Approximate Modal Analysis of Bilinear MDF Systems Subjected to Earthquake Motions

Tansirikongkol, V.; Pecknold, D.A.

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https://hdl.handle.net/2142/13910 Copy

Description

Title

Approximate Modal Analysis of Bilinear MDF Systems Subjected to Earthquake Motions

Author(s)

• Tansirikongkol, V.
• Pecknold, D.A.

Issue Date

1978-08

Keyword(s)

• earthquake motions
• Nonlinear dynamic analysis
• modal analysis

Abstract

The study investigated two approximate methods of modal analysis for hysteretic multi-degree-of-freedom lumped mass structural models subjected to earthquakes. The methods were (1) approximate modal analysis using elastic response spectra, and (2) approximate modal analysis using inelastic response spectra. Both modal analysis procedures were iterative and used a perturbation method to successively modify the original elastic mode shapes at each iterative step to reflect yielding in the system. The procedures were developed and evaluated only for shear beam structural systems consisting of members with bilinear hysteresis. Extensive comparisons of exact and approximate responses were made for various 1-, 3- and 10-degree-of-freedom systems. Four existing earthquakes were used, and several structural stiffness and strength parameters were varied. Maximum story displacements were generally predicted within about 5-40 percent accuracy. The equivalent nonlinear approach using inelastic response spectra appeared to give generally better accuracy than the equivalent linear approach using elastic response spectra.

Publisher

University of Illinois Engineering Experiment Station. College of Engineering. University of Illinois at Urbana-Champaign.

Series/Report Name or Number

Civil Engineering Studies SRS-449

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/13910

Sponsor(s)/Grant Number(s)

• National Science Foundation Grant ENV 75-08456
• National Science Foundation Grant ENV 77-07190

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