Rate-activated strapping for improved retention of protective eyewear during impact
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During impact, protective eyewear can be dislodged and leave the eyes and face vulnerable to injury from secondary impacts. In this study, a rate-activated eyewear retention system is studied and compared to a conventional elastic retention system. The rate-activated behavior of the retention system is due to an enclosed shear-thickening fluid, a high solids-loading colloid that undergoes a rapid increase in viscosity above a critical shearing rate. Tensile testing shows that the force required to elongate this retention system is over 10 times higher when stretched at 100 mm/s, compared to 1 mm/s. A women’s lacrosse goggle mounted to an anthropomorphic test dummy head is used as a model system to compare retention system response. Goggles are impacted by an NOCSAE-certified lacrosse ball at 27 m/s, with a trajectory oriented 45° relative to the anterior side of the midsagittal plane of the head, per ASTM F3077. High-speed video analysis shows that the rate-activated system provides improved retention relative to the conventional goggle strap, with an average of 12 mm of dynamic goggle deflection compared to 65 mm for the conventional design. These results suggest that a rate-activated retention system could reduce injuries by ensuring that personal protective equipment remains in place during impact events.
KeywordsRetention System Protective Eyewear Elastic Strap Effective Spring Constant Strapping Material
The authors are grateful to Dr. Richard Dombrowski (STF Technologies, Newark, DE) for the rheological measurements; Phil Davis and David Churn for experimental assistance during gas gun testing; Larry Long and Matt Langenstein for assistance during prototype construction; and Team 22 Innovation (Albany, NY) for donating the goggle components and lacrosse balls. This research was supported in part by an appointment to the Postgraduate Research Participation Program at the ARL administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and ARL.
- 2.Auvil JR (2016) Evolution of military combat eye protection. U.S. Army Med Department J. April–September. pp135–139Google Scholar
- 5.Wong TY, Seet B (1997) A behavioral analysis of eye protection use by soldiers. Mil Med 162(11):744–748Google Scholar
- 7.Lin NYC, Guy BM, Hermes M, Ness C, Sun J, Poon WCK, Cohen I (2015) Hydrodynamic and contact contributions to continuous shear thickening in colloidal suspensions. Phys Rev Lett 115(228304):1–5Google Scholar
- 13.Dawson MA, McKinley GH, Gibson LJ (2009) The dynamic compressive response of an open-cell foam impregnated with a non-Newtonian fluid. J Appl Mech 76(061011):1–8Google Scholar
- 14.Soutrenon M, Michaud V (2014) Impact properties of shear thickening fluid impregnated foams. Smart Mater Struct 23(035022):1–10Google Scholar
- 15.Zhang XZ, Li WH, Gong XL (2008) The rheology of shear thickening fluid (STF) and the dynamic performance of an STF-filled damper. Smart Mater Struct 17(035027):1–7Google Scholar
- 16.Nenno PT, Wetzel ED (2014) Design and properties of a rate-dependent ‘dynamic ligament’ containing shear thickening fluid. Smart Mater Struct 23(125019):1–10Google Scholar
- 17.Nenno PT, Wetzel ED (2014) Rate-dependent extensional “dynamic ligaments” using shear thickening fluids. Proc SPIE 9057(90373H):1–10Google Scholar
- 21.Standard specification for eye protectors for women’s lacrosse (2014) American National Standards Institute. ASTM F3077-14Google Scholar