1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

Existing reinforced concrete structures are subject to damage and performance degradation under external loads. It is then necessary to improve their performance using appropriate strengthening techniques. Over the last decades, new construction materials for strengthening and design have emerged. These are referred to as fiber- reinforced polymer (FRP) composites and have unique mechanical and in-service properties.
Investigation of FRP-strengthened RC members subjected to impact loads is warranted. In addition, there is also a lack of finite element (FE) studies concerning this topic. FE analysis is a powerful and economical tool to investigate the response of structures under various loads and examine virtually endless number of variables that would be otherwise very difficult to be performed experimentally, due time, cost, and laboratory limitations.
The existing RC column was strengthened with CFRP sheets, installed at the site where plastic hinge may occur. First of all, three-dimensional FE CFRP confined column was designed. Due to the complexity of the strengthened element, every element with different material characteristics was designed separately. Every element has different meshing. The nonlinear behavior of the concrete and steel material is accounted in the modeling by introducing the actual inelastic properties in the model. The boundary conditions between the concrete and CFRP material also were taken into account. At the end, the strengthened column was subjected to cyclic loading.
As a result of the FE analysis, hysteresis loop was obtained. In order to see the benefits of strengthening with CFRP materials using FE analysis, comparison between hysteresis loops for strengthened and unstrengthen column was performed.