Zone of Intrusion Study
John Reid, Dean Sicking
The Midwest Roadside Safety Facility (MwRSF) performed an analysis using LS-DYNA simulation to investigate the zone of intrusion (ZOI) of an NCHRP Report No. 350 2000p pickup truck when impacting a 40-in. high F-shape parapet. The ZOI for the 40-in. F-shape concrete barrier impacted by the 2000p vehicle at 62 mph at an angle of 25 degrees (equivalent to TL-3) is predicted to be 5 inches. The ZOI for the 40-in. F-shape concrete barrier impacted by the 2000p vehicle at 45 mph at an angle of 25 degrees (equivalent to TL-2) is predicted to be between 1.8 and 2.5 inches, depending on the impact conditions simulated. The variations in this relatively small ZOI are attributed to the mesh quality of the model and to the system geometry. The 2000p pickup truck front hood geometry is such that it will extend over a 40-in. high F-shape parapet during impact conditions examined in this study. Thus, some ZOI is inevitable at almost all impact speeds. However, compared to a 32-in. parapet, the amount of structure extending over the 40-in. barrier is possibly inconsequential. That is, with a 32-in. parapet a significant amount of vehicle structure will overhang the barrier and potentially cause problems within the ZOI. With the 40-in. parapet, the amount of vehicle structure overhanging the barrier is limited to the front corner of the hood and possibly a little bit of the fender. This limited amount of structure in the ZOI may not cause any problems during an impact event.
Zone of Intrusion, LS-DYNA Simulation, NCHRP Report 350, 40-in. F-shape conrete barrier