# Numerical Analysis for Critical Structures Protection against Blast Loading Using Metallic Panels
###### Abstract  
The need for building protection against blast loads is a crucial issue nowadays due to the escalating threat of terrorist attacks, which affect people's lives and critical structures. Consequently, design of protective panels to segregate building facades from the effect of a nearby explosion is required. Such design mainly depends on the ability of protective panels to mitigate and diffract the blast wave before reaching building facades. Five protective panel models with different designs, referred to as the Combined Protection System (CPS), are introduced in this paper. The main objective of this research was to achieve a design that could sustain a blast load with minimum plastic deformations. The introduced CPS designs included two steel plates linked by connector plates. The CPS dimensions were 3 m \(\times\) 3 m \(\times\) 0.35 m, representing length, width, and height, respectively. After that, the successful panel design was supported by placing these panels onto a masonry wall in different configurations. The protective panels were tested against 50 kg of trinitrotoluene (TNT) with a standoff distance of one meter. The final run of the optimum model was carried out using a blast load equivalent to 500 kg of TNT. The air-structure interactions were simulated using finite element analysis software called \"ANSYS AUTODYN\", where the deformation of the panel was the governing parameter to evaluate the behavior of different designs. The analysis showed minimum deformation of the CPS design with vertical and horizontal connecting plates in a masonry wall distanced at 500 mm from the panel. However, the other designs showed promising results, which could make them suitable for critical structural protection on different scales. blast load; charge weight; AUTODYN; plastic deformation; front and rear plate; connectors 2020 11 March 2020 20 March 2020 20 February 2020 11 March 2020 20 March 2020 20 February 2020 20 20 March 2020 20 February 2020 20 20 March 2020 20 February 2020 20 20 March 2020 20 20 February 2020 20 20 March 2020 20 February 2020 20 20 March 2020 20 20 March 2020 20  
researchers successfully reduced the effect of blast loading on building foundations by utilizing advanced material casts along with ultra-high performance concrete materials [18; 19]. A study of the protection of containers was conducted by [PERSON], [PERSON] et al. [20; 21], introducing a suppressive shield container to transport hazardous materials safely on Canadian roads. [PERSON] et al. [22] used composite materials for protection against an explosive charge of 100 kg of trinitrotoluene TNT. However, the cost of using composite materials was found to be too expensive and is not applicable for all buildings. [PERSON] et al. [23] evaluated the effect of material properties on the dynamic response of plates subjected to air explosions. Furthermore, [PERSON] et al. [24] experimentally investigated the dynamic response of four high-strength and armor-grade steels to blast load, in terms of deformation resistance and rupture threshold at different standoff distances. Additionally, [PERSON] et al. [25] studied the effects of introducing face-sheet materials and configurations on the blast resistance of sandwich-panel structures. Additionally, [PERSON] et al. [26] studied the relationship between the responses of circular plates subjected to different blast loads and standoff distances. The results illustrated that the standoff distance influenced the type of loading condition applied to a structure. [PERSON] et al. [27] analytically investigated the dynamic responses of thin square plates with various boundary conditions subjected to a blast load. [PERSON] et al. [28] investigated the mitigation capabilities of using fence walls for blast wave diffraction. The results illustrated that the fence walls could significantly reduce the peak blast pressure and impulse. [PERSON] et al. [29] numerically studied the protective performance of metallic foam cladding on reinforced concrete slabs.