures

Lin, Jonathan P.; Mahin, Stephen A.

UCB/EERC-85/08, Earthquake Engineering Research Center, University of California, Berkeley, 1985-06, 144 pages (530/L55/1985)

The effect is evaluated of inelastic deformation on the preliminary analysis and design of earthquake-resistant structures. Three related but separate concerns are addressed in this three-part study: (1) The interaction between ground motion and structural response parameters is examined to provide a more consistent basis for selecting the design earthquake for inelastic systems. Various suggested indices for measuring the damage potential of a ground motion are reviewed and tested for validity using two sets of ground motions. Guidelines for scaling ground motions are developed. (2) An efficient analysis procedure is developed for the preliminary stage of design. Responses are examined in typical shear beam structures in their initial linear elastic mode shape coordinate systems. Current practices in implementing response spectrum analysis for inelastic multiple degree-of-freedom systems are assessed. A rational procedure, using a proposed modal hysteresis model, for implementing the response spectrum method is presented and evaluated. (3) A preliminary investigation is made of the seismic behavior of nonstructural systems supported on inelastic structures. The effects of the severity of inelastic deformations, of different hysteretic characteristics of the structure, and of the amount of viscous damping of the subsystem are investigated. Current design recommendations for subsystems accounting for yielding of the support structure are assessed. An amplification factor is defined to quantify the effects of inelastic deformations in the support structure, and design guidelines are formulated for predicting the amplification factor. Results of the study are summarized and areas needing further research are identified.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-85-08.pdf (9 MB)