Finite Element Analysis Of Retrofitted Rc Structures

Abstract

For understanding behaviour of Reinforced Concrete (RC) members under di erent types of loading experimental methods or numerical methods are used. Finite ele- ment analysis (FEA) is a numerical method widely applied to the concrete structures based on the nonlinear behavior of material. Experimental methods are costly, time consuming and often di cult for considering more number of parameters. Numerical methods, on the other hand, are now widely used and become the choice of modern engineering tools for the researcher. Finite element modeling and analysis are fre- quently used to overcome experimental limitations in predicting and analyzing the performance of structures and structural components. Finite element analysis (FEA) can also be used for understanding the nonlinear behaviour of RC members under di erent types of loadings like axial, bending, torsion, etc. For analysis of new structure and strength assessment of existing reinforced con- crete structure, the non-linear nite element (FE) analysis has become an important tool. Understanding behaviour of retro tted RC member is further more complicated, where FEA proves to be e ective tool. The objective of the present project is to explore application of nonlinear FE model- ing and analysis of reinforced concrete (RC) member and its retro tting with FRP. In this project, nonlinear nite element analysis of retro tted RC beam, column, portal frame is presented. Carbon Fibre Reinforced Polymer (CFRP) is considered for retro tting of beam, column and portal frame. ANSYS software is used for FE modeling and analysis. SOLID 65 element is used for modeling concrete, SOLID 46 element is used for modeling CFRP wrap and LINK8 element is used for model- ing reinforcement. Nonlinear material properties for concrete and steel are considered. The analysis results in terms of load-displacement behaviour, ultimate load, crack patterns are presented. The result of RC element and retro tted RC element are compared to understand improvement in load carrying capacity. Further the e ect of di erent CFRP wrapping con guration on strengthening of RC beam, column and portal frame are studied using non-linear nite element analysis. The content of report is divided in to various chapters. Chapter 1 includes general introduction, objectives of study and scope of work. Chapter 2 discusses the review of the work carried out by various researchers in the eld of FE modeling of RC structural members as well as retro tting of members. Finite element modeling of RC elements using ANSYS and an illustrative example of FE modeling and analysis is included in Chapter 3. Finite element modeling and analysis of RC and strengthened RC beam using di erent CFRP wrapping con guration are covered in chapter 4. Finite element modeling and analysis of RC and strengthened column and e ect of orientation of FRP layer on RC element is covered in chapter 5. The nite element modeling and analysis of portal frame is presented in chapter 6. Finally summary, conclusions and future scope of work are included in chapter 7.