Energy absorbing post for roadside safety devices

Abstract

An energy-absorbing post for absorbing the impact energy of an errant vehicle wherein the impact energy is absorbed by out-of-place deformation in the material of the post. Out-of-plane deformation is provided by utilizing a through bolt extending through a splice connection between upper and lower posts sections. Alternatively, out-of-plane deformation is provided by leaving an axial gap on a splice bolts. For terminal applications, a single through-bolt is utilized to allow the upper post section to pivot during end on impacts. Bolt. tear out facilitators, including stress concentrators and pre-buckles, or an angled through-bolt decrease any initially high tear-out forces. Direct out-of-plane deformation is provided by extending a tab from a splice plate and connecting the tab to the post, by forming one or more slots in an upstream lateral face of the post and directly welding a splice plate near the slots, or by connecting a bent over splice plate on opposing planar sides thereof to facilitate out-of-plane deformation in a weldment area between the plate and the post.

1 . An energy absorbing post for roadside safety devices receiving impact from an errant vehicle comprising:
 a lower I-beam post section and an upper I-beam post section each having opposing front and rear lateral flanges connected by a central web portion;   the lower I-beam post section for engaging a foundation upon which the roadside safety device is mounted;   the upper I-beam post section for receiving the impact of an errant vehicle,   the upper I-beam post section and the lower post section being generally vertically aligned;   a splice connection between the lower and upper I-beam post sections, the splice connection including a splice plate attached to the front upper or lower lateral flange; and   a generally horizontal slot formed in a lateral portion of the other of the front upper or lower lateral flange, the lateral portion facing an anticipated direction of impact from an errant vehicle, the splice plate being rigidly attached to the other of the front upper or lower lateral flange near the slot;   such that energy of an errant vehicle impacting the upper I-beam section is absorbed by out-of-plane tearing of material in the lateral portion of the other of the upper or lower lateral flange, the out-of-plane tearing originating at the slot.   
     
     
         2 . The post of  claim 1  wherein the splice plate is welded to the other of the upper or lower lateral flange section near the generally horizontal slot. 
     
     
         3 . The post of  claim 1  further including one or more generally vertical slots adjacent to the generally horizontal slot, the generally vertical slots further facilitating out-of-plane tearing of the material in the lateral portion of the other of the upper or lower lateral flange. 
     
     
         4 . The post of  claim 1  further including a spacer located between the splice plate and the other of the upper or lower lateral flange to further facilitate out-of-plane tearing of the material in the lateral portion of the other of the upper or lower lateral flange. 
     
     
         5 . The post of  claim 2  further including one or more generally vertical slots adjacent to the generally horizontal slot, the generally vertical slots further facilitating out-of-plane tearing of the material in the lateral portion of the other of the upper or lower lateral flange. 
     
     
         6 . The post of  claim 2  further including a spacer located between the splice plate and the other of the upper or lower lateral flange to further facilitate out-of-plane tearing of the material in the lateral portion of the other of the upper or lower lateral flange. 
     
     
         7 . The post of  claim 2  further including:
 one or more generally vertical slots adjacent to the generally horizontal slot; and 
 a spacer positioned between the splice plate and the other of the upper or lower lateral flange;
 wherein the generally vertical slots and spacer further facilitate out-of-plane tearing of the material in the lateral portion of the other of the upper or lower lateral flange.