Effects of Plan Asymmetry in Inelastic Seismic Response of One-story Systems

The effects of plan asymmetry on the earthquake response of one­ story systems are identified by comparing the dynamic response of an asymmetric­ plan system and the corresponding symmetric-plan system for a wide range of system parameters-uncoupled lateral vibration period, uncoupled torsional-to-lat­ eral frequency ratio, stiffness eccentricity, and yield factor. Elastic as weI! as in­ elastic systems are studied. For the latter, two values of the strength eccentricity are considered: equal to the stiffness eccentricity and zero; the latter is represen­ tative of code-designed buildings. Based on the response results for a wide range of system parameters, this paper identifies how the structural response is affected by plan asymmetry and how these effects differ between elastic and inelastic sys­ tems. It is shown that the response of inelastic systems is affected less by plan asymmetry compared to elastic systems. Between the two types of inelastic systems considered, the response of strength-symmetric systems is affected by plan asym­ metry general!y to a smaller degree compared to systems with equal strength and stiffness eccentricities.