NONLINEAR FINITE ELEMENT ANALYSIS OF OVER REINFORCED CONCRETE PANELS MM. Saathir 1 , Dr. G. Tharmarajah 2 1 Sri Lanka Institute of Information technology, Faculty of engineering, Department of Civil engineering. Email: eng.mmsaathir@gmail.com 2 Senior lecturer, Faculty of engineering, Sri Lanka Institute of Information technology ABSTRACT: FRP reinforcement materials are corrosion resistance and high strength one when compare to steel reinforcement. They can be alternative to steel reinforcement in corrosive environment. Normally steel reinforced structures are design as under reinforced and GFRP/FRP structures are design as over reinforced. Steel is a ductile material; in over reinforced concrete the consumption of steel is large and thus the yielding of steel as compared to yielding of concrete will be very slow. As a result of which concrete fails without undergoing much deflection and it does not give enough warning prior to failure. But both GFRP/FRP and concrete are brittle material, while both materials are in over reinforced concrete, it will show enough warning prior to failure, namely the concrete shall undergo crushing failure rather than GFRP/FRP rupture. Therefore GFRP/FRP reinforced structures preferred as concrete crushing failure. This research has been discussed modelling GFRP/FRP concrete structure and it has been compared with existed experimental results and theoretical values. KEY WORDS: NLFEA, FRP, GFRP, NSC, ATENA 1.0 INTRODUCTION Since more than 100 years steel has been utilized as reinforcing material in concrete construction. Its high tensile strength, its ductile failure mode under tension and its thermal behavior like concrete claim for a most appropriate combination of both materials. However, the durability of concrete structures has always been a great concern. One of the most present problems in controlling durability relates to corrosion of steel reinforcement structures where situated in harsh environment. GFRP/FRP reinforcement considered as solution to solve this problem. GFRP/FRP bars are commonly used in costal environments, water treatment plant, chemical industry, ports, bridges and other harsh environments. GFRP/FRP bars are made of composite fibres and possess numerous distinct properties such as excellent fatigue behavior, high strength-to-weight ratio, high tensile strength, and non-conductivity, while their thermal expansion is close to that of concrete. When used as reinforcement in concrete flexural elements, their tensile strength, bond properties, and elastic modulus are the main mechanical properties that govern the structural behavior of these elements. Comparison of cost between FRP bars and steel bars, FRP bars are lower installation costs, less maintenance, longer product life allow for a lower lifecycle cost, transport saving and patching savings.