Crash impact attenuator systems and methods
A crash impact attenuator system for deployment in front of a structure includes a rail and a plurality of diaphragms initially disposed in spaced relation along the length of the rail. Each of the plurality of diaphragms moves along the rail, so that when a front end of the crash attenuator system receives an impact force from a vehicle, a first one of the diaphragms moves rearwardly along the rail and impacts a second one of the diaphragms so that both the first and second diaphragms move further rearwardly along the rail, this process continuing with additional ones of the diaphragms until the impact forces have been fully attenuated. A tearing member on the crash attenuator system engages material forming a side or fender panel of the crash attenuator system, the tearing member tearing material forming the side panel to attenuate the impact force.
1. A crash impact attenuator system for mitigating a direct vehicular impact with a structure, the system comprising:
an attenuator portion comprising a rail extending along a length of the crash impact attenuator system and a plurality of diaphragms initially disposed in spaced relation along the length of the rail, each of the plurality of diaphragms having a base end or foot adapted to be movably engaged with the rail, so that when the crash impact attenuator system receives an impact force from an impacting vehicle, a first one of the plurality of diaphragms moves rearwardly along the rail and impacts a second one of the plurality of diaphragms, wherein both the first and second ones of the plurality of diaphragms move further rearwardly along the rail, this process continuing with additional ones of the plurality of diaphragms until the impact forces have been fully attenuated;
the attenuator portion further including a plurality of side panels disposed along a side of the attenuator portion;
the plurality of side panels being adapted to slide rearwardly along the attenuator portion when the crash impact attenuator system is impacted by a vehicle, so that a first one of the plurality of side panels slides over a second one of the plurality of side panels as it the first one of the plurality of side panels slides rearwardly responsive to a vehicular impact, each of the plurality of side panels including a plurality of holes disposed in material comprising each of the plurality of side panels, the plurality of holes extending along a length of each of the plurality of side panels and being spaced lengthwise from one another; and
a tearing member disposed on the attenuator portion which is adapted to engage one of the plurality of holes in the material forming the first one of the plurality of side panels, wherein when the crash attenuator system is impacted by a vehicle, relative motion occurs between the first one of the plurality of side panels and the tearing member, thereby tearing a fracture or slit in the material forming the first one of the plurality of side panels which extends between adjacent ones of the plurality of holes, the tearing of the side panel material attenuating the impact force, the side panel material being tuned to optimize the tearing of the side panel material;
wherein the first one of the plurality of side panels comprises a first stage attenuator portion and a second stage attenuator portion is disposed on either a rearward portion of the first one of the plurality of side panels or on the second one of the plurality of side panels, the first stage attenuator portion being forward of the second stage attenuator portion, the plurality of holes disposed in the first stage attenuator portion being configured and tuned to have a first shape, pattern, and/or spacing between holes to trigger a Mode I tensile failure, and a plurality of holes disposed in the second stage attenuator portion being configured and tuned to have a second shape, pattern, and/or spacing between holes different than the first shape, pattern, and/or spacing between holes to trigger a Mode II shearing failure.
2. The crash impact attenuator system as recited in claim 1 , wherein the first stage attenuator portion is softer than the second stage attenuator portion.
3. The crash impact attenuator system as recited in claim 1 , wherein the tearing member comprises a bolt.
4. The crash impact attenuator system as recited in claim 3 , wherein the bolt is assembled together with a bent washer plate.
5. The crash impact attenuator system as recited in claim 4 , wherein the bent washer plate comprises a flared front wing.
6. The crash impact attenuator system as recited in claim 4 , wherein the bent washer plate has a limited front extension to allow curling of the one of the plurality of side panels with which the bent washer plate is engaged, and to prevent buildup as the one of the plurality of side panels is being torn by the bolt.
7. The crash impact attenuator system as recited in claim 1 , wherein the tearing member is disposed on one of the plurality of diaphragms.
8. The crash impact attenuator system as recited in claim 1 , wherein the tearing member comprises a plurality of tearing members.
9. The crash impact attenuator system as recited in claim 1 , wherein the plurality of holes are arranged to form first and second rows of holes spaced from one another along a height of the side panel in which they are disposed.
10. The crash impact attenuator system as recited in claim 9 , wherein corresponding ones of the holes forming each of the first and second rows of holes on the side panel in which they are disposed are aligned lengthwise with one another.
11. The crash impact attenuator system as recited in claim 9 , wherein corresponding ones of the holes forming each of the first and second rows of holes on the side panel in which they are disposed are staggered lengthwise from one another.
12. The crash impact attenuator system as recited in claim 1 , wherein the first stage attenuator portion is configured and tuned so that the plurality holes in the first stage attenuator portion have the first shape comprising a triangle and the second stage attenuator portion is configured and tuned so that the plurality of holes in the second stage attenuator portion have a second shape comprising a trapezoid.
13. The crash impact attenuator system as recited in claim 1 , and further comprising a third stage attenuator portion, a fourth stage attenuator portion, and a fifth stage attenuator portion extending lengthwise rearwardly of the second stage attenuator portion.
14. The crash impact attenuator system as recited in claim 1 , and further comprising a nose box disposed at the frontmost end of the crash attenuator system.
15. The crash impact attenuator system as recited in claim 1 , wherein the plurality of holes extending along the length of each of the plurality of side panels, and being spaced lengthwise from one another, comprise a row of holes on each of the plurality of side panels, the row of holes extending lengthwise along each of the plurality of side panels terminating before reaching a front end of each of the plurality of side panels, wherein termination of the row of holes in each of the plurality of side panels facilitates initiation of tearing in a next adjacent one of the plurality of side panels, thereby reducing spikes in attenuation of the impact force as the crash impact attenuator system is compressed.
16. The crash impact attenuator system as recited in claim 1 , wherein the rail comprises first and second rails disposed in parallel to one another and extending along a length of the attenuator portion, each of the first and second rails having a T-shaped configuration, including a top flange disposed horizontally and extending along a length of each rail, and further wherein the base end or foot of each of the plurality of diaphragms comprises first and second base ends or feet, the first foot being configured to wrap around the top flange of the first rail and the second foot being configured to wrap around the top flange of the second rail, so that lateral loads from oblique impacts to the crash impact attenuator system are distributed to each of the first and second rails.
17. A crash impact attenuator system for mitigating a direct vehicular impact with a structure, the system comprising:
an attenuator portion comprising a rail extending along a length of the crash impact attenuator system and a plurality of diaphragms initially disposed in spaced relation along the length of the rail, each of the plurality of diaphragms having a base end or foot adapted to be movably engaged with the rail, so that when the crash impact attenuator system receives an impact force from an impacting vehicle, a first one of the plurality of diaphragms moves rearwardly along the rail and impacts a second one of the plurality of diaphragms, wherein both the first and second ones of the plurality of diaphragms move further rearwardly along the rail, this process continuing with additional ones of the plurality of diaphragms until the impact forces have been fully attenuated;
the attenuator portion further including a plurality of side panels disposed along a side of the attenuator portion;
the plurality of side panels being adapted to slide rearwardly along the attenuator portion when the crash impact attenuator system is impacted by a vehicle, so that a first one of the plurality of side panels slides over a second one of the plurality of side panels as the first one of the plurality of side panels slides rearwardly responsive to a vehicular impact, each of the plurality of side panels including a plurality of holes disposed in material comprising each of the plurality of side panels, the plurality of holes extending along a length of each of the plurality of side panels and being spaced lengthwise from one another; and
a tearing member disposed on the attenuator portion which is adapted to engage one of the plurality of holes in the material forming the first one of the plurality of side panels, wherein when the crash attenuator system is impacted by a vehicle, relative motion occurs between the first one of the plurality of side panels and the tearing member, thereby tearing a fracture or slit in the material forming the first one of the plurality of side panels which extends between adjacent ones of the plurality of holes, the tearing of the side panel material attenuating the impact force, the side panel material being tuned to optimize the tearing of the side panel material;
wherein the tearing member comprises a bolt is assembled together with a bent washer plate.
18. The crash impact attenuator system as recited in claim 17 , wherein the bent washer plate comprises a flared front wing.
19. The crash impact attenuator system as recited in claim 18 , wherein the bent washer plate has a limited front extension to allow curling of the one of the plurality of side panels with which the bent washer plate is engaged, and to prevent buildup as the one of the plurality of side panels is being torn by the bolt.