Products  Guardrail Bracket (Shock-absorption bracket for guardrails)

Guardrails are for preventing vehicles to run out from the road. For this purpose, they are built and reinforced...
So why the reinforced guardrail does not work well to avoid accidents? Many accidents occur when vehicles run into guardrails with oblique angles, overrun the centerline as a reaction and crash into oncoming vehicles.
In order to reduce these kinds of accidents, we have tested our product repeatedly for many years and developed the shock-absorbing bracket for guardrails.

Basic specifications
Material Aluminum (AL5052)
Board thickness t6.0(partly t5.0)
Weight 890g(existing material +85g)
Dimensions 250mm(W):100mm(L):98mm(H)
Effective distortion length 55mm
Compatible  posts Ø114.3、Ø139.8
Loading weight tolerance 6ton
Compatible guardrail "A, B or C model" of "standard type or snow resistant type"
*The guardrail protrudes approx. 58mm on to the road over the existing guardrail
Installation procedure Since installation is finished by replacing the bracket part alone and using all the parts from existing equipment, no special parts nor tools are necessary.

In the result of the loading test (figure 1), the distortion is shown against the loading weight. When the conventional bracket was used, distortion was small and the loading weight tolerance was large. This indicates the bracket was only meant to reinforce the binding of the bracket to the guardrail support post.
On the other hand, when our product was used, distortion gradually increased as the loading weight increased. This indicates that no rapid increase of the loading weight tolerance happened. So when a vehicle collides into our product, the impact on both the support post and the vehicle becomes small.
In addition, our product has larger crashable zone (larger distortion). This increases the time of the impact force to reach to the support stay and meanwhile allow the metal to absorb the collision energy by plastic deformation. As the result, the impact force on the support post is suppressed and reduced.

In the result of the collision test (figure 2), the acceleration is shown against the collision time. When our product was used, acceleration was reduced by approx.82 % (162.857G⇒29.184G) and approx. 41%(51.735G⇒30.612G) to the front (forward direction) and to the back (reverse direction), respectively compared to the results when the conventional bracket was used. (Company experimental values)
These results indicates that "the shock absorption mechanism of the metal plastic distortion" and "larger crashable zone" used in our product was very effective in shock absorption.

 

These tests demonstrated that our product not only reduces the damage to the vehicle driver but reduces the impact to the guardrail post and other equipment. This will result in saving costs for the maintenance of the roads.


Road safety equipments, Road protection hardware, and Shock-absorption equipment for vehicles, HANAI CO., LTD.
12-1 Fujimi-cho, Naka-ku, Nagoya, 460-0014, Japan PHONE: +81-52-871-6311 FAX: +81-52-871-6312

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