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Cascos: certificaciones DOT, ECE y SNELL

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  • #16
    Re: Cascos: certificaciones DOT, ECE y SNELL

    a mi me lo habian explicado pero la verdad no me acuerdo, hay una norma no me acuerdo si americana o europea q solo testea el casco, como queda desp de un accidente y no lo q le pasa a la cabeza, la otra norma testea ademas del casco , como queda la cabeza, por eso en ese entonces me habian recomendado que siempre q compre casco primero le pegue un vistazo a la pag de sharp

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    • #17
      Re: Cascos: certificaciones DOT, ECE y SNELL

      Originally posted by meteorointerceptor View Post
      Te invito a que leas la página de Sharp
      Te invito a que leas los papers que publiqué, en especial este:

      https://www.birmingham.ac.uk/Documen...sweb600150.pdf

      En resumen:
      The SHARP ratings do not assess the rotational acceleration performance of helmets as claimed, because headform rotational accelerations were not measured. The use of direct impact test results with a friction coefficient to calculate oblique peak acceleration is based on an unsound mechanics model, treating the head and helmet as a rigid sphere sliding on the road.
      Extrapolation of the helmet response, from low velocity VN oblique impacts of the COST 327 program to much higher VN oblique impacts, was shown to be invalid. FEA is necessary to model the large geometry changes in helmet impacts, helmet rolling on the road surface, helmet rotation on the wearerís head, and the normal force FN contribution to the head rotational acceleration; it shows that the assumptions of the simple model are wrong.
      The SHARP star ratings are based on estimates of fatalities, if all motorcyclists wore the particular helmet model. As COST 327 statistics for the frequency of different impact types were misinterpreted, oblique impacts at the Regulation 22 side impact site were over-weighted in the SHARP calculations.
      The peak linear headform acceleration in an oblique impact is not a function of the total velocity V, as assumed, but of the velocity component VN. This is the most likely reason why fatalities were overestimated by 300%.
      To improve the protection of motorcyclists against rotational head acceleration, ideally headform rotational accelerations should be measured in oblique impacts with normal velocity components V
      N≥ 5ms-1. An effective interim measure would be to reduce the peak linear acceleration in direct impact tests.
      - - - Updated - - -

      Originally posted by pollolopez_22 View Post
      a mi me lo habian explicado pero la verdad no me acuerdo, hay una norma no me acuerdo si americana o europea q solo testea el casco, como queda desp de un accidente y no lo q le pasa a la cabeza, la otra norma testea ademas del casco , como queda la cabeza, por eso en ese entonces me habian recomendado que siempre q compre casco primero le pegue un vistazo a la pag de sharp
      La de sharp hace muchos años que anda muy bien, pero quedaron medio obsoletos los métodos de prueba que usan.
      Last edited by gonzalo; 05-11-2018, 23:27.

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      • #18
        Re: Cascos: certificaciones DOT, ECE y SNELL

        lo que si o si dany, tenes que usar gafas....( alla en tus pagos)....casco les chupa un huevo...sin gafas, rotura de ano...

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        • #19
          Re: Cascos: certificaciones DOT, ECE y SNELL

          Originally posted by HKS View Post
          lo que si o si dany, tenes que usar gafas....( alla en tus pagos)....casco les chupa un huevo...sin gafas, rotura de ano...
          En UK si te ven con el visor del casco levemente levantado al circular... te comés alto pijazo.

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