Design and Analysis of Approach Terminal Sections Using Simulation

Abstract

Turned-down guardrail terminal sections were analyzed using LS-DYNA3D, a dynamic, nonlinear, large deformation finite-element modeling package with capabilities for simulating vehicular impacts into roadside hazards. A baseline simulation was conducted on the existing turned-down approach terminal section, as well as on various retrofit options. Simulation findings were used to identify potential design changes and to select the two most promising options. Modified designs were subjected to six low-speed and one high-speed full-scale crash tests with a minisize automobile. The crash testing verified that one of the retrofit designs would allow the W-beam rail to drop down without causing vehicle rollover when impacted end on by a minisize automobile. However, the revised design did not meet recommended safety standards when one of the weakened posts failed to break away as designed. It is believed that by revising the post installation procedures, the modified turned-down terminal section would perform satisfactorily.