ABSTRACT
The study focuses on testing a simplified way of estimating the resultant force due to ballistic impacts resulting in a full fragmentation of the impactor with no penetration of the target. The method is intended to be useful for the parsimonious structural assessment of military aircrafts with integrated ballistic protection systems by means of large scale explicit finite element simulations. The research investigates the effectiveness of the method in allowing the prediction of the fields of plastic deformation collected by hard steel plates impacted by a wide range of semi-jacketed, monolithic, and full metal jacket .308 Winchester rifle bullets. The outcomes show the effectiveness of the method being strictly related to the full compliance of the considered cases with the bullet-splash hypotheses. The study therefore suggests the application of the load history approach only after careful experimental investigations on the specific impactor-target interactions.
ABSTRACT
The release of chromium, nickel, and manganese from knives stainless steel produced in Italy and People's Republic of China was investigated with the aim to check their quality and compliance with Italian Ministerial Decree 21.03.73, which is the most detailed text for the hygiene regulation of packaging, containers, and tools intended for food contact. Temperature effect on metal release is investigated in 18 sets of knives. Tests are performed by simulating discontinuous contact using a 3% glacial acetic acid solution in distilled water at 50°C and 100°C. Chromium, nickel, and manganese quantification is performed by total reflection X-Ray fluorescence. Chemical composition highlights low sulphur content, and most of them belong to the American Iron and Steel Institute (AISI) 420 type A stainless steel group. Tests performed at 100°C revealed higher concentration of released metals. Only three knives tested at 100°C exceed the limit of 100 µg L-1.
