An experimental program was performed on guardrail posts to learn the more significant dynamic properties. A special pendulum impact facility was used to subject test specimens to dynamic loading that simulated a vehicle-guardrail installation collision. One hundred specimens of douglas fir, southern pine, red oak, and red pine wood were evaluated; for comparison 6b8.5 and 315.7 steel members were tested. Sizes of wood posts ranged from 4 by 4 in. To 8 by 8 in. In cross section. The post specimens were rigidly secured in a base fixture, and the dynamic load was applied 24 in. Above grade. Basic test data include a complete load resistance-post deflection determination for each specimen. The dynamic properties of peak resistance force, average resistance force, and fracture energy are reported for wood species and steel members. Test results show that, while data scatter exist within a wood species and size test group, the average values of such groups can be plotted in a manner to give meaningful trends. Peak force, average force, and fracture energy are shown to be a direct and linear function of moment of inertia. (Author/publisher)
Abstract