Industry and market of ballistic protection materials and systems are characterized by a dynamic and competing succession of inventions for projectiles and protective systems. The requirements for the ballistic panels are many and complex, varying depending on the threat type, the required mobility in the tactical theater, and protection level. The safety degree, the price, and the dynamics of research in the field are also taken into account. This chapter underlines the necessity of testing ballistic protection panels made of LFT SB1 plus (multidirectional fiber fabrics, supplied by Teijin) against a certain threat in order to assess their resistance to this specific threat and the investigation of failure mechanisms in order to improve their behavior at ballistic impact. The models for ballistic impact are useful when they are particularly formulated for resembling the actual system projectile, target, and can be validated through laboratory experiments. Tests made on panels made of LFT SB1plus, according to NIJ Standard-0101.06-2008 gave good results for the panels made of 12 layers of this fabric, and the backface signature (BFS) was measured. The BFS upper tolerance limit of 24,441 mm recommends this system for protection level IIA, according to the abovementioned standard.
Part of the book: Ballistics
This chapter presents experimental data in the favor of using soybean oil, additivated or not, as lubricants, the market share of the soybean oil on the lubricants’ market, a SWOT analysis for better configuring the tribological characteristics of the soybean oil and tribological parameters as friction coefficient, wear scar diameter, wear rate of wear scar diameter, etc. and their dependence on testing regime (load and speed). Also, the influence of temperature, shear rate, and oxidation parameters on the soybean oil viscosity is discussed.
Part of the book: Soybean
This chapter means to explain the tribological behavior of polymer-based materials, to support a beneficial introducing of those materials in actual applications based on test campaigns and their results. Generally, the designers have to take into consideration a set of tribological parameters, not only one, including friction coefficient, wear, temperature in contact, contact durability related to application. Adding materials in polymers could improve especially wear with more than one order of magnitude, but when harder fillers are added (as glass beads, short fibers, minerals) the friction coefficient is slightly increased as compared to neat polymer. In this chapter, there are presented several research studies done by the authors, from which there is point out the importance of composite formulation based on experimental results. For instance, for PBT sliding on steel there was obtained a friction coefficient between 0.15 and 0.3, but for the composite with PBT + micro glass beads, the value of friction coefficient was greater. Adding a polymer playing the role of a solid lubricant (PTFE) in these composites and also only in PBT, decreased the friction coefficient till a maximum value of 0.25. The wear parameter, linear wear rate of the block (from block-on-ring tester) was reduced from 4.5 μm/(N⋅km) till bellow 1 μm/(N⋅km) for a dry sliding regime of 2.5…5 N, for all tested sliding velocities, for the composite PBT + 10% glass beads +10% PTFE, the most promising composite from this family of materials. This study emphasis the importance of polymer composite recipe and the test parameters. Also there are presented failure mechanisms within the tribolayer of polymer-based materials and their counterparts.
Part of the book: Tribology in Materials and Manufacturing