Numerical Analysis on the Influence of the Cross Section of Ultimate Capacity of Reinforced Concrete Columns Reinforced with CFRP

The most common method of strengthening columns is confining them with FRP composites, which increases their ultimate axial and lateral load capacity. The main objective of this research is to investigate square and rectangular RC columns strengthened with FRP composites. For this purpose, an existing laboratory sample was initially modeled in Abaqus software. As a result, the accuracy of modeling was proven as the laboratory test results and the results generated by the software were compared and showed to be close. Then, with regard to variables such as cross-sectional shape and dimensions of the column and the number of composite layers, 18 analytical samples were determined and modeled in Abaqus software. The samples were divided into two groups of 9: square cross-sections and rectangular cross-sections. Each group included three non-reinforced samples, three samples reinforced with one layer and three samples reinforced with two layers of CFRP. The results obtained from the finite element analysis of these samples showed that the cross-sectional shape of the column did not affect the ultimate axial load capacity, but affected the ultimate lateral load capacity. Also, adding CFRP layers had a profound effect on the ultimate lateral load capacity of the columns and unlike the ultimate axial load capacity, the presence of the second layer of CFRP was very effective. Moreover, as the length-to-width ratio in rectangular samples and the dimensions in square samples increased, the effect of the number of layers on the ultimate axial and lateral load capacity and the energy absorbed by the column decreased.