Characterization of the Impact Mechanics of Polymeric Foams Subjected to Quasi-Static and Dynamic Compressive Loading of Various Impact Energies

Impact mass and inbound velocity are important parameters defined in helmet standards, which represent the total energy transferred during a hit to the head. The purpose of this study was to determine the influence that impact mass and inbound velocity had on energy attenuation characteristics of polymeric materials used in helmet design. Materials consisted of three densities of expanded polystyrene, expanded polypropylene, and vinyl nitrile foam. Each sample was impacted once at 25 different levels of energy using a monorail drop test. Significant main effects were observed for impact mass, inbound velocity, and material density on peak linear acceleration and impulse (p<0.05). Using peak linear accelerations as the determinant for risk of injury, head mass and inbound velocity played a significant role in helmet material performance.

Year	Entry
2004	Zhang L, Yang KH, King AI. A proposed injury threshold for mild traumatic brain injury. J Biomech Eng. 2004;126(2):226-236.
2004	Hoshizaki TB, Brien SE. The science and design of head protection in sport. Neurosurgery. October 2004;55(4):956-967.
1995	King AI, Ruan JS, Zhou C, Hardy WN, Khalil TB. Recent advances in biomechanics of brain injury research: a review. J Neurotrauma. August 1995;12(4):651-658.
2003	Mills NJ, Gilchrist A. Reassessing bicycle helmet impact protection. In: Proceedings of the 2003 International IRCOBI Conference on the Biomechanics of Impact. September 25, 2003; Lisbon, Portugal.15-26.
1997	Myers BS, Nightingale R. The dynamics of head and neck impact and its role in injury prevention and the complex clinical presentation of cervical spine injury. In: Proceedings of the 1997 International IRCOBI Conference on the Biomechanics of Impact. September 24-26, 1997; Hannover, Germany.15-33.
2003	Gefen A, Gefen N, Zhu Q, Raghupathi R, Margulies SS. Age-dependent changes in material properties of the brain and braincase of the rat. J Neurotrauma. November 2003;20(11):1163-1177.
2004	Goldsmith W, Plunket J. A biomechanical analysis of the causes of traumatic brain injury in infants and children. Am J Forensic Med Pathol. June 2004;25(2):89-100.
1966	Gadd CW. Use of a weighted-impulse criterion for estimating injury hazard. In: Proceedings of the 10th Stapp Car Crash Conference. November 8-9, 1966; Hollomon Air Force Base, NM. Warrendale, PA: Society of Automotive Engineers:164-174. SAE 660793.
2002	Kleiven S, von Holst H. Consequences of head size following trauma to the human head. J Biomech. 2002;35(2):153-160.
2001	Camacho DLA, Nightingale RW, Myers BS. The influence of surface padding properties on head and neck injury risk. J Biomech Eng. October 2001;123(5):432-439.
2002	Ommaya AK, Goldsmith W, Thibault L. Biomechanics and neuropathology of adult and paediatric head injury. Br J Neurosurg. June 2002;16(3):220-242.

Year

Entry

2004

Zhang L, Yang KH, King AI. A proposed injury threshold for mild traumatic brain injury. J Biomech Eng. 2004;126(2):226-236.

2004

Hoshizaki TB, Brien SE. The science and design of head protection in sport. Neurosurgery. October 2004;55(4):956-967.

1995

King AI, Ruan JS, Zhou C, Hardy WN, Khalil TB. Recent advances in biomechanics of brain injury research: a review. J Neurotrauma. August 1995;12(4):651-658.

2003

Mills NJ, Gilchrist A. Reassessing bicycle helmet impact protection. In: Proceedings of the 2003 International IRCOBI Conference on the Biomechanics of Impact. September 25, 2003; Lisbon, Portugal.15-26.

1997

Myers BS, Nightingale R. The dynamics of head and neck impact and its role in injury prevention and the complex clinical presentation of cervical spine injury. In: Proceedings of the 1997 International IRCOBI Conference on the Biomechanics of Impact. September 24-26, 1997; Hannover, Germany.15-33.

2003

Gefen A, Gefen N, Zhu Q, Raghupathi R, Margulies SS. Age-dependent changes in material properties of the brain and braincase of the rat. J Neurotrauma. November 2003;20(11):1163-1177.

2004

Goldsmith W, Plunket J. A biomechanical analysis of the causes of traumatic brain injury in infants and children. Am J Forensic Med Pathol. June 2004;25(2):89-100.

1966

Gadd CW. Use of a weighted-impulse criterion for estimating injury hazard. In: Proceedings of the 10th Stapp Car Crash Conference. November 8-9, 1966; Hollomon Air Force Base, NM. Warrendale, PA: Society of Automotive Engineers:164-174. SAE 660793.

2002

Kleiven S, von Holst H. Consequences of head size following trauma to the human head. J Biomech. 2002;35(2):153-160.

2001

Camacho DLA, Nightingale RW, Myers BS. The influence of surface padding properties on head and neck injury risk. J Biomech Eng. October 2001;123(5):432-439.

2002

Ommaya AK, Goldsmith W, Thibault L. Biomechanics and neuropathology of adult and paediatric head injury. Br J Neurosurg. June 2002;16(3):220-242.

Year	Entry
2011	Coulson NR. The Influence of Impact Mass, Inbound Velocity and System Compliance on the Dynamic Response of a Hybrid III Head Form [Master's thesis]. University of Ottawa; 2011.

Year

Entry

2011

Coulson NR. The Influence of Impact Mass, Inbound Velocity and System Compliance on the Dynamic Response of a Hybrid III Head Form [Master's thesis]. University of Ottawa; 2011.