بررسی رفتار قاب بتن مسلح با استفاده از تحلیل غیرخطی به روش آسیب‌دیده پلاستیک در برابر بارهای ناشی از انفجار

Explosion occurs mainly due to unforeseen factors, such as terrorist attacks or performance disruption leading to explosion in facilities and infrastructure caused by fatigue and non-compliance with regulations. Considering the special status of reinforced concrete structures in the construction industry and the extensive usage of the lateral load-bearing system of flexural frames, this research aims to investigate the damage to flexural frames of reinforced concrete subjected to an explosion. For modeling reinforced concrete and in order to consider its nonlinear behavior, the modified plastic damaged concrete method with the latest and most efficient method for calculating the tensile and compressive damage parameters of concrete elements has been used. Identifying the nature of explosion loads and how they are applied to the structure is another important issue that requires to be studied,  In the present study, following presenting and explaining the previous models and equations for calculating the explosion load, the CONWEP model derived from the calculation of weapons effects and the equations and curves of Regulation TM5-855-1 has been described. While validating the results of the CONWEP model, with the laboratory results and the desired result, the three-floor flexural behavior of flexural reinforced concrete frames has been investigated in three dimensions in ABAQUS finite element software. Examination of the numerical results of the explosion of 50 kg of TNT at a distance of 5 m from the frame shows that the highest relative displacement is related to the third floor and is 25 mm, In less than 0.04 seconds, the base shear experiences a magnitude of 450 kN and also the damage rate in tensile elements is about 97% and this damage rate in compression elements is about 28%. Considering the conformity of the numerical modeling results to laboratory results, and the cost and difficulty of explosion experiments, numerical analysis can help reduce the number of experiments and better interpret the results.