The behavior of steel plate walls (SPWs) under various impulsive loadings and the effects of different mesh sizes are investigated in this paper. With the aim of accurately inspecting SPWs, a series of analyses with 250 models with different plate geometric assumptions and different blast impulsive loadings are performed to study the SPWs’ out-of-plane behavior. The mild steel material specifications are adopted for SPWs with different thickness and stiffener arrangement and ABAQUS software is utilized for the Finite Element analysis. Results of transferred impulse, maximum displacement and Von Mises stress of SPWs show that SPWs with thickness of 5 mm are the best choice against various impulsive loadings in comparison with SPWs with thickness of 20 mm. In fact, the SPWs having the thickness of 5 mm show better performance as a result of more energy dissipation against various impulsive loadings. Finally, the Von Mises stress contours investigated for some models show 28% more stress in P5 SPW than that in P20 SPW. Also, it can be concluded that various sizes of mesh have no remarkable effect on unstiffened SPW while effect of different mesh sizes is more significant with increasing the number of stiffeners
