TAGUCHI BASED – FUZZY METHOD OPTIMIZATION OF PROPOSED ULTRA-HIGH STRENGTH STEEL /UHMWPE HELMET UNDER VARIABLE IMPACTOR CONDITIONS.
Ultra high strength steel (UHSS) is known for its high strength, high modulus and high energy absorption ability through plastic deformation. However, it is less appealing for lightweight applications due to it relatively high density despite their cheap price. Therefore, all advanced helmets are made from advanced lightweight polymeric materials which are very expensive. The advantages of these classes of material can be harnessed by combining the synergies between them. This study seeks to investigate the application of thin layers of high strength steel and ultra-high molecular weight polyethylene (UHMWPE) in designing cheap and low weight helmet under impact application. Optimization of the proposed helmet under variable impact conditions has been performed through a Taguchi-based fuzzy logic approach. The optimization study investigated the integrity of the proposed helmet considering variable helmet weights, impact velocities and impactor masses. Optimum combinations of these design parameters were obtained through the utilization of Taguchi orthogonal array matrix. Maximization of fracture energy and reaction forces between inner shell and cushion of helmet were considered as criteria for the optimization procedure. Input data for the optimization process were obtained through numerical simulation using the explicit finite element program - LS-PrePost.