An experimental evaluation of crash helmet design and effectiveness in standard impact tests

Beusenberg, M. C.; Happee, R.

With respect to shock absorption, current motorcycle (crash) helmets are usually being developed towards one criterion only, specified in a regulation. From more basic research, however, various criteria are known to relate to head protection. This paper discusses the relationships between design parameters and helmet performance according to several criteria, on the basis of defined impact tests on a set of (approved) crash helmets. Main attention is given to outer and inner shell material properties.

The test set-up of ECE Regulation 22 (-03), is used to assess testhead and anvil responses in frontal (forehead) impact. From these responses helmet behaviour is detenined, showing typically different deformation modes between fiber reinforced plastic (FRP) shelled helmets and polycarbonate (PC) shelled helmets. Energy absorption of FRP shelled helmets is predominantly caused by deformation of the inner (foam) shell “from the inside” and the load distribution is determined by the compatibility of inner shell dimensions and headform shape. PC shelled helmets predominantly show deformation “from the outside” and load distribution is determined by the geometry of the object hit as well as the load distribution capacity of inner shell material. FRP shelled helmets show higher maximum load and rate of onset while force distribution and time duration of the impact are more favorable compared to PC shelled helmets The total energy absorbed by helmet deformation is quite similar for all helmets tested.

Year

Entry

1984

Vallee H, Hartemann F, Thomas C, Tarrière C, Patel A, Got C. The fracturing of helmet shells. In: Proceedings of the 1984 International IRCOBI Conference on the Biomechanics of Impact. September 4-6, 1984; Delft, The Netherlands.99-109.

1984

Otte D, Jessl P, Suren EG. Impact points and resultant injuries to the head of motor-cyclists involved in accidents, with and without crash helmets. In: Proceedings of the 1984 International IRCOBI Conference on the Biomechanics of Impact. September 4-6, 1984; Delft, The Netherlands.47-64.

1991

Chandler S, Gilchrist A, Mills NJ. Motorcycle helmet load spreading performance for impacts into rigid and deformable objects. In: Proceedings of the 1991 International IRCOBI Conference on the Biomechanics of Impact. September 11-13, 1991; Berlin, Germany.249-261.

1984

Newman JA. Do tougher standards lead to better helmets? In discussion of: In: Proceedings of the 1984 International IRCOBI Conference on the Biomechanics of Impact. September 4-6, 1984; Delft, The Netherlands.153-155.

1986

Chamouard F, Tarriere C, Got C, Guillon F, Patel A, Hureau J. Relationship between some biomechanical and dimensional characteristics of the skull and the risk of cerebral injuries. In: Proceedings of the 1986 International IRCOBI Conference on the Biomechanics of Impact. September 2-4, 1986; Zurich, Switzerland.133-152.