Development and Study of Hyperdamping Protective Material Systems for Shock Mitigation
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Publisher:The Ohio State University
Series/Report no.:The Ohio State University. Department of Mechanical and Aerospace Engineering Honors Theses; 2017
Helmets are used as personal protective equipment in a large variety of occupational and recreational activities. Despite the widespread use of helmets, concussions and traumatic brain injuries are still common due to ineffective diffusion and damping of the shock energies caused by impact events. Conventional foam liners for helmet designs require large quantities of stiff, deformable foam for shock absorption, increasing weight, and yet not providing adequate protection required to prevent head-related injuries. Hyperdamping materials are lightweight, elastomer materials able to absorb significant vibration and wave energy by harnessing principles from mechanics of beams for the material design. This research investigates the suitability for hyperdamping material systems to provide shock absorption properties without the conventional reliance of large quantities of energy-damping mass. Through the use of constrained arrays of elastomer beams, the development of hyperdamping protective materials for helmet design leads to substantial impact energy absorption with reduction in weight when compared to the host material itself. These new material designs are assessed through finite element analysis to gain an understanding of key design parameters and determine geometries suggesting promise to be explored in the laboratory. Experimentation then explores the practical aspects of attenuating shock and system acceleration due a variety of impulsive forces in two types of shock mitigation contexts. The first experimental context evaluates force reduction through the specimens according to significance of constraint. The second experimental context considers the relationship between impact force and system acceleration according to the change in constraint. Results of the experiments indicate that hyperdamping protective material systems provide significant reduction in force and acceleration with up to 40% reduction in mass compared to control specimens composed of the solid elastomer material. The results of this research demonstrate the viability of hyperdamping protective material systems as shock absorbers to be used in numerous shock mitigation applications, including helmets.
Academic Major: Mechanical Engineering
OSU College of Engineering