Design of Closed-Section Post For Use in a Non-Proprietary High-Tension Cable Median Barrier
Mojdeh Asadollahi Pajouh, Karla Lechtenberg, Ronald Faller, Jim Holloway, Bob Bielenberg
As part of research efforts to design a non-proprietary, high-tension, cable median barrier, closed-section posts were investigated through dynamic component testing. A closed-section post would mitigate the propensity for floor pan tearing and post penetration into the occupant compartment. A total of nineteen dynamic component tests were initially performed on closed-section posts to determine their strong- and weak-axis capacities and how their performance compares to the Midwest Weak Post (MWP). The post sections, including Hollow Structural Section (HSS) 3x2x⅛ (76-mm x 51-mm x 3-mm), Mechanical Tube (MT) 3x2x11 gauge (76-mm x 51-mm x 3-mm), and MT 4x2x14 gauge (102-mm x 51-mm x 2-mm), were evaluated with different patterns of post weakening holes. Both the HSS 3x2x⅛ and MT 3x2x11 gauge met the initial criteria and performed very similarly, however, since HSS 3x2x⅛ is more readily available, further dynamic component testing was conducted only with the HSS 3x2x⅛ section. Analysis of the test results indicated that the HSS 3x2x⅛ with two ¾-in. (19-mm) diameter holes at the ground line had 5% and 50% reductions in strong-axis and weak-axis bending strengths, as compared to the MWP, respectively. This section indicated the most promising potential to meet the desired strong- and weak-axis capabilities, while reducing the potential concern of floor pan tearing and post penetration into the occupant compartment while using less material than the MWP. In addition, this section is a standard, readily-available, and economical section. Thus, the use of this section was recommended for further evaluation through full-scale crash testing.
Highway Safety, Crash Test, Roadside Appurtenances, Compliance Test, Cable Barrier, Closed-Section Post, Bogie Testing, Dynamic Testing, Hollow Structural Section (HSS), Mechanical Tube