Studies on the effect of reinforcers types on flat and curved steel sheets’ performance under drop impact

In this research, laboratory investigations and numerical studies are performed on flat and curved steel sheets under the influence of impact caused by the free fall of weights, with and without reinforcers of different transections. In this study, a flat sheet (infinite curvature) and a curved sheet with the curvature radius of 110 mm and a specific level of impact energy (a free fall height) are used for st.12 steel sheets of 1 mm thickness with the dimensions of 220 * 200 mm. The material and thickness of the energy absorbers are similar as the original sheet, and rectangular, cylindrical, half cylindrical, sinusoidal and triangular transection shapes, are considered. In the experimental method, the pickup acceleration is measured by the accelerometer sensor and the post-blow-out plate deformation is measured. The evaluated parameters include the amount of impact acceleration, the rate of permanent deformation, and the amount of energy absorption by the sheet. The Abaqus finite element software is used for numerical modeling. The results show that the curvature reduces the acceleration of the impact and increases the steady deformation and the energy absorption. The reinforcers in general, reduce the amount of crush length, but tape reinforcers reduce also the energy absorption of these sheets compared to plain sheets. Regarding the variety of the reinforcers, the cylindrical element performs better, because it has less impact acceleration and more energy absorption than orthogonal reinforcers, however, there is an increase in the amount of deformation of these sheets.