عنوان مقاله [English]
Steel sheets are used in various industries such as automotive, aerospace, fuel transport and storage tanks, metal bridges. The issue of impact and penetration in steel sheets has been the main focus of many studies. In this study, laboratory studies of flat and curved steel sheets, as well as reinforced by hardening perpendicular to sheet plate. Under the influence of impact caused by the free fall of the weights are examined. In this study, three radii of infinite curvature (flat sheet), 300 mm and 110 mm were used. This study was conducted for three levels of impact energy (three free fall crashes). Steel sheets used are steel st.12 with dimensions of 220 * 200 mm and 1 mm thicken, fastened in one direction by the fixture and is free on the other side. The material and thickness of the pendentive used are similar to the sheet and have a width of 2 cm. The results also show that the use of hardening causes a slight increase in the acceleration of the sheet and a significant reduction in its permanent deformation. The amount of energy absorbed by the reinforced sheets is slightly less than that of plain sheets. In this research, the sheet with a curvature radius of 110 mm with a pendentive has a better performance than the rest of the sheets.