Development of a 100-km/h Reusable High-Molecular Weight/High-Density Polyethylene Truck-Mounted Attenuator

Abstract

A reusable truck-mounted attenuator has been developed that dissipates kinetic energy through the lateral deformation of a nested cluster of high-molecular weight/high-density polyethylene cylinders. This 100-km/h impact attenuation device, called the Vanderbilt truck-mounted attenuator (VTMA), satisfies the crash testing requirements of NCHRP Report 350. It has been approved by the Federal Highway Administration for use on the national highway system under these NCHRP Report 350 guidelines. Most impact attenuation devices currently employed require the replacement of damaged structural components and spent-energy-dissipating elements following an impact event. Until these repairs and refurbishments are carried out, these safety devices are largely ineffective because they are unable to dissipate kinetic energy in a subsequent impact in an acceptable manner such that relevant occupant risk parameters are within prescribed limits. The VTMA is a reusable and self-restorative truck-mounted attenuator. It can dissipate large amounts of kinetic energy, undergo significant deformations and strains without fracturing, and then, essentially, regain its original shape and energy-dissipation potential on removal of the load. The VTMA design was optimized through finite-element modeling using DYNA3D. This inexpensive modeling tool resulted in a reduction in the number of expensive full-scale crash tests required to develop the system. Computer modeling can optimize the probability for success of a given full-scale crash test, removing the trial-and-error approach to appurtenance design.