Evaluation of Soil Effect on the Response of Single Degree of Freedom System

Subject Areas : Nonlinear Vibration

علی  گل افشار ¹ (عضو هیات علمی گروه مهندسی عمران دانشگاه آزاد سمنان)
داوود  عدالتی ² (فارغ التحصیل مهندسی عمران)
محمد حسین  ثقفی ³ (عضو هیات علمی گروه عمران دانشگاه آزاد سمنان)

Received: 2016-11-19 Accepted : 2016-11-20 Published : 2014-01-21

Keywords: ductility, Nonlinear Spectrum, Linear Spectrum,

Abstract :

In the common practice design of structures, one of the most important design parameters is design spectrum. design spectrum can divided to two category. first linear design spectrum and second nonlinear design spectrum. Exact determination of nonlinear design spectrum needs to nonlinear dynamic Analysis of single degree of freedom system. Because of time consuming of such analysis previous researchers determine many relation for estimating of nonlinear spectrum from elastic spectrum. In this Article Three relations of previous study have been selected and then twenty records of earthquake for soil types have been extracted from earthquake database of PEER database. for each record linear and nonlinear exact dynamic time history carried out and maximum displacement and acceleration is drawn versus elastic period of single degrees of freedom system. After this, linear spectrum is estimated based on elastic exact analysis and nonlinear spectrum is estimated based on relations of previous researchers. Comparison of exact and approximate results are carried out for displacement and acceleration response of nonlinear spectrum. Assessing the result revealed that relation based on Miranda and Krawinkler are matching better than Bazan with respect to exact nonlinear dynamic analysis