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Abstract

Bicycle helmets are designed to reduce the acceleration/deceleration of the head during impacts. During an accident, the main parts of a helmet responsible for shock absorption are the energy-absorbing liner and the outer shell. In the present study, several geometrical structures of convex acrylonitrile butadiene styrene plastic shell, such as a truncated conical form and a semi-spherical form, were investigated for their energy-absorbing capacity. Moreover, several liner dimension parameters were also optimised. The energy was absorbed in these structures by a combination of folding and collapsing. The idea of a sandwich liner using the aforementioned structures was also constructed to analyse its advantages compared to their single structures. This study performs finite element analyses on helmet impact tests using LS-DYNA software based on the EN1078 standards. The purpose of the present study was to determine a structure of liner that reaches high effective protection and to design helmet models with single and dual liners. The final work in this study was performed to optimise the height cone of linear semi-sphere cones. This innovative design for a helmet liner demonstrated high energy-absorbing capabilities. Moreover, this helmet impact test model can serve as a valuable tool to assist future development of safety-helmet technologies.

Keywords

Bike helmet liner impact test EN1078 standards LS-DYNA

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References

Grujicic

LaBerge

Grujicic

. Potential improvements in shock-mitigation efficacy of a polyurea-augmented advanced combat helmet: a computational investigation. J Mater Eng Perform 2012; 21: 1562–1579.

Grujicic

Arakere

Pandurangan

. Computational investigation of shock-mitigation efficacy of polyurea when used in a combat helmet: a core sample analysis. Multidis Model Mater Struct 2012; 8: 297–331.

Mills

. Design of rigid foam protection in cycle helmets. Plast Microstruct Eng Appl 1993, pp. 326–336.

Blanco DH, Cernicchi A and Galvanetto U. FE modeling of innovative helmet liners. In: Proceeding of the 11^th international LS-Dyna users conference, Dearborn, MI, USA, 6–8 June 2010, pp.9–1.

Shuaeib

Hamouda

AMS

Hamdan

. Motorcycle helmet part III. Manufacturing issues. J Mater Process Technol 2002; 123: 432–439.

Hamouda

AMS

Saied

Shuaeib

. Energy absorption capacities of square tubular structures. J Achiev Mater Manufac Eng 2007; 24(1): 36–42.

Deshpande

Fleck

. Energy absorption of an egg-box material. J Mech Phys Solids 2003; 51: 187–208.

Tongxi

. Energy absorption of structures and material, Boca Raton: FL: CRC Press, 2003.

Alkateb

Mahdi

Hamouda

AMS

. On the energy absorption capability of axially crushed composite elliptical cones. Compos Struct 2004; 66: 495–501.

10.

BS EN 1078. Helmets for pedal cyclists and for users of skateboards and roller skates, British Standards Institution, London, 1997.

11.

Landro

Sala

Olivieri

. Deformation mechanisms and energy absorption of polystyrene foams for protective helmets. Polym Test 2002; 21(2): 217–228.

12.

Mills

Gilchrist

. Oblique impact testing of bicycle helmets. Int J Impact Eng 2008; 35(9): 1075–1086.

13.

Liua

Changa

Fanb

. Influence of environmental factors on energy absorption degradation of polystyrene foam in protective helmets. Eng Failure Anal 2003; 10(5): 581–591.

14.

European Enhanced Vehicle-safety Committee. Improved test methods to evaluate pedestrian protection afforded by passenger cars. EEVC/WG 17 Report, 1998, updated 2002. Washington, DC: European Enhanced Vehicle-safety Committee.

15.

Snell Memorial Foundation. 1995 Standard for protective headgear for use with bicycles, 1995. North Highlands, CA: Snell Memorial Foundation, http://www.smf.org/stds.html (accessed 15 June, 2012).

16.

BS EN 960. Headform for use in the testing of protective helmet , British Standards Institution, London, 2006.

17.

Mills

Gilchrist

. Finite-element analysis of bicycle helmet oblique impacts. Int J Impact Eng 2008; 35: 1087–1101.

18.

Houten JGA. Large strain behavior of polycarbonate. EUT, Faculty of Mechanical Engineering, Report no. WFW 94.108, Eindhoven, August 1994.

19.

Shuaeib

Hamouda

AMS

Wong

. A new motorcycle helmet liner material: the ﬁnite element simulation and design of experiment optimization. Mater Des 2007; 28: 182–195.

20.

Hertz E. A note on the head injury criterion (HIC) as a predictor of the risk of skull fracture. In: 37th annual proceedings of the association for the advancement of automotive medicine, San Antonio, TX, 4–6 November, 1993, vol. 37, p.303.

Innovative design of bicycle helmet liners

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