Performance Improvement of Masonry Infill Walls Strengthened With Steel Wall-Post Under Different Charges & Different Distances of Explosion Loading

With the increase in explosive attacks and the need for defensive preparedness, it is possible to consider strategies to improve the safety and resilience of non-structural members and their efficiency. In this paper, the nonlinear performance of a reinforced concrete frame with non-structural steel wall-reinforced interlayer under blast load is investigated. For this, in the first step, a concrete frame with steel wall-reinforced masonry frames, according to the latest recommendation of the Iranian seismic design code, in ABAQUS finite element software under the load of two explosive charges of 300 and 1000 kg by equivalent pressure method. The blast was located at distances of 5, 10, and 15 meters from the base of the structure, and the relative displacement response between the interfaces and the dissipated energy in the whole model were studied. In the second step, the necessity of strengthening this system has been discussed by adopting two strategies: increasing the cross-sectional number of wall-posts and reducing the distances of wall-posts. The results show that the relative displacement of peer-to-peer in the model with the strategy of increasing the cross-sectional number of wall-posts, at the expense of 1000 kg and 300 kg at a distance of 5 m by increasing the angle cross-section from L60x60x6 mm to L80x80x8 mm by 34.20%, respectively. And decreased by 48.25%. This reduction was achieved in the model with the strategy of reducing the distances of the wall posts at the expense of 1000 and 300 kg at a distance of 5 meters, respectively 5.51% and 3.53%, which was more than 2 times the amount of reduction of the first strategy. Also, the depleted energy in the model with the strategy of reducing distances compared to the model with a cross-section of L80x80x8 mm under 1000 kg explosion, more than 2.4 has been obtained.