بررسی عملکرد ستون‌های بتنی مقاوم سازی شده با صفحات FRP تحت اثر بارگذاری انفجاری

With the increase in the number of terrorist incidents worldwide, the resistance of structures, especially concrete structures, to explosions and their effectiveness under blast loads is of great importance. Over the past few decades, these terrorist attacks have left a lot of financial and human life damage around the world. The result of this event, have been Feeling the more need engineers for design structures to explosion-resistance. The columns of a building because they are one of the most important components of any structure and Failure of even one of them can lead to the failure of part or all of the main structure of the building, Should also be evaluated against this phenomenon. The main purpose of this study is to investigate the effect of using FRP sheets on the flexural and shear performance of columns of a structure against explosion and whether it is possible to achieve the necessary resistance to explosive loads by using reinforcement with FRP sheets or not. Concrete columns as one of the main load-bearing elements of the structure play an important role in bearing this type of load. Evaluation of strength and shear performance of concrete columns reinforced with FRP sheets against explosive loads is one of the innovations of this research that has been less discussed in previous studies. The use of explosions with different intensities and at different distances in order to calculate the intensity of safe explosions at any given distance is another innovation of this research. In order to evaluate the performance of concrete columns against explosion and the effect of their shear reinforcement by FRP sheets, a square column with specific cross-sectional dimensions and a height of 3 meters has been considered. The column was subjected to an explosion of 82 kg of TNT at different distances from the column and was analyzed. The concrete column was reinforced with full sheath using FRP sheets and the results were compared to investigate the effect of reinforcement on the performance of the concrete column against explosion. Then, by modeling a 5-storey concrete building and in two modes without and by reinforcing FRP sheets at the end of the column and the connection fountain, we tried to improve the performance of the concrete building by controlling the shear in these areas. The results show that the use of FRP plates in the concrete column under explosive loading causes a significant reduction in horizontal displacement and this reduction is greater at closer distances, so that at 2.5, 5 and 10 meters distance from the explosive charge, we saw a decrease of 52.6%, 32% and 31% of horizontal displacement, respectively. Also, the use of FRP causes a large amount of kinetic energy due to the explosion to be wasted in the form of structural damage.