Abstract
Lack of shock absorption capability of conventional steel bollards causes significant vehicle damage and, consequently, high repair costs. This research studies a solution to reduce vehicle damage by inserting polylactic acid (PLA) honeycomb structures. A honeycomb-inserted bollard was designed based on numerical simulations using LS-DYNA, which yielded the bollard designed for actual vehicle-bollard collision experiments. Simulation efforts were focused on calculating the acceleration characteristics when a vehicle collides with steel and honeycomb-inserted bollards. Compared to the simulated steel bollards, 20 MPa yield-strength honeycomb-inserted bollard showed 0.017 s delay in the maximum acceleration occurrence time, reduction of the maximum acceleration of 37.4% of that of steel bollards, and a 13.1% reduction in the B-pillar maximum acceleration. Actual vehicle-bollard collision experiments, with a gyro-sensor installed at the test vehicle front bumper frame, also proved improved shock absorption characteristics of the honeycomb-inserted bollards. An experiment with honeycomb-inserted bollard showed a 0.783 s delay in the maximum acceleration occurrence time, a significant delay when compared to steel bollards. The maximum acceleration measured by the gyro-sensor was 0.35 × 103 m/s2 when the simulation predicted it to be 0.388 × 103 m/s2, proving the similarity in the simulations and experiments. Thus, this study of shock absorption characteristics promised reduced damage to vehicles and lower repair cost.
Highlights
Bollard is a road safety structure that separates sidewalks from streets to prevent vehicles from entering into sidewalks [1,2,3]
Actual vehicle-bollard collision experiments, with a gyro-sensor installed at the test vehicle front bumper frame, proved improved shock absorption characteristics of the honeycomb-inserted bollards
Experiments were done by impacting the test vehicle with both steel and in-plane honeycomb bollards to collect acceleration time evolution evolution data to to compare compare with with the results
Summary
Bollard is a road safety structure that separates sidewalks from streets to prevent vehicles from entering into sidewalks [1,2,3]. In South Korea, stone or steel bollards were widely used until the “Act on Promotion of the Transportation Convenience of Mobility Disadvantaged Persons” was passed in 2019 [4]. This act mandated all bollards to be manufactured with either steel pipes or stainless coated with materials such as polyurethane for the improved safety of the physically-challenged (especially the blinded). These research papers, were mostly focused on reducing or distributing collision shocks to the bollards, instead of to the vehicle [5,6]. This paper, focused on the reduced shocks to the bollards and to the colliding vehicles
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
