بررسي رفتار استاتيكي غير خطي و ارائه مدل ماكرو براي تحليل غير خطي ديوارهاي برشي بتن مسلح سه بعدي

چكيده انگليسي :

011 Investigation of Nonlinear Static Behavior and Macro Model for Nonlinear Analysis of 3D RC Shear Walls Morteza Heydari Morteza heydari90@gmail com Date of Submission May 24 2015 Department of Civil Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisors Dr Farhad Behnamfar farhad@cc iut ac ir AbstractShear walls are important systems used to resist vertical loads and earthquakes Evaluation of building duringearthquakes shows successful performance of these walls to minimize damage The behavior of shear wallsdepends on the aspect ratio Shear walls with high aspect ratio more than two are called flexural or slenderwalls Walls with low aspect ratio less than one are called short or squat and if aspect ratio of walls is betweenone and two walls are called shear flexural In shear flexural wallboth flexural and shear behavior can occur The height to the length ratio of shear walls in tall building is 10 to 12 Hence these walls are flexural orslender and shear deformations are negligible Efficient analytical models that predict actual behavior ofstructures must be applied to analyse seismic behavior of flexural walls for design purposes The analyticalmodels should be able to contribute to the effective factors and main characteristic of the response of shearwall Moreover these models must have ability to simulate non linear behaviors of walls Three commonmethods of modeling aremicro or small scale meso or medium scale and macro or large scale Majority ofresearch have focused on walls with rectangular sections but walls with non rectangular and flanged sectionshave not yet been well studied Present regulations and guidelines do not have specific clauses for walls withnon rectangular sections However flanged walls has better performance than walls with rectangular sectiondue to participation of the Thus the present study focuses on analyzing and modeling behavior of slender shearwalls with non rectangular cross section including L shaped T shaped and H shaped sections However wehave also tried to propose a macro model based on the lumped plasticity to analyze and predict behavior ofthree dimensional shear walls In our proposed model linear behavior of the wall before cracking is considered For this purpose we initially used finite element method micro in software Abaqus 6 12 and fiber method meso in software Opensees 2 4 0 for nonlinear static analysis of shear walls In order to evaluate the accuracyof obtained results from two modeling methods three experimental RC shear walls samples were selected andresults of the modeling were compared The results show that analysis of slender RC shear walls with fibermodeling method is much more fasterand more accurate than the finite element method Although the finiteelement method and fiber method yield accurate information on the local behavior of walls they are complexand time consuming Also in some cases detailed local information is not required and overall predictionofwalls behavior are considered Due to these reasons researchers have considered macro modeling method Inthis study we tried to simulate and predict non linear behavior of shear wall using macro modeling In presentstudy shear wall model with two members rotation spring at the base of wall for modeling nonlinear behaviorof wall and elastic part that is equal length of wall The proposed macro model parameters are dependent onthe characteristics of wall geometry and mechanical properties of materials After determining modelparameters effective factors are identified and a direct formula is presented to express model parameters Acompressive axial load on the wall shape of cross section of wall a percontage of longitudinal reinforcementand aspect ratio of shear wall were identified as the effective factors By evaluation these factors in 460 samplesof wall we presented the formula to determine model parameters The advantage of the proposedmodelisefficiency and applicability for

حيدري، مرتضي

بررسي رفتار استاتيكي غير خطي و ارائه مدل ماكرو براي تحليل غير خطي ديوارهاي برشي بتن مسلح سه بعدي

ديوارهاي برشي با مقاطع بال دار , مدل هاي با مقياس بزرگ (ماكرو) , مفصل پلاستيك , لنگر خمشي تسليم معادل